EPA 600/3-81-028 April 1981 PRODUCTION AND RELEASE OF PLANT MATERIAL IN BRACKISH AND FRESHWATER WETLANDS by Paul L. Wolf and Donald Kinsey The University of Georgia Marine Institute Sapelo Island, Georgia 31327 R80583310 Project Officer Harold V. Kibby Corvallis Environmental Research Laboratory Environmental Protection Agency . Corvallis, Oregon 97330 CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY OFFICE OF RESEARCH AND DEVELOPMENT U.S. ENVIRONMENTAL PROTECTION AGENCY CORVALLIS, OREGON 97330 ------- TECHNICAL REPORT DATA (Please read Instructions on the reverse before completing) 1. REPORT NO. EPA-60Q/3-81-Q28 2. 3. ORD Report. 4. TITLE AND SUBTITLE Production and Release of Plant Material in Brackish and Freshwater Wetlands 5. REPORT DATE April 1981 6. PERFORMING ORGANIZATION CODE 7. AUTHOR(S) Paul L. Wolf and Donald Kinsey 8. PERFORMING ORGANIZATION REPORT NO. 9. PERFORMING ORGANIZATION NAME AND AOORESS The University of Georgia Marine Institute Sapelo Island, Georgia 31327 10. PROGRAM ELEMENT NO. 11. CONTRACT/GRANT NO. R80583310 12. SPONSORING AGENCY NAME AND AOORESS Environmental Research Laboratory Office of Research and Development U.S. Environmental Protection Agency Cnrvallis. Orpnnn Q733D 13. TYPE OF REPORT AND PERIOD COVERED final 4-78 to 4-79 14. SPONSORING AGENCY COOE EPA/600/02 1S. SUPPLEMENTARY NOTES 16. ABSTRACT Production, decomposition, and transport of detritus were investigated in the fresh- water and brackish water wetlands of the Altamaha River Delta, Georgia from April 17 1978. to 13 April 1979. Maximum live standing crop biomass of Spartina cynosuroides, a brackish water marsh plant, was observed in July(769 i 118 g dry wt m2). Live material was absent in January. Standing dead material ranged from a high of 1800 + 275 g dry wt m2 in November to a low of 158 +_ 57 in March. The quantity of fallen d"ead (litter) material was more constant throughout the year averaging 244 +_ 21 q do wt m2. Net aerial primary productivity (NAPP) of S_. cynosuroides was 2029 g m2 yH with no differences in productivities of plots relative to the distance from the riverbank because of minimal tidal activity in the entire area. Maximum live standing crop biomass of Zizaniopsis miliacea, a freshwater marsh plant, was obsterved in October (673 +_ 122 g dry wt m2). Live material dropped to a low of 81 +_ 12 g dry wt m2 in March. Standing dead material ranged from a high of 870 +_ 222 g dry wt m2 in April 1978 to a low of 308 +_ 101 in August. Aquatic respiration rates of standing anc fallen dead material showed a pattern of swamp litter > Z_. miliacea > S_. cynosuroides Rates for marsh grasses were generally higher in the spring dropping to a low in fall and winter. Rates in swamp litter were much more variable without distinct seasonal patterns. . . 17. KEY WORDS AND DOCUMENT ANALYSIS DESCRIPTORS b.lDENTIFIGRS/OPEN ENDED TERMS 'OUp iillation Resource r?. '\5r;,.--t Sire p -< ,v%;« "A r.i..._-....:.2, ii H Pi 1910? 18. DISTRIBUTION STATEMENT Release to public 19. SECURITY CLASS (ThisReport) unclassified 21. NO. OF PAGES 20. SECURITY CLASS (Thispage) unclassified 22. PRICE EPA Form 2220-1 (9-73) ------- DISCLAIMER This report has been reviewed by the Corvallis Environmental Research Laboratory, U. S. Environmental Protection Agency, and approved for publica- tion. Approval does not signify that the contents necessarily reflect the views and policies of the U. S. Environmental Protection Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. ii ------- EXECUTIVE SUMMARY Production, decomposition, and transport of detritus were investigated in the freshwater and brackish water wetlands of the Altamaha River Delta, GA, from 17 April 1978 to 13 April 1979. Maximum live standing crop biomass of Spartina cynosuroides, a brackish water marsh plant, was observed in July (769 ± 118 g dry wt m~z). Live material was absent in January. Standing dead material ranged from a high of 1800 ± 275 g dry wt m~2 in November to a low of 158 ± 57 in March. The quantity of fallen dead (litter) material was more constant throughout the year averaging 244 ± 21 g dry wt m~ . Net aerial primary productivity (NAPP) of £. cynosuroides was 2029 g m~^ yr"^- with no differences in productivities of plots relative to the distance from the riverbank because of minimal tidal activity in the entire area. Maximum live standing crop biomass of Zizaniopsis miliacea. a freshwater marsh plant, was observed in October (673 ± 122 g dry wt m~2). Live material dropped to a low of 81 ± 12 g dry wt m~2 ia March. Standing dead material ranged from a high of 870 ± 222 g dry wt m~2 in April, 1978, to a low of 308 ± 101 in August. Fallen dead material had an annual average of 159 ± 71 g dry wt m~2. NAPP for "L. miliacea was 1478 g m~2 yr~l. Productivities were higher in creekbank plots than in more inland plots (1824 and 1237 g m~2 yr~l, respectively) presumably because of longer tidal inundation times in the creekbank zone. In both areas NAPP peaked between April and May and was lowest between November and January. Leaf litter accumulation (primarily Nyssa aquatica, Liquidambar styraciflua. and Taxodium distichurn) was highest in November (253 ± 19 g dry wt m-2) and lowest in spring and summer (18 ± 2g dry wt. m~2). Aquatic respiration rates of standing and fallen dead material showed a pattern of swamp litter > _Z. miliacea > J5. cynosuroides. Rates for marsh grasses were generally higher in the spring dropping to a low in fall and 'winter. Rates in swamp litter were much more variable without distinct seasonal patterns. Aejrial_respiration rates of dead plant material ranked Z. miliacea > swamp litter > J3. cynosuroides.' Fallen dead marsh grass material had a higher respiration rate than standing dead material, with the highest rates occurring during the summer. DOC leaching rates for dead plant material ranked swamp litter > _Z. miliacea > ^. cynosuroides. Seasonal pat- terns of leaching were not evident in the marsh grasses, nor were there differences between fallen dead and standing dead materials. Swamp litter had high leaching rates in summer and fall with low rates during the winter months. iii ------- Weight losses in marsh grass litter bags ranked submerged > surface > suspended with decomposition rates being higher in _Z. miliacea than _S. cynosuroides. Z_. miliacea surface litter at 11 months decreased to 14% of the original weight while _§_. cynosuroides showed a decrease of only 40%. Z_. miliacea submerged litter at 6 months had only 6% of the original biomass, while ^. cynosuroides had 52% remaining. Decomposition rates for swamp litter were similar in both submerged and surface bags with the greatest weight losses occurring between 1 and 6 months. Aquatic respiration rates of dead material from litter bags were higher in more aquatic situations and were generally higher in the earlier stages of decomposition with the highest rates observed in swamp litter. Although more variable, aerial respiration rates exhibited a pattern similar to that of aquatic respiration. DOC leaching rates for litter bag material ranked ^. cynosuroides > Z. miliacea > swamp litter. Swamp litter had a negative leaching rate indicating a possible uptake of carbon. Submerged litter leaching rates were higher in submerged and surface bags for S_. cynosuroides while Z. miliacea suspended litter had the highest rate of leaching. Analyses of mineral composition data for litter bag material indicated an accumulation of Ba, Fe, Na, N, Zn and P over an 11-month period while Al, B, K, and Mg levels decreased. Concentrations of Ca, Cu, Mn, and Sr re- mained the same. For most of the elements analyzed, levels were generally higher in submerged and surface litter as compared to suspended material, and litter bag material was highest in elemental concentration than plant debris removed from the marsh surface. Species differences in levels of some elements were also demonstrated. Estimates of the quantity of carbon lost to the estuary as particulate detritus were 372 and 147 g C m~^ y~^ from ^. cynosuroides and Z. miliacea marshes, respectively. However, the results for the swamp forest indicated a possible import of carbon. This report^was submitted in fulfillment of Contract No. R805833010 by the University of Georgia Marine Institute under the sponsorship of the U. S. Environmental Protection Agency. The report covers the period 20 April 1978, to 19 April 1979. iv ------- CONTENTS Executive Summary . "... '. . . '. \ .......... ±±± Figures vi Tables vii Acknowledgments ix 1. Introduction 1 2. Conclusions and Recommendations 3 3. Materials and Methods 4 Study Area 4 Detritus Production and Aerial Productivity 4 Detritus Decay and Leaching Studies 6 Litter Bag Studies 6 4. Results and Discussion 8 Detritus Production and Aerial Productivity 8 Respiration and Leaching Studies 13 Litter Bag Studies (LBS) 24 LBS - Weight Losses 24 LBS - Aquatic Respiration 25 LBS - Aerial Respiration 25 LBS - Dissolved Organic Carbon (DOC) 26 LBS - Mineral Composition 32 Export Estimates 40 References 43 Appendices A. Biomass, Aquatic Respiration, Aerial Respiration and DOC Leaching from Dead Plant Material 45 B. Biomass, Aquatic Respiration, Aerial Respiration, DOC Leaching and Elemental Composition of Litter Bag Material 55 ------- FIGURES Number Page 1 Lower Altamaha River Delta 5 2 Mean dry weight of Spartina cynosure ides 9 3 Mean dry weight of Zizaniogsis miliacea 10 4 Mean dry weight of leaf litter 11 5 Aquatic respiration of fallen dead plant community in Spartina cynosuroides and Zizaniopsis miliacea 14 6 Aquatic respiration of standing dead plant community in Spartina cynosuroides and Zizaniopsis miliacea 15 7 Aquatic respiration of the dead plant community in swamp forest leaves 16 8 Aerial respiration of the dead plant community in Spartina cynosuroides 17 9 Aerial respiration of the dead plant community in Zizaniopsis miliacea 18 10 Aerial respiration of the dead plant community in swamp forest leaves 19 11 DOC released from dead Spartina cynosuroides 21 12 DOC released from dead Zizaniopsis miliacea 22 13 DOC released from decomposing swamp forest leaves 23 14 Aquatic respiration of litter bag material 29 15 Aerial respiration of litter bag material 30 16 DOC leaching of litter bag material 31 ------- TABLES Number 1 Results of Duncan's Multiple Range Test on biomass, aquatic and aerial respiration and DOC leaching for litter bag material 27 2 Results of Duncan's Multiple Range Test on biomass, aquatic and aerial respiration and DOC leaching for litter bag material - pooled data 28 3 Results of Duncan's Multiple Range Test for elemental composition of litter bag material - pooled data 33 4 Results of Duncan's Multiple Range Test for elemental composition of Spartina cynosuroides litter bag material. . . 36 5 Results of Duncan's Multiple Range Test for elemental composition of Zizaniopsis miliacea litter bag material. . . 37 6 Results of Duncan's Multiple Range test for elemental composition of swamp forest leaf litter bag material .... 39 A-l Mean dry weight of marsh grass from clear cut plots 46 A-2 Mean dry weight of marsh grass from previous cut plots 47 A-3 Mean dry weight of leaf litter 48 A-4 Aquatic respiration of the attached dead plant community in two species of marsh grasses 49 A-5 Aquatic respiration of the attached dead plant community for three species of swamp forest leaves 50 A-6 Aerial respiration of the attached dead plant community in two species of marsh grasses 51 A-7 Aerial respiration of the attached dead plant community for three species of swamp forest leaves 52 A-8 DOC released from dead plant parts for two species of marsh grasses 53 vii ------- TABLES (Continued) Number ' Page A-9 DOC released from three species of swamp forest leaves 54 B-l Biomass of litter bag material 56 B-2 Aquatic respiration of attached dead plant community in litter bag material 57 B-3 Aerial respiration of attached dead plant community in litter bag material 58 B-4 DOC leaching from litter bag material ' 59 B-5 Mineral content of Spartina cynosureides litter bag material. . 60 B-6 Mineral content of Zizaniopsis miliacea litter bag material . . 63 B-7 Mineral content of dead swamp forest leaf litter'bag material . 66 viii ------- ACKNOWLEDGMENTS The cooperation of the staff members of the University of Georgia Marine Institute is gratefully appreciated. We are particularly indebted to Mr. Charles Durant for his duties as boat captain, navigator, cook, historian, and general assistance in the scientific aspects of the study. The efforts of the following people are sincerely appreciated: Beth Green, Phyllis Hawkins, Lucy Knowles, Mary Musselman, Thomas Pearson, Steve Vozzo and Lebanon Valley College ecology students for their assis- tance in field collections and laboratory analyses; Steve Vozzo for preparing the figures; Mike Hardisky for conducting the .computer analyses; and Mrs. Charlotte Rittle for her untiring service in the preparation of the manuscript. Finally, we wish to acknowledge the efforts of Dr. John Gallagher who first initiated the Altamaha River Study in October, 1976; and Dr. Harold Kibby, who served as the project officer. ------- SECTION 1 INTRODUCTION The Altamaha River Delta, approximately 7 km south of Sapelo Island, Georgia, is characterized by extensive brackish water marshes, freshwater marshes, and river swamp hardwood forests. Although there have been a few studies of this freshwater to brackish water wetland system, processes within these wetlands and their relationship to the more intensively studied saline zones are poorly understood. The food webs in this system like those of saltwater marshes are predominantly based on detritus produced by the trees and grasses (Wharton and Brinson, 1978). Detrital productivity contributes to invertebrate and vertebrate production and is potential food for export to other components of the coastal system. The rivers associated with the marshes and forests may be point sources of inorganic nutrients and organic compounds for the salt marshes along the coast. Windora, Dunstan and Gardner (1975) have shown that river flow could contribute 20% of the inorganic nitrogen needed by marsh plants. Organic nitrogen compounds are also pre- sent in river flow (Dunstan and Atkinson, 1976). Brinson (1977) however, reported that, in some cases, swamp forest areas may act as nutrient sinks. It appears that any alterations in this system which cause a change in the amount, quality, and timing of detrital productivity, and a modification in nutrient transport patterns could have an effect on productivity at the primary and secondary levels within the system. Wharton (1970) reported that channelization and damming projects in freshwater areas have resulted in severe damage with little or no recovery even after a relatively long period of time. Furthermore, large quantities of detritus and nutrients are probably.processed in the saline Iportion of the coast since there is a net flow of water from fresh to saline areas. Without information on detrital productivity and the associated nutrient flux in the freshwater and brackish water wetlands, it would .be impossible to predict the impact of alterations of these wetlands on the adjacent estuarine. In October, 1976, investigators from the University of Georgia Marine Institute, Sapelo Island, Georgia, initiated studies which focused on the detrital and microbial processes in three types of wetlands (swamp, fresh- water marshes, and brackish water marshes) in the Altamaha River system. These studies provided some information on potential detritus production, detrital decay rates, and movement of detritus between freshwater wetlands and the adjacent estuary. A preliminary evaluation of the data indicated a need for further work in this area before conclusions could be made concerning the interaction of freshwater, brackish water and saline systems. Even if research would show that the dynamics in the freshwater areas do not result in a significant input into the already-rich coastal area, the timing ------- and placement of the input, the composition of the material, or the pulsing action during high water flow may be critical to the organic nutrition of coastal areas. For example, the river system seems ideally designed to release materials into the adjacent ecosystems in pulses, whereas flow from the salt marshes dominated by semi-diurnal tides would be more uniform and rhythmic. The main objective of the proposed research was to continue the work on the Altamaha River system. Specifically, we attempted to answer the following questions: 1. How much detritus is produced in the wetland types? 2. How fast does the detritus decay and what is the leaching rate of organic compounds into the water from the dead and dying leaves? 3. What is the quantity of detritus released into the river and transported to the estuary? 4. What are the chemical characteristics of the detritus from the river wetlands? Although the results of our research should enable the various agencies concerned with ecosystem management to assess the advantages and disadvan- tages of any alterations in coastal freshwater and brackish water ecosystems, it is apparent that further studies are necessary for a more complete understanding of these systems and their relation to the more saline coastal areas. ------- SECTION 2 CONCLUSIONS AND RECOMMENDATIONS The results of this study indicate that the brackish water marshes and freshwater marshes are areas of relatively high productivity which make significant contributions of particulate detritus, organic compounds, and inorganic nutrients to the coastal estuarine system. The role of the freshwater swamp forest has not been as clearly defined. There are indica- tions that these swamp forest areas may be "importers" rather than "exporters" of carbon and other nutrients. Clearly, there is a need for further work in these sensitive wetlands - particularly in the freshwater marshes and swamps. Specifically, the following projects and/or studies are recommended: 1) Underground biomass should be determined in the. Zizaniopsis miliacea marsh to give a more accurate assessment of net primary productivity and potential detritus production. 2) Studies on _Z. miliacea should be expanded to include stands in what were formerly areas of rice culture. These old rice fields occupy approximately 2544 ha in the Altamaha River Delta. The present study included only stands of _Z. miliacea in a rela- tively narrow zone (182 ha) along river and creekbanks. 3) A more intensive litter bag study should be initiated whereby more bags are utilized and samples are collected much more frequently. The results of this study would provide more accurate information on decomposition rates and nutrient exchanges. 4) The quantities of plant materials (live and dead) consumed by marsh and swamp fauna should be determined. 5) Finally, and perhaps most importantly, elevational data and information on tidal amplitude and frequency of inundation are needed for these areas. These data are needed to quantify more accurately the transport of detritus and nutrients to and from these areas, and will enable us to establish more clearly the relationships between the various type of coastal wetlands. ------- SECTION 3 MATERIALS AND METHODS STUDY AKEA The general study area was situated in the Altamaha River Delta approximately 16 km north of Brunswick, GA. Sampling sites (Figure 1) were located in Spartina cynosuroides, a brackish water (0-15 U/00) marsh on the south side of Broughten Island; in Zizaniopsis miliacea, a predominantly freshwater marsh bordering the north side of Hammersmith Creek, a tributary of the Altamaha River; and in two forested areas dominated by Nyssa aquatica, Taxodium distichum, and Liquidambar styraciflua. The forested area was located approximately 26 ra from the creekbank on the north side of Hammer- smith Creek adjacent to the Z_. miliacea productivity plots. This area, designated Riverbend, is subject to flooding only on extremely high tidal conditions. The other area, designated freshwater swamp, was situated on the south side of Hammersmith Creek approximately 0.5 km west of Riverbend. This area was flooded much more frequently than the Riverbend site. Nine collec- tions were made at approximately 6-week intervals between 17 April 1978 and 13 April 1979. DETRITUS PRODUCTION AND AERIAL PRODUCTIVITY The question of how much detritus is produced was approached by measuring the calculating net aerial primary productivity (NAPP) and the production of dead plant material. Changes in dead marsh plant biomass during each sampling interval were measured utilizing the paired.plots method of Wiegert and Evans (1964) as modified by Lomnicki et al. (1968). In the _S. cynosuroides marsh, six plots were placed at 6 m intervals on a transect from riverbank to the higher marsh dominated by Iva frutescens. Similarly, eight plots were placed at 3 m intervals in the Z. miliacea marsh on a transect from creekbank to the hardwood forest. At both sites, plant material in each 0.5 m^ plot was clear cut (Clear Cut Plots), and bagged, after which fallen 'dead material (litter) was removed from the marsh surface and bagged. In an 0.5 nr area adjacent to each of the clear cut plots, all of the dead material was removed and discarded. These plots were designated as previous cut plots. At the next sampling interval, approximately six weeks later, the previous cut plots were clear cut and the plant material was bagged. Following the collection at each sampling period, the plots were advanced approximately 1 m, and the process of establishing paired plots was repeated. Marsh grass was returned to the laboratory where it was sorted into live .and dead material, oven dried at 60° C and massed to the nearest gram. Litter was washed over a No. 18 brass sieve, oven dried at 60° C, and ------- Figure 1. The Lower Altamaha River Delta, Georgia, showing sampling sices. Sroughton Island, 1; Riverbend, 2; Freshwater Swamp, 3; and Reese Island, 4. ------- massed to Che nearest gram. Net aerial primary productivity was calculated with the formula NAPP = AG 4- M, where AG = change in live plant biomass during the time in- terval (Lomnicki et al., 1968). In summing the marsh grass productivities during each time interval to arrive at annual NAPP, negative values were treated as zero productivities. In each of the two forested areas 12 plastic trash containers (0.1 m in surface area) were mounted on poles to catch material falling from the trees. At each collection the material was harvested, bagged, and returned to the laboratory where it was oven dried at 60° C and massed to the nearest 0.1 gram. DETRITUS DECAY AND LEACHING STUDIES At each collection, samples of standing dead marsh plant material, fallen dead marsh plant material, and fallen leaves from the swamp forest were returned to the laboratory for respiration (aerial and aquatic) and leaching studies. Aquatic and aerial respiration rates of the attached dead plant community from each of the plant types were determined as described by Gallagher and Pfeiffer (1977); release of dissolved organic carbon (DOC) from the dead plant parts was measured according to Gallagher, Pfeiffer and Pomeroy (1976). LITTER BAG STUDIES Further information on detritus decay rates was obtained through litter bag studies utilizing a modification of Brinson (1977). Standing dead material from two marsh sites and fallen leaves from the river swamp forest were obtained and air dried in a greenhouse. Dried marsh plant material (100 g each) was placed in 120 x 30 cm fiberglass litter bags (1.5 mm mesh size) and returned to Altamaha River Delta. Bags containing Z_. miliacea standing dead were located at the productivity collection site. Because the S^. cynosuroides collection site had a history of frequent burnings each spring, bags containing that material were located in a _S. cynosuroides marsh 1 km NE of the productivity collection site. At the two sites, 18 bags each were suspended on wooden stakes above the marsh surface to simulate decay of standing dead, secured on the marsh surface to simulate decay of fallen dead, and submerged in the water adjacent to the marsh site to simulate decay of dead plant material after it is washed into the river and creek. Air dried swamp leaf litter (20 g each) was placed in 36 x 18 cm fiberglass litter bags (1.5 mm mesh size), returned to the swamp forest where 18 bags each were placed on the forest floor which was free of standing surface water at the time of placement, and submerged in the water of a narrow canal connecting the creek with the swamp forest area. To simulate decay rates in more saline water after material from the marshes and swamp forests had been transported to the estuary, 18 litter bags each with dead plant material from the two marsh sites (100 g each) and the swamp forest (20 g each) were submerged in a tidal creek adjacent to the University of Georgia Marine Institute facilities on Sapelo Island. Six bags were retrieved from each of the treatment areas ------- (suspended, surface, submerged) at each location at one, six, and eleven- month intervals. Following retrieval, plant material was air dried and massed to the nearest gram (marsh grass) and 0.1 gram (swamp leaf litter). Leaching and respiration measurements were made on representative litter samples from each of the treatments at each location. Samples of litter bag plant material and litter collected from the marsh and swamp surfaces at each retrieval were oven dried at 60° C and ground in a Wiley mill (40 mesh screen). Spectographic analyses of P, K, Ca, Mg, Mn, Fe, B, Cu, Zn, Al, Sr, Ba, and Ma; and determinations of total N were conducted by the Soil Testing and Plant Analysis Laboratory, Athens, GA. Statistical analyses were accomplished using the Statistical Analysis Computer Systems Program (SAS) (Barr et al., 1976). Duncan's Multiple Range test was used to evaluate statistical differences in decomposition, respira- tion, leaching and mineral composition of litter bag materials. ------- SECTION 4 RESULTS AND DISCUSSION DETRITUS PRODUCTION AND AERIAL PRODUCTIVITY _S_. cynosuroides living biomass for clear cut plots ranged from a high of 769 ± 98 g dry wt ra~2 in July to a low of zero in January (Figure 2). Stand- ing dead biomass peaked in November (1800 ± 275 g dry wt m~2) and reached a low in March (158 ± 57 g dry wt m~2). However, the latter figure does not represent the amount of standing dead material usually present in early spring because fire swept through the area destroying much of the dead ma- terial prior to the March, 1979 collection. In March, 1978, a year in which the marsh was not burned, standing dead biomass averaged 1087 ± 104 g dry wt m~2, and in April, 1978 the amount was 970 ± 94 compared .to 215 g dry wt m~2 for April, 1979. Fire caused a decrease in litter biomass (88 ± 21 g m~2) in March, 1979 compared to 427 ± 33 in March, 1978. With the exception of the unusually low amount of litter present at the March collection, litter bio- mass was relatively constant throughout the year. Z. miliacea living biomass for clear cut plots reached a maximum in October and a low in March (Figure 3). Unlike J3. cynosuroides, _Z. miliacea apparently does not experience a complete "die-back" each growing season. Live material was collected at each sampling throughout this study during a two-year period preceding the present study. Standing dead biomass was high- est in April, 1978 and lowest in August. Variations in litter biomass were not as pronounced as in live and standing dead material. Leaf litter accumulations at the forest sites were highest in November with the lowest accumulation occurring in April and July at Riverbend and the freshwater swamp site, respectively (Figure 4). Net aerial primary productivity for S_. cynosuroides was 2029 g dry weight m~2 yr~l with a turnover time of 2.64. Turnover time is equal to productivity divided by the maximum live biomass. NAPP reached a maximum between 17 April and 30 May 1978 (472 g m~2) and was lowest between 9 January and 5 March 1979 (9 g m~2). Odum and Fanning (1973) reported an NAPP of 2092 g dry wt m~2 yr"1 for _S_. cynosuroides on the south shore of Rabbit Island in the Altamaha River. However, they did not use the Lomnicki method for calculating productivity and therefore comparisons between the two figures may not be feasible. Linthurst and Reimold (1978) reported NAPP for S_. cynosuroides in the ------- 1900 1800 1700 1600 1500 r 1300 -o LIVE STANDING DEAD LITTER S.E.-1275 SE.'i362 20 60 100 140 17 APR 30 MAY IOJUL MAUG 1978 IBO I60CT -2 220 260 300 340 380 28NOV 9 JAN 5 MAR 13 APR 1979 Figure 2. Mean dry weight (g m *" ± S.E.) of Spartina cynoauroidea from clear cut plots in the Altamaha River Delta. ------- 1100 1000 900 N 600 l E 700 f 600 * I" S0° " 400 300 200 100 o o LIVE STANDING DEAD LITTER I I 20 66 100 140 17 APR 3OMAY IOJUL I4AUG 1978 I BO I6OCT -2 220 260 300 340 380 2QNOV 9 JAN 5 MAR 13 APR 1979 Figure 3. Mean dry weight (g m ± S.E.) of Zizaniopsis miliacea from clear cut plots in the Altamaha River Delta. ------- 180 170 160 150 140 130 120 l _ 100 -C I 90 £ 80 o- 70 60 50 30 20 10 RIVERBEND o o FRESHWATER SWAMP 20 6O JOO J40 17 APR 30 MAY IOJUL I4AUG 1978 180 I6OCT -2 220 260 28NOV 9 JAN 300 340 380 5 MAR 13 APR Figure 4. Mean dry weight (g ra " ± S.E.) of leaf litter at two forest locations in the Alt amaha River Delta. ------- Itamaha River Delta ranging from 1742 to 6039 g dry wt m~2 yr~l depending on he technique used for calculating NAPP. The Lomnicki method was not used or calculating NAPP in their study. However, Linthurst and Reimold, using he method of Smalley (1958) reported an NAPP of 2789 with a turnover time of ,.3. When we calculated NAPP by the Smalley method we obtained an NAPP of '33 g dry wt m~2 with a turnover time of 2.3. The possible explanation for :he rather sizable difference in NAPP between the two areas is that the Sroughton Island collection site was higher in elevation than the Linthurst- leimold site. Although elevations were not measured in the present study, it /as readily apparent that our area was higher and drier than the Linthurst- teimold area. Comparing the maximum living biomass between the two areas, -inthurst and Reimold reported a maximum of 2177 g m~^ whereas we found a naximum of only 769 g m~2. As a further check on living biomass, in July, L978, we collected 5, 0.5 m^ samples of S_. cynosuroides from the site where the litter bags had been placed. For that area we obtained a mean of 1395 ± 228 g m~2, a figure almost twice as high as the value for Broughton Island. Again, elevation was not measured, but it was obvious that the Reese Island area was lower and subject to more frequent tidal inundation. Odum and Fanning (1973), and others, have shown that creekbank _S. cynosuroides is much more productive than more inland areas, presumably because of more tidal influence in the lower areas. For comparison, we arbitrarily divided the collection site into two zones - a lower zone consisting of 3 pairs of plots within 18 m of the riverbank, and a higher zone of 3 pairs of plots between 19 and 30 m from the creekbank. NAPP in the lower and higher zones were 2048 and 1896 g dry weight m~2 yr~^-, respectively. Thus our area appears to be more homogeneous than the areas studied by Odum and Fanning. It should be noted that in the collection site, Spartina alterniflora was the dominant plant on the riverbank, occupying a zone approximately 3 m wide. Productivity in the Broughton Island area may have been adversely affected by fire which swept through the collection site in February, 1979. Although, standing live material is normally absent in late winter and early spring, dead material biomass is usually very high at that time of the year. As a result of the fire, a significant reduction in biomass of dead material was observed in the March collection. This reduction effectively lowered the NAPP value for that time period. The Linthurst-Reimold and Odum-Fanning NAPP values for ^. cynosuroides cited previously represent data for stands which had not been burned during the course of the study period. NAPP for Z. miliacea was 1478 g dry weight m~2 yr~^ with a turnover time of 2.37. Maximum NAPP was observed between 17 April and 30 May 1978 (351 g m~-) and dropped to zero for the period between 28 November 1978 and 9 January 1979. To determine differences between creekbank NAPP and NAPP farther inland we divided the collection site into two zones - one zone con- sisting of a series of 4 paired plots within 12 m of the creekbank; the other zone a series of 4 paired plots between 13 and 24 m from the creekbank. NAPP values were 1824 and 1237 g dry weight m~2 yr~^ for creekbank and inland zones, respectively. Presumably the higher NAPP in the creekbank zone is a result of more tidal activity in this area (Odum and Fanning, 1973). To properly assess the potential contribution of the marshes to the detritus food web, data on elevation and tidal inundation are needed for both areas. 12 ------- RESPIRATION AND LEACHING STUDIES la J5. cynosuroides Cbe attached dead community on the fallen dead had a higher respiration rate than that of standing dead (Figures 5 and 6). Generally, respiration rates were higher in the spring, somewhat reduced during the summer reaching a low in October, and maintained a low rate until early spring when a significant increase occurred. Aquatic respiration rates in the £. miliacea marsh followed the same pattern as that in S_. cynosuroides (Figures 5 and 6). However, the rates in Z. miliacea were somewhat higher, with the highest rates being observed in the standing dead community. Because of the frequent flooding at the River- bend site, the standing dead community was subjected to inundation for a larger period of time than the similar community at Broughton Island, which conceivably could have resulted in higher respiration rates. Incubation temperatures, which ranged from a low of 8° C in January to a high of 27° C in July, did not appear to have an effect on the pattern of respiration rates. It is more likely that the previous history of the dead material was the most important factor in the development of the microbial community and concomi- tant respiratory rates. Aquatic respiration rates for the swamp forest leaf community were, generally, significantly higher than the rates observed for the two marsh communities (Figure 7). Among the three species of tree leaves studied, Taxodium distichum showed the highest mean respiratory rate for the entire year (238 ± 90 ug C g~l dry wt hr"*) while Liquidambar styraciflua showed the lowest rate (121 ± 27). The highest rate recorded for Taxodium was almost an order of magnitude higher than that recorded for marsh grass. The reasons for these differences are not clear, although it may be related to nutrient mediated events in the two environments. In S.. cynosuroides. aerial respiration of the standing dead microbial community was fairly constant during the entire year with the exception of a peak in October (Figure 8). The fallen dead community generally had a higher respiration rate showing a relatively low rate in the spring and early summer, a fairly constant higher rate during late summer, fall, and winter, and a return to a lower rate in early spring. The differences in respiration rates between the fallen dead and standing dead communities may be related to a larger microbial biomass on the fallen dead material and/or differences in nutrient content. Likewise, at Rlverbend in _Z. miliacea, the standing dead community had a relatively low, constant respiration rate (Figure 9), while the fallen dead community had a much higher rate at each sampling period and , was much more variable. However, the annual cycle was different in that the lower rates were observed in November and January, rather then early spring. Aerial respiration data for the microbial community on swamp forest leaves are difficult to interpret. Over the entire year, Nyssa aquatica and Taxodium distichum communities had similar respiration rates, which were considerably higher than the L. styraciflua community (Figure 10). I. distichum microbial aerial respiration exhibited a pattern of higher rates for late spring and summer, a reduction in fall and winter with the lowest rate occurring in April. The JN. aquatica community showed an increase in respiration rates from early spring through July with a peak in August, a drop in October to early summer levels, and a series of high and low values 13 ------- o f >. u O T v o 9 ~55 60 155 17 APR 30 MAY to ML HAUG 1976 13 APR Figure 5. Aquatic respiration (yg C g~ dry wt h~ ± S.E.) of attached dead plant community in fallen dead material from Broughton Island (Spartina cynoauroides) and Riverbend (Zizaniopaia millacea). Incubation time, 3.5 h. ------- I o» o o> a. 140 130 120 MO 100 90 60 70 60 50 40 30 20 10 - BROUGHTON ISLAND -o RIVERBEND T A \ 20 60 100 HO 17APR 30MAY IOJUL HAUG 1978 ISO 220 260 300 340 380 I60CT 28NOV 9JAN 5MAR 13APR . 1979 Figure 6. -1 -1 Aquatic respiration (\ig C g dry wt h ± S.E.) of attached dead plant community in standing dead material from Broughton Island (Spartina cynosuroides) and Riverbend (Zizaniopsis miliacea). Incubation time, 3.5 h. ------- 692 Ic 400 1. 350 i >. 300 o 7 250 o» «J 200 * 150 100 50 a- o Nysso aqualica Liquidambar styraciflua Taxodium dislichum 100 20 60 17 APR 30 MAY IOJUL 1978 I4AUG 140 160 I60CT 220 28NOV 260 9 JAN 1979 300 340 380 5 MAR 13 APR Figure 7. Aquatic respiration (pg C g dry wt h ± S.E.) of the attached dead plant community for three species of swamp forest leaves. Incubation time, 3.5 h. ------- I fi .9" » o T o u CP 0. 90 80 70 60 50 40 30 20 10 20 60 100 140 I/APR 30MAY IOJUL MAUG 1978 -« FALLEN DEAD O STANDING DEAD 180 I6OCT 220 260 28 NOV 9 JAN 1979 300 340 380 5 MAR 13 APR Figure 8. -1 -1 Aerial respiration (pg C g dry wt h ** ± S.E.) of the attached dead plant community in fallen and standing dead Spartina cynosuroidea. Incubation time, 3 h. ------- CO « FALLEN DEAD o STANDING DEAD 2O 60 100 140 17 APR 30 MAY IOJUL I4AUG 1978 180 16 OCT 220 260 2B NOV 9 JAN 1979 300 340 380 5 MAR 13 APR Figure 9. -1 ,-1 Aerial respiration (pg C g dry wt h A ± S.E.) of the attached dead plant community in fallen and standing dead Zizaniopsls miliacea. Incubation time, 3 h. ------- I .e o '5 o 7 Nysso oquotica Liquidombor slyrocrflua Taxodium distichum 20 60 100 140 17 APR 30 MAY IOJUL 14 AUG 1978 ISO I6OCT 220 26 NOV 260 9 JAN 1979 300 340 360 5 MAR 13 APR Figure 10. Aerial respiration (pg C g dry wt h ± S.E.) of the attached dead plant community for three species of swamp forest leaves. Incubation time, 3 h. ------- for the remainder of the year. The L. styraciflua community, however, had a more constant rate with the exception of a lower and higher rate in July and October, respectively. Without further speculation, we conclude that these variations reflect only species differences. In j>. cynosuroides and Z. miliacea marshes seasonal patterns in DOC leaching rates are not apparent (Figures 11 and 12). For both species of grasses there are no significant differences in the rate of leaching between fallen dead and standing dead averaged over the entire year. However, Z. miliacea had a rate approximately 100 vg C g~"l dry weight h~^- higher than _S. cynosuroides which may have been a result of longer inundation times for the Z_. miliacea marshes. T_. distichum showed a definite increase in DOC release from May through August 1978 with a decline to a low in January, 1979 and then an increase through March and April of 1979 (Figure 13). L. styraflua exhibited a similar pattern except that the highest rate was observed in October, 1978, with a subsequent decline to a low in March, 1979, followed by an increase in April. N_. aquatica, on the other hand, had levels of DOC significantly lower than the other two species over the entire year. Seasonal trends in leaching rates were not as apparent as the patterns of leaching observed in the other two species. DOC leaching rates for N:. aquatica in this study for a 3 hr period were comparable to DOC rates for the same species reported by Brinson (1977). Leaching rates for the 3 species of the leaves were significantly higher than those of the marsh grasses. As indicated above, respiration and leaching rates were quite variable, and although we have not fully identified the factors causing these variations we might suggest probable causes. Marsh grass and swamp forest leaf litter were removed randomly from the marsh surfaces and forest floor. Consequently, data relative to residence times in these areas and times of tidal inundation were not available. Obviously, the age of the material and length of exposure to tidal inundation would have had significant effects on the rates. In addition, the proportion of leaves and stems in the sample may have affected dead plant microbial community respiration rates and DOC releases (Gallagher et al., 1976). Because no attempts were made to ensure equal masses of stems and leaves at each collection, it is conceivable that the disproportionate representation of these components would have caused the rather wide variations observed in this study. Furthermore, we would expect less variations in rates among newly fallen leaves and standing dead material com- pared to aged stems. Data for aerial respiration and DOC leaching rates over the entire year showed less variations in standing dead (predominantly leaves) compared to fallen dead (a mixture of leaves and stems). Also, aquatic respiration rates for _S. cynosuroides standing dead were less variable than for the fallen dead material. However, in Z_, miliacea, standing dead material had a wider variation in aquatic respiration rates than did the fallen dead. Thus, for a more accurate assessment of respiration and leaching rates, more information relative to the age of the material and tidal inundation times should be obtained, and in marsh grasses, measurements should be made separa- tely on stems and leaves. 2U ------- 7OO 600 500 to l .c o 0> o 300 CT 3. ZOO 100 FALLEN DEAD STANDING DEAD y 17 APR 30 MAY 1978 100 IOJUL I4AUG T4O~ ISO I60CT i 2SNOV 9 JAN 1979 5 MAR 13 APR Figure 11. -1 -1 DOC released (ug C g " dry wt h " ± S.E.) from fallen and standing dead Spartina cynosuroides. Incubation time, 3 h. ------- N> 1000 900 - FALLEN DEAD STANDING DEAD 20 60 100 HO 180 22O 260 300 340 380 17 APR 30 MAY 10 JUL I4AUG I60CT 28NOV 9 JAN 5 MAR 13APR 1978 1979 Figure 12. DOC released (pg C g~ dry wt h~ ± S.E.) from fallen and standing dead Zlzanlopsla mlllacea. Incubation time, 3 h. ------- ro u> Nysso oquolico Liquidombor slyracifkia Toxodium distichum / I 20 60 100 140 17 APR 30 MAY IOJUL I4AUG 1978 ieo I6OCT 220 28NOV 9 JAN 1979 300 340 380 5 MAR 13 APR Figure 13. DOC released ( g C g S.E.) from three species of decomposing swamp forest leaves. Incubation time, 3 h. ------- LBS - WEIGHT LOSSES In the _S. cyuosuroides marshes, suspended litter showed the slowest rate of decomposition (Tables 1 and 2). Significant weight losses did not appear until the 11-month collection. However, surface litter decomposed rather rapidly, showing a 31% weight loss at 6 months and a 60% loss at 11 months. The submerged litter experienced a significant weight loss during the first month (16%) and a subsequent loss of 32% at the 6-month collection. Litter submerged in salt water showed a pattern similar to that of other submerged bags at the 1-month collection. Rates of decay for suspended, surface, and submerged litter are expressed in the following formulae: suspended (11 months) y = 99.5 - 0.74X surface (11 months) y = 100.3 - 0.18X submerged ( 6 months) y = 96.5 - 0.2SX, where y = percent remaining at'time X, and X = time in days. Decomposition rates for _Z. miliacea litter follow the same general trends as those for ^. cynosuroides litter - submerged > surface > suspended. However, the rates in ^. miliacea are greater than those in £. cynosuroides. Suspended litter showed a 58% decrease at 6 months without a further signifi- cant decrease at 11 months. Surface bags exhibited a 17% decrease at 1 month and a 72% decrease at 6 months with an 86% decrease at 11 months. The greatest magnitude of decomposition was observed in the submerged bags - a 19% decrease in biomass at 1 month with a 94% decrease at 6 months. In fact, only one of six bags contained litter at the 6-months collection period. Thus, the decrease in biomass was indeed dramatic between the 1-month and 6-months collection periods. Linear regression equations depicting decompo- sition rates for the three types of litter are as follows: suspended (11 months) y = 94.8 - 0.19X surface (11 months) y = 93.5 - 0.27X submerged (11 months) ? = 98.5 - 0.52X Thus, suspended Z. miliacea litter had a decay rate comparable to ^. cynosuroides surface litter, while _Z. miliacea surface litter had a rate comparable to the ^. cynosuroides submerged litter. The submerged _Z. miliacea decay rate was approximately twice that of ^. cynosuroides submerged litter. The more rapid decay rates observed for Z. miliacea suspended and surface litter are probably related to the longer time of tidal inundation in the freshwater marshes. The rather wide difference in weight losses between the two types of submerged marsh grass litter cannot be fully explained at this time. We suggest that differences in current velocity and composition of the grasses are factors. _Z. miliacea has a higher water content than JS. cynosuroides (73 and 67% respectively). Swamp forest leaf litter showed significant decreases in weights at each time interval with the greatest losses occurring between one and six months (45%). Following the 6-months collection, only another 10% decrease occurred. A significant difference in the rate of decomposition between surface litter 24 ------- and submerged litter was not observed as is illustrated in the following linear regression equations: surface (11 months) y - 89.1 - 0.25X submerged (11 months) y = 93.5 - 0.25X The similarity in decomposition rates is probably related to the fact the sur- face bags were inundated for long periods of time during the study. At each of the collections, the surface bags were covered with approximately 25 cm of water which indicated that surface and submerged bags were exposed to the same general environmental conditions. LBS - AQUATIC RESPIRATION Respiration rates for the three types of saltwater submerged litter were significantly higher than in all other treatments (Figure 14; Tables 1 and 2). This is somewhat surprising in that Gallagher (1977) reported lower rates for similar material suspended in saltwater as compared to freshwater. In the latter work, material had been submerged for a period of only 7 days which may account, in part, for the differences observed. The aquatic respiration rate in suspended litter was significantly lower than in surface and submerged litter in both species of marsh grasses. No significant.differences were ob- served between surface and submerged litter for the three types of litter. In comparing aquatic respiration rates between species (Table 2), swamp litter showed a significantly higher rate (81 yg C g~l hr~l) than did S_. cynosureides (48 yg C g," hr~l) and Z. miliacea (42 ug C g~l hr~l) litter. In combining aquatic respiratory data for all types of litter, saltwater sub- merged litter had the highest rates, suspended litter the lowest rates, with surface and submerged litter having similar, intermediate rates. For £. cynosuroides and Z., miliacea combined aquatic respiratory rates for all types of litter were significantly higher at 1 month than at 6 months, with no differences between 6 months and 11 months. The combined respiratory rate for swamp litter was significantly higher at 1 and 6 months than at 11 months with no significant differences between 1 month and 6 months. Briefly summarizing the above material, aquatic respiratory rates were higher in more aquatic situations (excluding the saltwater treatment) and were generally higher in the earlier stages of decomposition. LBS - AERIAL RESPIRATION Generally, aerial respiration rates were higher in the earlier stages of decomposition as is indicated when comparing the combined rates of all litter types, or when comparing the rates of each type to time (Tables 1 and 2 and Figure 15). Rates were significantly higher at 1 month with no significant differences between 6 and 11 months. Unlike the situation for aquatic respiration, swamp litter exhibited the lowest aerial respiratory rate with Z. miliacea showing the highest rate. However, in comparing types of litter (all species) saltwater litter had the ------- highest rate followed in decreasing order (all significant differences) by submerged, surface and suspended litter. In comparing respiratory rates for litter representing each species, the trend observed above is not as pronounced. For _S. cynosuroides both salt- water and on-site submerged litter had higher aquatic respiration rates than suspended and surface litter but did not differ from each other. However, surface litter had a significantly higher rate than suspended litter. For Z_. miliacea, saltwater litter exhibited a significantly higher rate than the other three types, submerged was higher than surface and suspended, but no differences occurred between the latter two types. In swamp litter, salt- water submerged aerial respiratory rates were significantly higher than surface submerged rates while surface rates were higher than submerged rates. Thus, while the pattern for aerial respiration generally resembles that of aquatic respiration, more variation occurred within the individual species. LBS - DISSOLVED ORGANIC CARBON (DOC) When comparing the combined DOC leaching rates for all litter types, the following trends were noted (Tables 1 and 2, and Figure 16). As was observed for respiration rates (aquatic and aerial), leaching rates were generally higher in the earlier stages of decomposition. _S_. cynosuroides litter had significantly higher leaching rates than Z_, miliacea and' swamp litter, while Z. miliacea was significantly higher than swamp litter. Surprisingly, swamp litter showed a net negative leaching rate which indicates an uptake of car- bon. Ac this point, we cannot explain these results. When comparing types of litter for all species involved, suspended material had a higher rate than all other types with no significant differences in rates between the other types. This is also somewhat surprising, since we would have expected higher leaching rates in the submerged and surface litter. In terms of individual species, however, _S. cynosuroides on-site submerged litter showed a signifi- cantly higher leaching rate than the other types. Suspended, surface, and saltwater submerged litter did not differ in DOC leaching. In Z. miliacea, DOC leaching rates were significantly higher for suspended litter with no differences occurring between the other types. DOC leaching rates of swamp forest leaf litter in surface and submerged bags did not differ significantly. Many negative values were recorded which may indicate an uptake of DOC by the material. Comparisons of mean aquatic respiration, aerial respiration, and DOC leaching rates of litter bag material for the three collection periods to rates for material (standing dead and fallen dead) from "natural areas" averaged over the entire year show the following patterns. For both species of marsh grasses, aquatic respiration rates were similar for litter bag material, fallen dead, and standing dead. Aerial respiration rates for _S. cynosuroides litter were higher than those of fallen dead and standing dead. In Z_. miliacea, litter bag material and fallen dead aerial respiration rates were similar and significantly higher than standing dead rates. DOC leaching rates were similar in all _S. cynosuroides material, but Z_. miliacea litter bag material had a rate approximately 21/2 times lower than that of fallen dead and standing dead grass. 26 ------- ISJ TABLE 1. RESULTS OF DUNCAN'S MULTIPLE RANGE TEST FOR TIME AND TYPE DIFFERENCES IN MEAN BIOMASS (WT), AQUATIC RESPIRATION (AQUA), AERIAL RESPIRATION (AER), AND DOC LEACHING (DOC) FOR TWO SPECIES OF MARSH GRASSES AND SWAMP FOREST LEAVES ENCLOSED IN LITTER BAGS SUSPENDED (SUS), SURFACE (SUR), SUBMERGED (SUB) AND SALTWATER TREATED (SALT)t Spartina cynosuroides TIME 0 1 month 6 months 11 months 0 1 month 6 months 11 months 0 1 month 6 months 11 months WT 89b 74 c 55d lOOa 86b 30 c 25c 20a 16b 6c 4d AER 61a 31b 26b 84 a 43c 60b 56a 22b 19b AQUA 70a 19b 2 Ob 7 la 34b 21b 114a 90a 24b DOC 527a 109b -177c Zizanlopsis 181a 131a 296a Swamp - la -32a -49a TYPE SUS SUR SUB SALT millacea SUS SUR SUB SALT Litter SUR SUB SALT WT 90a 77c 84b 93a 70b 62c 62c 94a lie 12b 18c AER lie 44b 74 a 63a 47c 51c 85b 124a 34b 29c 58a AQUA 13c 37b 44b 14 3a 7c 46b 65b 14 la 83b 53b 16 3a DOC 261b 288b 692a 118b 322a 92b 75b 153b lla Sab -58b Means with the same letters are not significantly different Wt in grams dry weight; AER, AQUA and DOC in pg C g~ dry weight h~ ------- TABLE 2. RESULTS OF DUNCAN'S MULTIPLE RANGE TEST FOR TIME, SPECIES, AND TYPE DIFFERENCES IN MEAN BIOMASS (WT), AERIAL RESPIRATION (AER), AQUATIC RESPIRATION (AQUA), AND DOC LEACHING (DOC) FOR SPARTINA CYNOSUROIDES (SCYN), ZIZANIOPSIS MILIACEA (SMILI), AND SWAMP FOREST LITTER BAG MATERIAL - POOLED DATAt TIME 0 1 month 6 months 11 months SPEC SCYN ZMILI SWAMP TYPE SUS SUR SUB SALT WT 77a 67b 37c 29d 85a 70b 13c 80a 49c 47c 65b AER 67a 33b 35b 43b 65a 35c 32d 43c 55b 81a AQUA 82a 43b 22c 42b 48b 81 a lOc 55b 54b 149a DOC 250a 81b -60c 330a 16 5b -18c 290a 135b 15 8b 87b Means with the same letter are not significantly different r WT in grams dry weight; AER, AQUA, and DOC in ug C g~ dry weight h~ 28 ------- Swamp Forest leaves N> 135 130 105 !c 90 I » 75 >» TJ - 60 e» ° 45 i» a. 30 15 0 -15 S. cynosuroides fin 16 1 6 II 1 6 II SUB SUS SUR - - Z. mUlocea . - 1 6 SUB n a 1 6 II 1 6 II SUS SUR - . - - 1 6 II 1 6 II SUB SUR -1 -1 Figure 14. Aquatic respiration (ug C g dry wt h """ ± S.E.) of the attached dead plant community from dead plant material enclosed in suspended (SUS), surface (SUR), on-site sub- merged (SUB), and saltwater submerged (SAL) litter bags. Incubation time, 3 h. ------- ui O 120 (OS ~ 90 f !7 >» * GO o 45 30 15 S. cyno*urold«« Z. mlllacto Swamp Forttl 1 I 6 SUB I 6 II SUS I 6 II SUR I 6 SUB I 6 II SUS I 6 II SUR I 6 II SUB I 6 II SUR Figure 15. Aerial respiration (pg C g~ dry wt h~ ± S.E.) of the attached dead plant community from dead plant material enclosed in suspended (SUS), surface (SUR), on-slte submerged (SUB), and saltwater submerged (SAL) litter bags. Incubation time, 3 h. ------- eoo 700 !c 600 i 500 af >. 400 7 300 o> u 200 * 100 S. - - _ - - - cymxuroidet 1 1 6 II 1 6 II SUB SUS 350 300 250 200 ISO 100 50 Z. mlllocea . - - - 1 6 II SUR 16 1 6 II SUB SUS Swamp Fore it 100 75 50 25 n 1 6 II SUR -25 -50 -75 leaves " - - -41 - - 1 6 II 1 SUB W 6 II SUR Figure 16. DOC released (pg C g~ dry we h~ ± S.E.) from dead plant parts enclosed in suspended (SUS), surface (SUR), on-site submerged (SUB) and saltwater submerged (SAL) litter bags. Incubation time, 3 h. ------- Aerial respiration rates of swamp litter bags material was similar to the rates of fallen leaves. Aquatic respiration rates of litter bag material were much lower than rates for the three species of the leaves utilized in this study. Mean DOC leaching rates for litter bag material, a composite of fallen leaves representing several species of trees, was -18 ug C g~l hr~l. Rates for fallen leaves representing N^ aquatica, _L. styraciflua, and T. distichurn, were 541, 794, and 675 yg C g~i hr"1, respectively, Obviously, confining the swamp litter in bags served to reduce the leaching rates. The causes of these reductions are not known, and a repeat of the experiment would be helpful to determine whether the reduction was real or simply a result of experimental error. LBS - MINERAL COMPOSITION Swamp litter had significantly higher concentrations of P, Ca, Mg, N, Mn, Fe, Al, B, Cu, Sr, and Ba (Table 3). For the above elements, ^. cynosuroides and _Z. miliacea were similar in concentrations with the excep- tion of P, N, and Ba which were significantly higher in J3.. cynosuroides than 2^. miliacea. 7^. miliacea had significantly higher concentrations of Zn than did S_. cynosuroides with no differences in levels between Z_. miliacea and swamp litter, and no difference between swamp litter and J3. cynosuroides. ^. cynosuroides had a significantly higher level of Na than.the other two types with no differences occurring between swamp litter and Z_. miliacea. Marsh grasses and swamp litter did not differ significantly in K levels. When pooled data (Table 3, all treatments, all species) were compared to time, the following five trends were noted: 1) significant increases in P concentrations at 6 months; no significant decreases at 11 months; 11-month levels somewhat higher than 1-month level 2) significant increases of Ca, Cu, Mn, and Sr at 6 months; further significant decreases at 11 months to 1-month levels 3) significant increases of Ba, Fe, Na, and N at 6 months; no further changes at 11 months; 6 and 11-month levels significantly higher than 1-month level 4) no changes in Zn between 1 month and 6 months; increases at 11 months to a level significantly higher than at 1 month 5) significant decreases of K, Mg, Al, and B at 11 months; 6 and 11-month levels significantly lower than 1-month levels Thus, at the end of the 11-month period, levels of Ba, Fe, Na, N, Zn and P represent elemental accumulations while K, Mg, Al and B levels indicate losses. No significant changes appeared to have occurred in concentrations of Ca, Cu, Mn, and Sr. 32 ------- UJ LJ TABLE 3. RESULTS OF DUNCAN'S MULTIPLE RANGE TEST FOR TIME, SPECIES AND TYPE DIFFERENCES (POOLED DATA) FOR MEAN ELEMENTAL COMPOSITION OF SPARTINA CYNOSUROIDES (SCYN), ZIZANIOPSIS MILIACEA (ZMILI), AND SWAMP FOREST LEAF (SWAMP) LITTER BAG MATERIAL - SUSPENDED (SUS), SURFACE (SUR), SUBMERGED (SUB) AND SALTWATER TREATED (SALT) I" TIME 1 month 6 months 11 months SPEC SCYN ZMILI SWAMP TYPE SUS SUR SUB SALT P .0959b .U89a .1078ab .0676c .09665 .1659a .0622c .1087b .1296a .1372a K .0899a .0329b .0183b .0516a .0604a ,0558a .0276b .0364b .0463b .1887a Ca .5330b .8363a .6086b .2974b .3943b 1.3952a . 3051d .7480b .8878a .5239c Mg .1936a .1523b .1180b .1438b .1537b .2007a .1015b .1237b .1253b .4775a N .82b 1..29a 1.27a .76c 1.13b 1.39a .8867b 1.1967a 1.1429a ,8978b Mn lllOb 1758a 994b 576b 94 Ib 2597a 383d 1052c 1839b 2652a Fe 3980b 5257a 6405a 2602b 3827b 9365a 1655c 5922ab 6925a 4801b Al 6304a 5077b 4383b 4377b 4962b 7566a 2583c 5531b 6352b 9484a (Continued) ------- TABLE 3. (Continued) Cu Sr lia Na TIME 1 month 6 months 11 months SPEC SCYN 2MILI SWAMP TYPE SUS SUR SUB SALT 20.82a 9.91b 7.04b 8.32b 7.01b 31.06a 4.97c 8.75b 9.06b 59.23a 4.215b 5.400a 4.684b 3.001b 3.177b 8.734a 2.500c 4.973b 6.461a 4.785b 49. 4b 294. Ib 690. 2a 39. 3b 449. 2a 317. 2ab 579a 192a 15 7a 37a 38.92b 53.93a 41.36b 25.42b 29.90b 85.56a 18.51d 45.12c 55.35b 69.74a 46.92b 97.09a 75.50a 13.72c 43.79b 170. 94a 26.92b 90.16a 107. 89a 13.03b 194b 1393a 413a 1099a 376b 269b 958a 748ab 268b 116b Means with the same letter are not significantly different t P, K, Ca, Mg, N, in %; others in PPM ------- Comparison of mineral content among suspended, surface, on-site sub- merged, and saltwater litter showed that K, Mg, Mn, Sr, Al and B levels were significantly higher in saltwater submerged litter than in other types. When saltwater submerged litter is excluded from the comparisons, the following trends were noted. No differences in levels of K, Mg, and Zn were noted. For ?, Ca, Mn, Cu, and Sr concentrations in on-site submerged > surface > suspen- ded. N, Fe, Al, B, and Ba levels were equally higher in submerged and surface litter than, in suspended litter. Generally, surface litter was intermediate in elemental concentrations, with suspended material usually having the lowest concentrations with the exception of Na which was signifi- cantly higher in suspended material. The patterns of elemental composition for .S_. cynosuroides, _Z. miliacea, and swamp litter vary somewhat from those observed above. When comparing _S. cynosuroides litter concentrations at the collection periods, three general patterns were noted (Table 4). P, K, Al, and Cu showed steady decreases through time until 11-month levels were significantly lower than 1-month levels. Ca, Mn, Sr, Ba, Na, and Fe concentrations increased between 1 and 6 months followed by a decrease between 6 and 11 months to levels characteris- tic of the 1-month collection. N levels followed the latter pattern with the exception that although the 11-month value was lower than the 6-month value, it was significantly higher than the 1-month concentration. B, Mg, and Zn concentrations did not differ significantly with time. In ^. cynosuroides, elemental concentrations were highest in saltwater and/or on-site submerged litter. K, Mg, Mn, Al, and B concentrations were highest in saltwater treated litter. In comparing only suspended, surface, and on-site submerged litter the following relationships were noted. K, B, Zn, Mg, and Mn did not differ significantly. For P and N, on-site submerged > surface > suspended; on-site submerged litter levels of Ca, Cu, Ba, and Sr were higher than surface and suspended; and Al and Fe levels for surface and submerged were higher than suspended. Only in Na levels were higher levels seen for surface and suspended litter as compared to submerged litter. It appears that elemental accumulation was accelerated in the more aquatic conditions. No significant changes in P, Mn, Al, Ba, and Na concentrations in _Z. miliacea occurred during the 11-month study period (Table 5). Although Ca and Sr levels were significantly higher at 6 months, further decreases occurred so that 11-month levels were similar to 1-month levels. B, K, and Mg concentrations at the 11-month collection were significantly lower than at the 1-month collection. Cu, Fe, N, and Zn showed significant increases at 11 months with Cu and N accumulating more rapidly than Fe and Zn. As in £. cynosuroides, Z_. miliacea saltwater submerged litter was higher in K, Mg, Mn and B levels. In addition, Sr was significantly higher in the saltwater treatment. Comparing only suspended, surface, and on-site submerged litter showed again that suspended material was generally lower in elemental concen- trations than the other two types. No significant differences in concentra- tions of B, Ba, Ca, Mn, Na, and Zn were observed between the three types of litter. Al, Cu, Fe, and P levels were similar in submerged and surface bags with both being higher in concentration then suspended litter. Submerged ------- TABLE 4. RESULTS OF DUNCAN'S MULTIPLE RANGE TEST FOR TIME AND TYPE DIFFERENCES COMPOSITION OF SPARTINA CYNOSUROIDES LITTER BAG MATERIAL - SUSPENDED SURFACE (SUR), SUBMERGED (SUB), AND SALTWATER TREATED (SALT)t IN MEAN ELEMENTAL (SUS), TIME 1 month 6 months 11 months 1 month 6 months 11 months TYPE SUS SUR SUB SALT SUS SUR SUB SALT P K .0661b .0806a .8777a . 383b .0441c .0114c _B 8. 26a 10.23a 5.90a L K .0388c .0313b .0593b .0359b .1058a .0500b .0933a .1566a B 6.29b 7.91b 5.31a 21.00a Ca .2217b .4686a .2207b Cu 3.35a 3.64a 1.45b Ca. .2121b .2749b .4584a .2705b Cu 2.23b 2.72b 4.35a 3.21b Mg . 1508a .1525a .1181a Zn 30.45a 46.27a 47.84a M& . 1166b .1218b .1326b .3048a lo. 40.99a 36.87a 46.87a 27.23a N ,57c I.Ola .82b Sr 20.14b 38.87a 18.07b _N .65c .77b .95a .64c Sr 14. lie 23.05bc 38.42a 36. 7 lab Mn 473. 8b 1093. la 90. 9b JJa 10.23b 25.13a 5.51b Mn 114b 202b - lllOa M 4.87b 11.64b 31.28a 8.46b Fe Al 2604ab 5033a 3475a 4431ab 1435b 2995b Na 277. 6b 2396. 6a 996. Sab Fe Al 607b 1322c 2717a 4056b 4220a 5398b 4343a 11449a M 1253ab 1856a 39 8b 77b * Means with the same letter are not significantly different t P, K, Ca, Mg, N, in %; others in PPM ------- TABLE 5. RESULTS OF DUNCAN'S MULTIPLE RANGE TEST FOR TIME AND TYPE DIFFERENCES IN MEAN ELEhflilNTAL COMPOSITION OF ZIZANIOPSIS MILIACEA LITTER BAG MATERIAL - SUSPENDED (SUS), SURFACE (SUR), SUBMERGED (SUB), AND SALTWATER TREATED (SALT)t TIME 1 month 6 months 11 months 1 month 6 months 11 months TYPE SUS SUR SUB SALT SUS SUR SUB SALT * Means with the P K .0874a .1053a .1025a .0217b .0874a .Ol56b B 9.98a 5.20b 3.18c ' J? K ,089b .0247c . 1095a .0281c .0860ab .0414b . L2iOa 0.2950a K . . 3.92b 3.68b 2.58b 31.71a same letter are not sig Ca .3474b .4832a . 3847ab Cu 2.61b 3.97a 3.38a Ca .3795a .4400a .2742a .4391a ^u 2. 72b 3.77a 3.01ab 3. lOab nif icantly Mg .1943a .1325b .0971c Zn 29. Ib 105. 9b 1690. Oa Mg .0894b .1053b .0579c .6089a Zn 1099a 109a 34 a 18a different N .81b 1.36a l.Sla ll 25.92b 35.55a 31.25ab N. 1.08b 1.37a 0.82b 0.91b Sjr 22.02c 32.52b 14.26c 63.90a Mn 1043a 951a 758a Ba 37.28a 47.94a 51.97a Mn 59 8b 931b 612b 2449a Ba 44.56a 53.29a 46.05a 10.50b Fe Al 3260b 5309a 3909ab 4551a 4864a 4748a M 105a 105 2 a 130a Fe _/a 2494c 3592b 5349a 59lla 4918ab 5801a 261lbc 5840a Ma 721a 180a 164a 28a t 1', K, Ca, Mg, N, in %; others in PPM ------- litter was clearly higher in K concentration, while surface litter was significantly higher than both suspended and submerged litter. Significantly lower concentrations of Mg were recorded for submerged material. Patterns of elemental accumulation and loss in swamp litter appeared to be more clearly established than those of the marsh grasses (Table 6). Fe, P, and Cu showed significantly higher levels at 11 months than at 1 month with accumulation being most rapid for P and Cu. Al, B, K, and Mg levels were significantly lower at 11 months than at 1 month with losses occurring more rapidly for B, K, and Mg. Initial accumulation at 6 months followed by losses at 11 months to 1-month levels were observed for Ba, Ca, Mn, N, Na, Sr, and Zn. Brinson (1977) reported accumulations of Ca and Fe in swamp forest leaves with losses of K and Mg. He, however, showed also an accumula- tion of N and a strong accumulation of P followed by a loss. We also showed accumulation of N and P, however, the P levels remained higher than the 1 month level and N accumulation was followed by a loss. Forest leaf litter showed no significant differences in nutrient levels between surface and submerged litter. This is not surprising, since, as stated earlier, the environmental conditions, at least time of inundation, were similar. In comparing the three treatments, saltwater submerged litter showed accumulation of Al, B, K, Mn, P, and Sr, with losses of Ba, Ca, Mg, N, and Zn. No differences were observed between Cu, Fe, and Ba levels. Specific comparisons of mineral content of litter bag material to natural litter removed from the marsh surfaces at each collection are diffi- cult to make. The material collected from the marsh surface was more heterogeneous in composition because it consisted of stem and leaves in various stages of decomposition. Presumably, litter bag material was more homogeneous because standing dead marsh grass material at the same stage of decomposition was used for the litter bags. In addition, only one sample of marsh litter material was analyzed for mineral composition, making statisti- cal comparisons virtually impossible. Nevertheless, some generalizations can be made in comparing suspended, surface, and on-site submerged litter to natural litter for the two species of marsh grasses. Comparisons were not made for swamp forest leaf litter. Al, Cu, Fe, Mg, Mn, N, Na, Sr, and Zn levels were lower in natural litter than in litter bag material. Qualitatively, the differences ranged from somewhat lower to much lower. Al and Fe were particularly outstanding in that concentrations of these elements were, in some cases, two orders of magnitude lower in natural litter. Ca and B levels were more variable but generally similar in concentration in the four types of litter. K levels were lower in j>. cynosuroides litter but higher in _Z. miliacea litter. P concentrations showed definite similarities to suspended litter levels in ^. cynosuroides while being lower in concentration than surface and submerged material. In Z. miliacea, however, K levels in natural litter were more similar to surface litter levels at 1 month with no differences at 6 and 11 months. Thus, it appears that, for many of the elements analyzed, enclosure in litter bags re- sulted in an accumulation of minerals leading to an elevation of concentra- tions over natural levels. The causes of these increases are not clear. The 38 ------- TABLE 6. RESULTS OF DUNCAN'S MULTIPLE RANGE TEST COMPOSITION OF SWAMP FOKES'f LEAF LITTER SURFACE (.SUR), SUBMERGED (.SUB), FOR TIME AiND TYPE DIFFERENCES IN MEAN ELEMENTAL BAG MATERIAL - SUSPENDED (SUS), SALTWATER TREATED (SALT)t TIME 1 month 6 months 11 months 1 month 6 months 11 months TYPE SUR SUB SALT SUR SUB SALT P K .1469b .0818a .1800a .0387b .1836a .0298b B 52.03a 14.62b 13.06b P K .1574b .0454b .1637b .0456b .1974a .1146a B 14.65b 14.31b 125. OOa Ca 1. 195b 1.739a 1.343b Cu 7.51b 9.41a 10.13a Ca 1.533a 1.440a .862b Cu 8.42a 9. 34a 8.05a Mg .2498a ,1751b .1431b Zn 101. 6b 686. 7a 261. 7b MB .1442b .1451b .5187a la 431. 4a 286.0ab 57. 7b N 1.18b 1.58a 1.53b Sjr 81.26b 95.45a 81.42ab N 1.45a 1.41a 1.14b s*. 79.75b 83.45b 108. 61a Mn 2045b 3812a 2131b Ba 108. 7b 250. 4a 187. 8ab Mn 2025b 2564b 4398a Ba 205. 6a 188. 5a 20. Ib Fe 6775b 9207b 14217a Na 201. 4b 453. 7a 169. Ob Fe 9700a 9707a 7447a Na 330. 8a 209. Oa 243. 7a Al 9327a 6553ab 5612b Al 6627b 7273ab 11164a Means with the same letter are not significantly different t P, K, Ca, Mg, N, in %; others in PPM ------- litter enclosed in bags may act Co remove suspended sediments from water flowing through the bags and thus, through adsorption on the smaller particles of marsh grass, increase nutrient levels. On the other hand, the increases may be a reflection of a more rapid loss of organic matter than minerals from the litter. This, however, would not explain why natural litter levels are usually lower than the litter bag material unless one assumes that natural litter is continually "recruiting" material from the standing dead material and thus significant accumulations of elements do not occur. EXPORT ESTIMATES To estimate the quantity of organic material transported to the estuary, we modified a series of equations developed by Gallagher (1977). The equations are based on the model of carbon fixation and subsequent losses as shown in the following diagram: respiration respiration T net ~ primary ' m living plant (G) mortality ^ (M) . ^ standing dead plant (SD) frag- ment a- N tion (F) ' fallen dead (FD) lost ^ to the ^ estuary (T.TT.I leaching leaching where P AG + M, AG = G - G.; ASD AFD and T., and T = harvest at beginning and end of time interval, respectively. Decomposition of standing dead and fallen dead (litter) marsh plant material was calculated with the following equations: DE SD DE FD where, DE,,n = Decomposition (respiration and leaching) of standing dead during time interval, DE.. = Decomposition (respiration and leaching) of fallen dead during time interval, t = time submerged during time interval, 40 ------- t = time emergent during time interval, 3 SD1 = rate of leaching of DOC from the standing dead community, SD = submerged or aquatic respiration of the standing dead community, SD = emergent or aerial respiration rate of the standing dead community, & FD, = rate of leaching of DOC from the fallen dead community, FD = submerged or aquatic respiration rate of the fallen dead community, and FD = emergent or aerial respiration rate of the fallen dead community. 3. After calculating decomposition, export was estimated with the following equations: F = ASD + M - DE , and o U LIE = AFD + F - DEFD. Export values were determined for each time interval and then summed to yield total export of organic matter for the entire time period. It was assumed that the dry weight of plant material was about 50% carbon. Using a 2% tidal inundation time for the _S. cynosuroides marsh, the equation yielded an export of 372 g C m~2 yr~^. In the _Z. miliacea marsh, a 5% inundation time for standing dead and a 10% inundation time for fallen dead yielded an annual export rate of 147 g C m~2. These export values account for 37% and 20% of net annual primary productivity for ^. cynosuroides and _Z. miliacea, respec- tively. The lower export value for the _Z. miliacea marsh can be explained, in part, by the higher respiration and leaching rates in this area and by the greater proportion of time the freshwater marsh is exposed to tidal inunda- tion, Thus, more carbon is lost through respiration and leaching resulting in less being available for export as detritus. Nevertheless, it is apparent that both marsh areas are making significant contributions to the estuarine system. Values for carbon export from S_. cynosuroides and Z_. miliacea marshes have not been reported. However, Teal (1962) estimated that 45% of tall form Spartina alterniflora net annual primary productivity is removed by tidal action before it can be utilized by marsh consumers. Odum and Fanning (1973) reported export values of 25% and 8% of net annual primary productivity for tall form and short form _S. alterniflora, respectively. Thus the values reported in this study are comparable to estimates for tall form _S. alterniflora. Although the equations shown above were formulated to estimate export from marsh areas, we attempted to utilize them in calculating the potential export of carbon from the swamp forest areas. Combining leaf litter fall from the two forest collection sites (Figure 4), and assuming a 50% tidal inunda- tion time, the data show a negative export of carbon (-211 g C m~- yr~^) which may indicate a transport of carbon into these areas. Positive values for carbon export were obtained only for the April-May collection period 41 ------- (6 g C m~2) and the August-October period (42 g C ra~2). The latter value is associated with relatively large quantities of leaf litter fall during this time period, whereas the former value is probably related to lower rates of respiration and leaching during this time period resulting in more carbon available for transport in plant material. Thus it appears that the forest swamp areas may act as a sink not only in the accumulation of some nutrients ns shown in this study and by Brinsin (1977), but also as a recipient of carbon. A more accurate account of tidal inundation time will enable us to refine these estimates. 42 ------- REFERENCES Barr, A. J., J. H. Goodnight, J. P. Sail, and J. T. Helwig. 1976. A User's Guide Co SAS 76. SAS Institute, Inc., Raleigh, North Carolina. Brinson, M. M. 1977. Decomposition and nutrient exchange of litter in an alluvial swamp forest. Ecology 58:601-609. Dunstan, W. M. , and L. P. Atkinson. 1976. Sources of new nitrogen for the South Atlantic Bight. Pages 69-78 in M. Wiley, ed., Uses, stresses and adaptation to the estuary. Vol. I. Estuarine Processes. Academic Press, Inc. New York. Gallagher, J. L., W. J. Pfeiffer, and L. R. Pomeroy. 1976. Leaching and microbial utilization of dissolved organic carbon from leaves of Spartina alterniflora. Estuarine Coastal Marine Sci. 4:467-471. Gallagher, J. L. and W. J. Pfeiffer. 1977. Aquatic metabolism of the communities associated with attached dead shoots of salt marsh plants. Limnolg. Oceanogr. 22:562-565. Gallagher, J. L. 1977. Detritus dynamics and microbial aspects of food webs in river swamp wetlands and adjacent estuarine waters. Progress Report for Office of Planning and Budget, Atlanta, Georgia. 35 pp. Linthurst, R. A., and R. J. Reimold, 1978. Estimated net aerial primary productivity for selected angiosperms in Maine, Delaware, and Georgia. Ecology 59:945-955. * Lomnicki, A., E. Bandola, and K. Jankowska. 1968. Modification of the Wiegert-Evans method for estimations of net primary production. Ecology 49:147-149. Odum, E. P. , and Marsha E. Fanning. 1973. Comparison of the productivity of Spartina alterniflora and Spartina cynosuroides in Georgia coastal marshes. Bull. G. Acad. Sc. 31: 1-12. Smalley, A. E. 1958. The role of two invertebrate populations, Littorina irrorata and Occhelium fidicinum in the energy flow of a salt marsh ecosystem. Ph.D. Thesis. University of Georgia, Athens. 126 pp. 43 ------- Teal, J. M. 1962. Energy flow in Che salt marsh ecosystem of Georgia. Ecology 43:614-624. Wharton, C. H. 1970. The southern river swamp a multiple use environ- ment. Georgia State University, Atlanta, Georgia. Wiegert, R. G., and F. C. Evans. 1964. Primary production and the disappearance of dead vegetation on an old field in Southeastern Michigan. Ecology 45: 49-63. Windom, H. L., W. H. Dunstan, and W. S. Gardner. 1975. River input of inorganic phosphorus and nitrogen to the southeastern salt marsh environment. Pages 309-313 _in F. G. Howell, J. B. Gentry, and M. H. Smith, eds. Mineral cycling in southeastern ecosystems. U.S. Energy Research and Development Administration, Washington, D.C. 44 ------- APPENDIX A - BIOMASS, AQUATIC RESPIRATION, AERIAL RESPIRATION, AND DOC LEACHING FOR STANDING DEAD AND FALLEN DEAD IN TWO SPECIES OF MARSH GRASS, AND FOR SWAMP FOREST LEAVES. 45 ------- TAHLE A-l. MEAN DRY WEIGHT (g m~2 ± S.E.) OF TWO SPECIES OF MARSH GRASSES (N=6 AND N=8, RESPECTIVELY) IN CLEAR CUT PLOTS FROM THE ALTAMAHA RIVER DELTA cr* Spartina cynosuroides Da te 17 Apr 30 May 10 Jul 14 Aug 16 Oct 28 Nov 9 Jan 5 Mar 13 Apr Live 1978 1978 1978 1978 1978 1978 1979 1979 1979 216 582 769 682 584 173 0 9 218 ± ± ± ± ± ± t + 69 57 118 107 94 44 2 49 Standing 920 676 828 837 1105 1800 1530 158 215 ± ± ± ± ± t ± ± ± Zlzaniopsls 17 Apr 30 May 10 Jul 14 Aug 16 Oct 28 Nov 9 Jan 5 Mar 13 Apr 1978 1978 1978 1978 1978 1978 1979 1979 1979 179 357 459 593 623 426 222 81 135 ± t ± + ± + l ± ± 44 93 61 157 122 60 41 12 13 870 506 368 308 393 521 332 426 465 ± ± ± ± ± ± ± ± ± Dead 94 53 147 194 114 275 362 57 38 miliacea 222 138 101 24 51 76 39 61 65 Litter 276 ± 246 ± 316 ± 228 + 244 ± 256 ± 273 ± 88 ± 269 ± 235 ± 254 ± 106 ± 77 ± 129 ± 96 ± 168 ± 216 ± 147 ± 44 69 63 40 15 53 57 21 84 62 61 27 13 22 21 15 8 11 Total llioniass 1412 1504 1913 1747 1105 2229 1803 255 702 1284 1117 933 978 1145 1043 722 723 747 ± 126 ± 87 ± 201 ± 297 ± 193 l 320 ± 405 ± 42 ± 137 ± 321 ± 276 ± 199 ± 178 ± 168 ± 117 ± 67 i 77 ± 73 ------- TABLE A-2. MEAN DRY WEIGHT (g ra ± S.E.) OF TWO SPECIES OF MARSH GRASSES (N=6, AND N=8, RESPECTIVELY) IN PREVIOUS CUT PLOTS FROM THE ALTAMAHA RIVER DELTA Spartina cynosuroides Date 30 May 1978 10 Jul 1978 14 Aug 1978 16 Occ 1978 28 Nov 1978 9 Jan 1979 5 Mar 1979 '13 Apr 1979 Live 682 ± 96 596 ± 80 764 ± 98 593 ± 140 287 ± 33 0 Plots destroyed. 118 ± 23 Total Dead 106 ± 14 209 ± 35 305 ± 33 335 ± 73 638 ± 51 408 ± 81 by fire 5 ± 1 Total Biomass 788 ± 98 805 ± 96 1069 ± 100 928 ± 187 925 ± 79 408 ± 81 123 ± 22 Zizaniopsis miliacea 30 May 1978 10 Jul 1978 14 Aug 1978 16 Oct 1978 28 Nov 1978 9 Jan 1979 5 Mar 1979 13 Apr 1979 212 ± 64 490 ±47 468 ± 70 601 ± 186 453 ± 14 146 ± 16 70 ± 9 139 ± 15 17.2 ±32 193 ± 38 98 ± 16 209 ± 58 252 ± 75 178 ± 26 300 ± 47 66 ± 11 384 ± 80 683 ± 67 566 ± 80 810 ± 243 705 ± 89 324 ± 37 370 ± 57 205 ± 22 47 ------- TABLE A-3 MEAN DRY WEIGHT (g m~2 ± S.E.) OF LEAP LITTER AT TOO FOREST LOCATIONS (N=12) IN THE ALTAMAKA RIVER DELTA Date River bend Freshwater Swamp 17 Apr 30 May 10 Jul 14 Aug 16 Oct 28 Nov 9 Jan 5 Mar 13 Apr 1978 1978 197S 1978 1973 1978 1979 1979 1979 10.1 ± 0.9 29.9 ± 10.6 20.8 ± 5.2 23.9 ± 3.5 114. S ± 17.3 120.1 ± 18.0 27.7 ± 5.1 35.8 ± 11.6 15.8 ± 3.4 23.12 ± 3.1 24.30 ± 3.8 8.20 ± 1.2 12.30 ± 3.5 76.40 ± 11.1 152.80 ± 18.8 46.90 ± 6.2 23.90 ± 3.4 17.30 ± 2.6 48 ------- TABLE A- AQUATIC RESPIRATION" (MS c g ' DRY WEIGHT h L ± S.E.) OF ATTACHED DEAD PLANT' COMMUNITY IN TWO SPECIES OF MARSH GRASSES IN THE ALTAMAIIA RIVER DELTA Spartina c] Date 18 Apr 30 May 10 Jul 14 Aug 16 Oct 29 Nov 9 Jan 5 Mar 13 Apr 1978 1978 1978 1978 1978 1978 1979 1979 1979 Fallen 82 ± 50 ± 55 ± 31 t 8 ± 29 ± 25 ± 9 ± 51 ± Dead .12 7 20 1 4 6 4 3 4 ^nosuroides Standing Dead 27 63 55 13 21 15 9 41 ± ± ± ± ± ± ± ± 3 26 17 7 4 3 1 5 Zizariiopsis miliacea Fallen 41 36 44 54 9 30 26 23 94 + t ± ± ± J; ± ± ± Dead 4 8 15 14 5 9 2 4 18 Standing Dead 10 1 55 29 59 94 12 126 ± 2 ± 3 ± 3 ± 7 ± 1.4 ± 16 ± 5 ± 11 Incubation time, 3.5 h; N=3. ------- Ul o TAHLE A-5. AQUATIC RliSPIRATION* (|jg C g l DRY WEIGHT h *~ ± S.l::.) OF ATTACHED DEAD PLANT COMMUNITY FOR THREE SPECIES OF SWAMP FOREST LEAVES IN THE ALTAMAHA RIVER DELTA Da to Nyssn aquatlea Liquldanihar styracitlua TaxodLum distichuin 18 30 10 14 16 30 9 5 13 Apr May .Itil Aug Oct Nov Jan Mar Apr T: i.-;v.i: 1978 1978 1978 1978 1978 1978 1979 1979 1979 125 63 79 126 153 335 189 46 277 t ± i ± ± ± ± ± ± 9 2 4 6 30 21 26 9 28 95 77 190 92 236 243 81 24 47 ± ± ± ± + ± ± ± ± 16 30 53 22 56 17 14 1 11 383 160 161 296 97 892 59 31 62 ± 78 ± 7 ± 18 t 30 ± 14 t 72 ± 2 ± 5 ± 3 Incubation time, 3 h; N=3. ------- TABLE A-6. -1 -1 AERIAL RESPIRATION (ug C g " DRY WEIGHT-h " t S.E.) OF AIT ACHED DEAD PLANT COMMUNITY IN TWO SPECIES OF MARSH GRASSES FROM THE ALTAMAHA RIVER DELTA Spartina cynosuroides Date 17 Apr 30 May 10 Jul 14 Aug 16 Oct 30 Nov 9 Jan 5 Mar 13 Apr Fallen Dead 1978 1978 1978 1978 1978 1978 1979 1979 1979 . 4 11 6 28 22 25 18 28 1 ± 1 (6) ± 0.6 (6) ± 1 i 5 ± 3 i 1 ± 2 ± 2 ± 0.1 (6) Standing 1 1 0.8 -4 24 2 1 6 1 ± 0. ± 0. ± 0. ± 2 ± 1 ± 0. ± 0. t 1 ± 0. Dead 3 (6) 5 (6) 2 4 1 3 (6) Zizaniopsis Fallen Dead 72 ± 81 t 132 ± 82 i 106 ± 25 ± 28 ± 64 ± 55 ± 5 (6) 3 (6) 31 12 4 i 2 3 1 miliacea Standing Dead 1 9 8 -4 3 2 14 5 1 + + ± ± ± ± ± ± ± 0. 1 2 1 2 0. 1 1 0. 4 (6) (6) (8) 4 (7) (7) 2 Incubation time, 3 h; N=9, unless otherwise indicated. ------- Ul NJ TABLK A-7. AEE<1AL RESl-'IRATION" (jJg C g J DRY WEIGHT h l ± S.E.) OF AIT ACHED DEAD PLANT COMMUNITY FOR THREE SPECIES OF SWAMP FOREST LEAVES IN THE ALTAMAHA RIVER DELTA Date 1.7 Apr 30 May 10 Jul 1.4 Aug 16 Oct 30 Nov 9 Jan 5 Mar 13 Apr 1978 1978 1978 1978 1978 1978 1979 1979 1979 Nyssn 1 ± 18 ± 24 ± 142 ± 16 ± 110 ± 35 ± 68 ± 26 ± acj^uatica 0.4 1 4 28 5 7 7 5 7 (6) (6) (7) (8) (6) Liquidambar styraciflua 26 16 1 68 16 12 26 11 2 ± ± + ± ± + + ± ± 8 2 0.3 7 2 0.3 2 2 0.2 (6) (6) (8) (10) (6) (8) (7) Taxodium distichum 2 t 114 ± 45 ± 133 ± 27 ± 49 ± 29 ± 35 ± 5 ± 0.5 20 7 11 7 3 1 2 1 (6) (6) (10) (8) (7) Incubation time, 3 h; N=9, unless otherwise noted. ------- OJ TABLE A-8. DOC RELEASED (pg C g DRY WEIGHT h ± S-E.) FROM DEAD PLANT PARTS FOR TWO SPECIES OF MARSH GRASSES FROM THE ALTAMAHA RIVER DELTA Spartina cynosuroides Date 17 Apr 30 May 10 -lul 14 Aug 16 Oct 30 Nov 9 Jan 5 Mar 13 Apr Fallen Dead 1978 1978 1978 1978 1978 1978 1979 1979 1979 435 ± 18 573 ±83 552 ± 31 262 ± 48 290 ± 26 169 ± 18 335 ± 16 247 ± 32 (7) (7) (A) (3) (8) Standing Dead 425 ± 364 ± 379 ± 448 1 265 ± 501 ± 127 ± 142 304 ± 33 92 44 54 37 67 21 24 (6) (6) (3) (7) (1) Zizaniopsis Fallen Dead 201 ± 183 ± 313 ± 769 ± 954 ± 109 ± 346 ± 532 246 ± 15 3 25 71 49 24 126 24 (8) (8) (5) (4) (3) (1) millacea Standing Dead 594 ± 71 468 !: 12 441 ± 36 230 ± 41 628 ± 27 322 ± 65 107 270 ± 52 731 ± 62 (7) (8) (8) (4) (1) (3) fncubation time, 3 hr; N=9, unless otherwise indicated. ------- TABLE A-9. DOC RELEASED g C g l DRY WEIGHT h 1 ± S.E.) FROM THREE SPECIES OF SWAMl1 FOREST LEAVES COLLECTED IN THE ALTAMAHA RIVER DELTA Date 1.7 30 10 14 16 30 9 5 13 Apr May .Tu.1 Aug Oct Nov .Ian Mar Apr Nyssa aquatica 1978 1978 1978 1978 1978 1978 1979 1979 1979 660 ± 94 ± 746 ± 390 t 289 ± 842 ± 299 l 199 ± 1349 ± 104 20 78 77 41 46 25 46 143 (5) (8) (8) (2) (3) (3) (6) Liquldambar styraciflua 398 ± 22 ± 927 ± 342 ± 2570 ± 2183 ± 356 i 72 272 ± 33 11 35 40 249 219 143 4 ' (6) (6) (8) (3) (2) (1) (5) Taxodium 179 ± 224 ± 1578 ± 2054 ± 1308 ± 316 ± -22 25 ± 409 ± distich urn 9 37 135 113 175 41 5 47 (8) (8) (2) (1) (3) (7) Incubation time, 3 h; N=9, unless otherwise indicated. ------- APPENDIX B - BIOMASS, AQUATIC RESPIRATION, AERIAL RESPIRATION, DOC LEACHING AND ELEMENTAL COMPOSITION OF LITTER BAG PLANT MATERIAL FOR TWO SPECIES OF MARSH GRASSES AND SWAMP FOREST LEAVES. 55 ------- TABLE B-l. WEIGHT OF DECOMPOSING MARSH GRASS AND SWAMP FOREST LEAVES (g DRY WEIGHT 1 S.E.) FROM LITTER BAGS AT FOUR LOCATIONS IN THE ALTAMAHA RIVER DELTA AT THREE COLLECTION PERIODS'!" 1 month 6 months 11 months Sp art ina cynosuroides Suspended Surface Submerged Saltwater Zizaniopsis miliacea Suspended Surface Submerged Saltwater Forest Leaves Surface Submerged Saltwater 96. ± 1.0 95 ± 1.0 84 ± 1.0 82 ± 2.0 (A) 93 ± 1.0 83 ± 0.4 (5) 81 ± 2.0 (4) 88 ± 3.0 (6) 16 ±0.4 17 ± 1.0 16 ± 2.0 92 69 52 42 28 6 7 4 ± 0.3 ± 0.2 ± 1 (3) ± 4.0 ± 3.0 (4) ± 6.0 ± 0.6 ± 0.4 38 ± 5.0 (5) 14 ± 2.0 (4) 5 ± 0.8 3 ± 0.6 (5) Initial weight of marsh grass = lOOg/bag Initial weight of forest leaves = /Og/bag I N=fa, unless otherwise indicated ------- TABLE B-2. AQUATIC RESPIRATION (|Jg C g DRY WEIGHT h ± S.E.) OF ATTACHED DEAD PLANT COMMUNITY l-'KOM DEAD PLANT PARTS ENCLOSED IN SUSPENDED (SUS), SURFACE (SUR), SUBMERGED (SUB) LITTER BAGS AT THE COLLECTION SITE AND SUBMERGED BAGS IN SALTWATER (SAL) 1 month Spartina cynosuroides SUB SUS SUR SAL Zi zaniopsis miliacea SUB SUS SUR SAL Forest Leaves SUB SUR SAL 62 ± 15 ± 61 ± 143 ± 63 ± 20 ± 59 ± 141 ± 93 ± 85 ± 163 ± 7 5 25 19 3 10 10 13 12 19 21 6 months 11 months 27 t 3 13 ± 13 11 i 3 19 ±5 26 1 7 66 ± 24 -2 ± 10 15 ± 2 51 ± 23 28 ± 3 47 ± 17 18 ± 4 133 ±56 30 ± 8 * Incubation time, 3.5 h; N=3. ------- TABLE B-3. AERIAL RESPIRATION (»Jg C g DRY WEIGHT h ± S.E.) OF ATTACHED DEAD PLANT COMMUNITY FROM DEAD PLANT PARTS ENCLOSED IN SUSPENDED (SUS), SURFACE (SUR), SUBMERGED (SITU) LITTER BAGS AT THE COLLECTION SITE, AND SUBMERGED BAGS IN SALTWATER (SAL) CO Spartina cynosuroldes SUli SUS SUR SAL ZtzaniopsJ.3 miliacea SUB SUS SUR SAL Lorest Leaves SUB SUR SAL I 1 119 ± 3 ± 62 ± 63 ± 121 ± 31 ± 73 ± 124 ± 49 ± 58 ± 58 t no ri lh 5 .04 (7) 5 3 6 (6) 5 3 3 3 (8) 2 (10) 6 6 months 38 ± 3 (8) 17 ± 2 (6) 34 ± 2 60 ± 2 46 ± 3 21 ± 3 20 ± 1 (10) 24 ± 1 11 months 13 ± 2 (8) 36 ± 4 63 ± 2 57 ± 3 (8) 21 1 1 17 ± 2 Incubation time, 3h; N=9, unless otherwise indicated. ------- TABU: 11-4. DOC' RELEASED (ug c g DRY WEIGHT h ± S.E.) FROM DEAD PLANT PARTS ENCLOSED IN SUSPENDED (SUS), SURFACE (SUR), SUBMERGED (SUB) LITTER BAGS AT THE COLLECTION SITE AND SUBMERGED IN SALTWATER (SAL) Ul VO Spartina cynosuroidcs SUB SUS SUR SAL Zizaniopsis mlliacea SUB . SUS SUR SAL Forest Leaves SUB SUR SAL I (i 733 ± 473 ± 718 ± 78 ± 139 ± - 332 ± 100 ± 153 ± -65 ± 57 ± -4 ± nonth 37 205 119 (8) 20 11 9 13 26 4 14 14 6 months 11 months 203 ± 120 (2) 137 ± 27 (2) 123 ± 25 203 ± 98 (3) 73 ± 10 287 ± 145 (2) -4 ± 28 312 ± 82 (7) 296 (1) 70 ± 23 270 ± 52 (3) -27 ± 29 (8) -37 ± 85 (4) -28 ± 10 (7) -27 ± 24 (4) Incubation time, 3 h; N=9, unless otherwise indicated. ------- TABLE B-5. MINERAL CONTENT OF SPARTINA CYNOSUROIDES STANDING DEAD ENCLOSED IN SUSPENDED (SUS), SURFACE (SUR) AND SUBMERGED (SUB) LITTER BAGS AT THE COLLECTION SITE; SUBMERGED MATERIAL IN SALTWATER (SAL); AND FALLEN DEAD MATERIAL (LIT) COLLECTED FROM THE MARSH SURFACE AT EACH SAMPLING PERIODt cr> o 1 month SUS SUR SUB SAL LIT 6 months SUS SUR SUB LIT 11 months SUS SUR P .035 ± .050 ± .081 ± .093 ± .038 .038 ± .080 ± .125 ± .053 .041 ± .048 ± .007 .001 .011 .008 .009 .001 .002 .004 .006 K .048 ± .046 ± .072 ± .157 ± .058 .035 ± .047 ± .027 ± .014 <.008 .014 ± Ca .012 .014 .006 .015 .006 .003 .005 .004 .169 ± .238 ± .209 ± .270 ± .086 .181 ± .415 ± .708 ± .222 .270 ± .172 ± .002 .015 .025 .026 .015 .029 .133 .105 .029 Mg .079 ± .089 ± .131 ± .305 ± .0543 .164 ± .168 ± .134 ± .096 .128 ± .109 ± .003 .003 .004 .031 .022 .042 .004 .018 .003 0. 0. 0. 0. 0. 0. 0. 1. 0. 0. 0. 46 47 69 64 54 73 98 21 68 77 86 N ± 0.01 ± 0.03 ± 0.06 ± 0.06 ± 0.03 ± 0.13 ± 0.05 ± 0.01 ± 0.05 (Continued) ------- TABLE B-5. (Continued) Mn Fe Al Cu cr» 1 month SUS SUR SUB SAL LIT 6 months SUS SUR SUB LIT 11 months SUS SUR 157.8 ± 183.3 ± 444.0 ± 1110 ± 222.2 87.9 ± 322.2 ± 2527 ± 251.9 81.1 ± 100.6 ± 39.3 11.9 87.9 351 11.7 99.1 468 16.7 42.1 364 ± 1651 ± 4057 ± 4343 ± 73 503 ± 4200 ± 4383 ± 114 570 ± 2299 ± 24.4 507 521 237 165 1052 758 87 1430 479 ± 2342 ± 5862 ± 11449 ± 34 2527 ± 5701 ± 4935 ± 73 1865 ± 4125 ± 55 863 270 454 490 209 783 1215 774 3. 3. 5. 21. 4. 8. 14. 5. 6. 5. 6. 13 ± 33 ± 58 ± 00 ± 31 36 ± 35 ± 04 ± 92 75 ± 04 ± 0.38 0.24 0.37 2.07 5.64 5.41 0.27 0.86 0.69 2.66 3.13 4.38 3.21 3.21 2.43 3.75 4.31 1.80 1.61 1.29 ± 0.59 ± 0.42 ± 0.33 ± 0.72 ± 0.15 ± 0.41 ± 0.08 ± 0.13 ± 0.12 (Continued) ------- TABLE B-5. (Concluded) Zn Sr Ba Na cr> N) 1 month SUS SUR SUB SAL LIT 6 months SUS SUR SUB LIT 11 months SUS SUR 24. 33. 36. 27. 37. '44. 42. 57. 7. 61. 34. 28 ± 62 ± 67 ± 23 ± 34 85 ± 91 ± 07 ± 56 61 ± 07 ± 1.82 4.46 5.60 2.23 7.00 16.07 1.93 14.45 13.44 8. 16. 19. 36. 2. 16. 35. 57. 11. 18. 17. 18 ± 00 ± 67 ± 71 ± 19 00 ± 35 ± 18 ± 65 34 ± 80 ± 0.56 1.97 3.78 1.84 3.41 3.99 12.14 8.13 4.14 5. 12. 14. 8. 2. 2. 5. 48. 2. 5. 5. 46 ± 0. 48 ± 1. 51 ± 1. 46 ± 0. 64 97 ± 0. 24 ± 0. 05 ± 3. 56 42 ± 0. 61 ± 1. 27 42 89 28 47 21 56 94 15 343.30 273.90 416.70 76.73 92.90 4580 4769 379.00 - 385.50 1913 ± 53.80 ± 13.90 ± 25.00 ± 5.40 ± 691 ± 211 ± 37.00 ± 44.60 ± 82 P, K, Ca, Mg, N in %±S.E.; Mn, Fe, Al, B, Cu, Zn, Sr, Ba, Na in PPHtS.E. t N=3 for all values except LIT, where N=l. ------- TABLE B-6. MINERAL CONTENT OF ZIZANIOPSIS MILIACEA STANDING DEAD ENCLOSED IN SUSPENDED (SUS), SURFACE (SUR), AND SUBMERGED (SUB) LITTER BAGS AT TOE COLLECTION SITE; SUBMERGED MATERIAL IN SALTWATER (SAL); AND FALLEN DEAD MATERIAL (LIT) COLLECTED FROM THE MARSH SURFACE AT EACH SAMPLING PERIOD"!' 1 month SUS SUR SUB SAL LIT 6 months SUS SUR SUB LIT 11 months SUS SUR LIT 1' 0.079 ± 0.006 0.064 ± 0.002 0.086 ± 0.007 0.121 ± 0.010 0.063 0.097 ± 0.014 0.132 ± 0.004 0.140 0.047 0.084 ± 0.013 0.132 ± 0.009 0.108 K 0.046 ± 0.001 0.038 ± 0.002 0.414 ± 0.001 0.295 ± 0.008 0.088 0.020 ± 0.006 0.021 ± 0.004 0.016 0.048 <.008 0.023 ± 0.002 0.080 Ca 0.358 ± 0.022 0.639 ± 0.002 0.086 ± 0.007 0.439 ± 0.046 0.331 0.481 ± 0.061 0.592 ± 0.119 0.507 0.834 0.354 ±.0.032 0.416 ± 0.022 0.247 Mg 0.054 ± 0.001 0.056 ± 0.004 0.058 ± 0.003 0.609 ± 0.013 0.038 0.118 ± 0.015 0.133 ± 0.005 0.073 0.059 0.067 ± 0.008 0.127 ± 0.001 0.050 N 0.78 ± 0.74 ± 0.82 ± 0.91 ± 0.75 1.29 ± 1.65 ± 0.13 0.84 1.29 ± 1. 72 ± 0.88 0.02 0.02 0.05 0.04 0.06 0.08 0.11 0.04 (Continued) ------- TABLE B-6. (Continued) Mn Fe Al Cu 1 month SUS SUR SUB SAL LIT 6 months SUS SUR .SUB LIT 11 months SUS SUR LIT 601.9 ± 512.8 ± 611.6 ± 2449 ± 299 690.0 ± 1057 ± 3875 223 679.8 ± 1222 ± 504 25.2 30.1 44.3 279 82.3 329 104.6 675 2062 ± 3448 ± 4918 ± 2611 ± 546 3143 ± 5754 ± 7165 300 2884 ± 6844 ± 548 583 417 879 202 1183 652 1155 577 4047 ± 5548 ± 5800 ± 5840 ± 620 4098 ± 5841 ± 5558 61 3151 ± 6345 ± 755 336 733 771 281 1646 480 1266 144 3.04 2.59 2.58 31.71 2.37 3.83 4.50 3.27 3.98 2.40 3.97 2.45 ± 0. ± 0. ± 0. ± 0. ± 0. ± 0. ±.0. ± 0. 18 12 10 33 66 39 43 16 2.17 ± 2.17 ± 3.01 ± 3.10 ± 1.72 3.71 ± 4.78 ± 5.20 1.43 2.39 ± 4.37 ± 1.27 0.11 0.19 0.35 0.22 0.55 0.24 0.37 0.12 (Continued) ------- Ul TABLE B-6. (Concluded) Zn Sr Ba Na 1 month SUS SUR SUB SAL LIT 6 months SUS SUR SUB LIT 11 months SUS SUR LIT 36. 27. 34. 18. 16. 90. 145. 169 7. 3227 152. 16. 4. ± 2.3 6 ± 2.4 3, ± 3.6 1 ± 1.51 5 5 ± 3.4 3 ± 23.9 9 ± 1840 7 ± 21.3 8 12. 12. 14. 63. 10. 33. 44. 22. 15. 22. 40. 2. 70 ± 70 ± 26 ± 90 ± 07 68 ± 39 ± 66 46 14 ± 36 ± 74 1.87 2.56 2.16 2.15 3.65 2.71 4.27 2.22 48. 44. 46. 10. 30. 46. 64. 102. 25. 52. 51. 23. 52 ± 07 ± 05 ± 50 ± 78 54 ± 47 ± 70 91 62 ± 32 ± 11 4.22 0.86 5.00 0.69 5.20 7.20 10.50 7.71 108. 120. 164. 28. 75. 257. 229. 209. 35. 71. 189. 902. 7 1 3 83 4 3 3 9 8 4 3 1 ± 8.8 ± 10.2 ± 12.4 ± 2.26 ± 33.1 ± 24.1 ± 13.5 ± 12.1 P, K, Ca, Mg, N in %±S.E.; Mn, Fe, Al, B, Cu, Zn, Sr, Ba, Na in PPM±S.E. t N=3 for all values except LIT, where N=l. ------- TABLE B-7. MINERAL CONTENT OF DEAD SWAMP FOREST LEAVES ENCLOSED IN SURFACE (SUR), AND SUBMERGED (SUB) LITTER BAOS AT THE COLLECTION STIE; AND DEAD LEAVES SUBMERGED IN SALT WATER (SAL)t 1 6 11 month SUB SUR SAL mon t hs SUB SUR months SUB SUR P 0.128 ± 0.115 ± 0.197 ± 0.174 ± 0.186 ± 0.202 ± 0.171 ± 0.006 0.010 0.012 0.002 0.010 0.024 0.006 0/062 0.068 0.115 0.033 0.045 0.040 0.023 K ± 0.005 ± 0.005 ± 0.004 ± 0.009 ± 0.012 ± 0.009 ± 0.004 1.344 1.380 0.862 1.594 1..883 1.352 1.336 Ca ± 0.048 ± 0.019 ± 0.037 ± 0.161 ± 0.361 ± 0.142 ± 0.075 0.114 0.117 0.519 0.173 0.177 0.150 0.138 Mg ± 0.009 ± 0.005 ± 0.004 ± 0.009 ± 0.011 ± 0.002 ± 0.004 1.21 1.20 1.14 1.52 1.63 1.55 1.51 N ± 0.01 ± 0.15 ± 0.06 ± 0.01 ± 0.04 ± 0.20 ± 0.06 (Continued) ------- TABLE R-7. (Continued) Mn Fe Al Cu 1 6 11 month sun SUR SAL months SUB SUR months SUB SUR 1010 ± 727 ± 4398 ± 3733 ± 3892 ± 3144 ± 1456 ± 155 27 450 67 4 828 650 733 8347 ± 4530 ± 7447 ± 7094 ± 11319 ± 15665 ± 13252 ± 2540 330 416 161 1700 1173 1126 10868 ± 5949 ± 11164 ± 4782 ± 8325 ± 5619 ± 5608 ± 2765 318 513 365 1872 151 37 14.61 16.49 125.00 13.80 15.45 14.62 12.01 ± 1.00 ± 1.28 ±9.36 ± 0.82 ± 0.98 ± 0.94 ± 0.74 7.49 7.00 8.05 10.02 8.79 11.10 9.48 ± 0.65 ±0.23 ± 0.43 ± 0.88 ± 0.31 ± 0.94 ± 1.13 (Continued) ------- TABLE H-7. (Concluded) Zn Sr Ba Na j. month SUB SUR SAL 6 months SUB SUR 11 months cr> oo SUB SUR 134. 113. 57. 455. 918. 259. 263. 1 ± 0 ± 7 ± 3 ± 0 ± 4 ± 2 1.8 17.2 8.7 62.2 244 75.2 69 65 108 96 94 85 75 . 38 i .80 ± .60 ± .00 ± .90 ± .80 ± .50 ± 5.21 0.88 8.50 11.10 5.80 2.70 7.50 154. 151. 20. 202. 298. 218. 167. 3 ± 5 ± 1 ± 6 ± 0 ± 7 ± 1 ± 7.22 2.17 1.74 26.00 101.60 11.60 9.70 182.9 l 177.7 ± 249.7 ± 282.1 ± 631.9 ± 148.4 ± 182.8 ± 2.07 2.74 34.60 94.00 269.50 19.30 8.30 P, K, Ca, Mg, N In %±S.E.; Mn, Fe, Al, B, Cu, Zn, Sr, Ba, Na In PPM±S.E. t N=3 for all values. ------- |