United States
       Agency
Office of theV\s(6ciate. Dire
Compliance Assurance ana'
Region 6, DallasjTX-75202,
                       ' EPA 906-C-05-001
                   ^Division i March 2005  j,
                   ;    -vwvw.epa.gov/region6

       Environi
ental Resource Stewards
 (TERS)             •lwl
Texas Ecolpgica|>Assess
          Pfofeol (TEAR):
           lot  Pf©j4ct Report
  Flying in a "V" formation saves energy, wrwle enabling farther flights and greater
  communication. This is a "natural" exampleotoUeJiynergy" promoted by TERS.


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          Texas Environmental Resource Stewards (TERS):
         Texas Ecological Assessment Protocol (TEAP) Results
                           Pilot Project
                            Prepared by
U.S. Environmental Protection Agency Region 6, Texas Parks and Wildlife
              Department, and The Nature Conservancy
   S. L. Osowski, J. Danielson, S. Schwelling,  D. German, S. Gilbert, D.
         Lueckenhoff, D. Parrish, A. K. Ludeke, and J. Bergan
                          March 1, 2005
               EPA Publication Number: 906-C-05-001

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Citation Info:

Osowski, S. L., J. Danielson, S. Schwelling, D. German, M. Swan, D. Lueckenhoff, D. Fairish,
A. K. Ludeke, and J. Bergan.  2005. Texas Environmental Resource Stewards (TERS) Texas
Ecological Assessment Protocol (TEAP) Results, Pilot Project Report. Report Number EPA-
906-C-05-001. US Environmental Protection Agency Region 6, Dallas, TX.

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The Texas Environmental Resource Stewards (TERS) was formed by the Executive Leaders of
various federal and state agencies to collaborate on common ecosystem management and
regulatory streamlining issues.  The Texas Ecological Assessment Protocol (TEAP) is a product
of the TERS effort which analyzes existing broad-scale electronic data to identify important
ecological areas in Texas that should be avoided or protected, if possible. This report
communicates the initial results of this new tool. Agencies and the public will be able to use this
information to aid in project planning and scientific research, ultimately leading to better
environmental assessments, improved understanding, and enhanced decision-making. The
TEAP is not designed to be used to make final decisions on individual projects, but rather to
serve as a general screening tool to allow environmental professionals to focus limited resources
to protect critical ecological areas and to give the public an overview of environmental
conditions in Texas.

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    TC1Q
             -—-^

        U.S.
                                                                     US Army Corps
                                                                     of Engineers
                                                                     Southwestern Division
                                                                   s^The Nature
                                                                   {Conservancy.

                                   €»J»
Director

  and            Division
US EnvironmentaWrtJtSCtTon Agency Region 6
Robert L. Cool
Executive Director
Texas Parks and Wildlife Department

                                                                   i

                                             Gary Loew
                                             Director, Programs Directorate
                                             Southwestern Division
                                             U.S. Armycffp§4)f
                                             Texas Administrator       V
                                             US Fish and         Service
C.D.(Dan)%ag«ifiVE.
Texas Division Administrator
Federal Highway Administration
        W. Behrens, P. E.
Executive Director
                                             David C.             P. E,
                                             Chief Engineer
                                             Texas Commission on Environmental
                                             Quality

                                            f larrfes Bergan, Ph.D.
                                            V"O}fector of Science and Stewardship
                                             The Nature Conservancy

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                                   Table of Contents

Chapter	Page

EXECUTIVE SUMMARY	 1
       Background  	 1
             Diversity	2
             Rarity	2
             Sustainability	3
       Actions  	4

1.0 INTRODUCTION	9
       1.1 TERS History	9
       1.2 Texas Ecological Assessment Protocol (TEAP) Goals	11
       1.3 Background 	 12
             1.3.1  Geographical Information System (GIS)-Based Assessments	12
             1.3.2  Ecoregion Delineation	 14
                    1.3.2.1 Types of Ecoregion Delineation	 15
             1.3.3  Ecological Theory Used in TEAP	 15
                    1.3.3.1 Diversity	20
                           1.3.3.1.1 Appropriateness of Land Cover 	20
                           1.3.3.1.2 Contiguous Size of Undeveloped Land  	20
                           1.3.3.1.3 Shannon Land Cover Diversity Index	21
                           1.3.3.1.4 Ecologically Significant Stream Segments 	22
                    1.3.3.2 Rarity	23
                           1.3.3.2.1 Vegetation Rarity 	24
                           1.3.3.2.2 Natural Heritage Rank 	24
                           1.3.3.2.3 Taxonomic Richness	25
                           1.3.3.2.4 Rare Species Richness 	25
                    1.3.3.3 Sustainabilitv	26
                           1.3.3.3.1 Contiguous Land Cover Type 	26
                           1.3.3.3.2 Regularity of Ecosystem Boundary	27
                           1.3.3.3.3 Appropriateness of Land Cover 	30
                           1.3.3.3.4 Waterway Obstruction 	30
                           1.3.3.3.5 Road Density	30
                           1.3.3.3.6 Airport Noise 	31
                           1.3.3.3.7 Superfund National Priority List (NPU and
                                  State Superfund Sites 	31
                           1.3.3.3.8 Water Quality	32
                           1.3.3.3.9 Air Quality 	32
                           1.3.3.3.10 RCRA. TSD. Corrective Action and
                                  State VCP Sites	33
                           1.3.3.3.11 Urban/Agriculture Disturbance	34
             1.3.4  TEAP Development  	34
                    1.3.4.1 TPWD Conservation Planning	35

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                    1.3.4.2 The Nature Conservancy Ecoregional Planning Process 	35
                    1.3.4.3 EPA Region 5 CrEAM	37

2. 0 METHODS 	44
       2.1 Base Unit Selection	44
       2.2 TEAP Sub-layers and Layers 	47
             2.2.1 Diversity Layer	47
                    2.2.1.1 Appropriateness of Land Cover 	47
                    2.2.1.2 Contiguous Size of Undeveloped Land  	57
                    2.2.1.3 Shannon Land Cover Diversity Index	57
                    2.2.1.4 Ecologically Significant Stream Segments 	58
             2.2.2 Rarity Layer	59
                    2.2.2.1 Vegetation Rarity 	59
                    2.2.2.2 Natural Heritage Rank 	60
                    2.2.2.3 Taxonomic Richness	62
                    2.2.2.4 Rare Species Richness 	63
             2.2.3 Sustainability Layer	63
                    2.2.3.1 Contiguous Land Cover Type 	63
                    2.2.3.2 Regularity of Ecosystem Boundary	64
                    2.2.3.3 Appropriateness of Land Cover 	65
                    2.2.3.4 Waterway Obstruction 	66
                    2.2.3.5 Road Density	66
                    2.2.3.6 Airport Noise 	68
                    2.2.3.7 Superfund NPL and  State Superfund Sites 	69
                    2.2.3.8 Water Quality	69
                    2.2.3.9 Air Quality 	69
                    2.2.3.10 RCRA. TSD. Corrective Action and State VCP Sites  	70
                    2.2.3.11 Urban/Agriculture Disturbance	70
             2.2.4 Accuracy Assessment	71

3.0 RESULTS  	74
       3.1 Diversity Layer	74
       3.2 Rarity Layer	74
       3.3 Sustainability Layer	77
       3.4 Composite Layer 	77
             3.4.1 Ecoregion Composites 	80
                    3.4.1.1 Southern High Plains 	80
                    3.4.1.2 Texas High Plains 	80
                    3.4.1.3 Rolling Plains	83
                    3.4.1.4 Rio Grande Plain	83
                    3.4.1.5RedbedPlains	83
                    3.4.1.6 Cross Timbers and Prairie	83
                    3.4.1.7 Oak Woods and Prairies	88
                    3.4.1.8BlacklandPrairie	88
                    3.4.1.9 Mid Coastal Plains. Western Section	88
                    3.4.1.10 Coastal Plains and Flatwoods. Western Gulf Section	88

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                    3.4.1.11 Edwards Plateau	92
                    3.4.1.12 Stockton Plateau	92
                    3.4.1.13 Chihuahuan Desert Basin and Range	92
                    3.4.1.14 Sacramento-Manzano Mountain 	97
                    3.4.1.15 Louisiana Coast Prairies and Marshes 	97
                    3.4.1.16 Eastern Gulf Prairies and Marshes	97
                    3.4.1.17 Central Gulf Prairies and Marshes 	97
                    3.4.1.18 Southern Gulf Prairies and Marshes 	 102
             3.4.2 Overlays 	 102
             3.4.3 Accuracy Assessment	 102

4.0 DISCUSSION 	 112
       4.1 Data Limitations	 113
       4.2 Accuracy Assessment	 117
       4.3 Conservation  	 118

5.0 CONCLUSIONS	 120
       5.1 Streamlining	 120
       5.2 Next Steps 	120

6.0 ACKNOWLEDGMENTS 	 122

7.0 REFERENCES 	 123

APPENDIX A: Descriptions of Bailey's Ecoregions 	 134
       Southeastern Mixed Forest 	140
             Mid Coastal Plains. Western (Section 23 IE)	140
                    Geomorphology 	 140
                    Lithology and Stratigraphy	 140
                    Soil Taxa	140
                    Potential Natural Vegetation	141
                    Fauna	141
                    Climate	141
                    Surface Water Characteristics	141
                    Disturbance Regimes 	 141
                    Land Use 	141
             Eastern Gulf Prairies and Marshes (Section 23 IF) 	 141
                    Geomorphology 	 141
                    Lithology and Stratigraphy	 142
                    Soil Taxa	142
                    Potential Natural Vegetation	142
                    Fauna	 143
                    Climate	 143
                    Surface Water Characteristics	143
                    Disturbance Regimes 	 143
                    Land Use 	143

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Outer Coastal Plain Mixed Forest	143
       Louisiana Coast Prairies and Marshes (Section 232E) 	143
             Geomorphology  	 143
             Lithology and Stratigraphy	 144
             Soil Taxa	144
             Potential Natural Vegetation	144
             Fauna	 144
             Climate	 145
             Surface Water Characteristics	145
             Disturbance Regimes 	 145
             Land Use 	145
       Coastal Plains and Flatwoods. Western Gulf (Section 232F)	145
             Geomorphology  	 145
             Lithology and Stratigraphy	 146
             Soil Taxa	146
             Potential Natural Vegetation	146
             Fauna	 146
             Climate	 146
             Surface Water Characteristics	147
             Disturbance Regimes 	 147
             Land Use 	147

Prairie Parkland (Subtropical)	 147
       Cross Timbers and Prairies (Section 255 A)	 147
             Geomorphology  	 147
             Lithology and Stratigraphy	 148
             Soil Taxa	148
             Potential Natural Vegetation	148
             Fauna	 148
             Climate	 148
             Surface Water Characteristics	148
             Disturbance Regimes 	 149
             Land Use 	149
       Blackland Prairies (Section 255B) 	 149
             Geomorphology  	 149
             Lithology and Stratigraphy	 149
             Soil Taxa	149
             Potential Natural Vegetation	150
             Fauna	 150
             Climate	150
             Disturbance Regimes 	 150
             Land Use 	150
       Oak Woods and Prairies (Section 255O 	150
             Geomorphology  	 150
             Lithology and Stratigraphy	 151

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             Soil Taxa	151
             Potential Natural Vegetation	151
             Fauna	151
             Climate	 152
             Surface Water Characteristics	152
             Disturbance Regimes 	 152
             Land Use 	152
       Central Gulf Prairies and Marshes (Section 25 5D}  	 152
             Geomorphology  	 152
             Lithology and Stratigraphy	 153
             Soil Taxa	153
             Potential Natural Vegetation	153
             Fauna	 153
             Climate	 153
             Surface Water Characteristics	153
             Disturbance Regimes 	 154
             Land Use 	154

Great Plains Steppe and Shrub	154
       Redbed Plains (Section 311 A} 	154
             Geomorphology  	 154
             Lithology and Stratigraphy	 155
             Soil Taxa	155
             Potential Natural Vegetation	155
             Fauna	 155
             Climate	 155
             Surface Water Characteristics	155
             Disturbance Regimes 	 155
             Land Use 	155

Southwest Plateau and Plains Dry  Steppe and Shrub  	156
       Texas High Plains (Section 315B) 	 156
             Geomorphology  	 156
             Lithology and Stratigraphy	 156
             Soil Taxa	156
             Potential Natural Vegetation	156
             Fauna	 156
             Climate	 157
             Surface Water Characteristics	157
             Disturbance Regimes 	 157
             Land Use 	157
       Rolling Plains (Section 315O 	 158
             Geomorphology  	 158
             Lithology and Stratigraphy	 158
             Soil Taxa	158
             Potential Natural Vegetation	159

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             Fauna	 159
             Climate	 159
             Surface Water Characteristics	159
             Disturbance Regimes 	 159
             Land Use  	159
       Edwards Plateau (Section 315D} 	159
             Geomorphology  	 159
             Lithology and Stratigraphy	 160
             Soil Taxa	160
             Potential Natural Vegetation	160
             Fauna	 160
             Climate	161
             Surface Water Characteristics	161
             Disturbance Regimes 	 161
             Land Use  	161
       Rio Grande Plain (Section 315E}	 161
             Geomorphology  	 161
             Lithology and Stratigraphy	 161
             Soil Taxa	161
             Potential Natural Vegetation	162
             Fauna	 162
             Climate	 163
             Surface Water Characteristics	163
             Disturbance Regimes 	 163
             Land Use  	163
       Southern Gulf Prairies and Marshes (Section 315F)  	 163
             Geomorphology  	 163
             Lithology and Stratigraphy	 164
             Soil Taxa	164
             Potential Natural Vegetation	164
             Fauna	 164
             Climate	 164
             Surface Water Characteristics	164
             Disturbance Regimes 	 165
             Land Use  	165

Arizona-New Mexico Mountains Semi-Desert - Open Woodland -
       Coniferous Forest - Alpine Meadow	 165
       Sacramento-Manzano Mountain (Section M313B) 	 165
             Geomorphology  	 165
             Lithology and Stratigraphy	 165
             Soil Taxa	166
             Potential Natural Vegetation	166
             Climate	 166
             Surface Water Characteristics	166
             Disturbance Regimes 	 166

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                    Cultural Ecology 	 166

       Chihuahuan Semi-Desert 	167
             Basin and Range (Section 321A)  	 167
                    Geomorphology 	 167
                    Lithology and Stratigraphy	 168
                    Soil Taxa	168
                    Potential Natural Vegetation	168
                    Climate	 168
                    Surface Water Characteristics	168
                    Disturbance Regimes 	 169
                    Land Use 	169
                    Cultural Ecology 	 169
             Stockton Plateau (Section 32IE}  	169
                    Geomorphology 	 169
                    Lithology and Stratigraphy	 170
                    Soil Taxa	170
                    Potential Natural Vegetation	170
                    Fauna	 170
                    Climate	171
                    Surface Water Characteristics	171
                    Disturbance Regimes 	 171
                    Land Use 	171

       Great Plains-Palouse Dry Steppe 	171
             Southern High Plains (Section 33 IE} 	 171
                    Geomorphology 	 171
                    Lithology and Stratigraphy	 172
                    Soil Taxa	172
                    Potential Natural Vegetation	172
                    Fauna	 172
                    Climate	 172
                    Surface Water Characteristics	172
                    Land Use 	172

APPENDIX B: Individual sub-layer maps	 173
       Diversity layer	 176
       Rarity layer	 177
       Sustainability layer	 179
       Figures	 181

APPENDIX C: List of Acronyms 	200

APPENDIX D: List of contributors 	205

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                                     List of Tables


Table 1. TPWD planning results. Priority ecoregions for conservation efforts	36

Table 2. Relationship of the EPA SAB framework ecological attributes to EPA Region 5
             CrEAM and TEAP 	39

Table3. Summary of TEAP layers	48

Table 4. GIS data layers used for TEAP	53

Table 5. Kuchler (1964) PNV classifications and corresponding NLCD land cover types 	55
                                     List of Figures


Figure A.  Map of the diversity layer with ecoregion boundaries	5

FigureB.  Map of the rarity layer with ecoregion boundaries	6

Figure C.  Map of the sustainability layer with ecoregion boundaries	7

Figure D.  Composite map with ecoregion boundaries	8

Figure 1. Map of Bailey's ecoregion sections	16

Figure 2. Map of Omernik ecoregions	 17

Figure3. Map of Gould's vegetation types	18

Figure 4. Map of Texas natural areas	19

Figure 5. Map of the diversity layer with ecoregion boundaries. This map is a
              composite  of four sub-layers (Figures B1-B4)	75

Figure 6. Map of the rarity layer with ecoregion boundaries. This map is a
              composite  of four sub-layers (Figures B5-B8)	76

Figure 7. Map of the sustainability layer with ecoregion boundaries. This map is a
              composite  of eleven sub-layers (Figures B9-B19)	78

Figure 8. Composite map with ecoregion boundaries. This map is a composite
              of the diversity layer (Figure 5\ rarity layer (Figure 6). and

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              sustainability layer (Figure 7)	79

Figure 9. Southern High Plains composite map. A separate figure (Figure 8)
              shows the entire state	81

Figure 10. Texas High Plains composite map.  A separate figure (Figure 8)
              shows the entire state	82

Figure 11. Rolling Plains composite map.  A separate figure (Figure 8)
              shows the entire state	84

Figure 12. Rio Grande Plain composite map. A separate figure (Figure 8)
              shows the entire state	85

Figure 13. Redbed Plains composite map.  A separate figure (Figure 8)
              shows the entire state 	86

Figure 14. Cross Timbers and Prairie composite map.  A separate figure (Figure 8)
              shows the entire state 	87

Figure 15. Oak Woods and Prairies composite map. A separate figure (Figure 8)
              shows the entire state 	89

Figure 16. Blackland Prairie composite map. A separate figure (Figure 8)
              shows the entire state 	90

Figure 17. Mid Coastal Plains Western Section composite map.  A separate figure
              (Figure 8) shows the entire state 	91

Figure 18. Coastal Plains and Flatwoods Western Gulf Section composite map.
              A separate figure (Figure 8) shows the entire state	93

Figure 19. Edwards Plateau composite map. A separate figure (Figure 8)
              shows the entire state 	94

Figure 20. Stockton Plateau composite map. A separate figure (Figure 8)
              shows the entire state 	95

Figure 21. Chihuahuan Desert Basin and Range composite map. A separate
              figure (Figure 8) shows the entire state	96

Figure 22. Sacramento-Manzano Mountain composite map. A separate figure
              (Figure 8) shows the entire state 	98

Figure 23. Louisiana Coast Prairies and Marshes composite map. A separate
              figure (Figure 8) shows the entire state	99

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Figure 24. Eastern Gulf Prairies and Marshes composite map. A separate
             figure (Figure 8) shows the entire state	100

Figure 25. Central Gulf Prairies and Marshes composite map. A separate
             figure (Figure 8) shows the entire state	101

Figure 26. Southern Gulf Prairies and Marshes composite map. A separate
             figure (Figure 8) shows the entire state	 103

Figure 27. Composite map with public lands overlay. Public lands include
             National and State Parks, National Forests and Grasslands,
             Department of Defense lands, and National Wildlife Refuges	104

Figure 28. Composite map with transportation corridors overlay. IH69 and
             Trans Texas Corridor are included	 105

Figure 29. Composite map with watershed boundary overlay	 106

Figure 30. Map depicting areas used for the accuracy assessment	107

Figure 31. a) Statewide frequencies of TEAP composite scores (by class) that
             occur inside and outside TNC portfolio; b) statewide frequencies
             expressed as a percentage of TEAP composite scores occurring
             inside and outside TNC portfolio	108

Figure 32. Map of proposed IH69 corridor depicting areas used for
             the accuracy assessment	110

Figure 33. a) IH69 corridor frequencies of TEAP composite scores (by class)
             that occur inside and outside TNC portfolio; b) IH69 corridor
             frequencies expressed as a percentage of TEAP composite scores
             occurring inside and outside TNC portfolio 	 Ill

Figure Bl. Map of diversity sub-layer: appropriateness of land cover. This map
             is used to produce the map of the diversity layer (Figure 5)	 181

Figure B2. Map of diversity sub-layer: contiguous size of undeveloped land.
             This map is used to produce the map of the diversity layer (Figure 5)	 182

Figure B3. Map of diversity sub-layer: Shannon land cover diversity index.
             This map is used to produce the map of the diversity layer (Figure 5)	 183

Figure B4. Map of diversity sub-layer: ecologically significant stream segments.
             This map is used to produce the map of the diversity layer (Figure 5)	 184

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Figure B5. Map of rarity sub-layer: vegetation rarity. This map is
              used to produce the map of the rarity layer (Figure 6)	 185

Figure B6. Map of rarity sub-layer: natural heritage rank. This map
              is used to produce the map of the rarity layer (Figure 6)	 186

Figure B7. Map of rarity sub-layer: taxonomic richness. This map
              is used to produce the map of the rarity layer (Figure 6)	 187

Figure B8. Map of rarity sub-layer: rare species richness. This map is
              used to produce the map of the rarity layer (Figure 6)	 188

Figure B9. Map of sustainability sub-layer: contiguous  land cover type. This
              map is used to produce the map of the sustainability layer (Figure 6)	189

Figure BIO. Map of sustainability sub-layer: regularity  of ecosystem boundary. This
              map is used to produce the map of the sustainability layer (Figure 7)	190

Figure Bll. Map of sustainability sub-layer: appropriateness of land cover.  This
              map is used to produce the map of the sustainability layer (Figure 7)	191

FigureB 12. Map of sustainability sub-layer: waterway  obstruction. This map
              is used to produce the map of the sustainability layer (Figure 7)	192

FigureB 13. Map of sustainability sub-layer: road density.  This map is
              used to produce the map of the sustainability layer (Figure 7)	193

FigureB 14. Map of sustainability sub-layer: airport noise. This map is
              used to produce the map of the sustainability layer (Figure 7)	194

FigureB 15. Map of sustainability sub-layer: Superfund National  Priority
              List and state Superfund Sites.  This map is used to produce the map
              of the sustainability layer (Figure 7)	 195

FigureB 16. Map of sustainability sub-layer: water quality. This  map is
              used to produce the map of the sustainability layer (Figure 7)	196

Figure B17.  Map of sustainability sub-layer:  air quality. This map is
              used to produce the map of the sustainability layer (Figure 7)	197

FigureB 18. Map of sustainability sub-layer: RCRA TSD, corrective action and
              state VCP  sites. This map is used to produce the map of the
              sustainability layer (Figure 7)	 198

FigureB 19. Map of sustainability sub-layer: urban/agriculture disturbance.  This
              map is used to produce the map of the sustainability layer (Figure 7)	199

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                               EXECUTIVE SUMMARY









Background




       Texas Environmental Resource Stewards (TERS) was established in July 2002 to seek




greater federal and state interagency collaboration on identifying and supporting joint priorities,




particularly regarding transportation issues.  Leaders from participating agencies identified




common interests and target activities for collaborative ecosystem management of benefit to




each agency. Common interests included identification of ecologically important natural




resource areas (wetland, aquatic, and terrestrial) for avoidance, or potential compensatory




mitigation, preservation, or restoration; "streamlining" of regulatory processes; early




identification of some National Environmental Policy Act (NEPA) requirements in project




planning; and analysis of cumulative impacts. The TERS executives developed a vision which




included the following  actions:




              Improve mutual understanding




              Use collective knowledge to  support decision-making




              Strive for synergism









The initial approach to  achieving a portion of the TERS vision was to develop an ecosystem




approach to  organize strategies that achieve  effective and measurable environmental results, and




jointly communicate the results to the public. The initial goals of TERS were to identify




ecologically important  areas, identify potential mitigation areas, and streamline regulatory




processes. This report  serves to communicate progress on the first goal: the ecological




assessment and identification of ecologically important resources in the state of Texas.




                                            1

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       Technical experts from participating TERS agencies agreed to (1) develop a scientifically




valid, ecosystem prioritization protocol for Texas; (2) apply this protocol to existing, available




data using GIS: and (3) demonstrate the protocol to identify areas of highest ecological




importance in Texas. The Texas Ecological Assessment Protocol (TEAP) relies on a previously




developed methodology and consists of collecting and analyzing existing electronic data




available statewide, which was used to evaluate the following three ecological criteria:









       1.      Diversity                   What areas have the most diverse land cover?




       2.      Rarity                      What areas have the highest number of rare species




                                         and land cover types?




       3.      Sustainability               What areas can sustain ecosystems now and in the




                                          future?









Chapter 2 of the full report provides details of TEAP. The results of the analysis for each layer




within each ecoregion are summarized below (Figures A-C).  The eighteen ecoregion sections




developed by Bailey (1994) were used.









       Diversity (Figure A): The diversity map shows higher diversity in west Texas




       (Chihuahuan Desert Basin and Range ecoregion). There are areas of high diversity in the




       southern portion of the Rolling Plains ecoregion, and the Rio Grande Plain ecoregion.









       Rarity (Figure B):  The rarity map shows the areas of highest rarity are in the Stockton




       Plateau and the Coastal Plains and Flatwoods Western Gulf Section ecoregions.  In




                                            2

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       addition, areas in the Chihuahuan Desert Basin and Range, Edward's Plateau, Oak




       Woods and Prairies, and the southern portion of the Rio Grande Plain ecoregion show




       moderately high levels of rarity.









       Sustainability (Figure C):  Figure C shows the combination of all eleven layers in a map




       representing sustainability. There are only a few highly sustainable (top 1%, 10%)




       locations in the Chihuahuan Desert Basin and Range, Stockton Plateau, southern Rio




       Grande Plain, southern Rolling Plains, and a few other areas in Texas.  The more




       sustainable areas occur where there are fewer human disturbance activities. Most of the




       population lives in the eastern half of the state.  Thus, the Cross Timbers and Prairies,




       Central Gulf Prairies and Marshes, Mid Coastal Plains  Western Section, and Blackland




       Prairies ecoregions show the lowest sustainability.









These three layers were combined into a composite map that shows where ecologically




important areas occur in Texas (Figure D). The top 1% highly ecologically important areas in




Texas are highlighted in red.  Most of the ecologically  important (1%, 10%) areas are located in




Chihuahuan Desert Basin and Range, Stockton Plateau, and Rio Grande Plain ecoregions. Other




areas that have high or moderately high ecologically important areas are the Edwards Plateau




and the southern portion of the Mid Coastal Plains Western Section.  Conversely, the most




threatened areas are in the Blackland Prairies, Oak Woods and Prairies, Central Gulf Prairies and




Marshes, and Louisiana/Eastern Gulf Prairies and Marshes ecoregions which TEAP indicates




have the least sustainable ecological areas. The Nature Conservancy  (The Conservancy)




performed an independent accuracy assessment on the  TEAP comparing the composite scores




                                           3

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and The Conservancy portfolio sites. This assessment showed, in general, that those areas




ranked as highly important ecologically by TEAP corresponded to areas identified as very




ecologically important in The Conservancy portfolio. Field investigation would be necessary to




better determine the accuracy of locations that had low TEAP composite scores.




       TEAP was applied to rapidly assess the entire Texas landscape by ecoregion through the




use of a statewide GIS grid. The results of TEAP provide a tool for use in project planning and




for reducing very large corridors to more manageable areas for more detailed field investigation.




Identification of ecologically important areas in each ecoregion can be used as a tool to support




ecosystem-driven mitigation sequencing (avoidance of impacts, minimization, and then




compensation) and conservation planning throughout the state. TEAP can also be used to find




high quality habitat remnants in all ecoregions in Texas.  The TEAP is intended to be a




supplemental tool for agency use, not to circumvent or replace agency policies, processes, or




regulations.









Actions




       Updated analyses using 2002 land cover data can be performed once this data is made




available in a GIS format. In addition, several other databases (e.g., pipelines, oil and gas wells)




were suggested for incorporation.  These databases, as well as modifications to the current




protocol, can be made in subsequent iterations.  TEAP will be reevaluated every 2 to 3 years




when new land cover and other data become available. Therefore, TEAP can be used to identify




trends in ecological condition by comparing results from previous years.

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                                   Southern High Plains
                                                                            Oak Woods
                                                                                 ries
                                                                                        Mid Coastal
                                                                                        Plains, Western
                                                                                             Coastal Plains
                                                                                             and Flatwoods,
                                                                                             Western Gulf
                                                                                            Louisiana Coast
                                                                                            Prairies and
                                                                                            Marshes
   Top 1 %    (More Diverse)

   2-10%

   11 - 25%

   26 - 50%

   51 -100%  (Less Diverse)
Rio Grande Plain
                                                              200
                                                                                      Miles
Figure A.  Map of the diversity layer with ecoregion boundaries.  This map is a composite of
four sub-layers:  appropriateness of land cover, contiguous size of undeveloped land, Shannon
land cover diversity index, and ecologically significant stream segments.

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                                         Southern High Plains
                                                                                               Mid Coastal
                                                                                               Plains, Western
                                                                   Cross Timbers        Oak Woods
                                                                                   and Prairies
                                                                                                    Coastal Plains
                                                                                                    and Flatwoods,
                                                                                                    Western Gulf
                                                                                                   Louisiana Coast
                                                                                                   Prairies and
                                                                                                   Marshes
•




Top1%
2-10%
1 1 - 25%
26 - 50%
51 -100%
(More Rare)
A

•\
L

r
(Less Rare)
                                                                                                         200
                                                                                           Miles
Figure B. Map of the rarity layer with ecoregion boundaries.  This map is a composite of four
sub-layers: vegetation rarity,  natural heritage rank, taxonomic richness, and rare species richness.

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                                       Southern High Plain:
                                                                             Oak Woods
                                                                             and Prairies
                                                                                        Mid Coastal
                                                                                        Plains, Western
       Top1%

       2-10%

       11 - 25%

       26 - 50%

       51 -100%    (Less Sustainable)
                                                                                             Coastal Plains
                                                                                             and Flatwoods,
                                                                                             Western Gulf
                                                                                           Louisiana Coast
                                                                                           Prairies and
                                                                                           Marshes
200
                                                                                     Miles
Figure C. Map of the sustainability layer with ecoregion boundaries.  This map is a composite of
eleven sub-layers: contiguous land cover type; regularity of ecosystem boundary;
appropriateness of land cover; waterway obstruction; road density; airport noise; Superfund NPL
and state Superfund sites; water quality; air quality; RCRA TSD. corrective action, and state
VCP sites; and urban/agriculture disturbance.

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                                   Southern High Plains
                                                                          Oak Woods
                                                                               ries
                                                                                     Miles
Figure D. Composite map with ecoregion boundaries. This map is a composite of the diversity layer
(Figure A), rarity layer (Figure BX and sustainability layer (Figure C).

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                                 1.0 INTRODUCTION









1.1 TERS History




       Texas Environmental Resource Stewards (TERS) was established by various state and




federal resource agencies in July 2002 to create greater interagency collaboration on identifying




and supporting joint priorities in Texas. Leaders from the U.S. Environmental Protection




Agency (EPA),  U.S. Army Corps of Engineers (USAGE! U.S. Fish and Wildlife Service




(FWS), Federal Highway Administration (FHWA), Texas Commission on Environmental




Quality (TCEQX Texas Parks and Wildlife Department (TPWD), Texas Department of




Transportation (TXDOT), and the Texas Governor's Office met to develop a vision and




objectives for TERS.  Other target participants, such as the General Land Office (GLO), Texas




Water Development Board (TWDB), Texas Historical Commission (THC), Texas Department of




Agriculture, U.S. Forest Service (USFSX and non-governmental organizations (NGO's),  such as




The Nature Conservancy of Texas (The Conservancy) were also identified as possibly having an




interest in supporting the TERS vision and goals.  The Conservancy was subsequently asked to




participate because of its expertise in producing ecoregional portfolios of important conservation




areas.




       Participating agencies identified common interests and target activities for collaborative




ecosystem evaluation and management in Texas.  Common interests and uses included




identification of ecologically important areas (wetland, aquatic, and terrestrial) to be targeted for




avoidance, minimization of impacts, or compensatory mitigation (enhancement, preservation, or




restoration); "streamlining" of regulatory processes; generation of additional data to support




regulatory decisions; early assistance with National Environmental Policy Act (NEPA) planning




                                           9

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and analysis, project development and review; greater collaboration on environmental planning




and public outreach; analysis of cumulative impacts (also including direct, indirect, and




secondary impacts); preservation and improvement of surface water, ground water, and air




quality; identification of ecologically important habitats (wetland, aquatic, terrestrial,




endangered species); and providing improved indicators of biodiversity health and ecosystem




functionality (including fragmentation effects). Streamlining, as defined in this report, is a




cooperative and coordinated process that assures timely, cost effective, and environmentally




sound planning and project development based on concurrent, multi-agency review. Executive




Order (EO) 13274, Environmental Stewardship and Transportation Infrastructure Project




Reviews, suggests agencies take actions to expedite environmental reviews and permit decisions




specifically for transportation projects.









The following vision was developed for TERS:




              Improve mutual understanding of agency needs and expectations.









              Use collective knowledge and expertise to broaden perspectives and support




              decision-making affecting regional environmental, economic and societal




              policies, issues, and trends.









              Strive for synergism, so that the total effect is greater than the sum of individual




              agency efforts.









        The initial goals of TERS were to identify ecologically important areas, identify




                                           10

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potential mitigation areas, and streamline regulatory processes. The TERS agency




representatives chose to focus solely on environmental and ecological conditions, not historical




and cultural resources. This report is the initial step in meeting the first TERS goal: the




ecological assessment and identification of ecologically important resources in Texas.









1.2 Texas Ecological Assessment Protocol (TEAP) Goals




       The approach to achieving the TERS vision was to identify and collaborate on common




priorities using an ecosystem approach to organize strategies that achieve effective and




measurable environmental results, and to jointly communicate the results to the public.  The




TEAP is the method the TERS Steering Committee agreed to (1) develop a scientifically valid,




ecosystem-based process for Texas; (2) apply this process to existing available data and




information through the use of Geographical Information Systems (GIS): and (3) demonstrate




the process for identifying ecologically important resources throughout Texas. TERS




participants were asked to identify potential uses for the TEAP within each agency. However, at




the present time, no specific commitments or plans for the TEAP have been made.




       The TEAP is a screening level, rapid assessment tool using existing electronic data




available statewide. The TEAP is an "ecoregional" assessment, applied to an entire state.




Therefore, it is general in nature and design. It is a planning tool and screening-level  assessment




that should lead users to progressively narrow the scope of analysis. It is not an  all-




encompassing predictive model for each land cover type, species, etc.




       The potential intended use of the results of the TEAP include:  1) use in the NEPA




planning process (scoping, alternatives development, etc.), 2) use in streamlining the




authorization process for large projects (such as transportation) by narrowing the study corridor




                                           11

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necessary for further field investigation, and 3) use in mitigation discussions to avoid




ecologically important areas, minimize impacts to those areas, and compensate for unavoidable




impacts.  This list of intended uses is not exhaustive, nor all inclusive. The TEAP is not




designed to take the place of agency policies and procedures. It is a supplemental information




tool aiding in agency decision making. The initial TEAP product is a CD with the three main




layers and composite layer data in GIS format. The final version of this report will be included




on the CD.









1.3 Background









1.3.1 Geographical Information System (GIS)-Based Assessments




       GIS is used in the development of assessment and geospatial screening tools not only




because of its spatial data visualization abilities (i.e., maps of different data layers, coverages,




landscape level, etc.), but also because of its modeling and analysis functions, including




landscape metrics (e.g. FRAGSTATS), and other calculations such  as population density,




hydrological function.  Given the direction of the TERS executives, it was apparent that GIS




would be useful for TEAP.  GIS is a vital research and assessment tool (Dale et al. 1994.




Treweek and Veitch 1996. O'Neill etal. 1999. Iverson et al. 2001.  Clevenger et al. 2002. Ji and




Leeberg 2002).  When used at the landscape level, GIS can identify and prioritize areas for




protection to enable animal movement by evaluating different land management uses (Clevenger




et al. 20021




       Regionally-scaled projects, such as those that use the ecoregion (Mysz et al. 2000) or




watershed (Dickert and Tuttle 1985. Tinker etal. 1998. Espejeletal. 1999. Steiner et al. 2000a.




                                           12

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Steiner et al. 2000b. Serveiss 2002) as a base unit, have become more common with the advent




and subsequent increase in the use of spatial analysis tools such as GIS.  These tools have




inspired scientists concerned about landscape level patterns and their effect on terrestrial and




aquatic communities (Steiner et al. 2000a. Jones et al. 2001. H. John Heinz III Center for




Science. Economics and the Environment 2002). Assessments, whether landscape- or




geographically-based, are more holistic than assessments performed locally, or those based on




political boundaries, because of their ability to relate potentially unrelated factors (Miller et al.




1998) and for comparisons at other scales. For example, several geographic units can be




aggregated (Montgomery  et al.  1995).




       Geographically-driven approaches have also been used to analyze environmental




problems (e.g. nonpoint source water pollution, regional studies) that do not fit into traditional




programs or assessment methods (Boughton et al.  1999. Serveiss 2002.) as well as those




problems needing a holistic or comprehensive analysis such as broad assessments like TEAP.




Landscape-level assessments also lead to improved intergovernmental coordination and more




informed decision-making on regulatory and management initiatives (Steiner et al. 2000a.




Serveiss 2002). Better interagency coordination and cooperation are goals of the TERS group.




       As with TEAP. most geospatial tools use some sort of criteria or factors to evaluate the




data layers used in the assessment (Karydis 1996. Steiner et al. 2000b. Store and Kangas 2001.




Xiang2001). These ranks, or scores, simplify the  analysis (Serveiss 2002). normalize disparate




data sets onto one nominal scale (Wickham et al. 1999. Clevenger et al. 2002). and provide an




easily understandable format to communicate the results to various audiences  (Theobald et al.




2000). These 'scores' are helpful in comparing various aspects of projects since the 'score'




represents the relative value of one alternative to another (Abbruzzesee and Leibowitz 1997.




                                           13

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Wickham et al. 1999.  Steiner et al. 2000b).  These scoring systems may represent the difference




between an ideal state of the environment and reality (Tran et al. 2002).









1.3.2 Ecoregion Delineation




       TEAP uses eighteen ecoregion sections (hereafter referred to as ecoregions) developed




by Bailey (1994) as the base unit for calculation. Further details on the process of base unit




selection are provided in the Methods chapter. Ecoregions illuminate ecosystem patterns at




multiple scales, aiding the visualization of differences between ecosystems.  They can be defined




as regions of relative homogeneity in ecological systems (Griffith et al. 1999). Most ecoregions




include minimally impacted areas that can be used to define reference conditions necessary to




provide a basis for comparison to impacted areas. Since multiple areas within an ecoregion are




relatively similar, they should respond similarly to stresses or management actions.  Thus,




ecoregions are appropriate areas for extrapolation of monitoring, including statistical sampling




or research results (Bryce et all996. Harrison et al. 2000). Ecoregions can be used as reporting




frameworks that clarify patterns of environmental data (such as nutrient transport) reflecting




both natural and human influences. Griffith et al. (1999) contend that ecoregion frameworks are




highly effective tools for accomplishing comprehensive and integrative management approaches




due to their depiction of the whole mosaic of ecosystem  components - biotic and abiotic,




terrestrial and aquatic, including human-related factors that affect water quality and quantity




(major components of watershed assessment).




       Ecoregions allow the development of management strategies appropriate to regional




expectations. They define areas where standardized management practices can be applied after




being proven in individual sites or watersheds.




                                           14

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1.3.2.1 Types of Ecoregion Delineation




       Bailey (1985. 1987.  1994. 1996) developed a multi-tiered, broad-scale, hierarchical




system of ecoregions at a scale of 1:7,500,000 based on numerous environmental variables




(Figure 1).  The first two tiers are based on combinations of climate, physiography, topography




and soils which were used to provide a general description of the ecosystem geography.  The




ecoregion system can be used to address environmental issues that transcend agency, watershed,




and political boundaries and borders.  Details of the ecoregion sections in Texas can be found in




Appendix A. Other delineations of ecoregions include Omernik (1987.  1995) (Figure 2). Gould




(1975) (Figure 3). and Lyndon B. Johnson School of Public Affairs (1978) (Figure 4).  The




Omernik (1987) system constructs ecoregions based on perceived patterns of a combination of




causal and integrative factors including land use, land  surface form, potential natural vegetation,




and soils (Omernik 1987). Bailey (1994. 1996) and Omernik (1987) plan to merge ecoregion




maps.  The map of vegetative types of Texas (Gould 1975) provides a checklist and ecological




summary of Texas plants (Figure 3).




       An interdisciplinary team of scientists and laymen developed a system of classifying




Texas into natural regions (Lyndon B. Johnson School of Public Affairs 1978).  They recognized




that regions distinguished by physiographic or biologic differences could be readily identified by




scientists and local citizens, with the goal of preserving elements of Texas' natural diversity




(Figure 4).









1.3.3 Ecological Theory Used in TEAP




       TEAP divides nineteen individual measures from databases  into sub-layers which




comprise three separate main layers. These main layers are diversity, rarity, and sustainability.




                                           15

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                                    Southern High Plains
      Sacramento-
       Monzano
       Mountain
                                                                           Central Gulf
                                                                           Prairi^HB
                                                                             Marshes •,
                                                                       Southern Gulf
                                                                       Prairies and
                                                                       Marshes
                                                                                                   Coastal Plains
                                                                                                   and Flatwoods,
                                                                                                   Western Gulf
                                                                                                  Louisiana Coast
                                                                                                  Prairies and
                                                                                                  Marshes
Eastern Gulf
Prairies and
  Marshes
Figure 1.  Map of Bailey's ecoregion sections (Bailey 1994).
                                                   16

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                             Western
                            High Plains
                            Western
                              High
                              Plains
southwestern
                                                      Central Oklahoma/
                                                        Texas Plain
        Arizona/
      New Mexico
          Mtns
                                                                                         South
                                                                                        Central
                                                                                         Plains
               Southern Deserts
                                            Central Texas Plateau
                                                     Southern
                                                      Texas
                                                      Plains
Figure 2. Map of Omernik ecoregions (Omernik 1987).
                                               17

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                          High Plains  r\l   Rolling Plains
                                                                                        I Miles
                                               0    37.5  75        150       225        300
Figure 3.  Map of Gould's vegetation types (Gould 1975).
                                              18

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Figure 4. Map of Texas natural areas (Lyndon B. Johnson School of Public Affairs 1978).
                                          19

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1.3.3.1 Diversity




       The diversity layer shows land cover continuity and diversity in Texas. This layer




consists of four sub-layers: (1) appropriateness of land cover, (2) contiguous size of undeveloped




area, (3) Shannon land cover diversity, and (4) ecologically significant stream segments.




       The diversity layer demonstrates an important fundamental ecological principle: the




species-area relationship. The species-area relationship states that larger areas have higher




diversity and/or species abundance than smaller areas (Diamond and May  1976. Schafer 1990.




Harte and Kinzig 1997). There are several hypotheses to explain the species-area relationship.




The one pertinent for TEAP is the habitat diversity hypothesis, which states that increases in the




number of types of habitat in an area increases the number of niches able to be filled, therefore




larger areas would have more species or land cover types (Jonson and Fahrig 1997). Other




species-area hypotheses include island biogeography (MacArthur and Wilson 1967) and the




random sample hypothesis (Arrhenius 1921).









1.3.3.1.1 Appropriateness of Land Cover. Appropriateness of land cover describes the predicted




natural vegetation under no human influence (Kuchler 1964) and compares it to the current




vegetation cover.  The rationale for including this measure in the diversity layer is twofold: 1)




the area is ecologically stable and resistant to disturbance if pre-settlement vegetation and




current vegetation types are the same, and 2) it is a surrogate for species diversity.









1.3.3.1.2 Contiguous Size of Undeveloped Land. Contiguous size of undeveloped land is




calculated using the theory that the larger the contiguous area of undeveloped land, the higher




the diversity (MacArthur and Wilson 1967. Dale and Haeuber 2000).




                                           20

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       There are two similar measures calculated in the diversity and sustainability layers.




"Contiguous area of undeveloped area" is entitled and calculated slightly differently in the




diversity layer compared to the sustainability layer.  In the diversity layer, all undeveloped land




cover types that are adjacent to each other are lumped into one polygon.  In the sustainability




layer, the individual, undeveloped land cover types (that made up this larger polygon in the




diversity layer) are calculated separately. In diversity, the question being answered is, "how




extensive are the areas of undeveloped land?" In sustainability, the question answered is, "How




extensive are the cover types that make up the areas of undeveloped land?"




       All adjacent undeveloped land cover is merged into one polygon (e.g., forest adjacent to




wetland adjacent to grassland). One polygon could have any number of cover types. For




example, one contiguous polygon may consist of three different, undeveloped land cover types.




As long as they are all undeveloped and adjacent to each other, the contiguous size of




undeveloped land sub-layer is calculated as one polygon (until interrupted by a developed cover




type).









1.3.3.1.3 Shannon Land  Cover Diversity Index.  The Shannon land cover diversity index




calculates the diversity, in terms of land cover types, for each of the contiguous polygons




calculated in the previous section. The Shannon index is an established method used to measure




ecological (species) diversity (richness and evenness) (Begon etal. 1986).  It usually calculates




the proportion of individuals of a population related to the total number of individuals, but used




here to calculate the proportion of land cover types, related to the total number of land cover




types.  Other ecological  diversity measures used in landscape assessment are discussed in




Herzog et al. (20011




                                           21

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       The Shannon land cover diversity index does not view land cover diversity the same way




as the contiguous size of undeveloped land sub-layer. In general, the Shannon land cover




diversity index shows how many specific land cover types there are in these contiguous area




polygons and how they are dispersed.




       A low value for Shannon land cover diversity index means there are fewer undeveloped




land cover types and that they may be clumped, compared to a more evenly dispersed pattern




within the geographical boundary. A high value would indicate that there are several




undeveloped land cover types that are more evenly dispersed throughout the geographic area.




The idea that the Shannon land cover diversity index should increase with less contiguous area is




not exactly true because the measures are somewhat independent. Logic indicates that it may be




more likely that there are more land cover types in larger areas (polygons), but that is not




necessarily the case. For example, there could be a large unbroken tract of desert in west Texas.









1.3.3.1.4 Ecologically Significant Stream Segments. Significant stream segments (Norris and




Linum 1999. El-Hage and Moulton 2000a. Norris and Linum 2000a. El-Hage and Moulton




2000b. Norris and Linum 2000b. El-Hage and Moulton 2001) represent natural systems that are




increasingly rare habitat and is the aquatic equivalent of the  contiguous size of undeveloped land




sub-layer. Significant stream segments are ecologically unique areas determined by TPWD




based on biological function, hydrologic function, riparian conservation areas, high water quality




(including aquatic life and aesthetic value), and threatened or endangered species. TPWD used




scientific literature, existing data, and TPWD expertise to identify 228 segments meeting at least




one of the criteria listed above.




       Stream or river segments are considered significant using five criteria: 1) biological




                                           22

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function, where segments display a high level of biodiversity, age, and uniqueness; 2) hydrologic




function, where segments perform valuable functions related to water quality, flood attenuation,




flow stabilization, or ground water recharge; 3) riparian conservation areas, which includes state




and Federal refuges, wildlife management areas, preserves, parks, and mitigation areas; 4) high




water quality/exceptional aquatic life/high aesthetic value that represents unique or critical




habitat or exceptional aquatic life; and 5) threatened and endangered species/unique




communities where segments represent the presence of unique, exemplary, or unusually




extensive natural communities.




       The ecologically significant stream segment designation is not the same as the




ecologically unique stream segment designation. The former has no legal status, but the later




represents a statutorily defined legal category. The criteria used for both stream definition types




are identical in many respects. The act of officially designating a stream segment as




"ecologically unique" is a combined effort of TPWD, TWDB. and the Texas legislature and does




not protect the segment from physical degradation.  It prevents a state agency from obtaining a




fee title or easement that would compromise the ecological value of the  designated stream




segment. Designation of a segment recognizes the importance of protecting the ecological




legacy of Texas' rivers and streams.









1.3.3.2 Rarity




       The rarity layer was designed to show rarity of species and land cover in Texas. The




rarity layer consists of four sub-layers: (1) vegetation rarity, (2) natural heritage rank, (3)




taxonomic richness, and (4) rare species richness.
                                            23

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1.3.3.2.1 Vegetation Rarity.  The land cover or vegetation rarity measure is derived from the U.




S. Geological Survey (USGS) National Land Cover Dataset (NLCD) and represents rarity of all




natural cover types including water and bare rock. Vegetation rarity is a measure of the




particular land cover types that are considered rare within each ecoregion.









1.3.3.2.2 Natural Heritage Rank. The Global Heritage Ranking System created by The




Conservancy is described as:




              Gl. SI. Critically imperiled. Critically imperiled globally (G) (or in the state, .81)




              because of extreme rarity or because of some factor(s) making it especially




              vulnerable to extinction.  Typically, this rank consists of five or fewer




              occurrences or very few remaining individuals (< 1,000) or acres (< 2,000) or




              linear miles (< 10).









              G2. S2. Imperiled. Imperiled globally (or in the state, S>2) because of rarity or




              because of some factor(s) making it very vulnerable to extinction or elimination.




              Typically, this rank consists of 6-20 occurrences or few remaining individuals




              (1,000-3,000) or acres (2,000-10,000) or linear miles (10-50).









              G3. S3. Vulnerable. Vulnerable globally (or in the state,  S>3) either because they




              are very rare and local throughout its range, or found only in a restricted range




              (Even if abundant at some locations), or because of other factors making it




              vulnerable to extinction or elimination. Typically, this rank consists of 21 to 100




              occurrences or between 3,000 to  10,000 individuals.




                                           24

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              G4. S4. Apparently secure. Uncommon globally (or in the state, S4), but not rare




              (although it may be rare in parts of its range, particularly on the periphery), and




              usually widespread.  Apparently not vulnerable in most of its range, but possible




              cause for long-term concern.  Typically, this rank consists of more than 100




              occurrences and more than 10,000 individuals.









              G5. S5. Secure. Common globally (or in the state, S>5), widespread, and abundant




              (although it may be rare in parts of its range, particularly on the periphery).  Not




              vulnerable in most of its range. Typically, this rank consists of with considerably




              more than 100 occurrences and more than  10,000 individuals.









1.3.3.2.3 Taxonomic Richness. Taxonomic richness, or the number of rare taxa is another




measure of rarity. This sub-layer measures the richness of broad taxonomic groupings; that is,




the locations that have a high degree of rarity in multiple taxa, e.g., birds, mammals, reptiles,




amphibians, etc. The number of rare taxa (taxonomic richness) indicates taxonomic diversity.









1.3.3.2.4 Rare Species Richness.  Another measure of rarity is rare species richness, or the




number of rare species per ecoregion.  The number of rare species (rare species richness) may




indicate the amount of endemism in an area. Rare species may be keystone/umbrella species




(Launer and Murphy 1994) or very productive communities or typify a particular ecological




community type (Poiani etal. 2001).
                                           25

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1.3.3.3 Sustainability




       The sustainability layer describes the state of the environment in terms of stability; that




is, how resistant to disturbance an area is, and how capable is the area in returning to its pre-




disturbance state, that is, resilience (Begon et al. 1986).  For the purposes of this report,




sustainable areas are those that can maintain themselves into the future without human




management.




       Stability has two components: resistance and resilience. Resistance is defined as an




ecological community's ability to withstand disturbance (Begon et al. 1986). whereas resilience




is the ability of an ecological community to recover from a disturbance (Begon etal. 1986).




Highly sustainable ecosystems are able to resist disturbance, but once disturbed can return to the




pre-disturbance state within a short time period (resilience) (Begon et al. 1986).  The




sustainability layer consists of eleven measures that can be loosely grouped into fragmentors: (1)




contiguous land cover type, (2) regularity of ecosystem boundary, (3) appropriateness of land




cover, (4) waterway obstruction, and (5) road density and stressors: (1) airport noise, (2)




Superfund National Priority List (NPL) and state Superfund Sites, (3) water quality,  (4) air




quality,(5) Resource Conservation and Recovery Act (RCRA) Treatment-Storage-Disposal sites




(TSD), corrective action and state Voluntary Cleanup Program (VCP) Sites, and (6)




urban/agricultural disturbance.









1.3.3.3.1 Contiguous Land Cover Type. Contiguous land cover is based on the principle that




larger areas having similar ecosystem types have greater sustainability. Contiguous area of




undeveloped land supports connectivity, the opposite of the isolating effects of fragmentation




(Gustafson and Gardner 1996).  Larger habitat areas have less edge than smaller habitat areas




                                            26

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and therefore, can preserve biodiversity (Lee etal. 2001). Larger areas of contiguous habitat can




support large animals or widely-dispersing animals such as carnivores and large ungulates. As




these large areas are fragmented, either through direct habitat loss or through insularization, the




remaining habitat may not maintain viable population of these organisms (Tigas et al. 2002).




       Fragmentation of habitats comprises two ecological effects: 1) loss of habitat, and 2)




increased insularization (or isolation) of the remaining habitat (Noss and Csuti 1994).  It is a




spatial phenomenon that affects landscape continuity (Robinson et al. 1992) and poses some of




the most significant challenges to ecologists.  It is a major threat to landscape continuity and can




disrupt temporal and spatial habitat use by animals (Tigas et al. 2002).  The effects of




fragmentation have been demonstrated for a variety of taxa: mammals (Brown 1986. Foster and




Gaines 1991. Chiarello 1999. Lindenmaver et al. 1999):  birds (Askinsetal. 1987. Opdam 1991.




Walters et al. 1999): reptiles and amphibians (Johnson 1986. Vos and Stempel 1995): and insects




(Johnson 1986. Thomas and Harrison 1992. Wahlberg et al. 1996).









1.3.3.3.2 Regularity of Ecosystem Boundary.  For all land cover types except open water,




conventional ecological wisdom suggests that the smaller the perimeter for a given area, the




larger the core interior habitat.  It is based on the principle that the least amount of boundary




results in the lowest amount of "edge effect" thereby yielding the least disturbance and greatest




sustainability of the ecosystem.  The reverse is also true; areas with larger perimeters compared




to their areas, will have a greater amount of "edge" habitat and less "interior" or core area. The




more complex the edge, the more opportunities for negative influences to affect the location.




The more negative influences, the less  sustainable the location. Habitat edges differ from the




interior in their ecological processes (Donovan et al.  1997) and in physical impacts,  such as




                                           27

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changes in vegetation density, size, shape, matrix habitat, and fragment aggregation.  Small




patches may have properties similar to the edge throughout.




       The measure of regularity of ecoregion boundary reflects the perimeter to area ratios




(PAR) of areas of particular land cover types. Ecological theory suggests that perfectly circular




or square habitat areas will have higher diversity and/or species abundance compared to linear




habitat areas (Game 1980). However, small narrow areas may provide erosion control to




riparian areas (H. John Heinz III Center for Science. Economics and the Environment 2002).




Habitat edges differ from the interior in their ecological processes (Donovan et al. 1997)




including physical impacts, such as changes in vegetation density, size, shape, and matrix habitat




(Lidicker 1999).  Biological impacts to species (Yahner 1988) are well documented.  Edges are




transition zones where generalist species thrive. Conventional ecological wisdom concerning




"edge" demonstrate that invasive or opportunistic species prefer the types of habitat associated




with the "edge,"  or the boundary between two habitat types (H. John Heinz III Center for




Science. Economics and the Environment 2002).  As one moves away from the edge there is a




change in species composition (Lee etal. 2001) which can be associated with abiotic factors,




such as temperature, humidity, and vegetation structure flVIcCollin 1998). Unique or rare species




typically use "interior" habitat or may need a large amount of habitat as a home range.




       There are many examples concerning edge-interior species. For example, cowbirds and




other parasitic birds prefer the habitat on the agriculture-forest boundary and prey on birds, such




as the black-capped vireo or golden-cheeked warbler, that need a certain amount of habitat away




from this boundary, or interior habitat. Many birds, including warblers and red-cockaded




woodpeckers require forest interior habitat.  Large-bodied animals, such as bears and mountain




lions, may need extended habitat areas in which to forage and mate, without the intrusion of




                                           28

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urban or agricultural activities (Noss and Csuti 1994). Forest areas adjacent to non forest areas




may by more affected by abiotic elements (e.g., wind, heat) and consequently open to invasion




by exotic species (H. John Heinz III Center for Science. Economics and the Environment 2002).




       It is widely accepted that the nature of patch edge in aquatic and terrestrial  systems




differs greatly due to high differences in the land cover types (water vs land) and differences in




the nature of communities of the interface zones.  A more convoluted water/land edge allows for




a greater amount of habitat suitable for the species and communities that live (and  often can only




exist) in these interface zones.  At the most general level, this land/water edge differs from the




edge between two (or more) terrestrial land cover types because of the difference in the cover




type media (i.e. water vs. land). There is less transfer in species, materials and energy between




these two patch types (i.e., there is less invasion possible either from water to land or vice versa,




and thus less deleterious "edge effect." The term "edge effect" is not widely used in the literature




for water/land boundaries compared to the description of dynamics between terrestrial land




cover patches.




       As habitat areas become more fragmented and insularized, the edge habitat tends to




increase and the interior habitat tends to decrease; therefore, impacting the sustainability of rare




or unique species.  Because of internal modifications and the lack of intact core areas, small




patches may have properties similar to the edge. A preference for the edge results  in a negative




response to habitat area because large habitat areas have smaller PARs than small habitat areas




(Cappuccino and Root 1992). Studies describing habitat "shape" are related to edge effects




through the PAR (Collinge 1996. 1998. Collinge and Forman 1998). In addition, island




biogeographic theory (MacArthur and Wilson 1967) has been used to generate the following




"optimum" characteristics for land and species conservation: large circular, undivided sites (or




                                            29

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"reserves"), or if the site is divided, then connectivity by corridors (Wilson and Willis 1975.




Diamond and May 1976. Burel 1989) based on these shape and "edge effect" theories.









1.3.3.3.3 Appropriateness of Land Cover.  Appropriateness of land cover describes the predicted




natural vegetation under no human influence (Kuchler 1964) and compares it to the current




vegetation cover.  The rationale for including this measure in the sustainability layer is that if




pre-settlement and current vegetation types are similar then the seed bank is intact and therefore




the area can recover from a disturbance more quickly (resilience).









1.3.3.3.4 Waterway Obstruction.  The waterway obstruction sub-layer is based on the principle




that dams and corresponding reservoirs are interruptions to the continuity of waterways.




Waterway obstruction is a surrogate for fragmentation to water bodies. Dams disturb the natural




flow regime of a river, turning it into a reservoir and non-flowing system.  The river




environment, both aquatic and riparian, is fragmented and insularized, thus creating disturbances




for the fish, aquatic organisms and plant communities associated with this habitat.









1.3.3.3.5 Road Density.  The road density sub-layer is based on the principle that roads fragment




the landscape (Abbitt et al. 2000). In general, more roads and larger roads (multilane highways,




for example) occur near the population centers and also serve to connect them. The higher the




density of roads, the more fragmentation and  disturbance occurs to natural communities (Abbitt




et al. 2000).
                                           30

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1.3.3.3.6 Airport Noise. The airport noise sub-layer is based on the principle that noise around




airports stresses surrounding habitats thereby lowering the quality of wildlife habitat.  Airport




noise is a disturbance to natural communities based upon the noise level from airplanes and




associated activities, maintenance on the runways themselves, and because they serve as a




catalyst for development surrounding the airport.  Airports with larger runways typically have




wider areas of disturbance.




       Aircraft noise is known to impact wildlife patterns especially those of birds (e.g., feeding,




resting and nesting) and to increase predation on amphibians has been observed. According to




the Federal Aviation Administration (FAA), the noise generated by an aircraft is generally




determined by the thrust powering the aircraft; the amount of thrust an aircraft needs is




proportional to the weight of the plane.  That is, the heavier the aircraft, the more thrust it needs




and the more noise is produced. Runway length only defines the heaviest aircraft (total weight)




that can land and take off.  While newer aircraft have shorter runway length take off




requirements and reduced noise, many of the older aircraft (e.g., 747 and Lear 25) with high




noise potential remain in service. The buffer distance around airports was used as an indication




of disturbance due to noise. To estimate the distance, the noise disturbance was assumed to be




proportional to the size of the aircraft, and that was proportional to the runway length.









1.3.3.3.7 Superfund National Priority List (NPL) and State Superfund Sites. These are sites




where hazardous substances have been released and are, by definition, disturbances or stressors




on the natural environment. While efforts are made to minimize the impacts of these sites and to




clean up or contain contaminants to acceptable  risk level, the release of toxic chemicals may




permanently alter natural conditions. These areas and natural areas adjacent to them are less




                                            31

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likely to be self sustaining and more likely to require human management for their continued




existence. Once clean up efforts have been completed, further development may be restricted or




prohibited at portions of those sites where waste has been left in place in order to prevent




disturbance of containment areas and subsequent human exposure. For example, future highway




or other construction activities at some sites may need to be avoided. However, with proper




engineering, many such sites can and have been put to productive use.  As a consequence,




unique opportunities for low impact restoration of natural or near-natural habitat areas may be




available.









1.3.3.3.8 Water Quality. Water quality or the lack of water quality (defined by Clean Water Act




(CWA) Section 303(d), as not meeting designated uses) is another stressor on the natural




environment. This sub-layer in no way intends to abrogate any obligations or duties assigned by




law to TERS participating agencies.









1.3.3.3.9 Air Quality.  Air quality can impact ecological communities due to outfall of chemicals




or particulates that become incorporated in the soil of food chain. Poor air quality may be due to




mobile sources such as the amount of cars or industrial activities, such  as petroleum refining.




This sub-layer in no way intends to abrogate any obligations or duties assigned by law to TERS




participating agencies.




       High concentrations of ozone can have negative effects on flora and fauna (H. John




Heinz III Center for Science. Economics and the Environment 2002).  Ozone can affect water




movement, cycling of mineral nutrients, and habitats for various animal and plant species (EPA




2002). Pollutants such as lead, mercury, and others can be transported  and deposited in water or




                                           32

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soil where they may be incorporated into the food chain. Nitrogen and sulphur can acidify some




water bodies, making them uninhabitable for aquatic species (EPA 2002). Acid deposition can




leach nutrients from the soil, consequently affecting plant growth and soil fauna, and enhance




the movement of potentially toxic heavy metals, such as aluminum. Deposition of nitrogen can




cause eutrophic conditions such as algal blooms and decreased oxygen levels, which in turn may




result in fish kills.









1.3.3.3.10 RCRA TSD. Corrective Action and State VCP Sites.  These sites are typically smaller




than Superfund sites. RCRA TSD sites are active facilities where hazardous wastes are managed




on site.  RCRA corrective action sites are active TSD facilities which have had releases of




hazardous substances and are, by definition, disturbances or stressors  on the natural




environment. VCP sites are inactive facilities contaminated by various pollutants which




typically do not qualify for the state or federal Superfund programs and where a third party




wishes to conduct a cleanup in order to redevelop the site. While efforts are made to minimize




the impacts of these sites and to clean up or contain contaminants to acceptable risk level, the




release of toxic chemicals may permanently alter natural conditions.  These areas and natural




areas adjacent to them are less likely to be self sustaining and may require human management




for their continued existence.  Once clean up efforts have been completed, further development




may be restricted or prohibited at portions of those sites where waste has been left in place in




order to prevent disturbance of containment areas and subsequent human exposure.  For




example, future highway or other construction activities at some sites may need to be avoided.




However, with proper engineering, many such sites can and have been put to productive use.  As




a consequence, unique opportunities for low impact restoration of natural or near-natural habitat




                                           33

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areas may be available.









1.3.3.3.11 Urban/Agriculture Disturbance. This sub-layer is based on the principle that activities




in urban and agricultural areas generate disturbances (stressors) to surrounding areas.  Stressors




such as pesticides, fertilizers, and noise are included.




       The urban/agricultural disturbance sub-layer is a surrogate for general population




disturbance. These "developed" land cover types are not considered in the calculations in the




diversity and rarity layers, but are appropriate in this sustainability sub-layer. The sustainability




of an ecological community can be impacted by the amount of human activity, such as those




related to agriculture (e.g., pesticide use, nutrient runoff, erosion, etc.) and population (e.g.,




urban activities including roads, cars, urban sprawl, solid waste, Polycyclic Aromatic




Hydrocarbon (PAH) runoff, general environmental contamination, etc.) (White et al. 1996. H.




John Heinz III Center for Science. Economics and the Environment 2002. Tigas et al. 2002).




Urban uses and agriculture also fragment the community and change natural landscape from




desired vegetation types (e.g., wetland, forest, etc.) to undesirable vegetation types (e.g.,




agricultural monocultures, invasive or opportunistic species) (White et al. 1996. Tigas et al.




2002).









1.3.4 TEAP Development




       EPA reviewed over twenty applicable studies and protocols throughout the U.S. (Critical




Ecosystems Workshop 2002).  TERS participating agency representatives were invited to




identify studies and methodologies that could be helpful in addressing objectives and to decide




on an appropriate protocol. Reviews resulted in the selection of three protocols for further




                                            34

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adaptation and development: (1) processes and information developed in the TPWD Land and




Water Resources Conservation and Recreation Plan (Texas Parks and Wildlife Department




2002). (2) information generated by The Nature Conservancy of Texas Ecoregional Planning




Process (Groves et al. 2000) and (3) EPA Region 5 Critical Ecosystems Assessment Model




(CrEAM) (Mvsz et al. 2000. White et al. 2003).









1.3.4.1 TPWD Conservation Planning




       TPWD has drafted a strategic plan for ecological and recreational resources for both land




and water (Texas Parks and Wildlife Department 2002). TPWD performed an ecoregion priority




analysis, using three main criteria: conserved status, primary level of threat, and biological value.




Conserved status is determined by the percentage of publicly owned land, land owned by non-




governmental conservation groups, large local conserved parkland, and the percentage of the




ecoregion operated under TPWD management plans.  Primary level of threat is determined by




comparing the percentage of land converted to urban or agricultural use, fragmentation of




agricultural lands and population growth projections.  Biological value is determined by total




vertebrate species richness, vascular plant species richness or actual number of species occurring




in each ecoregion. Over twenty-two categories of data were collected and mapped. Results by




ecoregion are summarized in Table 1.









1.3.4.2 The Nature Conservancy Ecoregional Planning Process




       The Conservancy's Ecoregional Planning Process applies a planning and validation




process that includes GIS-based analysis, field investigations, and ecological expertise as to




endangered community types (Poiani etal. 1998.  Groves et al. 2000. Poiani etal. 2001).  The




                                           35

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Table 1.  TPWD planning results. Priority ecoregions for conservation efforts.
Ecoregion
Blackland
Prairie
Gulf Coast
Prairies &
Marshes
South Texas
Plains


Cross
Timbers &
Prairies
Edwards
Plateau


High Plains

Piney Woods
Post Oak
Savannah

Rolling
Plains
Trans Pecos

Priority
High
High

High


Medium


Medium


Medium

Medium
Low


Low
Low

Conserved
Status
Medium
High

High


Low


Medium


Low

Medium
Medium


Low
Highest

Threats
Severely
altered
Most
threatened

High (Lower
Rio Grande)


Medium


Low


Medium

High
Low


Medium
Lowest

Rare Plants Rare
Animals
Lowest Drastic
decline
High Many rare
birds in need
of attention
High Rich bird &
butterfly
faunas and
endangered
cats
Low 2 T&E birds


Highest Important for
herpetological
and
invertebrate
species
Low Numerous
birds and
other species
of concern
Low Highly
diverse
Low Several
species of
concern
One 2 Fed listed
1 state listed
Rarest & Highest
most unique percent of
vertebrate
species of
concern
                                              36

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Conservancy uses four criteria to identify and select areas of biodiversity significance:




occurrence of conservation elements, functionality of those elements, representativeness, and




complimentarity.  Conservation elements are those  species, natural communities, and ecological




systems that are chosen as the focus for conservation within an ecoregion.  The Conservancy has




completed this process, with multiscale mapping of priority  ecological areas for Gulf Coast




Prairies and Marshes, West Gulf Coastal Plain, Edwards Plateau, Chihuahuan Desert, Upper




West Gulf Coastal Plain, and the Southern Shortgrass Prairie in Texas.  The Cross Timbers and




Southern Tallgrass Prairie and Tamaulipan Thornscrub were scheduled to be completed by June




2003.




       The Conservancy process involved field verification of ecological type and because The




Conservancy has not completed its process statewide, The Conservancy data and portfolio




conservation areas are to be used in the preliminary accuracy assessment of TEAP results.









1.3.4.3 EPA Region 5 CrEAM




       The EPA Region 5 CrEAM (White et al. 2003) model incorporated three key criteria




based on established ecological theory: 1) diversity, 2) rarity, and 3) sustainability.  Twenty




geographically referenced data  sets were used to develop indicators for these three criteria.  All




data sets were pre-existing or derived from pre-existing data sets.  Because of the differences in




data sets, the CrEAM used 25 acres as  its smallest unit of measure.  Since TEAP modifies the




CrEAM. further details are located in the methods section.




       The CrEAM fits within the EPA Science Advisory Board (SAB) ecological framework.




In 2002, the EPA Science Advisory Board (SAB) Ecological Processes and Effects Committee




released a draft framework for assessing and reporting on ecological condition.  The purpose of




                                           37

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which was to guide practitioners on designing systems to assess and report ecological conditions.




The framework also helps investigators to organize and decide what features to measure for a




picture of ecological 'health.' Program goals and objectives are used to determine what essential




ecological attributes will be used.  There are six broad categories and several subcategories




under each: landscape condition, biotic condition, chemical and physical characteristics,




ecological processes, hydrology/geomorphology, and natural disturbance regimes. The set of six




attributes can be used to determine ecological indicators, or characteristics of ecological systems,




and specific measures and monitoring data used to determine the indicator, or endpoint. It is a




hierarchical structure where measures can be aggregated into indicators and indicators can be




aggregated into attributes. The six attributes are independent of program goals and objectives,




but serve as a stimulus for practitioners to decide what attributes and subcategories are essential




to a project.




       Not every attribute category or subcategory is appropriate in every situation; a user must




select those attributes from the SAB framework that provide the best measure and analysis of the




project objectives. Table 2 shows the SAB ecological attribute categories, subcategories,




suggested measure, and corresponding TEAP criterion. The SAB also suggests that the




framework aids in designing the assessment and subsequent report in that it should




"transparently record the decision tree and professional judgements used to develop it." The




TEAP follows this framework since the measures are aggregated into four broad categories




which follow the SAB framework of aggregating measures and indicators; therefore, both single




'media' and aggregate effects (ecological, socioeconomic, etc.) can be considered.




       The TEAP allows users to analyze ecological condition, project consequences, and




suggest mitigation within watersheds or ecoregions.  The TEAP also adheres to the SAB




                                            38

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framework by being 1) 'multimedia'; 2) interagency (a repository for coordinating other

agencies' data); and 3) understandable to non-scientists by using an intuitive 0 to 100 decision

structure.

       The SAB also suggests that reference conditions be defined so that ecological indicators

can be compared and later normalized for aggregation. This concept is imbedded within TEAP

by using a 0 to 100 ranking structure which serves to normalize disparate criteria values.
Table 2. Relationship of the EPA SAB framework ecological attributes to EPA Region 5
CrEAM and TEAP.
ECOLOGICAL PROCESSES
Category

Energy flow


Material flow


Subcategory

primary production
net ecosystem
production
growth efficiency
organic C cycling
N & P cycling
other nutrient
cycling
SAB example
measure
tree growth
CO2flux
carbon transfer
organic matter
quality
N-fixation capacity
input/output budgets
TEAP criterion

NONE
NONE
NONE
NONE
NONE
NONE
                              LANDSCAPE CONDITION
 Extent of habitat
 types
 Landscape condition
perimeter-area ratio
number of habitat
types

39
regularity of ecosystem
boundary

contiguous size of
undeveloped areas

land cover rarity

-------
Category
Subcategory
SAB example
measure
TEAP criterion
Landscape pattern
                   contagion
                     land cover diversity

                     significant stream
                     segments

                     contiguous land cover

                     appropriateness of land
                     cover

                     land cover suitability

                     urban & agricultural
                     disturbance

                     road density
                       NATURAL DISTURBANCE REGIMES





Ecosystems &
communities

frequency
intensity
extent
duration
BIOTIC
community extent
community
composition
recurrence interval

spatial extent
length of event
CONDITION
extent of
successional state
presence of focal
species
NONE
NONE
NONE
NONE

NONE
number of rare taxa
                     trophic structure

                     community
                     dynamics
                   feeding guilds

                   predation rate
                     number of rare species

                     species rarity using G/S
                     rankings

                     NONE

                     NONE
                                        40

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Category
Subcategory
SAB example
measure
TEAP criterion
Species &
populations
Organism condition
physical structure

population size


genetic diversity
                      population
                      structure

                      population
                      dynamics

                      habitat suitability
physiological
status

symptoms of
disease

signs of disease
tree canopy height

density


degree of
heterozygosity

age structure


dispersal rates


focal species
requirements

hormone levels


tumors, lesions


tissue burden  of
contaminants
NONE

NONE


NONE


NONE


NONE


Combination of GIS
layers

NONE


NONE
                                                               TRI weighted air/water
                                                               releases
                CHEMICAL AND PHYSICAL CHARACTERISTICS
Nutrient
concentrations
Trace inorganic &
organic chemicals
Nitrogen


Phosphorus


other nutrients


metals
concentration of N    water quality
concentration of total  water quality
P

concentration of Ca,   water quality
K,Si

Cu, Zn in sediment    NONE
                      trace elements        Se in water and soil    NONE

                      organic compounds   methyl-Hg            NPL (Superfund) Sites

                                                               RCRA corrective action
                                                               sites
                                         41

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Category
Chemical properties




Physical parameters
Subcategory
PH
dissolved O
salinity
organic matter
other
soil/sediment
SAB example
measure
pH in water & soil
DO in streams
conductivity
soil organic matter
buffering capacity
temperature, texture
TEAP criterion
NONE
water quality
NONE
NONE
NONE
soil permeability,
                       air/water
                     concentration of
                     particulates
                      air quality


                      change in elevation

                      airport noise

                      temperature &
                      precipitation maxima
                       HYDROLOGY & GEOMORPHOLOGY
Surface &
groundwater flows
Dynamic structural
characteristics
pattern of surface
flow
hydrodynamics

pattern of groundwater
flows

spatial salinity
patterns

water storage

channel morphology
complexity

dist. of connected
floodplain
water level
fluctuations
                                           water movement
watershed obstructions
                      waterway
                      impoundments

                      NONE
depth to groundwater  NONE

surface salinity        NONE
gradients

aquifer capacity       NONE

length of natural       NONE
shoreline

2yr or 1 Oyr floods      NONE
                                           42

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Category
Subcategory
SAB example
measure
TEAP criterion
Sediment & material
transport
aquatic physical
habitat

sediment
movement

particle size
distribution
                                         pool-riffle ratio
                     NONE
sediment deposition    NONE


distribution of grain    NONE
size
                                         43

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                                    2. 0 METHODS









2.1 Base Unit Selection




       Technical experts from TERS agencies discussed the relative merits of using ecoregions




or watersheds as the base unit for the assessment.  It is generally agreed that both watersheds and




ecoregions provide "essential geographic frameworks necessary to describe, diagnose, and




eventually, predict landscape influences on water resources" (Harrison et al. 2000). The TERS




Steering Committee concluded that ecoregions have the following distinct advantages over




watersheds for ecosystem management:




             An ecoregion approach provides a comprehensive review of an area's




             functionality in relationship to terrestrial habitat, aquatic habitat, and the species




             and communities they supported. Some species and communities depend upon a




             single large patch or several different kinds of habitat that span more than one




             watershed.









             Texas has over 200 watersheds.  A watershed-based assessment would be time




             and resource intensive.  Therefore, using watershed-based assessment  would not




             be expedient enough to meet the initial needs identified by the TERS executives.









             Large watersheds, particularly basins, do not necessarily correspond to areas that




             contain a similarity in the mosaic of geographic characteristics which include,




             physiography, soils, vegetation, geology, climate, that influence the physical,




             chemical or biological nature of water bodies (Omernik 1995. Omernik and




                                           44

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             Bailey 1997).  However, the quantity and quality of water tends to be similar




             within ecoregions (Griffith et al.  1999).









             Land cover and other spatial data are readily available by ecoregion to summarize




             and map numerous landscape features thought to be important to water quality




             concerns.









             Ecoregions are functional conservation areas that maintain focal species,




             communities, and/or systems, and support ecological processes within their




             natural ranges of variability (Poiani et al. 1998. Poiani and Richter 1999. Poiani et




             al. 2001).









       TEAP used ecoregions,  developed by Bailey (1985. 1987.  1994. 1996) because of




extensive delineation of representative ecoregions and sub-regions within Texas and the use of




plant community relationships (Bailey 1994) (Figure 1). There are eighteen ecoregions




identified by Bailey in Texas. The characteristics of each are described in Appendix A. Bailey's




ecoregions has broad usage by a number of agencies and organizations, including the USFS.




USGS. FWS. EPA, and The Conservancy.




       GIS data, particularly NLCD. used in specific  calculations were summarized for each




square kilometer (1km2).  Although NLCD has a 30 m2. pixel resolution, performing calculations




for a "1 km2 grid" allowed maintenance of confidentiality of rare species occurrences, as well as




reducing computer computation resources.




       The NLCD classification contains twenty-one different land cover categories with a




                                           45

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spatial resolution of 30 m.  The NLCD was produced as a cooperative effort between USGS and




EPA to produce a consistent, land cover data layer for the conterminous U.S. using early 1990s




Landsat thematic mapper data purchased by the Multi-resolution Land Characterization (MRLC)




Consortium. The MRLC Consortium is a partnership of federal agencies that produce or use




land cover data. Partners include the USGS. EPA. USFS. and the National Oceanic and




Atmospheric Administration (NO A A).




       Several steps are used to process NLCD: 1) an automated process is used to create




clusters of pixels for a given regional area, 2) these clusters are interpreted and labeled with the




help of aerial photographs, 3) in cases where clusters of pixels include multiple land cover types,




models that use data such as elevation or population  density, are  used to help assign land cover




classes,  and 4) lands that are bare and many grassy areas, such as parks and golf courses are not




easily distinguished from other land cover classes, so on-screen verifications are used for




clarification (Vogelmann et al. 1998. 20011




       The analysis and interpretation of the satellite imagery was conducted using very large,




sometimes multi-state image mosaics (i.e. up to eighteen Landsat scenes). Using a relatively




small number of aerial photographs for 'ground truth', the thematic interpretations were




necessarily conducted from a spatially-broad perspective.




       The accuracy of NLCD and satellite-derived data is related to many factors including the




amount of data available, the detail of the required land cover information, classification




methods, computing power, and time and money (H. John Heinz III Center for Science.




Economics and the Environment 2002). Furthermore, the accuracy assessments are performed




on groupings of contiguous states.  Thus, the reliability of the data is greatest at the state or




multi-state level.  Assessments of the NLCD for the eastern U.S. indicate an accuracy of




                                           46

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approximately 80% or higher for general land cover categories (e.g., forest, agriculture,




developed) (H. John Heinz III Center for Science. Economics and the Environment 2002).









2.2 TEAP Sub-layers and Layers




       Ultimately, the CrEAM (Mvsz et al. 2000. White et al. 2003) was selected as a base




method. Due to differences between Region  5, the Midwest U. S., and Texas, subsequent




modifications were made (Table 3).




       Data were provided by EPA. TPWD.  TCEQ (Table 4) and The Conservancy (for the




spatial accuracy assessment).  Data were processed and analyzed by EPA Region 6, TPWD. and




The Conservancy (spatial accuracy assessment).  Several processing steps were needed to




convert the data or coverages to the same scale. General descriptions of the layers and sub-




layers can be found in the Introduction.









2.2.1 Diversity Layer




       The overall diversity layer was calculated for each ecoregion by taking the mean of the




four diversity sub-layers and reseating on a 0-100 scale.  The values of the 30 m pixels that  made




up each 1 km2 grid cell were averaged to determine the Diversity Index score for each cell.









2.2.1.1 Appropriateness of Land Cover




       TEAP reclassified the Potential Natural Vegetation (PNV) 2000 (Kuchler 1964) grid to




the NLCD classification (Table 5). Reservoirs were also reclassified and grouped according to




ecoregion because of their anthropogenic nature. The current NLCD was compared to the




modified PNV 2000 data and values that were the same received a score of 10,000, representing




                                          47

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Table 3.  Summary of TEAP layers.
Criterion
Diversity
Indicator
Shannon land
cover diversity
index
Description
1 . Shannon Diversity
Index
2. Considers both
Data
Source
NLCD.
Bailey's
ecoregions
Analysis
Unit
ecoregion
Analysis
Resolution
1km

Pixel
Scoring
continuum,
exponential
distribution
             Land cover
             appropriate-
             ness
             Contiguous
             size of
             undeveloped
             land
             Ecologically
             significant
             stream
             segments
             Temperature
             and
             precipitation
             maxima
                             2.
   richness (# of different
   specific land cover
   types)  and evenness
   (dispersion of cover
   types)
   Undeveloped land
   cover types only
   Relative land cover
   diversity within
   ecoregions

   Evaluation of land
   cover type currently
   present (c. 1993)
   relative to potential
   dominant vegetation
   native to the  area as an
   appropriateness factor
   of measured  diversity
   Comparison  of NLCD
   land cover and PNV

   Selection of largest
   contiguous non-
   developed areas based
   on principle that larger
   non-developed areas
   favor diversity
   All undeveloped cover
   types that are adjacent
   form one polygon
1.  Relates health of
   waterways relative to
   pristine conditions of
   water quality, habitat
   quality, and occurrence
   of health indicator
   aquatic species

1.  Based on assumption
   that higher
   temperatures and
   greater precipitation
   favors diversity
NLCD.
PNV
Texas
30m
0/1
NLCD.
Bailey's
ecoregions
ecoregion    1 km
              continuum,
              exponential
              distribution
TPWD
Texas
stream
segments
0/1
             ecoregion
             meteoro-
             logical
             bands
                                        0/1
                                                   48

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Criterion
Rarity







Sustainability:
Fragmentation
Indicator
Vegetation
rarity
Natural
heritage rank
Rare species
richness



Taxonomic
richness

Contiguous
land cover
type
Description
1. Determination of
which land cover type
is the rarest
1. Gl, G2, G3, SI, S2,
and S3 occurrences
1 . The number of species
rated as Gl-3
2. The number of
observations
associated with each
species
1 . The number of species
rated as Gl-3
2. The number of broad
taxonomic groups
represented
1 . Selection of largest
contiguous areas by
specific land cover type
Data
Source
NLCD
BCD

BCD



BCD

NLCD.
Bailey
ecoregions
Analysis
Unit
ecoregion
7.5 minute
quadrangle
7.5 minute
quadrangle



7.5 minute
quadrangle

ecoregion
Analysis
Resolution
30m
point
observations
point
observations



point
observations

30m
Pixel
Scoring
continuum,
log
distribution
continuum,
exponential
distribution
continuum,
exponential
distribution



continuum,
exponential
distribution

continuum,
exponential
distribution
Appropriate-
ness of land
cover
2.  Based on the principle
   that larger areas having
   similar ecosystem
   types have greater
   Sustainability
3.  Each undeveloped land
   cover type is a separate
   polygon
4.  Only polygons >10 ha
   considered

1.  Comparison of NLCD
   land cover with PNV
2.  Evaluation of land
   cover type currently
   present (c. 1993)
   relative to potential
   dominant native
   vegetation as an
   indicator of resilience
   and the likelihood of
   Sustainability (seed
   bank) of the
   corresponding
   ecosystems
NLCD.
PNV
Texas
30m
0/1
                                     49

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Criterion Indicator Description Data Analysis Analysis Pixel
Source Unit Resolution Scoring
Road density 1.
2.
Roads fragment the TIGER 1km cells 1km
landscape
Road density index
continuum,
exponential
distribution
Regularity of
ecosystem
boundaries
Waterway
obstruction
Waterway
impoundment
applied to TIGER road
data set considers the
total road lengths of
different road
classifications,
classification of 1 km
cells into road density
ranges

Selection of contiguous
areas possessing the
smoothest or least
irregular boundaries
(i.e., lowest PAR by
land cover)
Based on the principle
that the least amount of
boundary results in the
lowest amount of "edge
effect" thereby yielding
the least disturbance or
greatest sustainability
of the interior
ecosystems
Only polygons >10 ha
considered

Dam density per
watershed (normalized
by stream miles)
Dams and the
corresponding
reservoirs are
interruptions
(fragmentation) to the
continuities of
waterways

Selection of reservoirs
for downgrading
Intersection of NLCD
open water class and
STORET dam
locations
NLCD.
Bailey's
ecoregions
ecoregion    30 m
continuum,
exponential
distribution
             8-digit
             HUC
             HUC
continuum,
log
distribution
STORET     Region 5     30 m
                           0/-1
                                      50

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Criterion Indicator
Sustainability: Airport noise
Stressors





NPL sites
(Superfund) &
state
Superfund
sites

RCRA TSD.
corrective
action, and
state VCP
sites

* Air quality

Description
1 . The zone of
disturbance
surrounding airports
are directly related to
the sizes of the
airplanes using them.
2. Airplane sizes are
directly related to
airport runway lengths.
3 . The extent of the zone
of disturbance is
directly related to the
runway length.
1. Un-owned sites where
hazardous waste was
released to the
environment and which
were in the formal
clean-up process
1 . Owned sites where
hazardous waste was
released to the
environment and which
were in the formal
clean-up process
1. Nonattainment and
state near
nonattainment areas
Data Analysis
Source Unit
Bureau of airport
Transportat
ion
Statistics
runway
length



CERCLIS Texas
data,
TCEO

RCRIS Texas
data,
TCEO


EPA green county
book,
TCEQ
Analysis Pixel
Resolution Scoring
site or runway
runway w/buffer
length w/
buffer





site w/buffer 0/1

facility 0/1
w/buffer



county 0/0.5/1

Urban/
agricultural
disturbance
Activities in urban &
agricultural areas
generate disturbances
to surrounding areas.
Takes into account
stressors such as
pesticides, fertilizers,
and noise
NLCD
Texas
30m
0/1
                                       51

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Criterion

Indicator
Water quality
Description
1 . Ambient levels of total
suspended solids,
dissolved oxygen, and
Data
Source
TCEQ
CWA
303(d) list
Analysis
Unit
Texas
Analysis
Resolution
stream
Pixel
Scoring
0/1
                                    ammonia based on
                                    modeling of 1990-1994
                                    NPDES permitted
                                    discharges levels
                                    Status of water quality
                                    use support, including
                                    waters identified as
                                    impaired, with water
                                    quality concerns, or
                                    fully meeting uses
                                    Only use support
                                    pertaining to aquatic
                                    life is included
                                    (includes depressed
                                    dissolved oxygen, pH
                                    extremes, ambient
                                    toxicity, elevated heavy
                                    metals, and nutrient or
                                    sediment quality
                                    concerns)	
*addition/modification to CrEAM
**deletion from CrEAM
                                                      52

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Table 4. GIS data layers used for the TEAP.
 Criterion
Database
Description
Scale
Date   Agency
 Diversity
NLCD
                PNV
                Bailey's
                ecoregions
                section map
                ecological
                stream
                segments of
                concern
 Sustainability   NLCD
                Bailey's
                ecoregions

                reservoirs/dams
                STORE!

                TIGER road
                data

                CERCLIS

                RCRIS
land use/land
cover interpreted
from satellite
imagery

PNV is the climax
vegetation that
will occupy a site
without
disturbance or
climatic change.
It is an expression
of environmental
factors such as
topography, soils,
and climate across
an area.

ecosystem
geography based
on plant
community
relationships

ecologically
significant
river/stream
segments
                waterway
                impoundments
                NPL sites

                RCRA corrective
                action sites
30m
                                   PNV map was
                                   digitized for the
                                   coterminous US
                                   then adjusted to
                                   match terrain
                                   using a 500 m
                                   DEM. 4th code
                                   HUC. and Bailey
                                   ecological
                                   subregions
                                   1:7,500,000
1990-  USGS
1992
                  1964   USFS
                  (v.
                  2000)
                  1994   USFS
                                   1:200,000
                  2000-  TPWD
                  2001
                                            EPA


                                            Census


                                            EPA

                                            EPA
                                         53

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Criterion Database
TMDLs
14-digit & 8-
digitHUC
TRI
Description Scale
CWA 303(d)
listed impaired
waterbodies
watersheds 1:1,000,000
reported facility
Date
1993-
1998
2002

Agency
TCEO
USGS,
NRCS
EPA
Rarity
Other
BCD


natural heritage


conservation
planning areas
air emissions

T&E elemental
occurrences

G/S species
rankings

aquatic and
terrestrial areas
capturing a range
of rare and
representative
native plants,
animals and
natural
communities
7.5' quadrangle
and county

7.5' quadrangle
and county
1994   TPWD


1994   TPWD


       TNC
                                          54

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Table 5. Kuchler (1964) PNV classifications and corresponding NLCD land cover types.
 PNV
Class. No.   NLCD
Class. No.
 Cross timbers             40



 Oak-hickory              45



 Pine-Douglas fir          3



 Pine forest               1



 Juniper-pinyon            22



 Chaparral                26



 Oak-hickory-pine         55



 Southern mixed forest     56



 Southwest shrub steppe    27



 Desert shrub              28



 Shinnery                 29



 Texas savannah           35







 Plains grassland           32



 Prairie                   33



 Desert grassland          34
             Open water                           11



             Perennial ice/snow                     12



             Low intensity residential                21



             High intensity residential               22



             Commercial/Industrial/Transportation    23



             Bare rock/sand/clay                    31



             Quarries/strip mines/gravel pits         32



             Transitional                           33



             Deciduous forest                      41



             Deciduous forest                      41



             Evergreen forest                       42



             Evergreen forest                       42



             Evergreen forest                       42



             Mixed forest                          43



             Mixed forest                          43



             Mixed forest                          43



             Shrubland                             51



             Shrubland                             51



             Shrubland                             51



             Shrubland                             51



             Orchards/vineyards/other               61



             Grasslands/Herbaceous                 71



             Grasslands/Herbaceous                 71



             Grasslands/Herbaceous                 71



             Pasture/Hay                           81
                                           55

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PNV




Southern floodplain
Wet grassland
Reservoirs
Class. No. NLCD
Row crops
Small grains
Fallow
Urban/recreational grasses
61 Woody wetlands
36 Emergent herbaceous wetlands
63 Various; dependent on ecoregion
Class. No.
82
83
84
85
91
92

no change from pre-settlement to modern times and those that were not the same received a




score of zero, indicating disturbance due to human activities. The 0 to 10,000 values, based on




thirty meter pixels, were then converted to a 0 to 250 scale and reclassified the resulting data




onto an 8-bit grid.  It was rescaled so that the data could be stored as 8-bit.  Eight-bit data avoids




computer memory  and buffer overloads during processing and in no way affects the outcome,




since the relative scores within the data set accurately reflect the content of the data. The final




score is an average of all pixels in a 1 km2.




       Kuchler's PNV map was refined by USFS to match terrain using a 500 m Digital




Elevation Model (DEM). 4th level Hydrologic Unit Codes (HUC), and Ecological Subregions




(Bailey's Sections). These biophysical data layers were integrated with current vegetation layers




to develop generalized successional pathway diagrams. Expert regional panels refined the PNV




map based on these successional pathways.  Summaries of the data were restricted to state or




USFS regional scales.
                                           56

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2.2.1.2 Contiguous Size of Undeveloped Land




       Using NLCD coverage and land cover classes, the data were classified as either




developed or non-developed within each ecoregion. "Non-developed" classes are identified by




the following land cover categories: 1) open water, 2) bare rock/sand/clay, 3) deciduous forest,




4) evergreen forest, 5) mixed forest, 6) shrubland, 7) grasslands/herbaceous, 8) woody wetlands,




and 9) emergent herbaceous wetlands.  All other classes are considered "developed."




       For this measure in  TEAP. adjacent undeveloped land cover types in each ecoregion are




combined into one polygon, e.g., adjacent forest, wetlands, and grasslands are all one polygon.




Thirty meter pixels of each land cover type were scored in each ecoregion.  The size of the




contiguous area in each Texas ecoregion was computed as was a linear index based on area using




the following parameters: (1) contiguous areas < 10 hectares (ha) received a score of zero,




indicating small areas of an  undeveloped land cover type; and (2) contiguous areas > 100,000  ha.




received a score of 250, indicating large areas of an undeveloped land cover type in each




ecoregion.  All other areas were ranked in the index by dividing the total contiguous area by 400.




Reseating was done so that the data could be stored as 8-bit data which avoids computer memory




and buffer overloads during processing. Reseating does not affect the outcome, since the




relative scores within the data set accurately reflect the content of the data.









2.2.1.3 Shannon Land Cover Diversity Index




       This calculation applies the Shannon-Weiner diversity index using the NLCD coverage




to the relative land cover diversity within each ecoregion. The Shannon index is an established




method used to measure ecological diversity (richness and evenness) (Begon et al.  1986).  It




usually calculates the proportion of individuals, but as used here, land cover types, related to the




                                           57

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total number of land cover types. Other ecological diversity measures used in landscape




assessment are discussed in Herzog et al. (2001).  The Shannon-Wiener equation considers both




richness (the quantity of different categories) and the evenness (the similarity of relative




abundance).




       The Shannon land cover diversity index for each ecoregion was calculated using the




Analytical Tools Interface for Landscape Assessments Version 3.0 (ATtlLA) (Harrison et al.




2000). Water land cover classes were removed in the GIS coverage used due to human-made




reservoirs.  Calculations were made by summarizing 30 rnf pixels into a one kilometer grid. The




results of the Shannon land cover diversity index calculations using ATtlLA were normalized to




a 1 to 250 scale so that the highest value in an ecoregion is equal to 250 and the lowest value is




equal to one.  The 1 to 250 scores were then used to populate the 1 km raster grid.




       Reservoirs are considered "developed" due to the managed and many, characteristically




"unnatural" attributes when compared to natural lakes.  Differences in shoreline shape, nutrient




balance, water temperature, drainage characteristics, salinity, plus the lack of or reduced




seasonal flow fluctuation (though this may be simulated by controlled dam releases) contribute




to lower biodiversity, and lower "ecological  value" of this land cover type as compared to




natural and non managed aquatic ecosystems.









2.2.1.4 Ecologically Significant Stream Segments




       For this sub-layer, the initial data was reprojected from the Texas  State Mapping System




(TSMS) to TxAlbers map projection and attribute data was added to facilitate overlays with




other coverages.  The results  were applied to the raster grid and all grid cells containing




significant stream segments received a value of 10,000.




                                           58

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2.2.2 Rarity Layer




       The overall rarity layer was calculated by taking the mean of the four rarity layer sub-




layers and reseating on a 0 to 100 scale. The values of the 30 m pixels that made up each 1 km2




grid cell were averaged to determine the rarity score for each cell.  Overall rarity was calculated




by receding rarity ranks using an exponential growth function 0 to 250 to produce a statewide




land cover rarity data set. Data were scaled 0 to 250, due to machine processing of 8-bit data.




Because the input data sets for Texas were large, reseating the data from 1 to 250 (8-bit) allowed




for much faster machine processing without any significant loss of granularity.  Exponential




scaling was chosen to  give appropriate weight to rarer features. The statewide land cover rarity




data set and the land cover rarity by ecoregion data set were input into an averaging model to




compute the mean value of each grid cell for the combined data sets.









2.2.2.1 Vegetation Rarity




       The land cover or vegetation rarity measure is derived from the NLCD and represents




rarity of all natural (undeveloped) cover types including water and bare rock. The following




cover types are represented in this data set: 1) open water, 2) bare rock/sand/clay, 3) deciduous




forest, 4) evergreen forest, 5) mixed forest, 6) shrubland, 7) grasslands/herbaceous, 8) woody




wetlands, and 9) emergent herbaceous wetlands. All developed (non-natural) cover types were




receded as no-data.  Because some land cover types may be common at the ecoregion level but




rare statewide (e.g.  coastal wetlands), land cover rarity was assessed at both the ecoregional and




statewide level, then combined to produce a final land cover rarity measure. This process avoids




under-evaluation of many important and rare cover types.  For example, wetlands are rare




statewide, but may be  locally common in an ecoregion. The results of the two analyses




                                            59

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(ecoregion and state) were combined by averaging the values of the corresponding grid cells to




obtain an "average score" reflecting both the ecoregional and state scales. Pixel counts were




conducted for each of the ecoregions and each cover type was receded to a rarity rank based on




its frequency distribution. Land cover rarity ranks were then receded using an exponential




growth function of 0 to 250 scale.  Reseating was done so that the data could be stored as 8-bit.




Eight-bit data avoids computer memory and buffer overloads during processing and in no way




affects the outcome, since the relative scores within the data set accurately reflect the content of




the data.  A shape file containing ecoregions was overlain on the NLCD coverage and a




frequency distribution of land cover type by ecoregion was tabulated.  The highest number of




occurrences  of a land cover type was considered the most common and given a score of one.




The smallest number of occurrences of a land cover type was considered the rarest, and it was




given a score of 10,000. Vegetation rarity was averaged over 30 m pixels in each 1 km2 grid




cell.









2.2.2.2 Natural Heritage Rank




       This  measure is derived from the TPWD's Biological Conservation Database (TXBCD).




TXBCD. established in 1983, is TPWD's most comprehensive source of information on rare,




threatened, and endangered plants, animals, invertebrates, high quality natural communities, and




other significant features. The TXBCD is continually updated, providing current or additional




information  on statewide status and locations of these unique elements of natural diversity.




However, the data are not all-inclusive.  There are gaps in coverage and species data due to the




lack of access to land or data, and insufficient staff and resources to collect and process data on




all rare and significant resources.




                                           60

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       The TXBCD was developed by The Conservancy back in the early 1970's and was




continually maintained and updated by The Conservancy until its central science function was




established as the Association for Biodiversity Information (now NatureServe).  The data set that




TPWD maintains as TXBCD is operating on an expired license. The official node of the




NatureServe network in Texas is the Texas Conservation Data Center (TxCDC) housed within




The Conservancy. The TxCDC collaborates with and provides data to TPWD. but there is no




data sharing agreement at this time. The TxCDC database (BIOTICS), is a geographically-based




system that contains records on nearly 9,000 species and communities in Texas.




       Natural heritage rank for TEAP is derived from TXBCD attributes of global rank, state




rank, federal protection and state protection.  Natural heritage rank for TEAP is an absolute rank




based upon natural heritage ranking criteria; which is itself a measure of rarity. Very specific




criteria are used to determine rarity both globally and statewide, which is reflected in the natural




heritage ranking system.




       The natural heritage rank sub-layer reflects the combination of the state and global




rankings for rare species in the state.  Those that have a combined Gl and £1 rank are the "most




imperiled." Locations that support Gl or £1  species are by definition unique ecological areas.




Any state or federal listed species gets a rank= 1.  TEAP ranks of 2-10 were  computed by




combining the SRANK and GRANK into a single score, e.g. Gl + S2 = TEAP rank 3 etc.




       Because the spatial accuracy of each TXBCD point ranged from 30m to 8km. initial




attempts at producing a polygon data set reflecting the spatial and attribute accuracy  of the




TXBCD produced a complex series of "regions" where polygons overlapped. Each of the




thousands of resulting regions had multiple values for the class attribute. Accordingly, a




decision was made to compute rarity by USGS quadrangle (7.5 minute) by intersecting the




                                           61

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TXBCD points with the USGS quadrangle boundaries. To better reflect the spatial extent of




actual TXBCD data, the resulting USGS quadrangle shapes (attributed for rarity) were then




intersected with the buffers (based on the spatial accuracy attribute of each point) of the TXBCD




points, thus eliminating areas of the quad sheets beyond the actual spatial limits of the buffered




points




       After Natural heritage rank was computed, its value was used to populate the "class"




field for TXBCD point shape file. Each class was then selected iteratively and separate shape




files were created for each class.  A spatial select of each TXBCD class was then done by USGS




quadrangle boundary using a USGS quadrangle boundary shape file.  Each quadrangle was




accordingly attributed with a single class attribute reflecting the highest class rank that occurred




within it. A separate polygon file was then generated from the TXBCD point shape file




corresponding to the documented spatial accuracy of each point using the "precision" field.




Seconds precise points were buffered to 30 m, minutes precise to 1800 m, etc.  This file was then




used to clip out the 7.5 minute quadrangle polygons to create a polygon coverage reflecting the




known spatial extent (spatial accuracy of the TXBCD points) attributed with the corresponding




USGS quadrangle's  "class" attribute.  Finally, the polygons were attributed for class rank using




the process used for the TXBCD point data described above.  The resulting attributed polygon




shape file was then merged with the output from the clip process described above to produce a




species rarity shape file.









2.2.2.3 Taxonomic Richness




       The taxonomic richness measure, or the number of rare taxa per USGS  quadrangle, is




derived from the TXBCD.  The TXBCD point data were filtered by the same method used for




                                           62

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the rarity rank measure. The number of observations of discrete broad taxonomic groups was




based on classifications by The Conservancy (bryophyte, pterodophyte, gymnosperm plant, dicot




plant, monocot plant, lichen, platyhelminthe, uniramian arthropod, insect, chelicerate,




crustacean, mollusk, fish,  amphibian, reptile, bird, and mammal). Unique values for the attribute




for taxa were summed for each quad in which an observation occurred. The unique number of




taxa per grid cell was sorted using a max filter to preserve the highest possible number of taxa




per grid cell then receded  0 to 250.









2.2.2.4 Rare Species Richness




       The rare species data set suffers from a lack of geographic coverage and up-to-date




inventories for many species, but is the best data set available.  The species richness measure, or




the number of rare species per USGS quadrangle, is derived TXBCD.  The TXBCD point data




were filtered by the same method used for the rarity rank measure and further processed and




computed similar to the taxonomic richness measure described above.










2.2.3 Sustainabilitv Layer
2.2.3.1 Contiguous Land Cover Type





       Sources used for this layer were the NLCD and Bailey's Ecoregion Sections. Only




undeveloped land cover types over 10 ha (100,000 square meters) were scored.  The land cover




types that were identified as undeveloped were 1) open water, 2) bare rock/sand/clay, 3)




deciduous forest, 4) evergreen forest, 5) mixed forest, 6) shrubland, 7) grasslands/herbaceous, 8)





                                          63

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woody wetlands, and 9) emergent herbaceous wetlands. The bare rock/sand/clay class




designation contains features such as natural rock exposures, beaches, and sandbars and does not




include mines and quarries.  Using the ArcGIS Spatial Analyst Extension, adjacent cells of the




same land cover type were grouped together and then the total area was calculated for each




region (contiguous cells of the same land cover type). The Iog10 of each area was calculated and




then normalized to a 0 to 100 in each ecoregion by land cover type. The largest area of each




land cover type within each ecoregion received a score of 100. The smallest area of each land




cover type within each ecoregion received a score of one.  Other areas were  scored exponentially




between 1-100. Developed lands and undeveloped lands under 10 ha received a score of zero.
2.2.3.2 Regularity of Ecosystem Boundary





       Sources used for this layer were the NLCD and Bailey's Ecoregions.  Only undeveloped




land cover types over 10 ha were scored.  The land cover types that were identified as




undeveloped were 1) open water, 2) bare rock/sand/clay,  3) deciduous forest, 4) evergreen forest,




5) mixed forest, 6) shrubland, 7) grasslands/herbaceous, 8) woody wetlands, and 9) emergent




herbaceous wetlands.





       The optimum case would be a perfect circle where the PAR approaches or is equal to




one. Therefore, PAR would be (2*pi*r)/(pir2) = 2/r. Since it is preferable to represent PAR as a




relative measure, rather than in absolute units, PAR is represented as [ideal PAR / real PAR].




This ratio is always less than or equal to one. Using the ArcGIS Spatial Analyst Extension,




adjacent cells of the same land cover type were grouped together and the area and perimeter




were then calculated for each region (contiguous cells of the same land cover type).  The values





                                           64

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for each polygon region ranged from 1.0 to 0.0000001. This value was then normalized to a 0 to




100 in each ecoregion by land cover type.  With the exception of open water cells, the largest




value of each land cover type within each ecoregion received a score of 100.  The smallest value




of each land cover type within each ecoregion received a score of one. Other values were scored




exponentially between 1 to 100. For open water, the smallest value received the score of 100




and the largest value received the score of zero.  Developed lands and undeveloped lands under




10 ha received a score of zero.  A score of 100 means that the polygon is nearly a circle and a




score of one is the most irregular polygon in the layer.  This was done for each land cover type.




For open water, irregular shorelines were deemed as being more ecologically important and




received a score of 100. The open water portion of these reservoirs was scored zero to account




for the reduced ecological value of open water as compared to the shoreline habitat.
2.2.3.3 Appropriateness of Land Cover





       Appropriateness of land cover is calculated as described in the diversity section.  TEAP




reclassified the PNV 2000 (Kuchler 1964} grid to the NLCD classification (Table 5Y




Reservoirs were also reclassified and grouped according to ecoregion because of their




anthropogenic nature.  The current NLCD data was compared to the modified PNV 2000 data




and values that were the same received a score of 10,000 representing no change from pre-




settlement to modern times and those that were not the same received a score of zero, indicating




disturbance due to human activities. The 0 to 10,000 values, based on thirty meter pixels, were




then converted to a 0 to 250 scale and reclassified the resulting data onto an 8-bit grid.




Reseating was done so that the data could be stored as 8-bit.  Eight-bit data avoids computer






                                           65

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memory and buffer overloads during processing and in no way affects the outcome, since the




relative scores within the data set accurately reflect the content of the data. The final score is an




average of all pixels in a 1 km2.
2.2.3.4 Waterway Obstruction





       Sources used for this layer were data on dams from TCEQ. the National Hydrography




Dataset (NHD) and 4th level (8-digit) HUCs from the USGS. This is the most refined level of




hydrologic data that covers the entire state and is the best available data for the State of Texas.




For each HUC in the state, the number of dams and the total length in miles of all streams and




rivers was calculated.  The number of dams was then divided by the stream miles to calculate




dams per stream mile.  This number was then normalized from 1 to 100 for each ecoregion.




Those hydrologic units without dams received a score of 100 and the hydrologic unit in each




ecoregion with the highest number of dams per stream mile received a score of one.
2.2.3.5 Road Density





       Sources used for this layer was the 2000 Topological Integrated Geographic




Encoding and Referencing System (TIGERVline files from the U.S. Bureau of the Census. For




each 1 km2 cell the number of road miles by road classification was calculated. The road miles




were then modified by multiplying the road miles with a factor based on the road classification.




The following factors were applied to each road type:
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                      TIGER Code      Classification          Factor
                      AO-A9           Miscellaneous Roads   1
                      A10-A29         Primary Roads        3
                      A30-A39         Secondary Roads      2.67
                      A40-A49         Local & Rural Roads   2
                      A50-A79         Miscellaneous Roads   1

After multiplying the road length by the road factor above, the totals for each classification were

summed for each 1 km2 cell.  The Iog10 was then calculated for each cell. These were then
normalized to 0 to 100. Cells having no roads would indicate no fragmentation and would be the
ideal condition. These cells were given a score of 100.  Cells having the highest density of roads
were scored zero. Road density was calculated using the following formula:

                                      (R*F) i-v = L

                              S = {l-[loglo(L)/5.919]}*100

where         R = the total road length of a classification code type within a grid cell
              F = the loading factor for a classification code type
              i-v = the five classification code types
              L = the total loaded road length for a grid cell
              S = the inverse loaded road length for a grid cell, i.e., road score
              5.919 = Iog10 [road length*F]

A road score of 100 indicates an absence  of roads and represents the ideal condition for self-
sustainability.

       The factors were derived from Sutherland (1994).  In this document, the conclusion is
made that disturbance effects may extend 500 to 600 m from quiet rural roads to 1600 to 1800 m
from busy highways.  Therefore, a factor  of three presumably exists between the zones of
disturbance generated by the  smallest, least used roads and large, interstate highways. Local and
                                           67

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rural roads are presumed to be intermediate generators of disturbance (thereby receiving a factor




of two), whereas secondary roads, which include U.S. highways and state roads, are presumed to




create disturbance regimes more similar to primary roads than to local and rural roads, thereby




receiving a factor of 2.67.  Since a road score of 100, indicates the complete absence of any




roads, it represents ideal road presence for ecological self-sustainability.
2.2.3.6 Airport Noise





       All runways were buffered, representing a zone of minimum disturbance around the




airport based on runway size (Sutherland 1994).  The buffer distances used were selected




because the size of the zone of disturbance surrounding an airport is proportional to the size of




the aircraft using it. Airplane size is directly related to the length of the runway. Therefore, the




extent of the area of disturbance around an airport is related to runway length.  The buffer zone




is proportional to the runway length and each runway was grouped as follows (White et al.




2003V





       Airport Category   Buffer (m)   =   Runway Length (m)
very large
large
medium
small
very small
very very small
7500
5300
3100
900
755
610
> 1950
1500-1800
1200-1500
540-1200
183-540
< 183
All areas in the state within the buffer were scored zero and areas outside the buffer were scored




100. This layer was then converted to a grid with a cell size of 1 km2.






                                           68

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2.2.3.7 Super fund NPL and State Super fund Sites





       Sources used for this layer include the NPL sites (in polygon and point format) from EPA




and state Superfund Sites from TCEQ (in point format). For sites where polygon data was




available, the polygon data was used.  Otherwise a buffer of 610 m was used as a default




(Sutherland  1994) and applied to the points. All areas in the state within a buffer were scored




zero and areas outside of the buffer were scored 100.  This layer was then converted to a grid




with a cell size of 1 km2.  These are un-owned sites where hazardous waste was released and




where there was a formal  clean up process during fiscal year 2000.
2.2.3.5 Water Quality





       This includes waters identified as impaired with water quality concerns or meeting




designated uses in CWA Section 303(d). Only designated use data pertaining to aquatic life is




included (e. g., dissolved oxygen, pH extremes, ambient toxicity, elevated heavy metals, nutrient




or sediment levels in excess of the statewide 85th percentile). The CWA 303(d) year 2000 list is




an assessment of water quality data collected during 1993-1998 by TCEQ. The impaired waters




layer was intersected with the 1 km2 cell grid. Cells with impaired waters were scored zero and




all others cells were given a score of 100.
2.2.3.9 Air Quality





       The Air Quality layer characterizes areas with poor air quality. The source for this layer




is ozone nonattainment from EPA's Office of Air Quality Planning and Standards (OAQPS) and








                                           69

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TCEQ. All the counties in Texas were scored from 0 tolOO based on their nonattainment status.
Counties that are in attainment were scored 100 and counties that are in severe nonattainment
status were scored zero. The scores were assigned as follows:

                      Attainment Status          Normalized Score
                      Severe Nonattainment        0
                      Serious Nonattainment      25
                      Moderate Nonattainment    50
                      Near Nonattainment        75
                      Attainment               100
2.2.3.10 RCRA TSD, Corrective Action and State VCP Sites

       Data sources used for this layer include RCRA corrective action sites (in point format)
from EPA. RCRA TSD sites (in polygon and point format) from EPA and state Superfund Sites
from TCEQ (in point format). For sites where polygon data was available, the polygon data was
used otherwise a buffer of 610 m was used as a default (Sutherland 1994) and applied to the
points. All areas in the state within a buffer were scored zero and areas outside of the buffer
were scored 100. This layer was then converted to a grid with a cell size of 1 km2.  These are
sites where hazardous waste was released and where there is a formal clean up process during
fiscal year 2000.
2.2.3.11 Urban/Agriculture Disturbance

       Sources used for this layer were land cover types from the NLCD. Only urban/
agricultural regions over 10 ha were included.  A buffer of 600 m was included around the

                                          70

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urban/agriculture areas to represent disturbance to surrounding areas.  This is a minimum buffer




size based on differences in road size and traffic in these developed land cover types (Sutherland




1994). The land cover types that were identified as urban and agricultural were low intensity




residential, high intensity residential, commercial/ industrial/transportation, orchards/vineyards,




pasture/hay, row crops, small grains, fallow, and urban/recreational grasses in NLCD. Using the




ArcGIS Spatial Analyst Extension, the land cover types in the NLCD were reclassified to




urban/agriculture or non-urban/agriculture.  Adjacent cells of the same type were then grouped




together and the area was calculated for each region (contiguous cells of the same land cover




type). Urban/agricultural areas that were smaller than 10 ha were reclassified to non-




urban/agriculture.  A buffer of 610 m was then created around the urban/agriculture areas. All




areas that are in urban/agriculture or within 610m of urban/agriculture received a score of zero.




All other areas were assigned a score of 100. This is  a binary sub-layer, with scores for either




developed land cover types (urban and agriculture) scoring zero and all natural land cover types




scoring  100.
2.2.4 Accuracy Assessment





       The Conservancy ecoregion portfolios for the Edwards Plateau, Southern Shortgrass




Prairie, Chihuahuan Desert, Upper West Gulf Coastal Plain, West Gulf Coastal Plain, and Gulf




Coast Prairies and Marshes were combined into a single GIS coverage.  Of these portfolios,




which consist of both aquatic and terrestrial conservation areas, only aquatic portfolio areas rated




as Tier I (strong confidence that viable target populations and/or high quality system occurrences
                                            71

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are present) within the Edwards Plateau and Southern Shortgrass Prairie were used since Tier II




portfolio sites have a lower conservation value primarily due to lack of ground-truthing.





       The single Conservancy portfolio coverage was then converted into a grid matching the




TEAP composite grid layer specifications. To ensure a similar area of comparison, the TEAP




composite grid was clipped to mask out data for the ecoregions not yet completed by The




Conservancy (Tamaulipan Thornscrub and Crosstimbers and Southern Tallgrass Prairie).




However, it should be noted that small areas of these two ecoregions were included where




adjacent ecoregion conservation areas crossed ecoregion boundaries.





       To reduce noise within the data, The Conservancy classified the data into thirty equal




classes. Each class contained ten pixel values; for example class 1 equals TEAP composite




values  1 tolO, class 2 equals TEAP composite values 11 to 20, and so on.





       All the data processing was performed utilizing ArcGIS 8.3 (ESRI Inc., Redlands, CA




2001).  The individual TEAP files were imported as ESRI GRID (raster) files and merged to




create four statewide grids representing Rarity,  Sustainability, Diversity, and Composite. The




resulting grids were 1,183 rows by 1,245 columns with each pixel representing 1 km2.





       The intersect between the TEAP composite layer and The Conservancy portfolio grids




was calculated using the raster calculator function in ArcGIS. The result was two statewide




grids, one for inside and one for outside The Conservancy combined portfolio. Summary




statistics generated for each grid layer (e.g., mean, standard deviation, count, minimum,




maximum, and sum). A frequency table of the TEAP composite pixel values was calculated and




used to compare the frequency of pixel values found inside The Conservancy portfolio versus




those found outside the portfolio.  An additional map focusing on the IH69 corridor study site





                                           72

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was created by clipping these three data sets to the IH69 corridor extent and recalculating the




summary statistics to generate a new frequency table.
                                            73

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                                     3.0 RESULTS
       The composite map and underlying three layers are designed to assess the State of Texas




by ecoregion and to identify the optimum ecological areas for protection and mitigation based on




ecological theory (i.e., no political boundaries or regulatory programs). For presentation




purposes, this report identifies "ecological importance" as percentages of the total score




(theoretical maximum of 300) a grid cell can receive. Figures depicting the individual sub-layer




data for the entire state can be found in Appendix B.
3.1 Diversity Layer





       The diversity layer was designed to show land cover continuity and diversity in Texas




(Figure 5).  The statewide depiction shows a number of locations that scored in the top 1% per




ecoregion.  The individual sub-layer maps can be found in Appendix B.  The diversity layer




consists of four sub-layers: (1) appropriateness of land cover (Figure BIX (2) contiguous size of




undeveloped land (Figure B2\ (3) Shannon land cover diversity index (Figure B3X and (4)




significant stream segments (Figure B4).
3.2 Rarity Layer





       The rarity layer was designed to show rarity of species and land cover in Texas (Figure




6). The individual  sub-layer maps can be found in Appendix B. The rarity layer consists of four




sub-layers: (1) vegetation rarity (Figure B5X (2) natural heritage rank (Figure B6X (3) taxonomic







                                           74

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                                    Southern High Plains
                                                                               foods
                                                                                       Mid Coastal
                                                                                       Plains, Western
                                                                                            Coastal Plains
                                                                                            and Flatwoods,
                                                                                            Western Gulf
                                                                                           Louisiana Coast
                                                                                           Prairies and
                                                                                           Marshes
     Top 1 %    (More Diverse)

     2-10%

     11 - 25%

     26 - 50%

     51 -100%  (Less Diverse)
Rio Grande Plain
                              0  25 50
                                         100
                                               150
                                                     200
                                                                                      Miles
Figure 5. Map of the diversity layer with ecoregion boundaries.  This map is a composite of four
sub-layers (Figures B1-B4).  Even though this map shows the entire state of Texas, the measures
included in the diversity layer and subsequent composite maps (Figures 8-26) were calculated
for each ecoregion.
                                               75

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                                    Southern High Plain;
                                                                                    Mid Coastal
                                                                                    Plains, Western
.   . ,.-i??^--f. '^ •:•• ,   :•»•/
m^WK^T^    (••'•
>•*W-  SrsSi'-JBKTB   ??=f. -:  T^-t**^ :
                                                                                         Coastal Plains
                                                                                         and Flatwoods,
                                                                                         Western Gulf
                                                                                        Louisiana Coast
                                                                                        Prairies and
                                                                                        Marshes
    Top 1 %      (More Rare)

    2-10%

    11 - 25%

    26 - 50%

    51 -100%    (Less Rare)
                                                                                Miles
Figure 6.  Map of the rarity layer with ecoregion boundaries. This map is a composite of four
sub-layers (Figures B5-B8). Even though this map shows the entire state of Texas, the measures
included in the rarity layer and subsequent composite maps (Figures 8-26) were calculated for
each ecoregion.
                                             76

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richness (Figure B7). and (4) rare species richness (Figure B8).





       The overall rarity map shows large areas of high rarity in the Stockton Plateau, Edward's




Plateau Chihuahuan Desert Basin and Range, Mid Coastal Plains Western Section, and the




southern portion of the Rio Grande Plain (Figure 6).
3.3 Sustainability Layer





       The sustainability layer (Figure 7) consists of eleven sub-layers that can be loosely




grouped into fragmentors: (1) contiguous land cover type (Figure B9). (2) regularity of




ecosystem boundary (Figure BIO). (3) appropriateness of land cover (Figure Bill (4) waterway




obstruction (Figure B12). and (5) road density (Figure B13) and stressors: (1) airport noise




(FigureB 14).  (2) Superfund NPL and state Superfund Sites (Figure B15). (3) water quality




(FigureB 16). (4) air quality (Figure B17).(5) RCRA TSD. corrective action and State VCP Sites




(FigureB 18). and (6) urban/agricultural disturbance (FigureB 19). The individual sub-layer




maps can be found in Appendix B.  The more sustainable areas occur where there are fewer




human disturbance activities.
3.4 Composite Layer





       The composite map is the combination of the diversity, rarity, and sustainability layers




(Figure 8).  The top 1% highly important ecological areas in each ecoregion in Texas are




highlighted in red.  Most of the highly important ecological areas (1%, 10%) are those areas that
                                           77

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                                    Southern High Plains
      Top1%

      2 - 10%

      11 - 25%

      26 - 50%

      51 -100%   (Less Sustainable)
                                                                                Miles
Figure 7. Map of the sustainability layer with ecoregion boundaries. This map is a composite of
eleven sub-layers (Figures B9-B19). Even though this map shows the entire state of Texas, the
measures included in the sustainability layer and subsequent composite maps (Figures 8-26)
were calculated for each ecoregion.
                                            78

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                    Texas
                     High
                     Plains
           Sacramento-
           Monzano
                                      Southern High Plains
                                                                           Oak Woods
                                                                              'rairies
                                        -
                          . .-.Jr-.  MKsLi'?:         "••-Fir. :.W -Si-'
Mid Coastal
 ains, Western
                                                                                          Coastal Plains
                                                                                          md Flatwoods,
                                                                                          .Western Gulf
                                                                                          Louisiana Coast
                                                                                          Prairies and
                                                                                          Marshes
                                                                                          150    200
                                                                                    Miles
Figure 8. Composite map with ecoregion boundaries. This map is a composite of the diversity
layer (Figure 5\ rarity layer (Figure 6). and sustainability layer (Figure 7). Even though this
map shows the entire state of Texas, the measures included in this map were calculated for each
ecoregion.  Individual sub-layer maps for each of the three main layers can be found in
Appendix B. Those areas identified in red as the top 1% represent higher ecological importance,
those identified in white as 51-100% represent lower ecological importance.
                                               79

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represent the intersection of the top 1% for diversity, rarity, and sustainability. Ecoregion results




(Figures 9-26) are explained in the following section.
3.4.1 Ecoregion Composites





       Descriptions of each of the ecoregions analyzed as well as representative photos appear




in Appendix A. The following paragraphs contain brief summaries of the TEAP results by




ecoregion.
3.4.1.1 Southern High Plains





       The Southern High Plains is represented by a thin section on the north edge of the Texas




panhandle. Most of the ecologically important areas (e.g., 1%, 10%, 25%) occur in the eastern




portion of this ecoregion (Figure 9).
3.4.1.2 Texas High Plains





       The Texas High Plains ecoregion shows several areas with high ecological importance.




For example, the Canadian River is highlighted at the 1% and 10% levels as well as a larger




riparian buffer at the 25% level. The northwest corner and an area southeast of the Canadian




River are also highlighted and may have a high degree of rarity (Figure 10).
                                           80

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                                                            0 510  20 30 40
                                                                —I	
                                                                Miles
Figure 10.  Texas High Plains composite map. A separate figure (Figure 8) shows the entire
state. Those areas identified in red as the top 1% represent higher ecological importance, those
identified in white as 51-100% represent lower ecological importance.

                                           82

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3.4.1.3 Rolling Plains





       The southern portion of the Rolling Plains ecoregion shows a high level of ecologically




important areas (Figure 11).  Other areas representing the top 1% ecologically important areas




are scattered throughout the ecoregion and may indicate locations of high rarity.
3.4.1.4 Rio Grande Plain





       The Rio Grande Plain ecoregion contains areas of high levels of ecological importance




throughout, although the northeastern portion of the ecoregion contains areas of lower




importance (Figure 12).  Relatively large ecological diversity and sustainable areas can be noted




at the 10% level in this ecoregion.
3.4.1.5 RedbedPlains





       The Redbed Plains is a very small, disjunct ecoregion in Texas, but extends into




Oklahoma. Most of the ecologically important areas occur in the western portion of this




ecoregion in Texas (Figure 13).
3.4.1.6 Cross Timbers and Prairie





       The Cross Timbers and Prairies ecoregion shows ecological areas in the top 1% and 10%




levels in the western half of the ecoregion (Figure 14).  Several important riparian areas are




noted.
                                           83

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                                                                 0 510  20  30 40
                                                                     ^	
                                                                     Miles
Figure 11. Rolling Plains composite map.  A separate figure (Figure 8) shows the entire state.
Those areas identified in red as the top 1% represent higher ecological importance, those
identified in white as 51-100% represent lower ecological importance.
                                           84

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            0 5 10   20  30  40
                 ^=
                  Miles
N
Figure 12. Rio Grande Plain composite map. A separate figure (Figure 8) shows the entire state.
Those areas identified in red as the top 1% represent higher ecological importance, those
identified in white as 51-100% represent lower ecological importance.
                                           85

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                                                              t«

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                                                          (L)
                                                          a
                                                              (L)
                                                              (L)
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86

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                                                                            20   30
                                                                            *=
                                                                           Miles
Figure 14.  Cross Timbers and Prairie composite map. A separate figure (Figure 8) shows the
entire state. Those areas identified in red as the top 1% represent higher ecological importance,
those identified in white as 51-100% represent lower ecological importance.
                                           87

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3.4.1.7 Oak Woods and Prairies





       There are ecologically important locations scattered throughout the Oak Woods and




Prairies Ecoregion (Figure 15).  The northern portion of this ecoregion may include the outskirts




of large population centers such as Fort Worth.  Several riparian corridors within this ecoregion




are  highlighted.
3.4.1.8 Blackland Prairie





       The Blackland Prairie ecoregion may be one of the least sustainable ecoregions because




of the large population centers, such as Dallas, located there; and the amount of ongoing




agricultural activities.  There seems to be a noticeable difference between the northern portion




and the southern portion of this ecoregion (Figure 16). The  southern portion shows much higher




levels of ecologically important areas, including noticeable riparian areas.
3.4.1.9 Mid Coastal Plains Western Section





       Traditionally called the "pineywoods", the Mid Coastal Plains Western Section contains




many areas of high ecological importance (Figure 17). Primarily in the southern portion of this




ecoregion, several areas of high rarity and riparian areas are highlighted.
3.4.1.10 Coastal Plains andFlatwoods Western Gulf Section





       Like the Mid Coastal Plains ecoregion, the Coastal Plains and Flatwoods Western Gulf




Section ecoregion shows several areas of ecologically importance, primarily related to a high





                                            88

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Figure 15. Oak Woods and Prairies composite map. A separate figure (Figure 8) shows the
entire state. Those areas identified in red as the top  1% represent higher ecological importanc
those identified in white as 51-100% represent lower ecological importance.
                                           89

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Figure 16. Blackland Prairie composite map. A separate figure (Figure 8) shows the enti
Those areas identified in red as the top 1% represent higher ecological importance, those
identified in white as 51-100% represent lower ecological importance.
entire state.
                                           90

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                                 ^"™—*1L
                                      .-. .Ttt-
Figure 17. Mid Coastal Plains Western Section composite map.  A separate figure (Figure 8)
shows the entire state. Those areas identified in red as the top 1% represent higher ecological
importance, those identified in white as 51-100% represent lower ecological importance.

                                           91

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degree of rarity throughout the ecoregion (Figure 18).
3.4.1.11 Edwards Plateau





       The Edwards Plateau ecoregion has been studied extensively and is noted for its




ecological importance, especially in terms of rare, endemic biota.  The results of the TEAP




indicate several relatively large areas in the south and southwest portions of the ecoregion due to




the high degree of rarity (Figure 19). The northeastern portion of this ecoregion has primarily




lower diversity, rarity, and sustainability. This area also includes the metropolitan center of




Austin.
3.4.1.12 Stockton Plateau





       The Stockton Plateau contains several relatively large areas of highly important




ecological locations scattered throughout the ecoregion (Figure 20).  These areas have a high




level of rarity as well as diversity.
3.4.1.13 Chihuahuan Desert Basin and Range





       The Chihuahuan Basin and Range ecoregion is a fairly large ecoregion in West Texas.




Ecologically important areas at the 1%, 10% and 25% levels are scattered throughout the




ecoregion.  A relatively large ecologically important area is located in the southern portion of




this ecoregion, representing a high degree of land cover diversity, rarity, and sustainablility




(Figure 21).






                                            92

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                                                                 Top1%

                                                                 2 - 10%

                                                                 11 - 25%

                                                                 26 - 50%

                                                                 51 -100%
                                                                N
                                                       0 2.5 5    10   15
                                                               *=
                                                               Miles
                                                                        20
Figure 18. Coastal Plains and Flatwoods Western Gulf Section composite map. A separate
figure (Figure 8) shows the entire state. Those areas identified in red as the top 1% represent
higher ecological importance, those identified in white as 51-100% represent lower ecological
importance.
                                           93

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               Top 1 %

               2 -10%

               11 - 25%

               26 - 50%

               51 -100%
Figure 19. Edwards Plateau composite map. A separate figure (Figure 8) shows the entire state.
Those areas identified in red as the top 1% represent higher ecological importance, those
identified in white as 51-100% represent lower ecological importance.
                                          94

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Figure 20.  Stockton Plateau composite map.  A separate figure (Figure 8) shows the entire state.
Those areas identified in red as the top 1% represent higher ecological importance, those
identified in white as 51-100% represent lower ecological importance.
                                           95

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     0 5 10  20   30  40
          ^t=
          Miles
N
Figure 21. Chihuahuan Desert Basin and Range composite map. A separate figure (Figure 8)
shows the entire state. Those areas identified in red as the top 1% represent higher ecological
importance, those identified in white as 51-100% represent lower ecological importance.
                                           96

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3.4.1.14 Sacramento-Manzano Mountain





       The Sacramento-Manzano Mountain ecoregion is represented in Texas, but extends into




New Mexico and Arizona. In this small ecoregion, the highly important areas occur near the




Guadalupe Mountains (Figure 22).
3.4.1.15 Louisiana Coast Prairies and Marshes





       The Louisiana Coast Prairies and Marshes ecoregion is represented as a small wedge in




eastern Texas, but extends further into Louisiana. There are a few areas that are within the top




1% and 10% for ecological importance near the Louisiana border (Figure 23).
3.4.1.16 Eastern Gulf Prairies and Marshes





       The Eastern Gulf Prairies and Marshes ecoregion contains highly ecologically important




areas on the coastline in the eastern portion ecoregion (Figure 24). The Houston metropolitan




area is located on western border of this ecoregion. A relatively large ecological area with a




high degree of rarity, is located just north of Galveston Bay.
3.4.1.17 Central Gulf Prairies and Marshes





       The Central Gulf Prairies and Marshes ecoregion represents a large portion of the Texas




coastline.  Several important ecological areas, mostly representing riparian areas or coastal areas




appear in this ecoregion (Figure 25).
                                           97

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                   Miles
Figure 22. Sacramento-Manzano Mountain composite map. A separate figure (Figure 8) shows
the entire state. Those areas identified in red as the top 1% represent higher ecological
importance, those identified in white as 51-100% represent lower ecological importance.

                                          98

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Figure 23. Louisiana Coast Prairies and Marshes composite map. A separate figure (Figure 8)
shows the entire state. Those areas identified in red as the top 1% represent higher ecological
importance, those identified in white as 51-100% represent lower ecological importance.
                                           99

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                                                       N
                                                               0  2.5  5
                                                                           10
                                                                                  15
                                                                                        20
Miles
Figure 24. Eastern Gulf Prairies and Marshes composite map.  A separate figure (Figure 8)
shows the entire state. Those areas identified in red as the top 1% represent higher ecological
importance, those identified in white as 51-100% represent lower ecological importance.
                                           100

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                                                                       Top1%

                                                                       2-10%

                                                                       11 - 25%

                                                                       26 - 50%

                                                                       51 - 100%
Figure 25. Central Gulf Prairies and Marshes composite map. A separate figure (Figure 8)
shows the entire state. Those areas identified in red as the top 1% represent higher ecological
importance, those identified in white as 51-100% represent lower ecological importance.
                                          101

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3.4.1.18 Southern Gulf Prairies and Marshes





       The Southern Gulf Prairies and Marshes ecoregion represents the southern portion of the




Texas coast and includes South Padre Island. Several ecologically important areas occur on the




barrier islands as well as being scattered throughout the ecoregion near the coastline (Figure 26).
3.4.2 Overlays





       The TEAP results can be used in conjunction with other databases to show where public




lands (Figure 27) or transportation corridors (Figure 28) or watershed boundaries (Figure 29) are




in relation to the ecologically important areas identified using TEAP. Each TERS agency can




use the TEAP and data and overlay other GIS layers of interest. For example, Figure 29 shows




the composite TEAP map with 6-digit HUCs overlaid.
3.4.3 Accuracy Assessment





       Figure 30 shows the overlap between highly ranked TEAP composite layer pixels and




The Conservancy portfolio locations. As mentioned in Section 2.0, the Tamaulipan Thornscrub




and Crosstimbers and Southern Tallgrass Prairie portfolio locations are excluded.  In general,




highly scored TEAP locations corresponded to the locations of The Conservancy portfolio sites.




Correspondence was particularly high for pixels in classes 26 to 30 which represent TEAP




composite scores of 251 to 300 (Figure 3 la). At lower ranked TEAP composite layer locations,




the match between TEAP and The Conservancy portfolio sites is lower.  This relationship can




also be expressed as a percentage of the TEAP pixel classes residing inside or outside The
                                          102

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                                                      0  5  10 15 20
                                                           •<	
                                                           Miles
Figure 26. Southern Gulf Prairies and Marshes composite map.  A separate figure (Figure 8)
shows the entire state. Those areas identified in red as the top 1% represent higher ecological
importance, those identified in white as 51-100% represent lower ecological importance.

                                           103

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                                                                                        200
Figure 27. Composite map with public lands overlay. Public lands include National and State
Parks, National Forests and Grasslands, Department of Defense lands, and National Wildlife
Refuges. Those areas identified in red as the top 1% represent higher ecological importance,
those identified in white as 51-100% represent lower ecological importance.
                                          104

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                                                                                           200
Figure 28. Composite map with transportation corridors overlay.  IH69 and Trans Texas
Corridor are included. Those areas identified in red as the top 1% represent higher ecological
importance, those identified in white as 51-100% represent lower ecological importance.
                                          105

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                                                                                         200
Figure 29. Composite map with watershed boundary overlay. Watershed boundaries reflect 6-
digit HUCs. Those areas identified in red as the top 1% represent higher ecological importance,
those identified in white as 51-100% represent lower ecological importance.
                                          106

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Classes

• -
   .11
    2fl

     Figure 30. Map depicting areas used for the accuracy assessment. The TNC portfolio does not
     include the areas in white. The scale reflects the different classes used in the accuracy
     assessment. A higher class equals a higher TEAP score for that location.
                                                 107

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   50000 i
                                                                                           State Composite

                                                                                           Outside TNC Portfolio

                                                                                           Inside TNC Portfolio
M illinium
M axinium
Pixel Count
                                     9   10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27 28  29  30
          1    2   3
        b)
  100%
                                                                                                      93.42%
                                                             \
PH  40%
                                                                                         	
                                                                                           \

                                                                                                       6.58%
         1234567
                                    9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24 25  26  27  28  29  30
                                                       Class
                                  Frequency - Inside TNC Portfolio —•—% Frequency - Outside TNC Portfolio
      Figure 31. a) Statewide frequencies of TEAP composite scores (by class) that occur inside and
      outside TNC portfolio; b) statewide frequencies expressed as a percentage of TEAP composite
      scores occurring inside and outside TNC portfolio.  A higher class equals a higher TEAP score
      for that location.
                                                     108

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Conservancy portfolio.  For example, Figure 31b shows that 93.42% of the pixels in class 30




(TEAP scores of 291 to 300) are found inside The Conservancy portfolio, whereas only 6.58%




of the pixels in this class exist outside The Conservancy's portfolio.





       A similar accuracy assessment was performed for the proposed IH69 corridor in Texas




(Figures 32 and 33). Most of the IH69 corridor is covered by The Conservancy portfolio except




for locations in south Texas (Tamaulipan Thornscrub and Crosstimbers and Southern Tallgrass




Prairie) (Figure 32). The results are similar to those seen for the entire state. Highly scored




TEAP composite layer locations (approximately classes 24 to 30) showed high correspondence




with The Conservancy portfolio sites and lower scored TEAP composite locations showed a




weaker match (Figure 33a). All TEAP composite layer pixels in the highest ranked classess




(classes 29-30) were located inside The Conservancy portfolio (Figure 33b). The opposite trend




is seen for TEAP scores located outside The Conservancy portfolio.  For example, 90-100% of




the pixels in classes 1 to 7 fall outside The Conservancy porfolio. This is expected since TEAP




classified all lands in Texas whereas The Conservancy's conservation process focuses on




identifying the highest quality ecological communities only.
                                          109

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                                                                              Classes
                                                                               •• 1

                                                                                  :
                                                                                 m
                                                                                   ]13
                                                                                 zi*
                                                                                  j"
                                                                                   118
                                                                                   I 19
                                                                                   | 20
                                                                                    21
                                                                                   | 22
                                                                                   | 23
                                                                                   | 24

                                                                                   | 26
                                                                                   I 27

                                                                                   | 29
                                                                                   I 30
Figure 32.  Map of proposed IH69 corridor depicting areas used for the accuracy assessment.
The scale reflects the different classes used in the accuracy assessment. A higher class equals a
higher TEAP score for that location.
                                           110

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   4000
        a)
   3500 -
   3000
   2500
O  2000
   1500
   1000
    500
        Mean
        Mode
                     11.4038
                     10
         Std. Deviation   4.5028
        Minimum
        Maximum
        Pixel Count
                     1
                     30
                     33,801
                                           77
               -Corridor Composite

               -Outside TNC Portfolio (1-69 corridor)

               -Inside TNC Portfolio (1-69 corridor)
                                                         Mean
                                                         Mode
                                                         Std.Deviation
                                                         Minimum
                                                         Maximum
                                                         Pixel Count
10.3612
10
3.8742
1
28
25,295
                                     9  10  11  12  13  14  15  16  17  18   19  20  21  22  23  24  25  26  27  28  29  30  31
         12345
          b)
          :
          :  /
     70%
^  50%


<->   40%


    30%


    20%


    10%
                                                     \
                                                       \

                                                                                                   \
                                                                                                               0%
                                                                                                             |—I—-—I
           1   2   3   4   5   6   7   8   9  10  1 1  12  13  14  15  16  17  18  19  20  21   22  23  24  25  26  27  28  29  30
                                                            Class
                                   Frequency - Inside TNC Portfolio
                                                                 —.— % Frequency - Outside TNC Portfolio
       Figure 33. a) IH69 corridor frequencies of TEAP composite scores (by class) that occur inside
       and outside TNC portfolio; b) IH69 corridor frequencies expressed as a percentage of TEAP
       composite scores occurring inside and outside TNC portfolio.  A higher class equals a higher
       TEAP score for that location.
                                                         Ill

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                                    4.0 DISCUSSION
       Similar to other reports that characterize the environment at a landscape-level (H. John




Heinz III Center for Science. Economics and the Environment 2002. Schweiger et al. 2002). the




individual sub-layers and main layers selected for TEAP reflect important attributes relating to




ecosystem condition, and by extension, ecosystem function. TEAP characterizes ecological




conditions in terms of three different aspects of ecosystems using existing data coupled with




ecological theory, while recognizing that there are judgements involved in such an enterprise.




Given the complexity of ecosystems, these judgements include determining which measures to




concentrate on and which to exclude, and communicating the uncertainties and limitations of the




data and TEAP analysis.





       The TEAP is a relatively simple model that uses stratified data that are combined to give




a total or composite picture of the state of Texas  at the ecoregion level.  Since complicated




modeling and analysis tools are less likely to be used in regulatory processes, beneficial




properties of GIS assessment tools such as TEAP include 1) simplicity (expert modeling abilities




are not needed), 2) use of available data (rather than experimentation), 3) analytical (numerical




simulation is not needed), 4) approximation (need matches level of effort), 5) measurable




change, and 6) expandability (use in more sophisticated models) (Leibowitz et al. 2000). TEAP




assesses and prioritizes locations when information is limited.  Due to the scale at which the




TEAP was performed it has limitations in utility  with regard to regulatory decisions or processes




requiring more detail. TEAP is a screening tool that  can assist in overall conservation efforts




(including project planning, mitigation, preservation, or restoration activities) and to identify






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areas where more detailed, site-specific data are needed. TEAP results should be used in




conjunction with agency-specific information to support decisions. (Schweiger et al. 2002).




TEAP should enable managers to consider specific decisions within an ecoregion context.
4.1 Data Limitations





       Several limitations of the data and analysis should be noted. No individual sub-layers




were removed a posteriori from this iteration of the protocol. The limitations and other issues




concerning specific sub-layers or their use in the protocol or their application to regulatory




processes are discussed, so that they can be modified or excluded in the next iteration of TEAP.




It was also felt that by removing individual sub-layers, the composite may only have a few




relatively non-ecological sub-layers to account for the majority of a main layer. Multivariate




evaluation of the results may yield a clearer picture of the relative contribution of each sub-layer




to each of the three main layers and the  composite.





       The scoring methods per layer and per ecoregion result in an issue at ecoregion




boundaries.  Two adjacent cells with the same land cover type and the same stressors can score




differently in different ecoregions. For  example, two cells both have a PAR of 0.123, but cell A




could get a score of 75 while cell B could receive a score of 50 because of the differences in




their respective ecoregions. The two cells could also have a composite score that is different,




even though they are basically the same. The reverse is also true; sites with the same composite




score could end up in a different category for similar reasons. Adjacent cells A and B both have




a composite score of 225, but cell A is in the top 1% cell (colored red) in its ecoregion, but cell B




scores in the top 10% cell (colored green) in an adjacent ecoregion.





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       Each sub-layer within the diversity layer represents different, but somewhat overlapping,




attributes of diversity, that when combined, gives a broader picture of diversity in each




ecoregion.  It can be true that there is a dichotomy between  contiguous area and appropriate land




cover.  These are reasons why the TEAP (and CrEAM) is a  stratified approach (i.e., equally-




weighted sub-layers feed into layers which are then combined into a composite).





       Kuchler (1964) data was used in the diversity and sustainability layers. The comparison




between the PNV (Kuchler 1964) and 1992 NLCD is the most common method of describing the




original spatial distribution of land cover and current conditions (Geneletti 2003). In addition,




maintaining vegetation in proportion to its former, pre-settlement abundance is a goal of




biodiversity conservation (Geneletti 2003).





       The TXBCD is an observational data set that does not specifically consider communities.




It is not comprehensive or  synoptic like the GIS coverages.  This is the reason that the TXBCD




(or any other individual sub-layer, for that matter) was not used to exclusively represent rarity,




but was combined with vegetation rarity (using NLCD). and is included as a separate sub-layer




of equal weight in the rarity main layer. Other studies use measures of rarity, and highlight its




relevance, especially for biodiversity conservation. However, there is no consensus on the




attributes to include for its evaluation (Geneletti 2003).





       Actual habitat information is better than somewhat arbitrary buffers around species




observation points. However, this type of data does not exist statewide, although gap analysis




data may be available in the future to address this concern.  Other databases or scientific studies




may exist, but did not meet the general guideline of TEAP to use pre-existing data that was




available statewide. The reason for not using localized study data is to avoid the bias that results






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because some species are better studied than others.  For example, a great deal is known about




the organisms that inhabit the Edwards Aquifer and recharge zone of the Edwards Plateau




ecoregion (Figure 19). However, biota in other portions of this ecoregion may not be as well




studied or have systematic data available. EPA Region 5 found a similar situation in its analysis




where one state had a much more active monitoring and data collection program than other




states. EPA Region 5 addressed this by using multiple measures or sub-layers to characterize




rarity.





      The TEAP sub-layers do not explicitly account for supporting habitat for species (versus




the actual observation point), although the contiguous size of undeveloped land (Figure B2)




describes polygons of adjacent undeveloped land cover types.  While it is correct that any land




cover patch is generally influenced in  some way by its adjacent neighboring patches, the TEAP




is not able to explicitly incorporate adjacency effects as would be possible in a dynamic




simulation model.  The TEAP is a static model which characterizes the landscape through a




mono-temporal multi-criteria  evaluation approach. Detailed spatial and temporal dynamics




between landscape patches cannot be modeled in this class of static models.  Given the goals and




objectives of TERS. it is unlikely that a dynamic model would provide a better solution than the




type of model used.





      Unlike EPA Region 5, Texas does not contain any natural lakes (other than isolated playa




basins).  Therefore, the open water land cover types (i.e., reservoirs) had to be excluded from




sustainability sub-layers  such as regularity of ecosystem boundary. It is a long and tedious




manual process in GIS to "mask out" these areas so that only the shoreline was used. Including
                                           115

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the entire area of these reservoirs (rather than just the shoreline) could tend to skew the area




included in the one percentile fraction of the total area in an ecoregion.





       The watershed obstruction sub-layer calculates dams per stream miles within each HUC




whereas the water quality sub-layer uses actual stream segments. These two sub-layers should




be more consistent in the next iteration because both could use stream segments (vs HUC5).




However, a significant amount of technical assistance would be required to modify the




calculations for these two layers for the next iteration of TEAR





       The road density sub-layer did not intentionally include or exclude water bodies.  Cells




that had zero roads scored 100, therefore cells that are all water are scored 100 (predominately




found in the coastal areas).





       In the urban/agriculture disturbance sub-layer (FigureB19\ a 600 m buffer around urban




and agricultural areas may tend to mask the presence of riparian and greenbelt areas. Though




highly susceptible to development pressures, these areas may be among the most important to




maintain and protect, especially for adequate water quality necessary to sustain  aquatic species




and to reduce downstream pollutant transport. TEAP is not intended to discourage use or




designation of buffer zones around riparian, urban, or recreation areas.  TEAP should point out




places for conservation and enhancement (especially in terms of potentially restoring landscape




connectivity) in areas that are currently not sustainable without intensive human management.





       Given the available data and timeline, the EPA Region  5 model was at a scale (300 m2)




that allowed them to pick out a single or a few pixels of important ecological areas in or near




cities (e.g., within the top 25% of all sites  in the midwest.).  This iteration of TEAP did not use




such a fine scale resolution because of data quality and computer calculation time.





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4.2 Accuracy Assessment





       The accuracy assessment was performed by The Conservancy, an independent entitynoy




involved with the calculations of the TEAP main and composite layers.  The portfolio sites used




in the accuracy assessment were derived independently from the TEAP using The Conservancy's




process. Both TEAP and The Conservancy's processes use GIS information at some level;




however, The Conservancy's process also includes field investigations whereas TEAP does not.




As explained in the results section, the match between The Conservancy's portfolio sites and




highly scored TEAP composite locations is good; however, there is less of a match at lower




TEAP scores. This may be due to the fact that The Conservancy's process is designed to




identify the highest quality or rare ecological communities for protection rather than identifying




lower quality sites for restoration or mitigation process opportunities.  It is difficult to determine




the degree or "goodness" of the match between TEAP and The Conservancy without further




field investigations. The decision to proceed with field investigations depends on the priority of




such investigations for the TERS member agencies and the usefulness of these lower scored




TEAP composite locations to agency programs (e.g., agencies looking for restoration




opportunities).





       Further analysis using multivariate statistics is needed to further verify the results of




TEAP. Future actions such as the application of landscape metrics to study the pattern found  at




a finer resolution are also recommended to understand the spatial landscape patterns (McGarigal




and Marks 1994. Riitters et al. 1995. Hargisetal. 1998. Roy and Tomar 2000. Herzog et al.




2001. Lee etal. 2001. Ochoa-Gaona2001. Lausch and Herzog 20021
                                          117

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4.3 Conservation





       TEAP uses generally accepted ecological theory as the basis for its analysis. However,




an aspect that affects potential conservation and protection of ecologically important locations in




Texas regards the protection of large contiguous tracts of land versus protection of small high-




value remnants that are possibly unsustainable areas without intense human management.  The




argument of protecting Several Small or Single Large areas/reserves (SLOSS) has been




discussed considerably in the scientific literature (see Ovaskainen 2003).  In the end, questions




related to the spatial configuration of reserves and how the surrounding matrix was managed




became more important as conservation goals.





       Conservation is not the primary mission  of many regulatory agencies.  For these




agencies, the TEAP may be useful in meeting NEPA requirements and in making project




planning level  analyses and decisions.





       It seems obvious that planners should avoid negatively impacting ecologically important




areas, especially in areas where there are few ecologically important areas remaining. On the




other hand, the most threatened and rarest species and communities are often found in areas that




TEAP would identify as less important.  The key is to strike a balance between protecting and




enhancing highly ecologically important areas versus protecting and enhancing vulnerable




species/communities in less ecologically important areas.





       Eventually, the decision should be determined by several factors.  Ovaskainen (2003)




suggested that the SLOSS decision should promote 1) maximizing the number of species that




will eventually survive, 2) maximizing the number of currently occurring species, 3) lengthening




species time to extinction, and 4) maximizing metapopulation capacity. Similarly, Noss and





                                          118

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Csuti (1994) proposed that 1) critical ecological processes must be maintained, 2) goals and




objectives must come from an ecological understanding of the system, 3) external threats must




be minimized and external benefits maximized, 4) evolutionary processes should be conserved,




and 5) management must be adaptive and minimally intrusive. Harris et al. (1996) and Noss




(1996) suggest a connectivity approach to protect landscapes from further fragmentation and to




restore connectivity to culturally fragmented landscapes, where possible.  Linking such areas




may enhance landscape connectivity (e.g., organism dispersal, optimal foraging areas) and




reduce the effects of fragmentation (Beier and Noss 1998. Hoctor et al. 2000. Swenson and




Franklin 2000).





       The ecologically important areas identified through TEAP do not  represent areas that, if




left undisturbed, would capture all of the remaining biodiversity in the state, nor does it give




license to destroy areas that have lower TEAP scores of ecological importance. The use of




TEAP would be the first step in avoidance of impacts, not the last. TEAP identifies the top  1%




ecologically important areas in each ecoregion and provides information to aid streamlining




agency decisions used to protect the biodiversity of Texas.  When communicating with decision-




makers concerning the results of TEAP. protecting (or avoiding) every square inch of an area




falling in the 1% category does not necessarily protect biodiversity per se. It can, however, help




protect places that make a significant contribution to the biodiversity of Texas.
                                           119

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                                  5.0 CONCLUSIONS
5.1 Streamlining





       The TEAP effort supports streamlining and the EO 13274 by providing a tool agencies




can use to rapidly assess some of the environmental impacts of large projects, including




transportation projects.  The TEAP accomplishes one of the goals of TERS, which is to develop




an ecosystem-based tool to assist in identifying important ecological areas in the state for use in




the planning of large scale projects. It may also aid in alternatives analysis, some compensatory




mitigation, and preservation.





       Another goal of the TERS is to improve the overall quality of agency decision-making,




with respect to the environmental concerns, in the state of Texas. The information provided by




TEAP better informs agencies facilitating better decisions.
5.2 Next Steps





       Large-scale projects present many special problems.  The following are obstacles to




achieving adequate mitigation of environmental impacts: 1) They often affect diverse habitats,




land forms and watersheds, 2) Adequate amounts or types of lands needed for appropriate




compensatory action may not be easily accessible, and 3) They may intersect numerous




regulatory agency jurisdictions that must be addressed (Reid and Murphy 1995). Linear projects




are a special challenge because the avoidance of impacts in one segment may define the impact




in the next. Identification of the most important resources present for an entire project is a tool
                                          120

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that can be used to avoid impacts, minimize impacts, identify potential compensatory mitigation,




and select the least environmental damaging project alternative.





       Large projects such as IH69, challenge agency staffing, funding, and the ability to




provide timely decisions if conducted in a "business-as-usual" manner.  Regulatory agency




authority and policy may or may not provide guidance to deal with the demands associated with




very large and complex projects.





       In the past, impacts of public works projects have not been evaluated on an ecoregion




scale in Texas. Inclusion of ecoregion information, such as that found in the TEAP. into the




planning process of large public works projects facilitates project impact analysis and the




mitigation of impacts while realizing conservation of ecologically important lands. This tool




may help streamline the project development process through early identification of project




impacts, and enhances the capability of avoidance and minimization of those impacts.





       TEAP has great potential for enhancing environmental impact analysis.  However, it still




needs to be validated.  TEAP should be updated approximately every two years to maximize




utility. This will allow the performance of trend analysis as new data becomes available.  The




results described in this report can be used in discussions for mitigation opportunities and




identification of key locations for more effective species protection (Abbitt et al. 2000). For




example, TEAP information can be of assistance in locating, designing and establishing




mitigation areas, mitigation banks, or other conservation areas. Finally, TEAP identifies




strategic indicators that can be modified in subsequent iterations, can be compared across time




periods, can potentially serve as reference points for project and long range planning, and can




provide supplemental data to aid in regulatory discussions.  TEAP is not designed to take the






                                           121

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place of agency policies and procedures, but to be a supplemental information tool to aid in




agency decision making.
                            6.0 ACKNOWLEDGMENTS
The TERS Steering Committee would like to thank the following individuals who also provided




input to the TEAP process: Mark Ball (TXDQI), Kathy Boydston (TPWD), Dale Davidson




(USAGE). Andrea Donio (TPWD). Lee Elliott (The Nature Conservancy). Luis Fernandez




(EPA). Jeff Francell (TPWD). Presley Hatcher (USAGE). Everett Laney (USAGE). Wayne Lea




(USAGE). Mike Leary (FHWA). David A. Manning (USAGE). Jessica Napier (USAGE).




Dianna Noble (TXDOT). Irene Rico (FHWA), Jeanne Roddy (TXDOT). Jeff Saitas (TCEO).




Terri Seales (TCEO).  Steve Swihart (USAGE). Tom Weber (TCEO). and Mary White (EPA).
                                       122

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                                  7.0 REFERENCES
Abbruzzese, B. and S. G. Leibowitz.  1997.  A synoptic approach for assessing cumulative
impacts to wetlands. Environmental Management 21:457'-41'5.
Abbitt, R. J. F., J. M. Scott, and D. S. Wilcove.  2000.  The geography of vulnerability:
incorporating species geography and human development patterns into conservation planning.
Biological Conservation 96:169-175.
Arrhenius, O.  1921. Species and area. Journal of 'Ecology 9:95-99.
Askins, R. A., M. J. Philbrick, and D. S. Sugeneo. 1987. Relationship between the regional
abundance of forest and the composition of forest bird communities. Biological Conservation
39:129-152.
Bailey, R. G.  1985.  The factor of scale in ecosystem mapping. Environmental Management
9:271-276.
Bailey, R. G.  1987.  Suggested hierarchy of criteria for multi-scale ecosystem mapping.
Landscape and Urban Planning 14:313-319.
Bailey, R. 1994. Bailey Ecoregion Map. Global View CD-ROM; Global Ecosystems Database,
Ecosystem and Global Change Program, National Geophysical Data Center, Boulder, Colorado.


Bailey, R. G.  1996.  Multi-scale ecosystem analysis.  Environmental Monitoring and
Assessment 39:21-24.
Begon, M., J. L. Harper, and C. R. Townsend.  1986. Ecology: Individuals, Populations, and
Communities.  Sinaur Associates.  Sunderland, MA.
Beier, P. and R. F. Noss. 1998. Do habitat corridors provide connectivity? Conservation
Biology 12:1241-1252.
Boughton, D. A., E. R. Smith, and R. V. O'Neill.  1999.  Regional vulnerability: a conceptual
framework. Ecosystem Health 5:312-3 22.
                                          123

-------
Brown, J. H.  1986.  Two decades of interaction between the Mac Arthur-Wilson model and the
complexities of mammalian distributions. Biological Journal of the Linnean Society 28:231 -
251.
Bryce, S. A. and S. E. Clarke.  1996.  Landscape-level ecological regions linking state-level
ecoregion frameworks with stream habitat classifications. Environmental Management 20:297-
311.
Burel, F. 1989. Landscape structure effects on carabid beetles spatial patterns in western
France.  Landscape Ecology 2:215-226.


Cappuccino, N. and R. B. Root.  1992.  The significance of host patch edges to the colonization
and development of Corythucha marmorata (Hemiptera: Tingidae).  Ecological Entomology
17:109-113.
Chiarello, A. G.  1999.  Effects of fragmentation of the Atlantic forest on mammal communities
in south-eastern Brazil.  Biological Conservation 89:71-82.


Clevenger, A. P., J. Wierzchowski, B. Chruszcz, and K. Gunson. 2002. GIS-generated, expert-
based models for identifying wildlife habitat linkages and planning mitigation passages.
Conservation Biology 16:503-514.
Collinge, S. K.  1996.  Ecological consequences of habitat fragmentation: implications for
landscape architecture and planning.  Landscape and Urban Planning 36:55-77.
Collinge, S. K.  1998.  Spatial arrangement of habitat patches and corridors: clues from
ecological field experiments. Landscape and Urban Planning 42:157-168.


Collinge, S. K. and R. T. T. Forman. 1998.  A conceptual model of land conversion processes:
predictions and evidence from a microlandscape experiment with grassland insects.  Oikos
82:66-84.
Critical Ecosystems Workshop. 2002. US Environmental Protection Agency, Office of
Research and Development, http://www.epa.gov/osp/regions/criteco.htm.
Dale, V. H. and R. A. Haeuber. 2000. Perspectives on Land Use. Ecological Applications 10:
671-672.
                                          124

-------
Dale, V. H., R. V. O'Neill, F. Southworth, and P. Pedlowski,  1994.  Modeling effects of land
management in the Brazilian Amazonian settlement of Rondonia.  Conservation Biology 8:196-
206.
Diamond, J. M. and R. M. May. 1976. Island biogeography and the design of natural reserves.
Pages 163-186 in R. M. May, editor. Theoretical Ecology.  Saunders College Publishers.
Philadelphia, Pennsylvania, USA.


Dickert, T. G. and A. E. Tuttle.  1985.  Cumulative impact assessment in environmental
planning: a coastal wetland watershed example. Environmental Impact Assessment Review 5:37-
64.
Donovan, T. M., P. W. Jones, E. M. Annand and F. R. Thompson, III.  1997. Variation in local-
scale edge effects: mechanisms and landscape context.  Ecology 78:2064-2075.


El-Hage, A. and D. W. Moulton.  2000a. Ecologically Significant River and Stream Segments of
Region M, Regional Water Planning Area.  Texas Parks and Wildlife Department. Austin, TX.


El-Hage, A. and D. W. Moulton.  2000b. Ecologically Significant River and Stream Segments of
Region N, Segional Water Planning Area. Texas Parks and Wildlife Department.  Austin, TX.


El-Hage, A. and D. W. Moulton.  2001. Ecologically Significant River and Stream Segments of
Region J, Regional Water Planning Area. Texas Parks and Wildlife Department.  Austin, TX.


EPA.  2002.  Latest Findings on National Air Quality: 200 J Status and Trends.  EPA 454-k-02-
001. US EPA Office of Air Quality Planning and Standards, September 2002 Research Triangle
Park, NC.


Espejel, I, D. W. Fischer, A. Hinojosa, C. Garcia, and C. Levya.  1999.  Land use planning for
the Guadalupe Valley, Baja California, Mexico. Landscape and Urban Planning 45:219-232.


Foster, J. and M.  S. Gaines.  1991. The effects of a successional habitat mosaic on a small
mammal community.  Ecology 72:1358-1373.


Game, M.  1980.  What is the best shape for nature reserves? Nature 207:630-632.
                                         125

-------
Geneletti, D.  2003.  Biodiversity impact assessment of roads: an approach based on ecosystem
rarity. Environmental Impact Assessment Review 23:343-365.


Gould, F. W.  1975. Texas Plants: A Checklist and Ecological Summary.  Texas Agricultural
Experiment Station Publication 585.
Griffith, G. E., J. M. Omernik, and A. J. Woods.  1999. Ecoregions, watersheds, basins, and
HUCs: How state and federal agencies frame water quality. Journal of Soil and Water
Conservation 54:666-677.
Groves, C., Valutis, L., Vosick, D., Neely, B., Wheaton, K., Touval, J., Runnels, B.  2000.
Designing a Geography of Hope: A Practitioner's Handbook to Ecoregional Conservation
Planning. The Nature Conservancy. Arlington, VA.
Gustafson, E. J. and R. H. Gardner.  1996. The effect of landscape heterogeneity on the
probability of patch colonization. Ecology 77:94-107.
Hargis, C. D., J. A. Bissonette, and J. L. David.  1998.  The behavior of landscape metrics
commonly used in the study of habitat fragmentation. Landscape Ecology 13:167-186.


Harris, L. D., T. Hoctor, D. Maehr, and J. Sanderson.  1996. The role of networks and corridors
in enhancing the value and protection of parks and equivalent areas. Pages 173-197 in Wright,
R. G. and J. Lemons (eds.) National Parks and Protected Areas: Their Role in Environmental
Protection. Blackwell Science, Inc. Cambridge, MA.
Harrison, J. E., Ebert, D., Wade, T. and Yankee, D. 2000. Using (ATtlLA) Analytical Tools
Interface for Landscape Assessments to Estimate Landscape Indicators and Target Restoration
Needs, [unpublished]
Harte, J., and A. P. Kinzig.  1997. On the implications of species-area relationships for
endemism, spatial turnover, and food web patterns.  Oikos 80:417-427.
H. John Heinz III Center for Science, Economics and the Environment.  2002.  The State of the
Nation's Ecosystems: Measuring the Lands, Waters, and Living Resources of the United States.
Heinz Center, Washington, DC.
                                          126

-------
Herzog, F., A. Lausch, H-H. Thulke, U. Steinhardt, and S. Lehmann. 2001.  Landscape metrics
for assessment of landscape destruction and rehabilitation. Environmental Management 27:91-
107.
Hoctor, T. S., M. H. Carr, and P. D. Zwick.  2000. Identifying a linked reserve system using a
regional landscape approach: the Florida Ecological Network. Conservation Biology 14:984-
1000.
Iverson, L. R., D. L. Szafoni, S. E. Baum, E. A. Cook.  2001.  A riparian wildlife habitat
evaluation scheme developed using GIS. Environmental Management 28:639-654.
Ji, W. and P. Leeberg. 2002. A GIS-based approach for assessing the regional conservation
status of genetic diversity: an example from the southern Appalachians. Environmental
Management 29:531-544.
Johnson, D. W. 1986. Desert buttes: natural experiments for testing theories of island
biogeography.  National Geographic Research 2:152-166.


Jones, K. B., A. C. Neale, M. S. Nash, R. D. Van Remortel, J. D. Wickham, K. H. Riitters, and
R. V. O'Neill.  2001. Predicting nutrient and sediment loadings to streams from landscape
metrics: a multiple watershed study from the United States Mid-Atlantic Region. Landscape
Ecology 16:301-312.
Jonsen, I. D. and L. Fahrig.  1997.  Response of a generalist and specialist insect herbivores to
landscape spatial structure. Landscape Ecology 12:185-197.


Karydis, M. 1996. Quantitative assessment of eutrophication: a scoring system for
characterizing water quality in coastal marine ecosystems. Environmental Monitoring and
Assessment 41:233-246.
Kuchler, A. W. 1964. Manual to Accompany the Map of Potential Vegetation of the
Coterminous United States. Special Publication No. 36. American Geographical Society. New
York.
Launer, A. E. and D. D. Murphy.  1994. Umbrella species and the conservation of habitat
fragments: a case of a threatened butterfly and a vanishing grassland system. Biological
Conservation 69:145-153.
                                          127

-------
Lausch, A. and F. Herzog.  2002.  Applicability of landscape metrics for the monitoring of
landscape change: issues of scale, resolution, and interpretability. Ecological Indicators 2:3-15.


Lee, J. T., S. J. Woddy, and S. Thompson.  2001. Targeting sites for conservation: using a patch
based ranking scheme to assess conservation potential. Journal of Environmental Management
61:367-380.
Leibowitz, S. G., C. Loehle, B-L. Li, and E. M. Preston. 2000. Modeling landscape functions
and effects: a network approach. Ecological Modelling 132:77'-94.


Lidicker, W. Z., Jr. 1999. Responses of mammals to habitat edges: a review. Landscape
Ecology 14:333-343.


Lindenmayer, D. B., R. B. Cunningham, and M. L. Pope. 1999. A large-scale "experiment" to
examine the effects of landscape context and habitat fragmentation on mammals. Biological
Conservation 88:387-403.
Lyndon B. Johnson School of Public Affairs. 1978.  Texas Natural Regions. Natural Heritage
Policy Research Project. University of Texas, Austin, TX.


MacArthur, R. H. and E. O. Wilson.  1967.  The Theory of Island Biogeography. Princeton
University Press, Princeton, N. J.


McCollin, D. 1998. Forest edges and habitat selection in birds: a functional approach.
Ecography 21:247-260.


McGarigal, K. and B. J. Marks. 1994. FRAGSTATS: Spatial Analysis Program for Quantifying
Landscape Structure. USDA Forest Service, General Technical Report PNW-GTR-351.
Corvallis, OR: Oregon State University.


McNab, W. H. and P. E. Avers. 1994. Ecological Subregions of the United States. US Forest
Service Publication WO-WSA-5.  http://www.fs.fed.us/land/pubs/ecoregions/


Miller, W., M. Collins, F. Steiner, and E. Cook.  1998.  An approach for greenway suitability
analysis. Landscape and Urban Planning 42:91-105.
                                          128

-------
Montgomery, D. R., G. E. Grant, and K. Sullivan. 1995. Watershed analysis as a framework for
implementing ecosystem management. Water Resources Bulletin 31:369-385.


Mysz, A. T., C. G. Maurice, R. F. Beltran, K. A. Cipollini, J. P. Perrecone, K. M. Rodriguez, and
M. L. White.  2000.  A targeting approach for ecosystem protection. Environmental Science and
Policy 3:347-35.


Norris, C. W. and G. W. Linum.  1999. Ecologically Significant River and Stream Segments of
Region H, Regional Water Planning Area. Texas Parks and Wildlife Department. Austin, TX.


Norris, C. W. and G. W. Linum.  2000a. Ecologically Significant River and Stream Segments of
Region C, Regional Water Planning Area. Texas Parks and Wildlife Department. Austin, TX.


Norris, C. W. and G. W. Linum.  2000b. Ecologically Significant River and Stream Segments of
Region D, Regional Water Planning Area. Texas Parks and Wildlife Department. Austin, TX.


Noss, R. F.  1996.  Protected areas: how much is  enough? Pages 91-120 in Wright, R. G. and J.
Lemons (eds.) National Parks andProtected Areas: Their Role in Environmental Protection.
Blackwell Science, Inc. Cambridge, MA.


Noss, R. F.  and B. Csuti.  1994. Habitat fragmentation. Pages 237-264 in G. K. Meffe and C. R.
Carroll, editors. Principles of Conservation Biology. Sinaur and Associates, Sunderland, MA.


Ochoa-Gaona, S. 2001.  Traditional land-use systems and patterns of forest fragmentation in the
highlands of Chiapas, Mexico. Environmental Management 27:571-586.


Omernik, J.M. 1987. Aquatic ecoregions of the coterminous United States.  Annals of the
Association of American Geographers 77:118-125.


Omernik, J. M.  1995.  Ecoregions: a spatial  framework for environmental management. Pages
49-62 in Davis, W. S. and T. P. Simon (eds.) Biological Assessment and Criteria: Tools for
Water Resource Planning andDecisionmaking.  Lewis Publishing, Boca Raton, FL.


Omernik, J. M. and R. G. Bailey. 1997. Distinguishing Between Watersheds and Ecoregions.
Journal of the American Water Resources Association 33:935-949.
                                          129

-------
O'Neill, R. V., K. H. Riitters, J. D. Wickham, and K. B. Jones.  1999.  Landscape pattern metrics
and regional assessment. Ecosystem Health 5:225-233.


Opdam, P.  1991.  Metapopulation theory and habitat fragmentation: a review of holarctic
breeding bird studies. Landscape Ecology 5:93-106.


Ovaskainen, O. 2003. Long-term persistence of species and the SLOSS problem.  Journal of
Theoretical Biology 218:419-433.


Poiani, K. A., J. A. Baumgartner, S. C. Buttrick, S. L. Green, E. Hopkins, G. D. Ivey, K. P.
Seaton, and R. D.  Sutler.  1998.  A scale-independent, site conservation planning framework in
The Nature Conservancy.  Landscape and Urban Planning 43:143-156.


Poiani, K. A., M. D. Merrill, and K. A. Chapman. 2001. Identifying conservation-priority areas
in a fragmented Minnesota landscape based on the umbrella species concept and selection of
large patches of natural vegetation.  Conservation Biology 15:513-522.


Poiani, K., and Richter, B. 1999. Functional Landscapes and the Conservation of Biodiversity.
The Nature Conservancy.  Arlington, VA.


Reid, T. A. and D. D. Murphy.  1995.  Providing a regional context for conservation action.
BioScience Supplement 8:84-90.


Riitters, K. J., R. V. O'Neill, C. T. Hunsaker, J. D. Wickham, D. H. Yankee,  S. P. Timmons, K.
B. Jones, and B. L. Jackson. 1995.  A factor analysis of landscape pattern and structure metrics.
Landscape Ecology 10:23-39.


Robinson, G. R., R. D. Holt, M. S. Gaines, S. P. Hamburg, M. L. Johnson, H. S. Fitch, and E. A.
Martinko. 1992. Diverse and contrasting effects of habitat fragmentation.  Science 257:524-
526.
Roy, P. S. and S. Tomar. 2000. Biodiversity characterization at landscape level using
geospatial modeling techniques. Biological Conservation 95:95-109.
Schafer, C. L.  1990.  Nature Reserves: Island Theory and Conservation Practice.  Smithsonian
Institution Press, Washington, DC.
                                          130

-------
Schweiger, E. W., S. G. Leibowitz, J. B. Hyman, W. E. Foster, and M. C. Downing.  2002.
Synoptic assessment of wetland function: a planning tool for protection of wetland species.
Biodiversity and Conservation 11:3 79-406.


Serveiss, V. B.  2002.  Applying ecological risk principles to watershed assessment and
management. Environmental Management 29:145-154.


Steiner, F., J. Blair, L.  McSherry, S. Guhathakurta, J. Marruffo, and M. Holm. 2000a. A
watershed at a watershed: the potential for environmentally sensitive area protection in the upper
San Pedro Drainage Basin (Mexico and USA). Landscape and Urban Planning 49:129-148.


Steiner, F., L. McSherry, and J. Cohen.  2000b. Land suitability analysis for the upper Gila
River watershed. Landscape and Urban Planning 50:199-214.


Store, R. and J. Kangas.  2001.  Integrating spatial multi-criteria evaluation and expert
knowledge for GIS-based habitat suitability modeling. Landscape and Urban Planning 55:79-
93.
Sutherland, M.  1994. Evaluation of Ecological Impacts from Highway Development. US EPA-
300b-94-006, US EPA, Washington, DC.


Swenson, J. J. and J. Franklin. 2000. The effects of future development on habitat
fragmentation in the Santa Monica Mountains. Landscape Ecology 15:713-730.
Texas Parks and Wildlife Department. 2002. Land and Water Resources Conservation and
Recreation Plan. August 29, 2002. [unpublished]
Theobald, D. M., N. T. Hobbs, T. Bearly, J. A. Zack, T. Shenk, and W. E. Riebsame. 2000.
Incorporating biological information in local land-use decision making: designing a system for
conservation planning. Landscape Ecology 15:35-45.


Thomas, C. D. and S, Harrison.  1992. Spatial dynamics of a patchily distributed butterfly
species. Journal of Animal Ecology 61:437-446.
Tigas, L. A., D. H. Van Vuren, and R. M. Sauvajot.  2002. Behavioral responses of bobcats and
coyotes to habitat fragmentation and corridors in an urban environment.  Biological
Conservation 108:299-306.
                                          131

-------
Tinker, D. B., C. A. C. Resor, G. P. Beauvais, K. F. Kipfmueller, C. I. Fernandes, and W. L.
Baker. 1998. Watershed analysis of forest fragmentation by clearcuts and roads in a Wyoming
forest. Landscape Ecology 13:149-165.
Iran, L. T., C. G. Knight, R. V. O'Neill, E. R. Smith, K. H. Riitters, and J. Wickham.  2002.
Fuzzy decision analysis for integrated environmental vulnerability assessment of the Mid-
Atlantic Region. Environmental Management 29:845-859.


Treweek, J. and N. Veitch.  1996.  The potential application of GIS and remotely sensed data to
the ecological assessment of proposed new road schemes.  Global Ecology andBiogeography
Letters 5:249-257.
Vogelmann, J. E., S. M. Howard, L. Yang, C. R. Larson, B. K. Wylie, and N. van Driel.  2001.
Completion of the 1990s national land cover data set for the conterminous United States from
Landsat Thematic Mapper data and ancillary data sources. Photogrammetric Engineering and
Remote Sensing 67:650-662.


Vogelmann, J. E., T. L. Sohl, P. V. Campbell, and D. M. Shaw. 1998. Regional land cover
characterization using LANDSAT Thematic Mapper data and ancillary data sources.
Environmental Monitoring and Assessment 51: 415-428.
Vos, C. C. and A. H. P. Stempel. 1995. Comparison of habitat-isolation parameters in relation
to fragmented distribution patterns in the tree frog (Hyla arborea).  Landscape Ecology 11:203-
214.
Wahlberg, N., A. Moilanen, and I. Hanski.  1996.  Predicting the occurrence of endangered
species in a fragmented landscapes. Science 273:1536-1538.


Walters, J. R., H. A. Ford, and C. B. Cooper.  1999. The ecological basis of sensitivity of brown
treecreepers to habitat fragmentation a preliminary assessment.  Biological Conservation 90:13-
20.
Wickham, J. D., K. B. Jones, K. H. Riitters, R. V. O'Neill, R. D. Tankersley, E. R. Smith, A. C.
Neale, and D. J. Chaloud. 1999. An integrated environmental assessment of the Mid-Atlantic
Region. Environmental Management 24:553-560.
White, M. L., C. G. Maurice, A. T. Mysz, R. F. Beltran, and M. Gentleman. 2003. CrEAM,
Getting the Best Ecosystems to Float to the Top.  US EPA Region 5, Chicago, IL. [unpublished]


                                          132

-------
White, P. C., L. G. Saunders, and S. Harris.  1996. Spatio-temporal patterns of home range use
by foxes (Vulpes vulpes) in urban environments. Journal of Animal Ecology 65:121-125.


Wilson, E. O. and E. O. Willis.  1975. Applied biogeography.  Pages 522-534 in M. L. Cody and
J. M. Diamond, editors. Ecology and Evolution of Communities. Belknap Press of Harvard
University, Cambridge, Massachusetts, USA.


Xiang, W-N.  2001.  Weighting-by-choosing: a weight elicitation method for map overlay.
Landscape and Urban Planning 56:61-73.


Yahner, R. H.  1988.  Changes in wildlife communities near edges. Conservation Biology 2:333-
339.
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         APPENDIX A
Descriptions of Bailey's Ecoregions
     (McNab and Avers 1994)
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                                  Table of Contents

Chapter	Page
Southeastern Mixed Forest 	140
      Mid Coastal Plains. Western (Section 23 IE)	140
             Geomorphology  	 140
             Lithology and Stratigraphy	 140
             Soil Taxa	140
             Potential Natural Vegetation	141
             Fauna	141
             Climate	141
             Surface Water Characteristics	141
             Disturbance Regimes 	 141
             Land Use 	141
      Eastern Gulf Prairies and Marshes (Section 23 IF) 	 141
             Geomorphology  	 141
             Lithology and Stratigraphy	 142
             Soil Taxa	142
             Potential Natural Vegetation	142
             Fauna	 143
             Climate	 143
             Surface Water Characteristics	143
             Disturbance Regimes 	 143
             Land Use 	143

Outer Coastal Plain Mixed Forest	143
      Louisiana Coast Prairies and Marshes (Section 232E) 	143
             Geomorphology  	 143
             Lithology and Stratigraphy	 144
             Soil Taxa	144
             Potential Natural Vegetation	144
             Fauna	 144
             Climate	 145
             Surface Water Characteristics	145
             Disturbance Regimes 	 145
             Land Use 	145
      Coastal Plains and  Flatwoods. Western Gulf (Section 232F)	145
             Geomorphology  	 145
             Lithology and Stratigraphy	 146
             Soil Taxa	146

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             Potential Natural Vegetation	146
             Fauna	 146
             Climate	 146
             Surface Water Characteristics	147
             Disturbance Regimes 	 147
             Land Use  	147

Prairie Parkland (Subtropical)	 147
      Cross Timbers and Prairies (Section 255 A)	 147
             Geomorphology  	 147
             Lithology  and Stratigraphy	 148
             Soil Taxa	148
             Potential Natural Vegetation	148
             Fauna	 148
             Climate	 148
             Surface Water Characteristics	148
             Disturbance Regimes 	 149
             Land Use  	149
      Blackland Prairies (Section 25 5B) 	 149
             Geomorphology  	 149
             Lithology  and Stratigraphy	 149
             Soil Taxa	149
             Potential Natural Vegetation	150
             Fauna	 150
             Climate	150
             Disturbance Regimes 	 150
             Land Use  	150
      Oak Woods and Prairies (Section 255O 	150
             Geomorphology  	 150
             Lithology  and Stratigraphy	 151
             Soil Taxa	151
             Potential Natural Vegetation	151
             Fauna	151
             Climate	 152
             Surface Water Characteristics	152
             Disturbance Regimes 	 152
             Land Use  	152
      Central Gulf Prairies and Marshes (Section 25 5D)  	 152
             Geomorphology  	 152
             Lithology  and Stratigraphy	 153
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             Soil Taxa	153
             Potential Natural Vegetation	153
             Fauna	 153
             Climate	 153
             Surface Water Characteristics	153
             Disturbance Regimes 	 154
             Land Use 	154

Great Plains Steppe and Shrub	154
       Redbed Plains (Section 311 A) 	154
             Geomorphology 	 154
             Lithology and Stratigraphy	 155
             Soil Taxa	155
             Potential Natural Vegetation	155
             Fauna	 155
             Climate	 155
             Surface Water Characteristics	155
             Disturbance Regimes 	 155
             Land Use 	155

Southwest Plateau and Plains Dry Steppe and Shrub 	156
       Texas High Plains (Section 3 \5E} 	 156
             Geomorphology 	 156
             Lithology and Stratigraphy	 156
             Soil Taxa	156
             Potential Natural Vegetation	156
             Fauna	 156
             Climate	 157
             Surface Water Characteristics	157
             Disturbance Regimes 	 157
             Land Use 	157
       Rolling Plains (Section 315O 	 158
             Geomorphology 	 158
             Lithology and Stratigraphy	 158
             Soil Taxa	158
             Potential Natural Vegetation	159
             Fauna	 159
             Climate	 159
             Surface Water Characteristics	159
             Disturbance Regimes 	 159
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             Land Use  	159
       Edwards Plateau (Section 315D} 	159
             Geomorphology  	 159
             Lithology and Stratigraphy	 160
             Soil  Taxa	160
             Potential Natural Vegetation	160
             Fauna	 160
             Climate	161
             Surface Water Characteristics	161
             Disturbance Regimes 	 161
             Land Use  	161
       Rio Grande  Plain (Section 315E^	 161
             Geomorphology  	 161
             Lithology and Stratigraphy	 161
             Soil  Taxa	161
             Potential Natural Vegetation	162
             Fauna	 162
             Climate	 163
             Surface Water Characteristics	163
             Disturbance Regimes 	 163
             Land Use  	163
       Southern Gulf Prairies and Marshes (Section 315F)  	 163
             Geomorphology  	 163
             Lithology and Stratigraphy	 164
             Soil  Taxa	164
             Potential Natural Vegetation	164
             Fauna	 164
             Climate	 164
             Surface Water Characteristics	164
             Disturbance Regimes 	 165
             Land Use  	165

Arizona-New Mexico Mountains Semi-Desert - Open Woodland - Coniferous Forest - Alpine
Meadow	'	165
       Sacramento-Manzano Mountain (Section M313B) 	 165
             Geomorphology  	 165
             Lithology and Stratigraphy	 165
             Soil  Taxa	166
             Potential Natural Vegetation	166
             Climate	 166
             Surface Water Characteristics	166

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             Disturbance Regimes 	 166
             Cultural Ecology 	 166

Chihuahuan Semi-Desert 	167
      Basin and Range (Section 321A) 	 167
             Geomorphology  	 167
             Lithology and Stratigraphy	 168
             Soil Taxa	168
             Potential Natural Vegetation	168
             Climate	 168
             Surface Water Characteristics	168
             Disturbance Regimes 	 169
             Land Use 	169
             Cultural Ecology 	 169
      Stockton Plateau (Section 32IE) 	169
             Geomorphology  	 169
             Lithology and Stratigraphy	 170
             Soil Taxa	170
             Potential Natural Vegetation	170
             Fauna	 170
             Climate	171
             Surface Water Characteristics	171
             Disturbance Regimes 	 171
             Land Use 	171

Great Plains-Palouse Dry Steppe 	171
      Southern High Plains (Section 33 IE) 	 171
             Geomorphology  	 171
             Lithology and Stratigraphy	 172
             Soil Taxa	172
             Potential Natural Vegetation	172
             Fauna	 172
             Climate	 172
             Surface Water Characteristics	172
             Land Use 	172
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                               Southeastern Mixed Forest
Mid Coastal Plains, Western (Section 231E)
                              Photo courtesy Texas Parks and Wildlife Dept. O2003


Geomorphology.  This Section is in the Coastal Plains geomorphic province. The predominant
landform occupying about 80% of the Section consists of moderately dissected irregular plains
of marine origin.  The plains were formed by deposition of continental sediments onto
submerged, shallow continental shelf, which was later exposed by sea level subsidence.  Other
landforms consist of plains with hills and smooth plains.  Elevations range from  80 to 650 ft (25
to 200 m). Local relief ranges from 100 to 300 ft (30 to 90 m).
Lithology and Stratigraphy. Rock units formed during the Cenozoic Era.  Strata consist of
Tertiary marine deposits (glauconitic sands and clays with lenses of coquinid limestone; clay and
silty clay).


Soil Taxa. Soils are predominantly Udults. Paleudults, Hapludults, Hapludalfs, Paleudalfs, and
Albaqualfs are on uplands. Fluvaquents, Udifluvents, Eutrochrepts, and Glossaqualfs are on
bottom lands along major streams.  Soils have a thermic temperature regime, a udic moisture
regime, and siliceous or mixed mineralogy.  Most soils have formed from sandstone and shale
parent materials.  Soils are generally coarse textured, deep, and have adequate moisture for plant
growth during the growing season.
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Potential Natural Vegetation.  Kuchler mapped this area as oak-hickory-pine forest, southern
mixed forest, and southern floodplain forest.  The predominant vegetation form consists of
needle-leaved evergreen trees.  Belts of cold deciduous, broad-leaved hardwoods are prevalent
along rivers.  The principal forest cover type is loblolly and longleaf pines. Where hardwoods
are prevalent, species consist of post, white, blackjack, and southern red oaks.  Species of bottom
lands are red maple, green ash, Nuttall oak, sweetgum, and swamp hickory.


Fauna. The elk, mountain lion, wolf, Carolina parakeet, and ivory-billed woodpecker once
inhabited this Section. Presently, the fauna include white-tailed deer, black bear, bobcat, gray
fox, raccoon, cottontail rabbit, gray squirrel, fox squirrel, striped skunk, swamp rabbit, and many
small rodents and shrews. The turkey, bobwhite, and mourning dove are game birds in various
parts of this Section.  In flooded areas, ibises, cormorants, herons, egrets, and kingfishers are
common. Songbirds include the red-eyed vireo, cardinal, tufted titmouse,  wood thrush, summer
tanager, blue-gray gnatcatcher, hooded warbler, and Carolina wren. The herpetofauna include
the box turtle, common garter snake, and timber rattlesnake.


Climate.  Annual precipitation averages 40 to 54 inches (1,000 to 1,300 mm). Temperature
averages 61 to 68 F (16 to 20 CT).  The growing season lasts about 200 to 270 days.


Surface Water Characteristics.  There is a moderate density of small to medium size perennial
streams and associated rivers,  most with moderate volume of water flowing at low velocity.
Dendritic drainage pattern has developed. Major rivers draining this Section include the Red and
Ouachita.
Disturbance Regimes. Fire has probably been the principal historical disturbance. Climatic
influences include occasional summer droughts and winter ice storms, and infrequent hurricanes.
Insect disturbances are often caused by southern pine beetles.
Land Use. Natural vegetation has been cleared for agriculture on about 25% of the area. Much
of the non-cleared land is managed for forestry.
Eastern Gulf Prairies and Marshes (Section 231F)
Geomorphology.  This Section is in the Coastal Plains geomorphic province.  The predominant
landform is a flat, weakly dissected alluvial plain formed by deposition of continental sediments
onto submerged, shallow continental shelf, which was later exposed by sea level subsidence.
Along the coast, fluvial deposition and shore zone processes are active in developing and
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maintaining beaches, swamps, and mud flats. Elevation ranges from 10 to 330 ft (3 to 100 m).
Local relief ranges from 0 to 100 ft (0 to 30 m).
Lithology and Stratigraphy.  Rock units formed during the Cenozoic Era.  Strata consist of
Quaternary marine deposits (non-glacial sand, silt, and clay deposits of upland origin).
Soil Taxa.  Aquolls, Saprists, Aquents, and Hemists are the principal soils along the coast.  Also
along the coast are Aquolls, Haplaquolls, Medisaprists, Hydraquents, and Medihemists, all of
which are poorly drained and subject to flooding and high water tables. These soils have a
thermic temperature regime and an aquic moisture regime. Farther inland, Uderts and Aqualfs
are the main soils, especially where saline prairie vegetation is present. Soils farther inland on
low lands are Pelluderts, Pellusterts, Albaqualfs, Ochraqualfs, and Glossaqualfs.  Situated on
flood plains are Argiaquolls, Haplaquolls, and Haplaquepts.  Soils have a thermic to
hyperthermic moisture regime, and an aquic moisture regime. These soils are deep, clayey,
poorly drained, and have subsoils that are slowly permeable.
                               Photo courtesy Texas Parks and Wildlife Dept. O2003


Potential Natural Vegetation. Kuchler classified vegetation as bluestem-sacahuista prairie and
southern cordgrass prairie.  Predominant vegetation is mid to tall grass grasslands. Species
consist of little bluestem, indiangrass, switchgrass, and big bluestem. Occasional areas of live
oak are present.  Poorly drained areas along the coast support freshwater and saltwater marsh
vegetation of sedges, rushes, saltgrass, and cordgrass.
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Fauna. Typical large herbivores and carnivores include manatee, coyote, red wolf, ringtail,
ocelots, and river otter. Smaller herbivores include swamp rabbit, fulvous harvest mouse,
eastern wood rat, and nutria.  Common birds of freshwater marshes, lakes, ponds, and rivers
include reddish egret, white-faced ibis, white-fronted goose, and olivaceous cormorant.
Attwater's prairie chicken was once common in the grasslands.  Reptiles and amphibians include
American alligator, Gulf coast salt marsh snake, Gulf coast toad and pig frog, diamondback
terrapin, Mediterranean gecko, and the Texas horned lizard.


Climate.  Average annual precipitation is from 30 to 55 inches (750 to 1,400 mm).  Temperature
averages 66 to 74 F (19 to 23 C°).  The growing season lasts 250 to 330 days.


Surface Water Characteristics. There is a moderate density of small to medium size perennial
streams and very low density of associated rivers; most have a moderate volume of water at very
low velocity.  Water table is high in many areas, resulting in poor natural drainage and
abundance of wetlands. Poorly defined drainage  pattern has developed on this very young,
weakly dissected plain. Abundance of palustrine systems having seasonally high water level.
This Section adjoins the Louisianian Marine and  Estuarine Province delineated by the USDI
FWS.
Disturbance Regimes. Fire and ocean tides have likely been the principal historical disturbance.
Climatic influences include occasional hurricanes.
Land Use. Natural vegetation has been cleared for agricultural crops on about 40% of the area.
                            Outer Coastal Plain Mixed Forest


Louisiana Coast Prairies and Marshes (Section 232E)


Geomorphology. This Section is in the Coastal Plains geomorphic Province.  The predominant
landform is a flat, weakly dissected alluvial plain formed by deposition of continental sediments
onto submerged, shallow continental shelf, which was later exposed by sea level subsidence.
Along the coast, fluvial deposition and shore zone processes are active in developing and
maintaining beaches, swamps, and mud flats.  Elevation ranges from 0 to 160 ft (0 to 50 m).
Local relief ranges from 0 to 50 ft (0 to 15 m).
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                               Photo courtesy Texas Parks and Wildlife Dept. O2003
Lithology and Stratigraphy.  Rock units formed during the Cenozoic Era.  Strata consist of
Quaternary marine deposits of terrestrial origin, non glacial sand, silt, and clay.
Soil Taxa. Aquolls, Saprists, Aquents, and Hemists are the principal soils along the coast. Also
along the coast are Aquolls, Haplaquolls, Medisaprists, Hydraquents, and Medihemists, all of
which are poorly drained and subject to flooding and high water tables. These soils have a
thermic temperature regime and an aquic moisture regime.


Potential Natural Vegetation. Kuchler classified vegetation as bluestem-sacahuista prairie and
southern cordgrass prairie.  Much of the existing vegetation is nonforested grasslands.  Prairie
grasslands dominate areas inland from the coast and consist of little bluestem, indiangrass,
switchgrass, and big bluestem. Occasional areas of live oak are present.  Poorly drained areas
along the coast support freshwater and saltwater marsh vegetation of sedges, rushes, saltgrass,
and cordgrass.
Fauna. Large herbivores and carnivores include manatee, coyote, red wolf, ringtail, and river
otter. Ocelots were once common, but are now rare.  Smaller herbivores include swamp rabbit,
fulvous harvest mouse, eastern wood rat, and nutria. Birds of fresh water marshes, lakes, ponds,
and rivers include reddish egret, white-faced ibis, white-fronted goose, and olivaceous
cormorant. Birds of grasslands include Attwater's prairie chicken. Reptiles and amphibians
include the Gulf coast salt marsh snake,  Gulf coast toad, pig frog, American Alligator,
diamondback terrapin, Mediterranean gecko, and Texas horned lizard.
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Climate. Annual precipitation averages 25 to 55 inches (620 to 1,400 mm).  Temperature
averages 68 to 70 F (20 to 21 CT).  The growing season lasts 280 to 320 days.
Surface Water Characteristics.  There is a moderate density of small to medium size perennial
streams and very low density of associated rivers, most with moderate volume of water at very
low velocity.  Water table is high in many areas, resulting in poor natural drainage and an
abundance of wetlands.  The Mississippi River flows through this Section into the Gulf of
Mexico.  Palustrine systems are abundant and have seasonally high water levels. This Section
adjoins the Louisianian Marine and Estuarine Province delineated by the USDIFWS.
Disturbance Regimes. Fire and ocean tides have probably been the principal historical
disturbance. Climatic influences include occasional hurricanes.
Land Use. Natural vegetation has been converted to agricultural crops on about 40% of the area.
Coastal Plains and Flatwoods, Western Gulf (Section 232F)
                              Photo courtesy Texas Parks and Wildlife Dept. O2003


Geomorphology.  This Section is in the Coastal Plains geomorphic province.  The predominant
landform consists of weakly to moderately dissected irregular plains of alluvial origin formed by
deposition of continental sediments onto a submerged, shallow continental shelf, which was later
exposed by sea level subsidence. Along the coast, fluvial deposition and shore zone processes
are active in developing and maintaining beaches, swamps, and mud flats. About 80% of this
Section consists of irregular plains. Other landforms include flat plains and plains with hills.
Elevation ranges from 80 to 660 ft (25 to 200 m).  Local relief mostly ranges from 100 to 300 ft

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(30 to 90 m) on irregular plains; however, relief ranges from 0 to 100 ft (0 to 30 m) on flat plains
and 300 to 500 ft (90 to 150 m) where plains with hills are present.


Lithology and Stratigraphy. Rocks in this Section formed during the Cenozoic Era. About 80%
of the geologic strata consist of Tertiary marine deposits, including glauconitic, calcareous, and
fossiliferous strata with lignitic sandy and argillaceous contents.  Quaternary marine deposits are
present along the Red River.


Soil Taxa.  Soils are mostly Udults. Paleudults, Hapludults, Hapludalfs, Paleudalfs, and
Albaqualfs are on uplands. Fluvaquents, Udifluvents, Eutrochrepts, and Glossaqualfs are along
major streams.  Soils are mostly derived from weathered sandstone and shale.  Soils have a
thermic temperature regime, a udic moisture regime, and siliceous or mixed mineralogy.  Soils
are deep, coarsely textured, mostly well drained, and have an adequate supply of moisture for
use by vegetation during the growing season.


Potential Natural Vegetation.  Kuchler mapped vegetation as southern mixed forest, oak-
hickory-pine forest, and southern flood plain forest. The predominant vegetation form is
evergreen needle-leaved forest with a small area of cold-deciduous alluvial forest.  The slash
pine and longleaf pine cover type dominates most of the Section. The loblolly pine-shortleaf
pine cover type is common in the northern parts of the Section.  A bottomland type is prevalent
along most major rivers and consists of cottonwood, sycamore, sugarberry, hackberry, silver
maple, and red maple.


Fauna. The elk, mountain lion, wolf, Carolina parakeet, and ivory-billed woodpecker once
inhabited this Section. The endangered Florida panther may be encountered rarely. Presently,
the fauna include white-tailed deer, black bear, bobcat, gray fox, raccoon, cottontail rabbit, gray
squirrel, fox squirrel, striped skunk, swamp rabbit, and many small rodents and shrews.  The
presence of turkey, bobwhite, and mourning dove is widespread. Resident and migratory
nongame bird species are numerous, as are species of migratory waterfowl.  In flooded areas,
ibises, cormorants, herons, egrets, and kingfishers are  common.  Songbirds include the red-eyed
vireo, cardinal, tufted titmouse, wood thrush, summer tanager, blue-gray gnatcatcher, hooded
warbler, and Carolina wren.  The endangered red-cockaded woodpecker and bald eagle inhabit
this Section.  The herpetofauna include the box turtle,  common garter snake, eastern
diamondback rattlesnake, timber rattlesnake, and American alligator.


Climate.  Precipitation averages 40 to 54 inches (1,020 to 1,350 mm) annually. Annual
temperature averages 61 to 68 F (16 to 20 CT).  The growing season lasts 200 to 270 days.
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Surface Water Characteristics. This Section has a moderate density of small to medium size
perennial streams and associated rivers. Dendritic drainage pattern has developed without
bedrock structural control. Major rivers include the Sabine, Red, and Mississippi.
Disturbance Regimes. Fire has probably been the principal historical disturbance. Climatic
influences include occasional summer droughts and winter ice storms and infrequent hurricanes.
Insect disturbances are often caused by southern pine beetles.


Land Use. Natural vegetation has been cleared for agriculture on about 60% of the area.
                              Prairie Parkland (Subtropical)
Cross Timbers and Prairies (Section 255A)
                              Photo courtesy Texas Parks and Wildlife Dept. O2003
Geomorphology.  This Section is in the Central Lowlands geomorphic province.  The
predominant landform on about 70% of the Section consists of irregular plains that originated
from uplift of level bedded continental sediments, that had been deposited into a shallow inland
sea, followed by a long period of erosion. Other landforms include plains with hills and open
high hills. Elevation ranges from 330 to 1,300 ft (100 to 400 m).  Local relief ranges from 100
to 300 ft (30 to 90 m).

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Lithology and Stratigraphy. Rock units were formed during the Paleozoic (30%) and Mesozoic
(70%) Eras. Paleozoic strata consist of Pennsylvanian marine deposits (sandstone, shale, coal,
and limestone). Mesozoic strata consist of Lower Cretaceous marine deposits (limestone).


Soil Taxa.  Soils in the Cross Timbers region are mainly Ustalfs. Paleustalfs and Haplustalfs are
on uplands. Ustifluvents and Haplustolls are on narrow flood plains.  Soils have a thermic
temperature regime, a ustic moisture regime, and mixed or siliceous mineralogy. Soils are deep,
well drained, and moderate textured; moisture is limited for use by vegetation during part of the
growing season. Soils in the Prairie region are Ustolls, Userts, and Ochrepts.  Pellusterts and
Chromusterts are on upland valleys. Calciustolls are on smooth uplands. Haplustolls,
Calciustolls, and Argiustolls are on areas of limestone parent material. Ustochrepts and
Calciustolls occur on steep plateau sideslopes. Haplustolls are on flood plains.  Argiustolls and
Haplustalfs are on  smooth uplands in northern areas of the Section.  Soil temperature regime is
thermic, moisture regime is ustic, and mineralogy is montmorillonitic, mixed, or carbonatic.
Generally,  soils are deep, fine textured, and well drained; moisture is limited for use by
vegetation  during parts of the growing season.


Potential Natural Vegetation.  Kuchler classified vegetation as cross timbers (Quercus-
Andropogon), oak-hickory forest, and oak-hickory-pine forest. The predominant vegetation
form is  cold-deciduous broad-leaved forest and extensive areas of tall grassland with a tree layer.
Forest cover consists of post, live, and blackjack oaks, and pignut and mockernut hickories.
Grasses consist of big and little bluestems, indiangrass, and sunflower.


Fauna.  Among the fauna in this Section are white-tailed deer, black bear, bobcat, gray fox,
raccoon, cottontail rabbit, gray squirrel, fox squirrel, eastern chipmunk, white-footed mouse,
pine vole, short-tailed shrew, and cotton mouse.  The turkey, bobwhite, and mourning dove are
game birds in various parts of this Section. Songbirds include the red-eyed vireo, cardinal,
tufted titmouse, wood thrush, summer tanager, blue-gray gnatcatcher, hooded warbler,  and
Carolina wren. The herpetofauna include the box turtle, common garter snake and timber
rattlesnake.
Climate. Precipitation averages 35 to 40 inches (900 to 1,050 mm). About 5 to 18 inches (120
to 450 mm) of snow falls annually. Temperature averages 55 to 63 F (13 to 17 CT). The
growing season lasts 190 to 235 days.


Surface Water Characteristics. This Section has a low to moderate density of perennial streams
and associated rivers, mostly with low to moderate rates of flow and moderate velocity.
Dendritic drainage patterns have developed.  One of the major rivers draining this Section is the
Red River. A relatively large number of water reservoirs have been constructed.
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Disturbance Regimes. Fire and drought have probably been the principal historical sources of
disturbance.
Land Use. Natural vegetation has been cleared for agricultural crops on about 75% of the area.
Blackland Prairies (Section 255B)
                              Photo courtesy Texas Parks and Wildlife Dept. O2003


Geomorphology.  This Section is in the Coastal Plains geomorphic province. The predominant
landform is irregular plains.  This Section is an elevated sea bottom that has been shaped by
marine and shore-zone processes resulting from repeated episodes of submergence and
emergence of the land from the ocean.  Some geomorphic processes currently active throughout
the area are gentle gradient valley stream erosion, transport and deposition.  Elevation ranges
from 330 to 660 ft (100 to 200 m). Local relief ranges from 100 to 300 ft.
Lithology and Stratigraphy. Rock units in this Section formed during the Mesozoic (10%) and
Cenozoic (90%) Eras. Mesozoic strata consist of Upper Cretaceous marine deposits (shales,
marls, and chalks). Cenozoic strata consists of Tertiary marine deposits.


Soil Taxa.  Soils are Usterts, Ustolls, Aqualfs, and Ustalfs. Pellusterts are in upland valleys.
Chromusterts are on eroded uplands.  Haplustrolls and Ustorthents are along an Austin chalk
escarpment. Calciustolls and Haplustolls are along stream terraces. Albaqualfs, Ochraqualfs,
and Paleustalfs are on uplands. Pelluderts, Haplaquolls, and Chromusterts are on flood plains.
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These soils have a thermic temperature regime, a ustic or aquic moisture regime, and
montmorillonitic or mixed mineralogy. Generally, soils are deep, mostly well drained, medium
to fine textured, and have limited soil moisture supplies for use by vegetation during parts of the
growing season.
Potential Natural Vegetation. Kuchler mapped vegetation as blackland prairie (Andropogon-
Stipa) and juniper-oak savanna.  The predominant vegetation form is tall grassland consisting
mainly of bunch grasses, such as indiangrass, big bluestem, switchgrass, and eastern gamagrass.
A savanna community occurs along many major rivers, consisting of elm, pecan, cottonwood,
and hackberry, with grasses between the trees.
Fauna. Faunal communities are characterized by species associated with a prairie climate and
vegetation. Typical large herbivores and carnivores include coyote, ringtail, and collared
peccary.  Smaller herbivores include plains pocket gopher, fulvous harvest mouse, and northern
pygmy mouse. Ocelots were once common, but are now rare.  The bison is historically
associated with the Section. Birds are typical of grass and shrublands; residents include many
common species, such as turkey vulture, hairy woodpecker, cardinal, and yellow warbler.
Smith's longspur, a bird of the Arctic tundra, winters here. Amphibians and reptiles typical of
this area include eastern spadefoot toad, Great Plains narrow-mouthed frog, green toad, Texas
toad, Gulf Coast toad, yellow mud turtle, Texas horned lizard,  Texas spiny lizard, and Texas
blind snake.
Climate. Precipitation ranges from 30 to 45 inches (750 to 1,150 mm), occurring mainly in
spring from April through May.  Temperature averages 63 to 70 F (17 to 21 CT). The growing
season lasts 230 to 280 days.
Disturbance Regimes. Fire and drought have probably been the principal historical sources of
disturbance.
Land Use. Natural vegetation has been changed to agricultural crops on about 75% of the area.
Oak Woods and Prairies (Section 255C)
Geomorphology. This Section is in the Coastal Plains geomorphic province. The predominant
landform on about 80% of the Section consists of irregular plains.  Other landforms include
plains with hills and smooth plains. This Section is an elevated sea bottom that has been shaped
by marine and shore-zone processes resulting from repeated episodes of submergence and
emergence of the land from the ocean.  Some geomorphic processes currently active throughout


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the area are gentle gradient valley stream erosion, transport and deposition. Elevation ranges
from 650 to 1,310 ft (200 to 400 m).  Local relief ranges from 100 to 300 ft.
                              Photo courtesy Texas Parks and Wildlife Dept. O2003


Lithology and Stratigraphy.  Rocks units formed during the Cenozoic Era.  Strata are Tertiary
marine sediments consisting of glauconitic, calcarious, fossiliferous strata with lignitic sandy
and argillaceous deposits.


Soil Taxa.  Soils are mostly Ustalfs. Paleustalfs and Albaqualfs are on uplands and other areas
with thick sandy surface. Pelluderts, Pellusterts, and Hapludolls are on flood plains and clayey
terraces along major rivers.  These soils have a thermic temperature regime, an ustic moisture
regime, and montmorillonitic mineralogy.  Soils are deep, medium textured, and generally have
a slowly permeable, clayey subsoil. Moisture may be limiting for plant growth during parts of
the year.


Potential Natural Vegetation. Kuchler classified vegetation as oak-hickory forest, cross timbers
(Querciis-Andropogon), and juniper-oak savanna. The predominant vegetation type is cold-
deciduous, broad-leaved forest. The oak-hickory cover type consists of scarlet, post, and
blackjack oaks, and pignut and mockernut hickories. Forests of elm, pecan, and  walnut are in
bottomlands. Little bluestem is the dominant grass.


Fauna. Faunal communities are characterized by species associated with a temperate, subhumid,
forested environment. Common large herbivores and carnivores include  coyote, ringtail, ocelot,
and collared peccary.  Smaller herbivores include plains pocket gopher, fulvous harvest mouse,
northern pygmy mouse, southern short-tailed shrew, and least shrew. Jaguar and bison are
historically associated with this Section. Birds typical of this Section include many wide-spread

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species, such as eastern bluebird, eastern meadowlark, grasshopper sparrow, mourning dove,
Cooper's hawk, and mockingbird. Amphibians and reptiles include eastern spadefoot toad, Great
Plains narrow-mouthed frog, green toad, yellow mud turtle, Texas horned lizard, Texas spiny
lizard, and Texas blind snake.
Climate. Annual precipitation ranges from 27 to 40 inches (700 to 1,000 mm).  Temperature
ranges from 63 to 70 F (17 to 21 CT).  The growing season lasts 200 to 260 days.


Surface Water Characteristics. There is a low density of small to medium size perennial streams
and associated rivers, most with moderate volume of water flowing at low velocity.  A major
river draining this Section is the Trinity.
Disturbance Regimes. Fire and drought have probably been the principal historical disturbances.
Land Use. Natural vegetation has been converted to agricultural crops on about 75% of the area.
Central Gulf Prairies and Marshes (Section 255D)
                              Photo courtesy Texas Parks and Wildlife Dept. O2«)«
Geomorphology.  This Section is in the Coastal Plains geomorphic province.  The predominant
landform consists of a flat, weakly dissected alluvial plain formed by deposition of continental
sediments onto a submerged, shallow continental shelf, which was later exposed by sea level
subsidence.  Along the coast, fluvial deposition and shore-zone processes are active in
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developing and maintaining beaches, swamps, and mud flats. Elevation ranges from sea level to
160 ft (0 to 50 m). Local relief ranges from 0 to 100 ft.


Lithology and Stratigraphy. Rock units formed during the Cenozoic Era.  Strata consist of
Quaternary marine deposits (non-glacial sand, silt, and clay deposits) of continental origin.


Soil Taxa.  Soils are Aquents, Aqualfs, Aquolls, and Aquepts.  Psammaquents, Udipsamments,
Fluvaquents, and Salorthids are on barrier islands and long bays. Haplaquolls, Natraqualfs,
Pelluderts, and Pellusterts are on low coastal terraces. Ochraqualfs, Albaqualfs, and Paleudalfs
are found on plains. Haplaquolls,  Haplaquents, and Fluvaquents are on coastal flats and flood
plains. These  soils have a hyperthermic and thermic temperature regime, an aquic moisture
regime, and montmorillonitic, mixed, or siliceous mineralogy.  Soils are fine to coarse textured,
saline, and mostly poorly drained with high water tables.


Potential Natural Vegetation.  Kuchler classified vegetation as bluestem-sacahuista prairie and
southern cordgrass prairie. The predominant vegetation form is tall grassland consisting mainly
of bunch grasses. Prairie grasslands dominate areas inland from the coast and consist of little
bluestem, indiangrass, switchgrass, and big bluestem. Occasional areas of live oak are present.
Poorly drained areas along the coast support freshwater and saltwater marsh vegetation of
sedges, rushes, saltgrass, and cordgrass.


Fauna. Large to medium size herbivores and carnivores include coyote, ringtail, hog-nosed
skunk, river otter, ocelot, and collared peccary. Smaller herbivores include swamp rabbit, plains
pocket gopher, fulvous harvest mouse, northern pygmy mouse, and nutria.  Bison and jaguar are
historically associated with this Section. Birds of fresh water marshes, lakes, ponds, and rivers
include reddish egret, white-faced egret, white-fronted goose, and olivaceous cormorant. Birds
of these grassland include white-tailed hawk, bronzed cowbird, and Attwater's prairie chicken.
The rare whooping crane winters in this Section at the Aransas National Wildlife Refuge.
Reptiles include American alligator, Gulf coast salt marsh snake, Mediterranean gecko,  keeled
earless lizard, Texas horned lizard, Texas spiny lizard, and Texas blind snake. Amphibians
common to this Section include Gulf coast toad and diamondback terrapin.


Climate. Annual precipitation ranges from 25 to 55 inches (620 to 1,400 mm). Temperature
averages 68 to 70 F (20 to 21 C°).  The growing season lasts 280 to 320 days.


Surface Water Characteristics. There is a moderate density of small to medium size perennial
streams and a low density of associated rivers, most with  moderate volume of water flowing at
very low velocity. The water table is high in many areas, resulting in poor natural  drainage and
abundance of wetlands. A poorly  defined drainage pattern has developed on very young plains.
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An abundance of palustrine systems are present, having seasonally high water level.  This
Section adjoins the Carolinian and Louisianian Marine and Estuarine Provinces.
Disturbance Regimes. Ocean tides have probably been the principal historical disturbance.
Climatic influences include occasional hurricanes.
Land Use. Natural vegetation has been converted to agricultural crops on about 40% of the area.
                             Great Plains Steppe and Shrub
Redbed Plains (Section 311 A)
Geomorphology.  This Section is in the Central Lowlands geomorphic province. Platform uplift
of continental sediments deposited previously into a shallow inland sea, followed by a long
period of erosion; these processes resulted in a moderately to strongly dissected region. About
70% of this Section consists of irregular plains. Other landforms include about equal areas of
plains with low mountains, smooth plains, and tablelands.  Elevation ranges from 1,600 to 3,000
ft (500 to 900 m). Local relief in much of the Section ranges from 100 to 300 ft (30 to 90 m).
Smaller areas are present where relief ranges from 30 to 60 ft (10 to 20 m) in tablelands and up
to 1,000 ft (300 m) in low mountains.
                              Photo courtesy Texas Parks and Wildlife Dept. G2003
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Lithology and Stratigraphy. Rocks formed during the Paleozoic Era.  About 80% of the geologic
strata consist of Permian marine deposits (sandstone, shale, and limestone).  Other strata include
Quaternary marine deposits and small isolated areas of Lower Cretaceous marine deposits
(limestone).


Soil Taxa.  Soils are Ustolls, Ustalfs, and Ochrepts. Most soils are on uplands and include
Argiustolls, Paleustolls, Natrustolls, Haplustalfs, Paleustalfs, and Ustochrepts. Localized areas
of Ustifluvents are on flood plains. These soils have a thermic temperature regime, a ustic
moisture regime, and mixed mineralogy. Most soils are deep, well drained, variable in texture,
and have limited moisture supplies for use by vegetation during part of the growing season.


Potential Natural Vegetation.  Kuchler classified vegetation as bluestem-grama prairie, and cross
timbers (Quercus-Andropogon); shinnery (Quercus-Andropogon); and sandsage-bluestem
prairie.  The predominant vegetation form is medium-tall grasslands with sparse tree cover.
Grasses consist mainly of sand bluestem, little bluestem, and sand saltbrush.


Fauna. Representative large to medium size herbivores and carnivores include coyote, ringtail,
and ocelot. Small herbivores include eastern cottontail, desert shrew, plains pocket mouse,
Texas kangaroo rat, and prairie vole. Bison and black-footed ferret are historically associated
with this Section. Common birds of thickets and grasslands include the roadrunner, bobwhite,
barn owl, scissor-tailed flycatcher, and common crow. The golden-fronted woodpecker has a
more  restricted range. Amphibians common to this environment include Plains spadefoot toad,
Great Plains narrow-mouthed frog, green toad, spotted chorus frog, and yellow-mud turtle.
Typical reptiles include lesser earless lizard, Texas horned lizard, Prairie skink, and Texas blind
snake.
Climate. Precipitation averages 20 to 30 inches (500 to 750 mm): snow averages 20 to 30 inches
(500 to 750 mm) annually.  Temperature averages 57 to 64 F (14 to 18 C°). The growing season
lasts 185 to 230 days.


Surface Water Characteristics.  The area has a low density of small to medium intermittent
streams and associated rivers, most with a low volume of water flowing at low velocity.
Dendritic drainage pattern has developed without bedrock structural  control.  Major rivers
include the Washita, Canadian, and Red Rivers.
Disturbance Regimes. Fire and drought have probably been the principal historical disturbances.
Land Use. Natural vegetation has been converted to agricultural crops or pasture on about 90%
of the area.
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                   Southwest Plateau and Plains Dry Steppe and Shrub
Texas High Plains (Section 315B)


Geomorphology.  This Section is in the Great Plains geomorphic province.  The predominant
landform consists of a broad, extensive flat plain formed by fluvial sedimentation of continental
erosional products from adjacent mountain ranges, followed by sheet erosion and transport.
These processes resulted in a region of moderate dissection.  Elevation ranges from 2,600 to
6,500 ft (800 to 2,000 m).  Local relief in most of the Section ranges from 100 to 300 ft,
however, relief in the tablelands ranges from 300 to 500 ft.


Lithology and Stratigraphy. Rocks were formed during the Paleozoic (10%), Mesozoic (10%),
and Cenozoic (80%) Eras. Paleozoic strata consist of Permian marine deposits (sandstone, shale,
and limestone). Mesozoic strata consist of Triassic continental deposits (sandstone). Cenozoic
strata consist of Tertiary Period deposits (poorly consolidated silt, sand, and gravel in varying
proportions).


Soil Taxa.  Soils are Ustolls and Ustalfs. Paleustolls, Argiustolls, Paleustalfs, and Haplustalfs are
on uplands.  Calciustolls, Haplustolls, and Paleustolls are on ridges and steeper slopes.
Haplustolls occur on young valley floors.  Pellusterts are in clayey playa-lake basins.
Calciorthids, Paleorthids, and Torriorthents are on steep slopes in breaks.  These soils have a
mesic or thermic temperature regime, a ustic moisture regime, and mixed or carbonatic
mineralogy. Soils are deep, fine to coarse textured, well drained, and have limited soil moisture
for use by vegetation during parts of the growing season.


Potential Natural Vegetation.  Kuchler classified vegetation as grama-buffalo grass and shinnery
(Quercus-Andropogon). The predominant vegetation form is short grass communities  composed
of bunch grasses with a sparse shrub layer. Species include short grasses (blue gramma, and
buffalograss), sagebrush, mesquite, and yucca.


Fauna. Typical large to medium size herbivores and carnivores include pronghorn, coyote, swift
fox, ringtail, and ocelot. Typical smaller herbivores include desert shrew, desert cottontail,
black-tailed prairie dog, yellow-faced pocket gopher, plains pocket mouse, silky pocket mouse,
hispid pocket mouse, and white-throated woodrat.  Bison are historically associated with this
Section.  Birds of grasslands include many species that typically occur over a wide area, such as
roadrunner, house finch, yellow warbler, willow flycatcher, cedar waxwing, western kingbird,
and golden eagle.  The lesser prairie chicken, found here, is restricted to the more arid
grasslands. Amphibians found in this Section include plains spadefoot toad, Couche's spadefoot
toad, western spadefoot toad, plains leopard frog, Great Plains toad, green toad, red spotted toad,

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spotted chorus frog, and yellow-mud turtle. Reptiles include species such as Texas horned
lizard, round-tailed horned lizard, Great Plains skink, Texas blind snake, and plains black-
headed snake.
                              Photo courtesy Texas Parks and Wildlife Dept. O2003


Climate. Precipitation averages 14 to 18 inches (350 to 450 mm), occurring mainly in the spring
and fall.  Temperature averages 55 to 63 F (13 to 17 CT). The growing season lasts 130 to 220
days.


Surface Water Characteristics. There is a low density of small intermittent streams and few
associated rivers, all with low volume of water flowing at low velocity. A shallow dendritic
drainage pattern has developed. Major rivers include the Canadian and Red. The Canadian
River, in north Texas, is deeply incised into the Great Plains plateau and has developed a broad
area (up to 50 miles wide) of complex topography locally known as "The Breaks."  Playa lakes
are common in the western part of this Section.


Disturbance Regimes. Fire and drought have probably been the principal historical disturbances.
Land Use. Natural vegetation has been converted to agricultural crops or pasture on about 90%
of the area.
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Rolling Plains (Section 315C)
                              Photo courtesy Texas Parks and Wildlife Dept. O2003


Geomorphology.  This Section is in the Central Lowlands geomorphic province.  Landforms
originated from platform uplift of continental sediments deposited previously into a shallow
inland sea, followed by a long period of erosion. These processes resulted in a moderately
dissected landscape.  About 80% of this Section is equally divided between irregular plains and
tablelands. Smaller areas of smooth plains and plains with hills are also present. Elevation
ranges from 1,640 to 2,950 ft (500 to 900 m). Local relief in most of the Section ranges from
100 to 300 ft.  Smaller areas are present where local relief ranges  from 300 to 500 ft.
Lithology and Stratigraphy. Rocks were formed during the Paleozoic and Mesozoic Eras.
Geologic strata consist of about equal amounts of Permian marine deposits and Triassic
continental deposits (sandstone). A small area of Permian continental deposits (sandstone, shale,
and limestone) is also present.


Soil Taxa.  Soils are Ustolls, Ustalfs, and Ochrepts. Most soils are on uplands and include
Argiustolls, Paleustolls, and Natrustolls, Haplustalfs, Paleustalfs, and Ustochrepts. Localized
areas of Ustifluvents are on flood plains. These soils have a thermic temperature regime, a ustic
moisture regime, and mixed mineralogy. Most soils are deep, well drained, variable in texture,
and have limited moisture supplies for use by vegetation during part of the growing season.
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Potential Natural Vegetation.  Kuchler classified vegetation as mesquite-buffalo grass.  The
predominant vegetation form is medium-tall grassland with a sparse shrub cover.  The vegetative
community consists of sand and little bluestems and sagebrush.


Fauna. The faunal community consists of species suited to a semi-arid environment. Large to
medium-size mammals include coyote, ringtail, ocelot, and collared peccary. Typical smaller
herbivores include desert cottontail, hispid pocket mouse, Texas kangaroo rat, Texas mouse,
desert shrew, and rock squirrel.  Bison and black-footed ferret are historically associated with
this Section. Domesticated cattle are the most common large herbivore.  Birds of thickets and
grasslands include black-capped vireo, Harris' sparrow, scaled quail, golden-fronted
woodpecker, and pyrrhuloxia. Amphibians include Couche's spadefoot toad, Great Plains
narrow-mouthed frog, green toad, red-spotted toad, and Texas toad.  The spotted chorus frog,
yellow-mud turtle, and Texas map turtle are in wetter areas.  Common reptiles include lesser
earless lizard, crevice spiny lizard, Texas spotted whiptail, Great Plains skink, prairie skink,
four-lined skink, western hook-nosed snake, Harter's water snake, and plains black-headed
snake.
Climate. Precipitation averages 18 to 24 inches (450 to 600 mm). Temperature averages 57 to
64 F (14 to 18 CT). The growing season lasts 185 to 230 days.
Surface Water Characteristics.  There is a low density of small intermittent streams and few
associated rivers, all with low volume of water flowing at low velocity. A dendritic drainage
pattern has developed.  Major rivers include the Colorado and Brazos.


Disturbance Regimes. Fire and drought have probably been the principal historical disturbances.


Land Use.  Natural vegetation has been converted to agricultural crops or pasture on about 90%
of the area.
Edwards Plateau (Section 315D)


Geomorphology.  This Section is in the Great Plains geomorphic province. The predominant
landform consists of a broad, extensive flat plain formed by fluvial sedimentation of continental
erosional products from adjacent mountain ranges, followed by sheet erosion and transport; these
processes resulted in a region of moderate dissection.  About 90% of this Section consists of
landforms equally divided between smooth plains and tablelands having moderate relief.  Also
included are smaller areas of open high hills, high hills, and plains with hills. Elevation ranges
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from 650 to 4,000 ft (200 to 1,200 m). Local relief in most of the Section ranges from 100 to
300 ft (30 to 90 m). In a small area of hills, relief ranges from 300 to 500 ft (90 to 150 m).
                              Photo courtesy Texas Parks and Wildlife Dept. O2003


Lithology and Stratigraphy. Rock units in this Section were formed during the Precambrian
(10%), Paleozoic (30%), and Mesozoic (60%) Eras. Precambrian strata consist of metamorphic
rocks of paragneiss and schist structures and plutonic and intrusive rocks of granitic
composition. Paleozoic strata consist of a mixture of Cambrian (carbonates) and lower
Ordovician marine deposits (carbonates).  Mesozoic strata consist of Cretaceous marine deposits
(limestone and sandstone).
Soil Taxa.  Soils are mostly Ustolls. Calciustolls are on limestone hills and plateaus.
Chromusterts are on outwash plains and broad plateaus. Ustochrepts are on marl and chalk hills.
Haplustolls are on stream deposits of valley floors. These soils have a thermic temperature
regime, a ustic moisture regime, and carbonatic or montmorillonitic mineralogy. Soils are
generally shallow, fine textured, and have limited soil moisture for use by vegetation during
parts of the growing season.


Potential Natural Vegetation. Kuchler classified vegetation as juniper-oak savanna and
mesquite-acacia-savanna.  The predominant vegetation form is mid to short grasslands and
evergreen scale-leaved woodlands with a sparse cover of drought-deciduous shrubs.  A mixture
of species may occur, including blackjack oak, red cedar, mesquite, live oak, and species of mid
and short grass grasslands.


Fauna.  Common large to medium size herbivores and carnivores include coyote, ringtail, coati,
hog-nosed skunk, ocelot, and collared peccary.  Smaller herbivores include Mexican ground
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squirrel, white-ankled mouse, and prairie vole.  Bison are historically associated with this
Section.  Domesticated cattle are the most common large herbivores. Birds of thickets typically
found here include scaled quail, golden-fronted woodpecker, golden-cheeked warbler,
pyrrhuloxia, and long-billed thrasher. Amphibians include Couche's spadefoot toad, Rio Grande
leopard frog, Great Plains narrow-mouthed frog, green toad, Texas toad, spotted chorus frog,
barking frog, cliff chirping frog, and Texas map turtle. A number of salamanders in this Section
have a very restricted range: San Marcas, Texas, Cormal blind, Valdina Farms, and Texas blind.
Typical reptiles include Mediterranean gecko, spot-tailed earless lizard, keeled earless lizard,
Texas spiny lizard, Great Plains skink, and four-lined skink.


Climate.  Annual precipitation ranges from 15 to 30 inches (375 to 750 mm).  Average
temperature is 64 to 68 F (18 to 20 CT).  The growing season lasts 230 to 270 days.


Surface Water Characteristics. A low density of small intermittent and occasional perennial
streams occurs here.  All generally have a low volume of water flowing at low velocity, except
along the plateau escarpment, where flow rates  can be high.  A dendritic drainage pattern has
developed. Major rivers include the Brazos and Colorado.


Disturbance Regimes. Fire and drought have probably been the principal historical disturbances.


Land Use. Natural vegetation has been changed to agricultural crops or pasture on about 90% of
the area.
Rio Grande Plain (Section 315E)


Geomorphology.  This Section is in the Coastal Plains geomorphic province. The predominant
landform in this Section is a flat, weakly dissected alluvial plain formed by deposition of
continental sediments onto submerged, shallow continental shelf, which was later exposed by
sea level subsidence. Elevation ranges from 80 to 1,000 ft (25 to 300 m). Local relief in most of
the Section ranges from  100 to 300 ft (30 to 90 m).


Lithology and Stratigraphy. Rocks formed during the Cenozoic Era.  These strata consist of
Tertiary marine deposits (glauconitic, calcareous, fossiliferous layers with lignitic sandy and
argillaceous deposits).


Soil Taxa.  Soils are Usterts, Torrerts,  and Ustalfs. Pellusterts are on plains over clayey marine
sediments. Paleustalfs are on eolian plains. Torrerts, Haplustolls, Calciustolls, Paleustalfs, and
Haplustalfs are on plains.  Calciustolls and Calciorthids are on plains over marine sediments.

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Soils have a hyperthermic temperature regime, a ustic or aridic moisture regime, and mixed
mineralogy. Soils are mostly deep, fine to coarse textured, well drained, and have limited soil
moisture for use by vegetation during the growing season.


Potential Natural Vegetation. Kuchler classified vegetation as mesquite-acacia-savanna and
ceniza shrub. The predominant vegetation form is short grassland with a sparse cover of drought
deciduous shrubs.  Species include mesquite, cactus, and tall and mid grasses. Live oaks and
cottonwoods may be present along stream banks.
                              Photo courtesy Texas Parks and Wildlife Dept. O2003
Fauna. Typical large to medium size herbivores and carnivores include coyote, ringtail, hog-
nosed skunk, and ocelot.  Smaller herbivores include Mexican ground squirrel, Texas pocket
gopher, and southern plains woodrat. Bats typical of this Section include the ghost-faced and
Sanborn's long-nosed.  Bison, jaguar, and jaguarundi are historically associated with this
Section. This Section and adjacent 315E form the northern range of a number of birds common
to Mexico and South America.  Typical birds include chachalaca, green kingfisher, pauraque, elf
owl, white-winged dove, red-billed pigeon, black-headed oriole, kiskadee flycatcher, yellow-
green vireo, Lichtenstein's oriole, tropical kingbird, beardless flycatcher, buff-bellied
hummingbird, green jay, long-billed thrasher,  and white-collared seedeater.  Amphibians include
Mexican burrowing toad, Rio Grande leopard frog, sheep frog, giant toad, spotted chorus frog,
Mexican tree frog, Rio Grande chirping frog, and Berlandier's tortoise. Reptiles include Texas

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banded gecko, reticulate collared lizard, spot-tailed earless lizard, keeled earless lizard, blue
spring lizard, mesquite lizard, rose-bellied lizard, Laredo striped whiptail, black-striped snake,
indigo snake, speckled racer, and cat-eyed snake.
Climate. Precipitation ranges from 17 to 30 inches (420 to 750 mm), decreasing from east to
west and occurring mostly during May and June. Temperature averages 70 to 72 F (21 to 22 C°).
The growing season lasts 260 to 310 days.


Surface Water Characteristics. A sparse density of small to medium intermittent streams is
present in a dendritic drainage pattern. Major rivers include the Rio Grande and Nueces.


Disturbance Regimes. Drought has probably been the principal historical disturbance.


Land Use.  Natural vegetation has been converted to dry-land pasture for cattle grazing on about
90% of the area.
Southern Gulf Prairies and Marshes (Section 315F)
                              Photo courtesy Texas Parks and Wildlife Dept. O2003
Geomorphology.  This Section is in the Coastal Plains geomorphic province.  The predominant
landform consists of a flat, weakly dissected alluvial plain formed by deposition of continental
sediments onto a submerged, shallow continental shelf, which was later exposed by sea level
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subsidence.  Along the coast, fluvial deposition and shore-zone processes are active in
developing and maintaining beaches, swamps, and mud flats. Elevation ranges from sea level to
160 ft (0 to 50 m). Local relief ranges from 0 to 50 ft (0 to 18 m).


Lithology and Stratigraphy. Rock units formed during the Cenozoic Era.  These strata consist of
Quaternary marine deposits of non-glacial sand, silt, and clay.


Soil Taxa.  Soils are Aquents, Aqualfs, Aquolls, and Aquepts. Psammaquents, Udipsamments,
Fluvaquents, and Salorthids are on barrier islands and long bays. Haplaquolls, Natraqualfs,
Pelluderts, and Pellusterts are on low coastal terraces.  Ochraqualfs, Albaqualfs, and Paleudalfs
are found on plains. Haplaquolls,  Haplaquents, and Fluvaquents are on coastal flats and flood
plains. These  soils have a hyperthermic and thermic temperature regime, an aquic moisture
regime, and montmorillonitic, mixed, or siliceous mineralogy. Soils are fine to coarse textured,
saline, and mostly poorly drained with high water tables.


Potential Natural Vegetation.  Kuchler classified vegetation as bluestem-sacahuista prairie and
southern cordgrass prairie. The predominant vegetation form is tall grassland with little tree
cover.  Grasslands dominate areas inland from the coast and consist of little bluestem,
indiangrass, switchgrass,  and big bluestem.  Occasional areas of live oak are present.  Poorly
drained areas along the coast support freshwater and saltwater marsh vegetation of sedges,
rushes, saltgrass, and cordgrass.


Fauna. The faunal communities typically include coyote, ringtail, hog-nosed skunk, ocelot, and
collared peccary. Smaller mammals include Mexican ground squirrel, Texas pocket mouse,
northern pygmy mouse, and southern Plains woodrat.  Birds of freshwater marshes, lakes, ponds,
and rivers include reddish egret, white-faced ibis, black-billed whistling duck, white-fronted
goose, and olivaceous cormorant.  Reptiles and amphibians include eastern spadefoot toad, Gulf
coast toad, American alligator, diamondback terrapin, spiny-tailed iguana, Texas horned lizard,
Texas spotted  whiptail, and indigo snake.


Climate. Precipitation ranges from 25 to 55 inches (620 to 1,400 mm).  Temperature averages
68 to 70 F (20 to 21 (T).  The growing season lasts 280 to 320 days.


Surface Water Characteristics. A low density of small to medium perennial streams is present in
this Section. The water table is high in many areas, resulting in poor natural drainage and
abundance of wetlands. A poorly  defined drainage pattern has developed on very young alluvial
plains. There is an abundance of palustrine systems with seasonally high water levels. This
Section adjoins the West Indian Marine and Estuarine Provinces.
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Disturbance Regimes.  Ocean tides and grazing have probably been the principal historical
disturbance. Climatic influences include occasional hurricanes.
Land Use. Natural vegetation has been changed for agricultural crops on about 40% of the area.
   Arizona-New Mexico Mountains Semi-Desert - Open Woodland - Coniferous Forest -
                                    Alpine Meadow
Sacramento-Manzano Mountain (Section M313B)
Geomorphology. This Section is in the Basin and Range physiographic province; it is located in
central and south-central New Mexico. Major landforms are mountains, hills, plains, and scarps.
Major landform features are the Sacramento, Manzano and Sandia Mountains and the Canadian
Escarpment. Elevation ranges from 6,000 to 11,000 ft (2,130 to 3,690 m).
                             Photo courtesy Texas Parks and Wildlife Dept. O2003
Lithology and Stratigraphy.  There are Paleozoic sedimentary and Cenozoic aged igneous rocks
and a few metamorphic rocks.
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Soil Taxa.  Soils include Eutroboralfs, Glossoboralfs, Dystrochrepts, Ustochrepts, Argiustolls,
Calciustolls, Haplustolls, and Ustorthents with mesic and frigid temperature regimes and ustic
and udic soil moisture regimes.  A few Cryoboralfs and Cryochrepts occur with cryic soil
temperature regimes and udic soil moisture regimes.


Potential Natural Vegetation. Vegetation consists of ponderosa pine in frigid soil temperature
regimes and ustic and udic soil moisture regimes, Douglas-Fir in frigid-udic regimes, pinyon-
juniper in mesic-ustic regimes, and Engelmann spruce, and subalpine fir in cryic-udic regimes.
A few areas support grey oak at the lowest elevations.


Climate. Precipitation ranges from 12 to 35 inches (305 to 900 mm), with less than half of the
precipitation falling during the winter. Temperature averages 40 to 57 F (4 to 8 CT); winter
temperatures vary throughout this Section.  The growing season lasts less than 70 to 170 days.


Surface Water Characteristics.  This Section supplies much of the water to the Rio Grande and
Pecos Valley basins. Several streams are perennial.


Disturbance Regimes. Natural fire regime averages 3 to 10 years of frequency in ponderosa pine
forests. Much of this area is covered with timber, with some areas of commercial quality.
Another use of land is as range.


Cultural Ecology. The earliest human occupation of the Sacramento-Manzano Mountain Section
was characterized by an emphasis on big game hunting supplemented with gathering wild plant
foods. Evidence for these activities is primarily restricted to the lower elevations and the base of
the mountains.  Around 6000 B.C., a gradual climate change from cooler and wetter to drier
conditions resulted in a change of subsistence patterns. Highly mobile populations hunted and
gathered a variety of resources throughout the region.  The pinon-juniper zone was intensely
exploited for both hunting and gathering.  The mixed conifer forests were utilized to some extent
for hunting and religious purposes, but the climate and scarcity of resources resulted in only
sporadic use.  As agriculture became important during the past 2000 years, most of the
inhabitants became more sedentary and populations increased.  Villages tended  to be located
close to water in the pinon-juniper woodland and lower alluvial fans at the base of the
mountains. Athabascan groups entered the area sometime before the 1600's, utilizing many of
the same resources; by the mid 1700's, Comanches occupied the plains immediately to the  east.
Today, Native Americans continue to use the mountains for gathering and ceremonial purposes.
       The earliest historic settlement began in the late 1500's with the Spaniards.  A few
villages were established in the foothills of the Manzanos, Sandias, and near the headwaters of
the Canadian and Pecos Rivers, but the Apaches kept most European settlers out of the
Sacramentos and mountain ranges to the south. These settlers concentrated on the pinon-juniper
woodlands and grasslands for hunting, fuel wood gathering, post cutting, and small subsistence
farming. Beginning in the late 1800's, discoveries of gold and an increase in European

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settlement throughout the mountains resulted in more intensive use of the higher elevations for
mining, logging, and ranching activities. Most of the homesteads and villages were located in
the larger valleys or on the eastern slopes of the mountains near permanent water sources.  By
the turn of the century,  logging dominated the activities in the mixed conifer zone, with ranching
still playing an important role throughout the mountains.  Currently, the area continues to consist
primarily of small rural communities, with logging, fuel wood gathering, ranching, hunting, and
recreation as the primary subsistence base.  Anglo, Hispanic, and Mescalero Apache cultures  are
present.  Recreational use has increased dramatically over the past few decades, particularly near
the larger cities.
                                Chihuahuan Semi-Desert
Basin and Range (Section 321A)
                              Photo courtesy Texas Parks and Wildlife Dept. O2003
Geomorphology.  This area, which is in the Basin and Range physiographic province, is located
in southeast Arizona and southwest and central New Mexico.  Relatively recent episodes of
continental rifting, volcanism, erosion, and sedimentation have dominated this Section.

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Oligocene faulting created the Rio Grande rift in New Mexico and west Texas and initiated
volcanism. Subsequent Miocene composite volcanoes emitted silicic lava and ash. Along with
Pliocene and Pliestocene mass wasting and cyclic erosion events, and associated with glacial
cycles farther north, this combination of processes gradually filled the basins with deep
sediments from adjacent mountain ranges.  Current erosion cycles dissect these deposits and
continue to modify the rift valley through transport and deposition processes. Various landforms
comprise about equal areas: (1) plains with low mountains consisting of 50 to 80% of gently
sloping area and local relief of 1,000 to 3,000 ft; (2) plains with high hills where relief is 1,000
to 3,000 ft; (3) open high hills with relief of 500 to 1,000 ft; and (4) tablelands with moderate
relief averaging 100 to 300 ft. Elevation ranges from 2,600 to 5,500 ft (800 to 1676 m).


Lithology and Stratigraphy. Geologic strata consist of an undifferentiated mixture of Quaternary
marine deposits, Miocene volcanic rocks, lower Tertiary volcanic rocks, and Lower Cretaceous
marine deposits; Permian marine deposits of Ochoan and Guadalupian series; Paleocene
continental deposits; Upper Cretaceous marine deposits; Precambrian plutonic and intrusive
granitic rocks; Quarternary volcanic rocks;  Permian continental deposits of Wolcampian age,
and Miocene felsic volcanic rocks; upper Paleozoic marine deposits; Precambrian sedimentary
rocks of Pahrump and Unkar groups; Precambrian Mazatal quartzite, Yavapai series, pinal
schist, and metavolcanic formations.


Soil Taxa.  Types are mostly Torriorthents with Calciorthids, Haplargids, and some Alfisols
(10%) and Mollisols (10%) with a thermic temperature regime, an aridic moisture regime, and
mixed or carbonatic mineralogy.


Potential Natural Vegetation. Kuchler mapped vegetation  as trans-Pecos shrub savanna
(Flourensia-Larreci); grama-tobosa desert grasslands; oak-juniper woodland; and mesquite-
tarbush desert scrub.
Climate. Precipitation ranges from 8 to 13 inches (200 to 320 mm): it occurs mostly during July
and August. Temperature ranges from 55 to 70 F (13 to 20 CT) and winters are mild. The
growing season lasts 200 to 240 days.
Surface Water Characteristics.  There is a low density of intermittent streams and very few
associated rivers, most of which originate in distant mountainous areas. Flow rates are low to
moderate, except during periods of heavy rain, when large amounts of surface runoff can occur.
Dendritic drainage pattern has developed on dissected mountain slopes, largely without bedrock
structural control. Playa lakes are common following periods of rains, but are ephemeral in the
hot, dry climate prevalent in this Section.
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Disturbance Regimes. Drought has probably been the principal historical source of disturbance.


Land Use. Land use includes range for cattle grazing on about 90% of the area.


Cultural Ecology.  The Basin and Range Section is a physiographically diverse area
characterized by expansive playas and open grassland basins cut by steep, rugged mountain,
mesa, and canyon terrain. Humans have been utilizing the area for 8,000 to 10,000 years,
although evidence of occupation prior to 7,000 B.C. remains scarce and scattered.  Paleo-Indian
materials are especially prevalent, however, from the foothills of the Tularosa Mountains.  The
area was widely utilized by Cochise and Oshara Tradition Archaic populations between 7,000
B.C. and 200 A.D. Site distribution points to a highly mobile hunting and gathering nomadic
subsistence pattern initially, followed by use of increasingly smaller areas and a  seasonal cycle
of upland and lowland exploitation. Puebloan use and occupation were most prevalent between
200 and 1150 A.D. in the south and 200 and 1400 A.D. in the north.  Southern basin, range, and
mountain areas supported the Mogollon culture, while more northern mountain areas also
included the southern fringe of the Anasazi tradition.  Puebloan settlement reflected gradual
movement toward major drainages and waterways over time.  Basin and range deserts were
widely used for wild plant procurement, agriculture,  and settlement.
       References to the Apache appear in 16th century Spanish documents and later historic
accounts.  Spanish expeditions passed through the area, but major settlements were restricted to
the Rio Grande and the area east of the Mogollon and Tularosa Mountains.  Livestock ranching
and mining gained prominence in the 1800's.  Gold, silver, copper, and turquoise were mined in
the Mogollon, Burro, and Black Range Mountains of New Mexico.  Introduction of the railroad
in the 1800's witnessed an influx of European settlement along the Rio Grande, the southern
Burro Mountains (Deming, Lordsburg, and Silver City, New Mexico) and more  northern reaches
of the Mogollon Mountains. In more northern, remote mountain areas, small ranching, mining,
and timber-related settlements were established along major rivers and ephemeral drainages.
Ranching and tourism flourish in the area today, and both Anglo and Hispanic cultures influence
contemporary life.
Stockton Plateau (Section 321B)
Geomorphology. This Section is in the Great Plains geomorphic province. The predominant
landform consists of open high hills with smaller areas of tablelands. These landform were
formed by fluvial sedimentation of continental erosional products from adjacent mountain
ranges, which was followed by sheet erosion and transport. These processes resulted in a region
of shallow dissection.  Elevation ranges from 2,600 to 4,500 ft (800 to 1,300 m).  Local relief in
most of the Section ranges from 500 to 1,000 ft. Relief in a small area of tablelands ranges from
300 to 500 ft.
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                               -:-^rr;?swsiiiBS^jgjrTt ,.„n,
                  ^t.ta:.%:^:~ ~'^i33ss:---.aap«p»»     --'•*;!-»'-.»; I   >*•••-
                               Photo courtesy Texas Parks and Wildlife Dept. O2003


Lithology and Stratigraphy.  Rocks were formed during Paleozoic (35%), Mesozoic (40%), and
Cenozoic (25%) Eras.  Paleozoic strata consist of Pennsylvanian marine deposits.  Mesozoic
strata consist of nondifferentiated mixture of Lower and Upper Cretaceous marine deposits
(limestone, and sandstone).  Cenozoic strata consist of lower Tertiary volcanic rocks of high
alkalic content.
Soil Taxa.  Soils are Argids and Orthids.  Haplargids, Paleargids, and Calciorthids are on
uplands, piedmont plains, and dissected terraces. Calciorthids, Ustolls, and Torriorthents are on
uplands with shallow depths to bedrock.  Paleorthids are on mesas and terraces.  Gypsiorthids
are in closed basins. Natragids and Torrerts are on basin floors. Torrifluvents are on flood
plains and Torripsamments are on sandy uplands. These soils have a thermic temperature
regime, aridic moisture regime, and mixed or carbonatic mineralogy. Soils are well drained,
shallow to deep, and medium textured. Soil moisture is limited for use by vegetation during
most of the growing season.


Potential Natural Vegetation. Kuchler classified vegetation as trans-Pecos shrub savanna
(Flourensia-Larrea); with juniper and red cedar woodlands.  The predominant vegetation form is
short to mid height grasslands with sparse cover of drought-deciduous and scale-leaved shrubs
and small trees.  Species include desert shrubs in association with short to mid height grasses and
oak savannas.
Fauna. Typical large to medium size herbivores and carnivores include pronghorn, coyote, swift
fox, ringtail, hooded skunk, ocelot, and collared peccary.  Smaller herbivores include desert
shrew, desert cottontail, Mexican ground squirrel, yellow-faced pocket gopher, Nelson's pocket
mouse, and Merriam's kangaroo rat. Several bats, western mastiff and yuma myotis, are present
here.  Birds of grasslands include bronzed cowbird, Baird's sparrow, and white-necked raven.

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Birds of thickets include black-capped vireo, scaled quail, Harris' hawk, Inca dove, cave
swallow, golden-fronted woodpecker, and pyrrhuloxia.  Amphibians include Couche's spadefoot
toad, western spadefoot toad, Rio Grande leopard frog, Great Plains toad, red-spotted toad,
spotted chirping frog, and Mexican mud turtle. Reptiles include Texas banded gecko, Big Bend
gecko, desert spring lizard, canyon lizard, crevice spiny lizard, gray checkered whiptail, little
striped whiptail, plateau  spotted whiptail, checkered whiptail, Texas-Pecos rat snake,  gray-
banded kingsnake, Big Bend patch-nosed snake, Mexican black-nosed snake, Big Bend black-
headed snake, rock rattlesnake, and black-tailed rattlesnake.
Climate. Precipitation ranges from 8 to 13 inches (200 to 320 mm). Temperature ranges from
55 to 64 F (13 to 18 (T). The growing season lasts 200 to 240 days.


Surface Water Characteristics.  This section has a low density of intermittent streams that
originate in nearby mountainous areas and flow mainly following rains.  Major river systems
include the Rio Grande and Big Canyon. Flow rates are low except during periods of heavy rain,
when large amounts of surface runoff can occur. Dendritic drainage pattern has developed.
Playa-type lakes are present following rains but quickly dry up, leaving high salt concentrations.


Disturbance Regimes. This section is part of the Chihuahuan Desert and drought has been the
principal disturbance.


Land Use. Cattle grazing occurs on about 90% of the area.
                            Great Plains-Palouse Dry Steppe
Southern High Plains (Section 331B)


Geomorphology. This Section is in the Great Plains geomorphic province.  The predominant
landform is a broad, extensive flat plain formed by fluvial sedimentation of continental erosional
products from adjacent mountain ranges, followed by sheet erosion and transport.  These
processes resulted in a region of moderate dissection. Landforms consist mostly of smooth
plains with smaller areas of tablelands. Elevation ranges from 2,600 to 4,000 ft (800 to 1,200
m). Local relief ranges mainly from 100 to 300 ft (90 m).  A small area of tablelands is present
where relief ranges from 300 to 500 ft (90 to 150 m).
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Lithology and Stratigraphy. Rocks were formed during the Paleozoic (20%), Mesozoic (20%),
and Cenozoic (60%) Eras. Paleozoic strata consist of Permian marine deposits (shale and
limestone). Mesozoic strata consists of Upper Cretaceous marine deposits (limestone and
sandstone). Cenozoic strata consists of Quaternary continental deposits (poorly consolidated silt,
sand, and gravel in varying proportions) and other localized marine deposits.


Soil  Taxa.  Soils are Ustolls and Ustalfs. Paleustolls, Argiustolls, Paleustalfs, and Haplustalfs
are on uplands. Calciustolls, Haplustolls, and Paleustolls are on ridges and steeper slopes.
Haplustolls occur on young valley floors.  Pellusterts are in clayey playa lake basins.
Calciorthids,  Paleorthids, and Torriorthents are steep slopes in breaks. These soils have a mesic
or thermic temperature regime, an ustic moisture regime, and mixed or carbonatic mineralogy.
Soils are deep, fine to coarse textured, well drained, and have limited soil moisture for use by
vegetation during parts of the growing season.


Potential Natural Vegetation.  Kuchler classified vegetation as sandsage-bluestem prairie and
bluestem-grama prairie. The predominant vegetation form is short to mid-height grasslands.
Species composition includes bluegrama, buffalograss, hairy grama, and little bluestem.


Fauna. Large to medium size herbivores and carnivores typical of this Section include
pronghorn, coyote, and ringtail. Smaller herbivores include desert shrew, black-tailed prairie
dog, Plains pocket mouse, silky pocket mouse, and hispid pocket mouse.  Bison and black-footed
ferret are historically associated with this Section. Birds of grasslands include lesser prairie
chicken, Swainson's hawk, and burrowing  owl. Typical reptiles and amphibians include Great
Plains toad, red spotted toad, lesser earless lizard, round-tailed horned lizard, Great Plains skink,
and Plains black-headed snake.
Climate. Annual precipitation averages 16 to 20 inches (400 to 520 mm).  Between 16 to 35 in
(400 to 900 mm) of snow occurs.  Temperature ranges from 50 to 57 F (10 to 14 C°).  The
growing season lasts 140 to 185 days.


Surface Water Characteristics. There is a low density of small intermittent streams with low
volume of water flowing at low velocity.  A dendritic drainage pattern has developed  on a
weakly dissected plateau, largely without bedrock structural control. Major rivers include the
Cimarron and North Canadian.
Land Use. Natural vegetation has been converted to agricultural crops and range for cattle
grazing on about 90% of the area.
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      APPENDIX B
Individual Sub-Layer Maps
           173

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                                    Table of Contents


Chapter	Page
Diversity layer	 176
Rarity layer	 177
Sustainabilitv layer	179
                                     List of Figures

 Figure	Page

Figure Bl.  Map of diversity sub-layer: appropriateness of land cover. This map
              is used to produce the map of the diversity layer (Figure 5)	 181


Figure B2.  Map of diversity sub-layer: contiguous size of undeveloped land.
              This map is used to produce the map of the diversity layer (Figure 5)	 182


Figure B3.  Map of diversity sub-layer: Shannon land cover diversity index.
              This map is used to produce the map of the diversity layer (Figure 5)	 183


Figure B4.  Map of diversity sub-layer: ecologically significant stream segments.
              This map is used to produce the map of the diversity layer (Figure 5)	 184


Figure B5.  Map of rarity sub-layer: vegetation rarity. This map is
              used to produce the map of the rarity layer (Figure 6)	 185


Figure B6.  Map of rarity sub-layer: natural heritage rank. This map
              is used to produce the map of the rarity layer (Figure 6)	 186


Figure B7.  Map of rarity sub-layer: taxonomic richness.  This map
              is used to produce the map of the rarity layer (Figure 6)	 187


Figure B8.  Map of rarity sub-layer: rare species richness. This map is
              used to produce the map of the rarity layer (Figure 6)	 188
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Figure B9. Map of sustainability sub-layer: contiguous land cover type. This
              map is used to produce the map of the sustainability layer (Figure 6)	189


Figure BIO. Map of sustainability sub-layer: regularity of ecosystem boundary. This
              map is used to produce the map of the sustainability layer (Figure 7)	190


Figure Bll. Map of sustainability sub-layer: appropriateness of land cover.  This
              map is used to produce the map of the sustainability layer (Figure 7)	191


FigureB 12. Map of sustainability sub-layer: waterway obstruction. This map
              is used to produce the map of the sustainability layer (Figure 7)	192


FigureB 13. Map of sustainability sub-layer: road density.  This map is
              used to produce the map of the sustainability layer (Figure 7)	193


FigureB 14. Map of sustainability sub-layer: airport noise. This map is
              used to produce the map of the sustainability layer (Figure 7)	194


FigureB 15. Map of sustainability sub-layer: Superfund National  Priority
              List and state Superfund Sites.  This map is used to produce the map
              of the sustainability layer (Figure 7)	 195


FigureB 16. Map of sustainability sub-layer: water quality. This  map is
              used to produce the map of the sustainability layer (Figure 7)	196


Figure B17.  Map of sustainability sub-layer:  air quality. This map is
              used to produce the map of the sustainability layer (Figure 7)	197


FigureB 18. Map of sustainability sub-layer: RCRA TSD, corrective action and
              state VCP  sites. This map is used to produce the map of the
              sustainability layer (Figure 7)	 198


FigureB 19. Map of sustainability sub-layer: urban/agriculture disturbance.  This
              map is used to produce the map of the sustainability layer (Figure 7)	199
                                           175

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       The figures displayed in this appendix represent the individual sub-layers that constitute




the main layers and ultimately the composite. The data for each sub-layer was calculated at the




ecoregion level. However, for GIS technical reasons and presentation purposes, the legends of




Appendix B figures reflect statewide ranking (i.e., the red shaded areas indicate the particular




range of values statewide). This is different from the report text where sub-layers were




combined and the results presented by ecoregion (i.e., the red areas indicate the 1%, 10%, etc. in




that particular ecoregion).  The data is the same (i.e., all calculated by ecoregion), only the




presentation legend and scaling is different.  On some figures, there were enough cells with a




score of 100 that there was no way to separate the top 1% and top 10% (the top 1% of cells




scored 100 and the top  10% of cells also scored 100), for example,  road density (Figure B13).
Diversity layer





       The statewide trend shows a higher level of appropriate vegetation in Rio Grande Plain,




Stockton Plateau, Chihuahuan Desert Basin and Range, the southern part of Rolling Plains




ecoregion.  The Mid Coastal Plains Western Section, Oak Woods and Prairies, and Coastal




Prairies and Marshes ecoregions show more disturbance in terms of what type of vegetation




cover would exist without human influence (Figure Bl).  The amount of potential natural




vegetation is also related to the amount of human disturbance, i.e. issues concerning




sustainability of the area (see Sustainability section below).





       There are many areas of larger tracts of undeveloped land including Chihuahuan Desert




Basin and Range and Stockton Plateau ecoregions, portions of the Rolling Plains ecoregion, Rio




Grande Plain ecoregion, northern Texas High Plains ecoregion (around the Canadian River),





                                           176

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southern portion of the Edwards Plateau, Mid Coastal Plains Western Section, and Coastal




Plains and Flatwoods Western Gulf Section (Figure B2).





       The Shannon land diversity index map shows higher levels in the Blackland Prairie, Oak




Woods and Prairies, Mid Coastal Plains Western Section, and Coastal Plains and Flatwoods




Western Gulf Section ecoregions which might seem contradictory to the previous measure of




contiguous land cover.  Figure B3 shows that there are more, different types of undeveloped land




cover in the eastern part of the state, covering several ecoregions and not as many undeveloped




land cover types (nor as well dispersed), in the northern and western portions of the state. For




various  ecological reasons, the central and eastern portions of the state maintain this vegetative




stratification. The amount of water adds another dimension of diversity, in that wetland areas




are present. Fewer wetland areas or vegetative stratification exists in the western and northern




parts of Texas.





       Ecologically significant stream segments (Figure B4) are ecologically unique areas




determined by TPWD based on biological function, hydrologic function, riparian conservation




areas, high water quality (including aquatic life and aesthetic value), and threatened or




endangered species.  Significant stream segments are fairly well distributed throughout the




central and eastern portions of the state.
Rarity layer





       Oak Woods and Prairies, and Central Gulf Prairies and Marshes ecoregions show the




highest levels of vegetation rarity.  The pattern of these rare areas is indicative of riparian areas




(Figure B5). This is particularly evident in the Mid Coastal Plains Western Section, and the




                                            177

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northern portion of the Oak Woods and Prairies ecoregion. In addition, the Central Gulf Prairies




and Marshes ecoregion shows a high density of rare vegetation types.





       The Rolling Plains, Cross Timbers and Prairie and Texas High Plains ecoregions have




species with lower natural heritage ranks (Figure B6). Most of the areas that have high natural




heritage ranks are located Chihuahuan Desert Basin and Range ecoregion, Edwards Plateau,




southern Rio Grande Plain, Central Gulf Prairies and Marshes, and Southern Gulf Prairies and




Marshes, ecoregions (Figure B6). The Rio Grande Plain along the border with Mexico




constitutes the northernmost range of several subtropical species that exist principally in Mexico




and Central America. The Big Bend area in the Chihuahuan Desert Basin and Range (due to




diverse topography) and Edwards Plateau (due to karst features) are known as centers of high




endemism.





       There are several areas in Texas that show moderate and moderately high taxonomic




richness, but only very few areas show the highest numbers of rare taxa (Figure B7).  In




particular, the Edwards Plateau is an area of high endemism due to the karst geologic features.





       There are only very few areas that show the greatest number of rare species (or richness),




including the  Big Bend area of the Chihuahuan Desert Basin and Range ecoregion in west Texas,




Sacramento-Manzano Mountains ecoregion (primarily the Guadalupe Mountains), Coastal Plains




and Flatwoods Western Gulf Section, parts of the Edwards Aquifer and Rio Grande Plain scored




in the highest percentage (i.e., most rare number of species) (Figure B8).
                                          178

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Sustainability layer





       Calculation of contiguous land cover types shows that there are larger portions of these




ecoregions with contiguous land cover types in the Rio Grande Plain, Chihuahuan Desert Basin




and Range, Stockton Plateau, Edwards Plateau, northern portions of the Texas High Plains, and




portions of the Rolling Plains (Figure B9). This may be due to larger unbroken tracts of a single




land cover type (i.e., shrubland or desert community types) compared to other areas of the state.




In the eastern half of the state, Blackland Prairie, Oak Woods and Prairie, and Mid Coastal Plain




Western Section, there may be more different types of undeveloped land cover, but none are




very large. These areas lack the  connectivity of the west.





       Figure BIO shows the locations where the perimeter-to-area ratio is small, and therefore




ecological communities more sustainable.  Land cover types with smaller PAR are scattered




through the Rolling Plains, Cross Timbers and Prairie, Blackland Prairie, Oak Woods and




Prairie, Mid Coastal Plain Western Section, Gulf Coast Prairies and Marshes, and Coastal Plains




and Flatwoods Western Gulf Section. These areas are the top 1% with the smallest PAR and




thus, more sustainable areas in Texas.





       Areas that most closely match pre-settlement vegetation (Figure BID and have been less




disturbed by human activities are the Rio Grande Plain ecoregion, the Stockton Plateau, portions




of the Edwards Plateau and Chihuahuan Desert Basin and Range ecoregions. The eastern




portion of the state has been impacted more by human activity and the land cover types present




do not reflect pre-settlement conditions (Kuchler 1964).





       Portions of the Chihuahuan Desert Basin and Range, Stockton Plateau, Rio Grande Plain,




Texas High Plains, and Coastal Plain and Flatwoods Western Gulf Section have the fewest





                                          179

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number of dams per HUC and therefore are more sustainable (FigureB 12). Cross Timbers and




Prairies, Blackland Prairies, and Oak Woods and Prairies have areas in the top 25% most




sustainable areas in terms of waterway obstructions.





       Road density (Figure B13) reflects populated areas and the means to connect them




throughout Texas.  For example, IH35 connects Austin, San Antonio, and Dallas-Ft. Worth.




Consequently, this transportation corridor is well-developed with side roads and urban activities.





       FigureB 14 shows the buffered locations of airports in Texas.  Large population centers,




such as Dallas-Ft Worth and Houston, where there may be multiple airports are evident.





       Several Superfund NPL sites are located near high population areas, including Houston,




San Antonio, and Dallas-Ft.Worth (FigureB 15).





        The bulk of impacted stream segments not meeting their designated use (CWA Section




303(d)) are in the eastern half of the state where the majority of the water in Texas occurs




(FigureB 16).





       Areas of poor air quality are located near the major cities in Texas: Houston, San




Antonio, Dallas, El Paso, and Midland-Odessa (Figure B17).





       Most of the RCRA sites are located near the major population centers in Texas: Houston,




Dallas-Ft Worth, Austin , and San Antonio (FigureB 18).





       The population centers and much of the agricultural activities are in the Blackland




Prairies, Texas High Plains, and Oak Woods and Prairies ecoregions.  Additional urban and




agricultural activities are scattered throughout the Rolling Plains, Mid Coastal Plains Western




Section, and portions of the South, Central, and Eastern Gulf Prairies and Marshes ecoregion




(FigureB 19).






                                           180

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       1 - 25.9  (Less Appropriate Vegetation)

       26-61.5

       61.6-87.5

       87.6 - 99.9

       100     (More Appropriate Vegetation)
Figure Bl. Map of diversity sub-layer: appropriateness of land cover.  This map is used to
produce the map of the diversity layer (Figure 5). Even though this map shows the entire state of
Texas, the measures included in the diversity layer were calculated for each ecoregion.
                                            181

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        0       (Smaller Area)

        1

        2-59

        60-99

        100     (Larger Area)
200
Figure B2.  Map of diversity sub-layer: contiguous size of undeveloped land.  This map is used
to produce the map of the diversity layer (Figure 5). Even though this map shows the entire state
of Texas, the measures included in the diversity layer were calculated for each ecoregion.
                                           182

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                                  -,••

      0 - 35.9    (Less Diverse)

      36-51.1

      51.2-62.3

      62.4-77.5

      77.6-100  (More Diverse)
200
Figure B3. Map of diversity sub-layer: Shannon land cover diversity index.  This map is used to
produce the map of the diversity layer (Figure 5). Even though this map shows the entire state of
Texas, the measures included in the diversity layer were calculated for each ecoregion.
                                           183

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          0   (Absence of Streams)

          100 (Presence of Streams)
                                                                                   150    200
Figure B4. Map of diversity sub-layer: ecologically significant stream segments.  This map is
used to produce the map of the diversity layer (Figure 5).  Even though this map shows the entire
state of Texas, the measures included in the diversity layer were calculated for each ecoregion.
                                            184

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                             ,,;#;^>,
                             >^^%-:
            0 -1     (Less Rare)

            2-6

            7-16

            17-60

            61 - 250  (More Rare)
200
Figure B5.  Map of rarity sub-layer: vegetation rarity. This map is used to produce the map of
the rarity layer (Figure 6). Even though this map shows the entire state of Texas, the measures
included in the rarity layer were calculated for each ecoregion.
                                          185

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                                                                                      150    200
Figure B6. Map of rarity sub-layer: natural heritage rank. This map is used to produce the map
of the rarity layer (Figure 6). Even though this map shows the entire state of Texas, the
measures included in the rarity layer were calculated for each ecoregion.
                                           186

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0        (Fewer Rare Taxa)

1 -28

29-110

111 - 250  (More Rare Taxa)
                                                                                             200
Figure B7. Map of rarity sub-layer: taxonomic richness.  This map is used to produce the map of
the rarity layer (Figure 6). Even though this map shows the entire state of Texas, the measures
included in the rarity layer were calculated for each ecoregion.
                                           187

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           0      (Fewer Rare Species)

           1 -17

           18-86

           87 - 250  (More Rare Species)
Figure B8. Map of rarity sub-layer: rare species richness. This map is used to produce the map
of the rarity layer (Figure 6). Even though this map shows the entire state of Texas, the
measures included in the rarity layer were calculated for each ecoregion.
                                           188

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              0 - 29   (Less Area)

              30-91

              92-99

              100     (More Area)
Figure B9. Map of sustainability sub-layer: contiguous land cover type.  This map is used to
produce the map of the sustainability layer (Figure 7). Even though this map shows the entire
state of Texas, the measures included in the sustainability layer were calculated for each
ecoregion.
                                           189

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                                     '  -:-• •  i :''^^;
             0 -1      (Less Regular)

             2-3

             4-15

             16-46

             47-100   (More Regular)
200
Figure BIO. Map of sustainability sub-layer: regularity of ecosystem boundary. This map is
used to produce the map of the sustainability layer (Figure 7).  Even though this map shows the
entire state of Texas, the measures included in the sustainability layer were calculated for each
ecoregion.
                                           190

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           1-25.9   (Less Appropriate)

           26-61.5

           61.6-87.5

           87.6-99.9

           100       (More Appropriate)
0 25 50
r
100
J
150 20
Miles
Figure B11. Map of sustainability sub-layer: appropriateness of land cover.  This map is used to
produce the map of the sustainability layer (Figure 7). Even though this map shows the entire
state of Texas, the measures included in the sustainability layer were calculated for each
ecoregion.
                                            191

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          0 - 35.5   (More Obstruction)

          35.6-56.1

          56.2 - 99.9

          100       (Less Obstruction)
200
Figure B12. Map of sustainability sub-layer: waterway obstruction.  This map is used to produce
the map of the sustainability layer (Figure 7). Even though this map shows the entire state of
Texas, the measures included in the sustainability layer were calculated for each ecoregion.
                                            192

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                             Hli    1

                      B^^iFft;^^                   •-  /   /~  v
                                                                       /
                               \                          /    /  (
            0 - 28.9  (More Roads)

            29 - 42.3

            42.4 - 99.9

            100     (Fewer Roads)
200
Figure B13. Map of sustainability sub-layer: road density. This map is used to produce the map
of the sustainability layer (Figure 7). Even though this map shows the entire state of Texas, the
measures included in the sustainability layer were calculated for each ecoregion.
                                       193

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              0   (More Airport Noise)

              100 (Less Airport Noise)
                                                                                              200
Figure B14. Map of sustainability sub-layer: airport noise.  This map is used to produce the map
of the sustainability layer (Figure 7).  Even though this map shows the entire state of Texas, the
measures included in the sustainability layer were calculated for each ecoregion.
                                             194

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             0    (Presence of Sites)

             100  (Absence of Sites)
                                                                                             200
Figure B15. Map of sustainability sub-layer: Superfund NPL and state Superfund sites. This
map is used to produce the map of the sustainability layer (Figure 7). Even though this map
shows the entire state of Texas, the measures included in the sustainability layer were calculated
for each ecoregion.
                                            195

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              0    (Lower Water Quality)

              100  (Higher Water Quality)
                                                                                              200
Figure B16. Map of sustainability sub-layer: water quality.  This map is used to produce the
map of the sustainability layer (Figure 7).  Even though this map shows the entire state of Texas,
the measures included in the sustainability layer were calculated for each ecoregion.
                                            196

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           0   (Lower Air Quality)

           33

           50

           67

           100 (Higher Air Quality)
150    200
Figure B17. Map of sustainability sub-layer: air quality. This map is used to produce the map of
the sustainability layer (Figure 7). Even though this map shows the entire state of Texas, the
measures included in the sustainability layer were calculated for each ecoregion.
                                             197

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              0    (Presence of Sites)

              100  (Absence of Sites)
                                                                                            200
Figure B18. Map of sustainability sub-layer: RCRA TSD. corrective action and state VCP sites.
This map is used to produce the map of the sustainability layer (Figure 7). Even though this map
shows the entire state of Texas, the measures included in the sustainability layer were calculated
for each ecoregion.
                                           198

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                0   (More Disturbance)

                100 (Less Disturbance)
r

0 25 50

r
\
J
100


150 200
                                                                                 Miles
Figure B19. Map of sustainability sub-layer: urban/agriculture disturbance. This map is used to
produce the map of the sustainability layer (Figure 7).  Even though this map shows the entire
state of Texas, the measures included in the sustainability layer were calculated for each
ecoregion.
                                            199

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 APPENDIX C
List of Acronyms
      200

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                           List of Acronyms
ATtlLA





BCD, TXBCD





C





C°





Ca





CD





CERCLIS
CO2





CrEAM





Cu





CWA





DEM





DO





EO





EPA





ESRI





F
Analytical Tools Interface for Landscape Assessments





TPWD Biological Conservation Database





Carbon





Celsius





Calcium





Compact Disc





Comprehensive Environmental Response, Compensation, and




Liability Information System





Carbon Dioxide





Critical Ecosystems Assessment Model





Copper





Clean Water Act





Digital Elevation Model





Dissolved oxygen





Executive Order





U.S. Environmental Protection Agency





Environmental Systems Research Institute





Farenheit
                                     201

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FAA





Fed





FHWA





ft





FWS





GIS





GLO





G, GRANK





ha





Hg





HUC





ffl





K





km2, km





m2, m





mm





MRLC





N





NEPA





NGO
Federal Aviation Administration





Federal





Federal Highway Administration





Feet





U.S. Fish and Wildlife Service





Geographical Information System





General Land Office





Global natural heritage rank, TEAP variable





Hectare





Mercury





Hydrologic Unit Code





Interstate Highway





Potassium





Square kilometer, kilometer





Square meter, meter





Millimeter





Multi-resolution Land Characterization





Nitrogen





National Environmental Policy Act





Non-governmental Organization
                                     202

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NHD





NLCD





NOAA





NPDES





NPL





NRCS





O





OAQPS





P





PAH





PAR





PNV





RCRA





RCRIS




SAB




Se




Si




SLOSS




S, SRANK




STORE!




T&E
National Hydrography Dataset





National Land Cover Dataset





National Oceanic and Atmospheric Administration





National Pollutant Discharge Elimination System





National Priority List (Superfund)





Natural Resources Conservation Service





Oxygen





Office of Air Quality Panning and Standards





Phosphorus





Polycyclic Aromatic Hydrocarbon





Perimeter-to-Area Ratio





Potential Natural Vegetation






Resource Conservation and Recovery Act




Resource Conservation and Recovery Information System




EPA Science Advisory Board




Selenium




Silicon




Single Large or Several Small




State natural heritage rank, TEAP variable




EPA Storage and Retrieval System




Threatened and Endangered species
                                     203

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TCEQ




TEAP




TERS




THC
Texas Commission on Environmental Quality




Texas Ecological Assessment Protocol




Texas Environmental Resource Stewards




Texas Historical Commission
The Conservancy, TNC   The Nature Conservancy of Texas
TIGER









TMDL




TPWD




TRI




TSMS




TSD




TxCDC




TXDOT




TWDB




USACE




USDA




USDI




USFS




USGS




VCP




Zn
Topological Integrated Geographic Encoding and Referencing




System




Total Maximum Daily Load




Texas Parks and Wildlife Department




Toxic Release Inventory




Texas State Mapping System




Treatment-Storage-Disposal sites




Texas Conservation Data Center




Texas Department of Transportation




Texas Water Development Board




U.S. Army Corps of Engineers




U.S. Department of Agriculture




U.S. Department of the Interior




U.S. Forest Service




U.S. Geological Survey




Voluntary Cleanup Program




Zinc
                                    204

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   APPENDIX D
List of Contributors
        205

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Sharon Osowski, Ph. D.
US EPA Region 6
Ecologist
Preparation of TEAP report, analysis
TEAP report point of contact
Steering Committee Member

Jeff Danielson
US EPA
Lockheed Martin
GIS Specialist
Analysis of sustainability layer and
composite data

Steve Schwelling
TPWD
GIS Analyst
Report Reviewer
Analysis of rarity layer data

Duane German
TPWD
Biologist
Analysis of diversity layer data

Jim Bergan, Ph. D.
TNC
Science Director
TEAP Report Reviewer
Steering Committee Member

Malcolm Swan
TNC
GIS Specialist
Analysis of data for Accuracy
Assessment
Dominique Lueckenhoff
US EPA
Transportation Liasion
Steering Committee Member
Luis Fernandez, Ph.D.
US EPA
Environmental Scientist
TEAP Report Reviewer

David Parrish
US EPA Region 6
GIS Coordinator
Analysis of GIS data

A. Kim Ludeke, Ph. D.
TPWD
GIS Coordinator
TEAP Report Reviewer
Steering Committee Member

Russ Baier
TCEQ
Senior Policy Analyst
TEAP Report Reviewer
Steering Committee Member

Vicki Dixon
USAGE, Southwestern Division
Regulatory Program Manager
TEAP Report Reviewer
Steering Committee Member

John Machol
US ACE, Galveston District
TEAP Report Reviewer
Steering Committee Member

Ann Irwin
TXDOT
Director, Environmental Affairs Div.
TEAP Report Reviewer
Steering Committee Member

Sandra E. Allen
FHWA
IH69/TTC Environmental Coordinator
Steering Committee Member
                                    206

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Jimmy Tyree
TxDOT
Environmental Planner
Steering Committee Member

David Certain, Ph.D.
TNC
Data accuracy assessment
TEAP Report Reviewer

Jack Bauer
TPWD
Director, Land Conservation
Steering Committee Member

Carlos Mendoza
FWS
Field Supervisor
Steering Committee Member

Norm Sears
US EPA
Life Scientist
TEAP Report Reviewer

Fred T. Werner
FWS
Biologist
Steering Committee Member
                                    207

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