EPA-600/3-76-102 September 1976 Ecological Research Series SUSCEPTIBILITY OF WOODY PLANTS TO SULFUR DIOXIDE AND PHOTOCHEMICAL OXIDANTS Environmental Research Laboratory Office of Research and Development U.S. Environmental Protection Agency Corvallis, Oregon 97330 ------- RESEARCH REPORTING SERIES Research reports of the Office of Research and Development, U.S. Environmental Protection Agency, have been grouped into five series. These five broad categories were established to facilitate further development and application of environmental technology. Elimination of traditional grouping was consciously planned to foster technology transfer and a maximum interface in related fields. The five series are: 1. Environmental Health Effects Research 2. Environmental Protection Technology 3. Ecological Research 4. Environmental Monitoring 5. Socioeconomic Environmental Studies This report has been assigned to the ECOLOGICAL RESEARCH series. This series describes research on the effects of pollution on humans, plant and animal species, and materials. Problems are assessed for their long- and short-term influences. Investigations include formation, transport, and pathway studies to determine the fate of pollutants and their effects. This work provides the technical basis for setting standards to minimize undesirable cha'nges in living organisms in the aquatic, terrestrial, and atmospheric environments. This document is available to the public through the National Technical Informa- tion Service, Springfield, Virginia 22161. ------- EPA-600/3-76-102 September 1976 SUSCEPTIBILITY OF WOODY PLANTS TO SULFUR DIOXIDE AND PHOTOCHEMICAL OXIDANTS A Literature Review by Donald D. Davis Department of Plant Pathology Center for Air Environment Studies The Pennsylvania State University University Park, Pennsylvania 16802 and Raymond 6. Wilhour Terrestrial Ecology Branch Ecological Effects Research Division Corvallis, Oregon 97330 CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY OFFICE OF RESEARCH AND DEVELOPMENT U.S. ENVIRONMENTAL PROTECTION AGENCY CORVALLIS, OREGON 97330 ------- 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. 11 ------- FOREWORD Effective regulatory and enforcement actions by the Environmental Protection Agency would be virtually impossible without sound scien- tific data on pollutants and their impact on environmental stability and human health. Responsibility for building this data base has been assigned to EPA's Office of Research and Development and its 15 major field installations, one of which is the Corvallis Environmental Research Laboratory. The primary mission of the Corvallis Laboratory is research on the effects of environmental pollutants on terrestrial, freshwater, and marine ecosystems; the behavior, effects and control of pollutants in lake systems; and the development of predictive models on the movement of pollutants in the biosphere. Evidence of great diversity in the effect of gaseous air pollutants on woody vegetation motivated the development of this report. The intent was to summarize the scientific literature regarding species sensitivity to major air pollutants. It is becoming more apparent that species sensitivity to air pollutants is a significant character- istic in the selection of species for planting in pollution-stressed areas. This document should be a valuable reference for scientists, foresters, horticulturists, city planners and others concerned with the culture of woody vegetation. A. F. Bartsch Di rector- Co rvall is Environmental Research Laboratory m ------- ABSTRACT This report presents the result of a detailed review of European and United States literature regarding the sensitivity of woody vegetation to sulfur dioxide, ozone, peroxyacetyl nitrate (PAN), and nitrogen oxides. Reference is made to Russian, Japanese and Australian literature only when species examined are commercially important in the United States. The manner in which the original sensitivity data were collected may influence the relative position of a species in a composite sensiti- vity table. Therefore, many original tables are presented as cited by specific authors for individual interpretation. Composite summary sensiti- vity tables are presented for each pollutant. Relative sensitivity compilations should be used with caution and with an understanding of inherent limitations. The sensitivity categories of "very sensitive" and "very tolerant" should be of great assistance in selecting woody vegetation for planting in areas of high air pollution potential. However, for species found in the "intermediate" sensitivity category, greater emphasis should be placed on predominant local environmental conditions and economic factors than on air pollution sensitivity. iv ------- CONTENTS Page Abstract iv List of Tables vi SECTIONS I. Introduction 1 Selection of Criteria 1 Collection of Original data 1 Compilation of Lists 4 Geographic Location 4 II. Conclusions 6 III. Recommendations 7 IV. Sulfur Dioxide 8 North America 8 Summary Table (Table 17) 25 Europe - Russia 28 Summary Table (Table 26) 41 V. Photochemical Oxidants 47 Introduction 47 Ozone 47 Summary Table (Table 30) 58 Peroxyacetyl Nitrate (PAN) 55 Summary Table (Table 31) 61 Oxides of Nitrogen 55 Summary Table (Table 32) 63 VI. References 64 ------- LIST OF TABLES No. Page 1 Suitable Criteria for Injury Caused by Air Pollution to Forest Trees and Forests 2 2 Some Suitable Criteria of Fume Damage to Forest Trees and Forests 3 3 Relative Susceptibility of Western Coniferous Trees to S02 9 4 Relative Susceptibility of Western Broad!eaved Trees to S02 10 5 Relative Susceptibility of Western Woody Shrubs to SO,,. . 11 6 Approximate Order of Susceptibility, Beginning with the Most Susceptible, of Trees in the Upper Columbia River Valley to Acute Sulfur Dioxide Injury 12 7 Approximate Order of Susceptibility, Beginning with the Most Susceptible, of Forest Shrubs in the Upper Columbia River Valley to Acute Sulfur Dioxide Injury 13 8 Approximate Order of S02 Susceptibility of Trees Growing Near a Smelter in Montana 14 9 Relative Sensitivity of Selected Woody Plants to Injury by S02 15 10 Susceptibility of Selected Native Woody Desert Vegetation to S02 17 11 Relative S02 Susceptibility of Forest Tree Species Growing Near Sudbury, Ontario 19 12 Sensitivity of Trees to S02 20 13 Observed Sensitivity of Woody Plants to S0? in Vicinity of Sulphite Pulp and Paper Mill in Ontario .... 21 14 Relative Susceptibility of Woody Plants Growing Near a Source of S09 in Southern Quebec 22 VI ------- No. Page 15 Selected Woody Plants That Are Relatively Susceptible to S02 23 16 Sulfur Dioxide Concentrations Causing Threshold Injury to Various Sensitivity Groups of Vegetation 24 17 The Relative SCL Sensitivity of Woody Plants Grown in North America [Compilation of previously listed species] 25 18 The Relative SCL Susceptibility of European Deciduous Woody plants . 29 19 The Relative S02 Susceptibility of European Coniferous Woody plants . 7 31 20 Susceptibility of Hardwoods to "Smoke" Damage from a Copper Smelter in Turkey 33 21 Susceptibility to S02 of 30 - to 40-Year Old Woody Species Planted Near a Zinc Plant Emitting S02 in Germany 34 22 Relative S02 Sensitivity of Woody Plants Grown in Containers and Placed in an Industrial Area of Norway Having High S02 Levels 35 23 Preliminary Ranking of Woody Species Exposed to S02 in Chambers or in the Field Using the "Fumigation Cannon" in The Netherlands 36 24 Relative Susceptibility of Forest Conifers Determined After 2 Years of Fumigations in Germany 37 25 Percent Foliar Injury Produced by S02 on Plants, Based on 3 Years of Experimental Exposures in Russia 38 26 Sequence List According to Leaf Damage as a Result of S02 Test Exposure from 1967 to 1969 in Germany 41 27 Relative Ozone Susceptibility of Shrubs, Trees, and Ornamentals Exposed to Ozone Applied at Bi-Weekly Intervals Throughout the Growing Season in Chambers 43 28 Threshold Concentration of Ozone Needed to Cause Injury on Plants Growing in Native Habitat in Utah 53 vi i ------- No. Page 29 Daily Dose of Ozone Needed to Cause Injury to Various Plant Species for Time Periods Up to 2 Weeks 55 30 Relative Sensitivity of Woody Plants Grown in North America to Ozone [Compilation of previously listed species] 58 31 Relative Sensitivity of Woody Plants Grown in North America to PAN [Artificial exposures; compilation but mainly from (9)] 61 32 Relative Susceptibility of Woody Plants to NO 63 X vm ------- SECTION I INTRODUCTION SELECTION OF CRITERIA The placement of a plant species or variety as to its susceptibility or tolerance to a given air pollutant is often influenced by the specific criteria used for ranking. Criteria may range from cellular or physio- logical effects to changes in species composition or plant community succession. The same species may be ranked differently depending upon the criterion used. Criteria used to assess susceptibility are sometimes based upon the ultimate use of the plants. Timber species or fruit trees may be rated by direct yield loss; ornamentals or Christmas trees by foliar discolor- ation. Trees used for wildlife management, recreation, or watershed stabilization may require more complex rating schemes since they can tolerate different amounts of injury and still fulfill their primary functions. Regenerative capacity, regardless of degree of foliar injury, is very important and must also be considered. Foliar injury is often one of the early manifestations which leads to other more significant effects. It is an obvious response, easy to quantify, and most universally used measure of plant response. Thus, the majority of the species listed in this review were ranked into sensitivity categories by percentage of foliar injury induced by a given air pollutant. Knabe (20) summarized specific criteria for measuring the impact of air pollution on forest trees (Table 1). In addition, Guderian, as cited in (20), discussed the more general criteria which also influence the ultimate impact of air pollution on forest stands (Table 2). The tables also indicate the usefulness of each criterion in ranking injury, from the specific plant organ level to general ecosystem effects. COLLECTION OF ORIGINAL DATA A critical aspect which must be considered when compiling relative sensitivity tables is the manner in which the original data were collected. Data may have originated from: field observations of injury on native vegetation; symptoms on vegetation purposely transplanted into an area exposed to air pollution; artificial exposure in chambers in the laboratory or in the field; and artificial exposure of plants in the field without use of chambers. Each method has its advantages and limitations. Field observations and rankings may be complicated by the presence of other air pollutants, especially in industrial regions. Symptom intensity may vary with pheno- ------- TABLE 1. SOME SUITABLE CRITERIA OF INJURY CAUSED BY AIR POLLUTION TO FOREST TREES AND FORESTS (20) Part of Criteria of Effect a Plant Changes in cell components xa Changes in metabolism x Changes in cell structure x Degree of chlorosis or necrosis x Premature leaf abscission or needle cast x Decreased growth (x) Percentage of plants injured to a certain degree Percentage of dead plants Decreased production of organic matter or decreased increment per area Changes in number of species Changes in abundance Changes in coverage Changes in general health conditions Subject of Investigation Individual Number of Plant Individuals x x x x x x x x x x x x x x • - - - - X Population (Stand) - - - (x) (x) X X X X (x) (x) (x) X Ecosystem - - - - - (x) (x) X X X X X x = useful criterion. (x) = possible criterion. (Reprinted from "Air Quality Criteria and Their Importance for Forests," 1971 by W. Knabe with permission from Forstliche Bundesversuchsanstalt) ------- TABLE 2. SOME SUITABLE CRITERIA OF FUME DAMAGE TO FOREST TREES AND FORESTS (20) Criteria of Effect Part of a Plant Individual Number of Population Plant Individuals (Stand) Ecosystem GJ Impairment in Economic Value: By reduced yields By reduced quality (constit- uent value, external appearance) By impact on soil and surrounding By decreased resistance to biotic and abiotic influences (e.g. bark beetles, frost) By increase of forest pests Impairment in Welfare Functions: By reduced recreational value By alterations in forest influences (e.g. filter capacity) Impairment in Ideal Value: x x x x x x x x x x x = useful criterion. (Reprinted from "Air Quality Criteria and Their Importance for Forests," 1971 by W. Knabe with permission from Forstliche Bundesversuchsanstalt) ------- type, as well as with local environmental factors. In addition, field observations near a long-established source of air pollution may only reflect the relative sensitivity of a residual, tolerant plant population, since highly sensitive individuals or species would have long since been replaced. Transplanting species into an area overcomes this latter problem, but results are still confounded by local environmental factors. Artificial exposure of trees in fumigation chambers is usually restricted to small seedlings. Due to age difference, the results from such studies are not necessarily valid to predict the response of mature stands of the same species to the test pollutant. Environmental conditions within the exposure chamber may also bias the results, since it is difficult to duplicate ambient environmental parameters in artificial exposure facilities. Fumigation techniques also vary among researchers, further complicating resulting sensitivity ratings. Also, it is imperative that each plant species and/or variety be identified as clearly as possible, since definite interspecific as well as intraspecific differences in sensitivity occur within the same genus. COMPILATION OF LISTS In spite of the above limitations, a listing of the relative sensitivity of various plant species to specific air pollutants can be reasonably derived. Field observations have supported results obtained from artifical fumigations, and vice versa, especially at the extremes of sensitivity or tolerance. Species found to be extremely tolerant in artifical exposures seldom develop injury from that specific air pollutant under ambient fumigation conditions. Likewise, artificial exposures usually produce injury on species known to be very sensitive to ambient levels of a specific air pollutant. However, the broad category of "intermediate sensitivity" is of less value, since sensitivity of these species to a given pollutant may vary with phenotype or environmental conditions. GEOGRAPHICAL LOCATION Many of the following lists were derived in various countries of the world. This is an important consideration when compiling composite sensitivity tables, since phenotypic characteristics and environmental parameters may differ radically from country to country. These differences may in turn drastically affect relative sensitivity. Thus, separate tables are given for studies conducted in North America and Europe- Russia. This separation is not intended to suggest that similar pheno- typic and environmental differences do not exist between research results reported within a particular country. It is, however, reasonable to assume that the magnitude of difference in sensitivity attributed to phenotypic and environmental factors is directly related to distance between investigations. In summary, compilations or lists of relative sensitivity of plant species to air pollution must be used with caution and understanding. ------- Although rankings at the extremes of sensitivity or tolerance are most useful, those in the intermediate category are still of considerable value. Tables from individual reports are included in this text. The table format is generally the same as presented by the original author, except when adapted slightly to improve clariety or continuity. These original tables are valuable in affording the reader the ability to compare the relative sensitivity of species within the-same study area. Scientific and common names are generally as supplied by the original author. ------- SECTION II CONCLUSIONS Woody plant species differ widely in susceptibility to given air pollutants. This characteristic is useful in selecting species for culture in areas of moderate to high air pollution potential. Species sensitivity to air pollution along with ambient environ- mental conditions and economic considerations should dominate the selec- tion process leading to the culture of superior vegetation in areas experiencing atmospheric pollution. The knowledge of relative sensitivity would also be of great value in utilizing woody plants as biological monitors. Field surveys for air pollutant effects should be aided significantly by reliable information on relative sensitivity. ------- SECTION III RECOMMENDATIONS The relative susceptibility tables presented should provide great assistance to landscape architects, nurserymen, foresters, and others in selecting woody plant species for culture in areas prone to air pollution exposure. The susceptibility tables should be used with a degree of caution and with an understanding of their inherent limitations. Very tolerant species should be selected and very susceptible ones avoided. The usefulness of species listed as intermediate in sensitivity will depend on local conditions. In fact, air pollution sensitivity, local environmental conditions, and economic factors should have significant influence on selection of vegetation suitable for areas with high air pollution potential. ------- SECTION IV SULFUR DIOXIDE NORTH AMERICA One of the earliest listings of the SO,, sensitivity of North American woody plants was compiled by Katz et al_. (17, 18, 19) in 1939. The reports were based on studies conducted during the mid-thirties near a smelter at Trail, British Columbia. In addition to years of field observation, Katz and associates exposed numerous species in outdoor plastic chambers to varying concentrations of S02 at different times of the year. Sulfur dioxide doses of 0.1 to 0.8 ppm for 6 to 151 hours or 0.25 to 5.0 ppm for 165-1656 hours were utilized and one study plot was exposed to 20 ppm S02 for a short time. Foliar injury and growth loss data were recorded along with length of time needed to initiate injury. A summary of the results is presented in Tables 3, 4 and 5. In 1955 Scheffer and Hedgcock (32) reported on the relative SOp sensitivity of northwestern forest trees and shrubs. The report was based on observations made near smelters in Stevens County, Washington, during 1928 to 1936, and on observations 20 years earlier near a smelter at Anaconda, Montana. The bulk of the data was based on field observation, but artificial fumigations were also conducted in portable exposure chambers. In the artificial fumigation experiments a small number of trees and shrubs were exposed to 0.5 and 1.0 ppm S02 for 4 to 7 hours. Results of field observations and artifical exposures in Washington are shown in Tables 6-8. The order of sensitivity does not agree with the earlier work of Katz et al. (17, 18, 19). According to the authors, this is due "...partly to a difference in the criterion of susceptibility and partly to the fact that the relative amounts of injury to many species tended to differ considerably with location, year, and injury zone." Scheffer and Hedgcock (32) made less detailed observations in the Montana study. The only sensitivity list that they published was based on the amounts and frequency of foliage thinning at different distances from the smelter (Table 8). Thomas (35) published a list of the relative S02 sensitivity of numerous plant species based on a numerical rating system (O'Gara factor). The ratings were actually determined by O'Gara, who exposed each species for one hour to different concentrations of S02 until a concentration was reached that caused traces of visible injury. The concentration needed to injure each species was divided by 1.25. This value was used since it took 1.25 ppm S02 for one hour to injure alfalfa, the most sensitive species. Thus 511 ratings were compared to alfalfa as unity. Table 9 was adapted from Thomas (35) and illustrates the relative S02 sensitivity of woody plants as determined by O'Gara. 8 ------- TABLE 3. RELATIVE SUSCEPTIBILITY OF WESTERN CONIFEROUS TREES TO S02a (17) Western larch (Larix occidental is) Douglas fir (Pseudotsuga taxi folia) Yellow pine (Pinus ponderosa) Engelman spruce (Picea engelmanni) Western white pine (Pinus monticola) Hemlock (Tsuga heterophylla) Lodgepole pine (Pinus contorta) Si 1ver fir (Abies amabilis) White fir (Abies concolor) Western red cedar (Thuja plicata)0 aField observations and exposures. Most susceptible (especially in Spring). cMost tolerant. (Reprinted from "Symptoms of Injury on Forests and Crop Plants," 1939 by M. Katz, 6. A. Ledingham, and A. W. McCallum with permission of National Research Council of Canada) ------- TABLE 4. RELATIVE SUSCEPTIBILITY OF WESTERN BROADLEAVED TREES TO S0/'b (17), Very Sensitive: n Birch (Betula papyrifera) Bitter Cherry (Prunus elnarginata) Aspen (Populus tremuloides) Sensitive to Intermediate: Apple (Maius sp. - cultivated) Mountain maple (Acer glabrum) Red hawthorn (Craetaegus columbiana) Willow (Salix sp.) Black cottonwood (Populus trichocarpa) Western mountain ash (Sorbus scopulina) Locust (Robinia (?)) Mountain alder (Alnus tenuifolia) Intermediate: Chokecherry (Prunus demissa) Elder (Sambucus glauca) Plum (Prunus sp. - cultivated) Elder (Sambucus glauca) Plum (Prunus sp. - cult Pear (Pyrus sp. - cultivated) Cherry (Pfuhus sp. - cultivated) Peach (Prunus sp. - cultivated) Apr icot~( Prunus sp. - cultivated) Tolerant: Elm (Ulmus sp.) . Horse chestnut (Aesculus sp.) aField observations and exposures. In order of increasing resistance within each group. cMost sensitive. Most tolerant. (Reprinted from "Symptoms of Injury on Forests and Crop Plants," 1939 by M. Katz, G. A. Ledingham, and A. W. McCallum with permission of National Research Council of Canada) 10 ------- a,b TABLE 5. RELATIVE SUSCEPTIBILITY OF WESTERN WOODY SHRUBS TO SOg '° (17) Very Sensitive: Ninebark (Opulaster malveceus) Ocean spray (Holodiscus ariaefolius) Serviceberry (Amelanchier aim'folia) Sensitive to Intermediate: Mountain laurel (Ceanothus sanguineus) Hazel (Cory!us rostrata) Grape (Vitis spT) CurrentTRibes sp.) Gooseberry (Ribes sp.) Intermediate: Mock orange (Philadelphus lewisii) Snow berry (Symphoricarpos racemosus) Thimbl eberry (Bossekia parvi flora") Elderberry (Sambucus spT) Tolerant: Lilan (Syringa sp.) Spiraea (Spiraea sp.) Oregon grape (Od'ostemon aquifolium) Buck brush (Ceanothus velutinus) Buffalo berry (Lepargyrea canadensia) Dogwood (Cornus sto!onfferal Sumac (Rhus glabra") Kinnikinm'ck (Arctbstaphylos uva-ursi) aField observations and exposure. In order of increasing resistance within each group. (Reprinted from "Symptoms of Injury on Forests and Crop Plants," 1939 by M. Katz, G. A. Ledingham, and A. W. McCallum with permission of National Research Council of Canada) 1.1 ------- TABLE 6. APPROXIMATE ORDER OF SUSCEPTIBILITY, BEGINNING WITH THE MOST SUSCEPTIBLE, OF TREES IN THE UPPER COLUMBIA RIVER VALLEY TO ACUTE SULFUR DIOXIDE INJURY (32) Conifers Broadleaf Trees Grand fird Abies grandis (Dougl.) Lindl. Subalpine fir Abies lasiocarpa (Hook.) Nutt. Western redcedar Thuja piicata Donn. Western hemlock Tsugaheterophylla (Raf.) Sarg. Douglas-fir Pseudotsuga menziesii (Mirb.) Franco. Western white pine Pinus monticola Dougl. Ponderosa pine Pinus ponderos Laws. Lodgepole pine Pinus contorta Dougl. Western larch Larix occidental is Nutt. Engelmann spruce Picea engelmannii Parry. Western juniper Juniperus occidental is Hook. Pacific yew , Tarus brevifolia Nutt. Thinleaf alder Alnus tehuifolia Nutt. Western paper birch Betula papyrifera var. commutata (Reg.) Fern Sitka mountain-ash Sorbus sitchensis Roem. Water birch Betula occidental is Hook. Douglas maple Acer glabrum var. douglasii (Hook)D'ipp. Bitter cherry Prunus emarginata Dougl. Common chokecherry Prunus virginiana L. Blueberry elder Sambucus glauca Nutt. Willow Salix spp. Columbia hawthorn Crataegus columbiana Howel1. Black cottonwood Populus trichocarpa Torr. & Gray. Black hawthorn Crataegus douglasii Lindl. Quaking aspen . Populus tremuloides Michx. •Most susceptible. Most tolerant. (Adapted from Sheffer, T. C. and G. C. Hedgcock. 1955. Injury to northwestern trees by sulfur dioxide from smelters. U.S.D.A. Forest Service Tech. Bull. No. 1117, 49 pp.) 12 ------- TABLE 7. APPROXIMATE ORDER OF SUSCEPTIBILITY, BEGINNING WITH THE MOST SUSCEPTIBLE, OF FOREST SHRUBS IN THE UPPER COLUMBIA RIVER VALLEY TO ACUTE SULFUR DIOXIDE INJURY (32) Pacific ninebark9 Physocarpus capitatus(Pursh) Kuntze Creambush rockspirea Holodi'scus discolor (Pursh) Maxim. Lewis mockorange Philadelphus lewisii Pursh Wild rose Rosa spp. Saskatoon serviceberry Amelanchier alnifolia Nutt. California hazel Cory!us cornuta var. californica Sharp Shinyleaf spirea Spiraea lucida Dougl. Sticky currant Ribes viscosissimum Pursh Columbia snowberry Symphoricarpos rivularis Suksd. Redstem ceanothus Ceanothus sanguineus Pursh. Snowbrush ceanothus Ceanothus velutinus Doubl. Redosier dogwood Cornus stolonifera Michx. Smooth sumac Rhus glabra L. Western poisonivy Toxicodendron radicans var. rydbergii (Small) Kelsey & Dayton ?Most susceptible. Most tolerant. (Adapted from Sheffer, T. C. and G. C. Hedgcock. 1955. Injury to northwestern trees by sulfur dioxide from smelters. U.S.D.A. Forest Service Tech. Bull. No. 1117, 49 pp.) 13 ------- TABLE 8. APPROXIMATE ORDER OF S02 SUSCEPTIBILITY OF TREES GROWING NEAR A SMELTER IN MONTANA3 (32) Subalpine fir (Abies laslocarpa (Hook.) Nutt.) Douglas fir (Pseudotsuga menziesii (Mirb.) Franco.) Lodgepole pine (Pinus contorta Dougl.) Engelman spruce (Picea engeltnannii Parry.) Ponderosa pine (Pinus ponderosa Laws.) Limber pine (Pinus f1exi1is James) Rocky mountain juniper (Juniperus scopulorum Sarge) ^H Common juniper (Juniperus communis L.) Field observations. Most susceptible. cMost resistant. (Adapted from Sheffer, T. C. and G. C. Hedgcock. 1955. Injury to northwestern trees by sulfur dioxide from smelters. U.S.D.A. Forest Service Tech. Bull. No. 1117, 49 pp.) 14 ------- TABLE 9. RELATIVE SENSITIVITY OF SELECTED WOODY PLANTS TO INJURY BY SO, (AS DETERMINED BY 0'GARA)a (35) Species Alfalfa Apple Catalpa Gooseberry Grape Linden Peach Apricot Elm Birch Plum Poplar Sumac Maple Boxelder Mockorange Snowbal 1 Ci trus Arborvitae Live oak Privet O'Gara Factor5 1.0C 1.8 1.9 2.1 2.2-3.0 2.3 2.3 2.3 2.4 2.4 2.5 2.5 2.8 3.3 3.3 3.5 5.8 6.5-6.9 7.8 14.0 15.0d Artificial exposure. Based on 1.0 for alfalfa, the most sensitive species studied. cMost sensitive. Most tolerant. (Reprinted from "Air Pollution Handbook," 1956 by M. D. Thomas and R. H. Hendricks with permission of McGraw-Hill Book Company) 15 ------- Hill et al. (15) recently examined the S02 sensitivity of native desert species by exposing plants in portable exposure chambers. Plants were subjected to S02 concentrations ranging from 0.5 to 11.0 ppm for 2 hours. Concentrations above 2.0 ppm were required to injure all but a few of the 87 species examined. This generally high degree of tolerance was probably due to an inherent tolerance of desert plants to sulfur dioxide. The results are adapted and summarized in Table 10. A concen- tration of 6 ppm was selected from Hill's table and used to compare relative sensitivity of woody species except where otherwise noted, since this data set was most complete. Recent comprehensive listings of plants sensitive to SO, were developed in eastern Canada. Linzon and co-workers conducted field observations for a number of years around the large smelter complex at Sudbury, Ontario (8,22). They developed lists in which the relative sensitivity of numerous plants was given a numerical value based on the pollutant concentration and time required to cause injury in the field (8). This table is based on years of observations and is probably very accurate for woody species of the Northeast (Table 11). Linzon also compiled a general list (Table 12) of the sensitivity of trees to S02 based mainly on his own experience, but with some input from other studies (22). In addition, a recent publication (23) listed the relative S02 sensitivity of species growing near a pulp and paper mill (Table 13). Temple (34) determined the dosage of S02 needed to injure four trees commonly planted in urban areas of the Northeast. Trees were exposed to 0.5 to 8.0 ppm S02 for 2 hours to 30 days. Results indicated that tolerance to S02 increased in the following order: Chinese elm (Ulmus parvifolia Jacq.), Norway maple (Acer platanoides L.), ginkgo (Ginkgo biloba L.), and pin oak (Quercus palustris munechh.). Pellisier (29) ranked the relative sensitivity of plants growing near a source of S02 in southern Quebec. Table 14 summarizes his findings based on field observations. A very general compilation was presented in the Air Pollution Control Association Atlas (4). The list indicated only sensitive plants and was quite restricted (Table 15). Another general list which included significant dosage values was recently presented by Jones et al. (16). Although only a few general species or groups of plants are listed, Table 16 is quite useful in evaluating the dosage of S02 needed to injure different groups of woody plants. Table 17 was compiled from data in Tables 3-16. Whenever the sensitivity rating of a species did not obviously fit one of the three sensitivity categories, the original reference was searched for the author's personal comments and observations which might help categorize the species. If a species was rated differently in various reports, the original reports were compared to ascertain which listing was likely to 16 ------- TABLE 10. SUSCEPTIBILITY OF SELECTED NATIVE WOODY DESERT VEGETATION TO S02a (15) Species Percent Foliar Injury After Exposure to 6 ppm S02 for 2 hrs Rocky mountain maple (Acer glabrum) River birch (Betula occidental is) Utah serviceberry (Amelanchier utahensis) Snowberry (Symphoricarpos oreophilus) Narrow!eaf cottonwood (Populus angustifolia) Big sagebrush (Artemisia tridentata) Quaking aspen (Populas tremuloides) Mountain mahogany (Cercocarpus montanus) Douglas fir (Pseudotsuga taxi folia) Curl-leaf mountain mahogany (Cercocarpus ledifolius) Squawbush (Rhus trilobata) Pinyon pine (Pinus edulis) Alpine fir (Abies lasiocarpa) Blue spruce (Picea pungens) Gambel oak (Quercus gambelii) 60 50b 33 32 20 9 7 5a 0.8 0.4 0.3 0.06 0.0 0.0 0.0 17 ------- TABLE 10. Continued. Percent Foliar Injury After Exposure to 6 ppm Species SOp for 2 hrs Oregon grape 0.0 (Mahonia repens) Ponderosa pine 0.0 (Pinus ponderosa) Rocky Mountain juniper 0.0 (Juniperus scopulorum) Utah juniper 0.0 (Juniperus osteosperma) White fir 0.0 (Abies concolor) aField exposure. Based on 4 ppm exposure for 2 hr. (Reprinted from "Sensitivity of Native Vegetation to S0? and to NCL Combined," 1974 by A. C. Hill, S. Hill, C. Lamb, and T. W. Barrett with permission of the Air Pollution Control Association) 18 ------- TABLE 11. RELATIVE S02 SUSCEPTIBILITY OF FOREST TREE SPECIES GROWING NEAR SUDBURY, ONTARIO3 (8) Species Intensity Factor Trempling aspen Jack pine White birch White pine Larch Large-toothed aspen Willow Alder Red pine Balsam poplar Austrian pine Witch hazel Red oak Sugar maple White spruce Cedar 74C 83 84 84 104 106 120 123 126 129 132 136 175 184 200 e aField exposure. Intensity factor based on S02 concentration and time needed to cause injury. cMost sensitive. Will not tolerate repeated exposures as well as trembling aspen or white birch (poorer regenerative capacity). eMost tolerant, never injured. (Reprinted from "Monitoring Atmospheric Sulfur Dioxide and Correlating Its Effects on Crops and Forests in the Sudbury Area," 1973 by B. R. Dreisinger and P. C. McGovern with permission of the Air Pollution Control Association) 19 ------- TABLE 12. SENSITIVITY OF TREES TO SOg (22) Sensitive Intermediate Tolerant Black Willow Chinese Elm Douglas-Fir Eastern White Pine Jack Pine Largetooth Aspen Manitoba Maple Trembling Aspen Western Larch Western Yellow Pine White Ash White Birch Austrian Pine Balsam Fir Basswood Catalpa Choke Cherry Eastern Cottonwood Englemann Spruce Mountain Maple Red Pine Western Hemlock Western White Pine White Elm Balsam Poplar Carolina Poplar Grand Fir Little-leaf Linden Lodgepole Pine London Plane Red Oak Silver Maple Sugar Maple Western Red Cedar White Cedar White Spruce Field observations. (Reprinted from "Effects of Sulfur Oxides on Vegetation," 1972 by S. N. Linzon with permission of the Canadian Institute of Forestry) 2Q ------- TABLE 13. OBSERVED SENSITIVITY OF WOODY PLANTS TO S02 IN VICINITY OF SULFITE PULP AND PAPER MILL IN ONTARIO9 (23) Sensitive: Ash, Red Birch, European Birch, White Birch, Yellow Cottonwood Mahonia Maple, Manitoba Fraxinus pennsylvam'ca Marsh. Betula pendula Roth Betula papyrifera Marsh. Betula lutea Michx. Populus del toides Marsh. Mahonia sp. Acer negundo L. Intermediate: Apple Basswood Catalpa Currant, Red Dogwood, Red Elm, Chinese Grape, Wild Honeysuckle, Hydrangea Lilac Mock Orange Mock Orange Mountain Ash Oak, White Spiraea Spruce, White Wei gel a Osier Tatarian Pyrus malus L. Tilia americana L. Warder Catalpa speciosa Ribes sp. Cornus stolonifera Michx. Ulmus parvifolia Jacq. Vitis riparia Michx. Lonicera tatarica L. Hydrangea paniculata Sieb. Syringa vulgaris L. Philadelphus coronarius L. Philadelphus virginal is Rehd. Pyrus (Sorbus) aucuparia (L.) Gaertn. Pyrus Querci uercus alba L. Spiraea Vanhouttei label. Picea glauca (Moench.) Voss. Wei gel a sp. Tolerant: Forsythia Linden, Little-leaved Maple, Norway Forsythia viridissima Lindl Tilia cordata Mill. L. \cer platanoides Maple, Silver Maple, Sugar Spruce, Blue Acer saccharinum L. Acer saccharum Marsh. Picea pungens Engelm. Field observations. (Reprinted from "Sulfur Dioxide Injury to Vegetation in the Vicinity of a Sulphite Pulp and Paper Mill," 1973 by S. N. Linzon, W. D. Mcllveen, and P. J. Temple with permission of D. Reidel Publishing Company) 21 ------- TABLE 14. RELATIVE SUSCEPTIBILITY OF WOODY PLANTS GROWING NEAR A SOURCE OF S02 IN SOUTHERN QUEBEC9 (29) Very Sensitive: Birch, gray (Betula populifolia) Birch, paper (Betula papyrifera) Hazel (Cory!us cornuta) Pine, jack (Pinus divaricata) Pine, red (Pinus resi'nosa) Pine, white (PiTTus strobus) Serviceberry (AmeTanchier stolonifera) Sumac, staghorn (Rhus typ~hina) Vaccinium, blueberry (Vaccinium angustifolium) Sensitive: Boxelder (Acer negundo) Maple, red (Acer riibrum) Tolerant: Aspen, bigtooth (Populus grandidentata) Aspen, quaking (Populus trenuiloides) Maple, silver (Acer saccharinum) Spruce, white (Picea~g~lauca) aField observations. (Adapted from Pellissier, M. 1972. [Atmospheric pollution and its effects on vegetation]. Unnumbered pub. of the Queb. Gov't. and Univ. of Quebec at Trois-Rivieres, 40 pp. (Trans!. from French). 22 ------- TABLE 15. SELECTED WOODY PLANTS THAT ARE RELATIVELY SUSCEPTIBLE TO S02a (4) Apple (Maius sp.) Birch (Betula sp.) Catalpa (Catalpa speci'osa Warder) Elm, American (Ulmus americana L.) Larch (Larlx sp.) Mulberry (Morus microphylla Buck!.) Pear (Pyrus communis L.) Pine, eastern white (Pinus strobus L.) Pine, ponderosa (Pinus ponderosa Laws.) Poplar, Lombardy (Populus nigra L.) aA compilation. (Reprinted from "Sulfur Dioxide," 1970 by T. W. Barrett and H. M. Benedict with permission of the Air Pollution Control Association) 23 ------- TABLE 16. SULFUR DIOXIDE CONCENTRATIONS CAUSING THRESHOLD INJURY TO VARIOUS SENSITIVITY GROUPINGS OF VEGETATION a,b (16) Maximum Average Sensitive Concentration (ppm $02) Peak 1.0-1.5 1-Hour 0.5-1.0 3-Hour 0.3-0.6 Southern Pines Red and Black Oaks White Ash Sumacs Sensitivity Grouping Intermediate (ppm S02) 1.5-2.0 1.0-2.0 0.6-0.8 Maples Locust Sweetgum Cherry Elms Tul i ptree Tolerant (ppm S02) > 2.0 > 2.0 > 0.8 White Oaks Dogwood Peach Based on observations over a 20-year period of visible injury occurring on over 120 species growing in the vicinities of coal-fired power plants in the southeastern United States. Field observations. (Adapted from Jones, H. C., D. Weber, and D. Basillie. 1974. Acceptable limits for air pollution dosages and vegetation effects: sulfur dioxide. Proc. Air Pollut. Control Assoc. Annu. Meet. 67: Paper No. 74-225, 31 pp.) 24 ------- TABLE 17. THE RELATIVE S02 SENSITIVITY OF WOODY PLANTS GROWN IN NORTH AMERICA9 SENSITIVE v Alder, thinleaf (Alnus tenulfolia) Aspen, large-toothed (Populus grandidentata) Aspen, trembling (Populus tremuloides] Ash, red (green) (Fraxinus pennsylvanica) Birch, European (Betula pendula) Birch, gray (Betula populifolia) Birch, western paper (Betula papyrifera commutata) Birch, white (paper) (Betula papyrifera) Birch, yellow (Betula alleghanensis (lutea)) Blueberry, lowbush (Vaccinium angustifolium) Cherry, bitter (Prunus emarginata) Elm, Chinese (Ulmus parvifolia) Hazel, beaked (Cory!us cornuta (rostrata)) Hazel, Cal iform'a (Cory!us cornuta californica) Larch, western (Larix occidental is) Maple, Manitoba (Acer negundo interius) Maple, Rocky Mountain (Acer glabrum) Mock-orange, Lewis (Philadelphus lewisi) Mountain-ash, Sitka (Sorbus sitchensis) Mulberry, Texas (Morus microphylla^) Ninebark, Pacific~(Physcocarpus capitatus) Ocean-spray (Holodiscus arieafolius) Pine, eastern white (Pinus strobus) Pine, jack (Pinus banksianal Pine, red (Pinus resinosa) Poplar, Lombardy (Populus nigra hybrid) Rockspirea, creambush (Holodiscus discolor) Serviceberry, low (Amelanchier spicata (stolonifera)) Serviceberry, Saskatoon (Amelanchier alnifolia) Serviceberry, Utah (Amelanchier utahensis) Sumac, staghorn (Rhus typhina) Willow, black (Salix nigra^) 25 ------- TABLE 17. Continued INTERMEDIATE Alder, mountain (Alnus tenuifolia) Apricot, ChineseTPrunus armeniaca var. Chinese) Basswood (Tilia americanal Birch, water (Betula occidentalis (fontinalisj) Boxelder (Acer negundol Cherry, bitter "(Primus emarginata) Chokecherry (Prunus demissa) Cottonwood, black (Populus trichocarpa) Cottonwood, eastern"! Populus deltoides) Cottonwood, narrowleaf (Populus angustifolia) Currant, sticky (Ribes viscosissimum) Dogwood, red osier (Co'rnus stolonifera) Douglas fir (Pseudotsuga menziesii) Elder, blueberry (Sambucus cerulea) Elm, American (white) (Ulmus americana) Fir, balsam (Abies balsamea) Fir, grand (Abies grandis) Grape, wild (VitTs riparia) Hawthorn, red (Crataequs columbiana) Hazel, witch (Hamamelis virginiana) Hemlock, western (Tsuga heterophylla) Honeysuckle, tatarian (Lonicera tatarica) Hydrangea (Hydrangea paniculata) Lilac, common (Syringa vulgariT) Mahogany, mountain CCercocarpus montanus) Maple, Douglas (Acer glabrum douglassi) Maple, Rocky Mountain (Acer glabrum) Maple, red (Acer rubruin) Mock-orange, coronarius (Philadelphus coronarius) Mock-orange, virgfnalis (Phi 1adelphus virginalis) Mountain-ash, European (Sorbus aucuparia) Mountain-ash, western (Sorbus scopulina) Mountain-laurel (Ceanothus sanguineus) Oak, white (Quercus alba) Pine, Austrian (Pinus nigra) Pine, lodgepole (Pinus contorta) Pine, ponderosa (Pinus pdhderosa) Pine, western white (Pinus monticola) Poplar, balsam (Populus balsamifera) Sagebrush, big (Artemsia tridentata) Snowberry, mountain (Symphoricarpos oreophilus) Snowberry, Columbia (Symphdricarpos rivulanTs) Spirea, Van Houts (Spiraea vanhouttei) Spirea, shineyleaf (Spiraea lucida) Spruce, Engleman (Picea engelmanni) Spruce, white (Picea glauca) 26 ------- TABLE 17. Continued. TOLERANT Arborvitae (white cedar) (Thuja occidental is) Buck-brush (Ceanothus velutinus) Buffalo-berry (Lepargyraea canadensis Ceanothus, redstem (Ceanothus sangulneus) Cedar, western red (Thuja plicata) Fir, silver (Abies amabilis") Fir, white (Abies concolor) Forsythia (Forsythia yiridissima) Ginkgo (Ginkgo bilobal Hawthorn, black (Crataequs douglasii) Juniper, common (Juniperus communis) Juniper, Rocky Mountain (Juniperus scopulorum) Juniper, Utah (Juniperus osteosperma) Juniper, western (Juniperus occidental!s) Kinnikinnick (Arctostaphy1os~uva-ursi) Linden, littleleaf (Ti1ia~cordata) Mahogany, curl-leaf mtn. (Cercocarpus ledifolius) Maple, Norway (Acer platanoides) Maple, silver (Acer saccharinum) Maple, sugar (Acer saccharum) Oak, Gambel (Quercus gambelii) Oak, pin (Quercus palustris) Oak, (northern red) (Quercus rubra) Oregon grape Pine, Limber Pine, pinyon . . Plane, LondonTPIatanus acerifolia) Poison-ivy, western (Toxicodendron radicans rydbergii) Poplar, Carolina (Populus canadensisl Spruce, blue (Picea pungensl Squawbush (Rhus trilobata) Sumac, smooth (Rhus glabra) Yew, pacific (Taxus brevifolia) aCompiled from previously listed species. Odostemon aquifol Pinus flexilis) Pinus edulis) 27 ------- be more accurate or included the largest number of observations. Of course, a certain amount of subjectivity is inherent in any such compil- ation. However, plants in the "sensitive" category should show injury at ambient levels of S02. Those species in the intermediate category may or may not be injured, depending upon local environmental factors, phenotype, etc. Tolerant plants should generally tolerate ambient levels of S02. EUROPE-RUSSIA Differential species sensitivity to S02 has been recognized for nearly a century in Europe. In 1883 von Scnroeder and Reuss (33) reported that oaks were very tolerant to SO? under field conditions. They ranked several other tree species Tn the following order of increasing sensitivity: maple, ash, elm, poplar, white beech, red beech, and birch. Haselfhoff and Lindau (14) also cited birch as most sensitive to "smoke" (mainly S02) in 1903, and included red and white beech as sensi- tive. Plum was listed as the most sensitive of the cultivated fruit trees while cherry was given a more tolerant rating. Mulberry was observed to be very tolerant. In 1924, Neger (26) ranked both coniferous and broadleaved trees as to their sensitivity or tolerance to S02. He rated the conifers in the following order of decreasing sensitivity: fir, spruce, Scotch pine, white pine, Douglas fir, larch, black pine, and yew. He also observed that chronic S02 exposures caused conifers to prematurely shed several years of older needles. Broadleaved species were ranked in order of decreasing sensitivity as: red beech, oak, maple, linden, ash, mountain ash, and birch. Since 1924, numerous European scientists have studied various aspects of S02 effects on vegetation. The more modern literature is of primary concern in this review. For a more extensive review of the historical aspects of S02 injury to vegetation see references 17, 18, 19 and 35. Russian literature was reviewed in references 2 and 3. One of the most useful general European publications dealing with S02 and vegetation is a color-plate atlas (37). It contains excellent photographs as well as significant text material published in German, French, and English. The text also summarizes many important aspects of the relative sensitivity of woody plants which cannot be tabulated. The authors also include tables (Tables 18 and 19) listing the relative S02 sensitivity of European deciduous and coniferous trees. These tables are based on years of field observations and artificial exposures and should be relatively accurate. Many European reports are based on the sensitivity of plants to "smoke" "industrial fumes," or "city air pollution." Sulfur dioxide may 28 ------- TABLE 18. THE RELATIVE S02 SUSCEPTIBILITY OF EUROPEAN DECIDUOUS WOODY PLANTS (37) ro 10 Most Sensitive Juglans regia English walnut Ribe^ grossularia Sensitive Sorbus intermedia Rowan tree Prunus persica Less Sensitive Pyrus communis var. Pear Acer campestre sativa Gooseberry Ribes rubrum Red currant Acer palmatum Japanese maple Ti 1i a grandifolia Lime, Linden or Basswood Tilia cordata Small leaved linden Peach Acer platanoides Norway maple Betula pendula European birch Aesculus hippocastanum Horse chestnut Mai us communis, sylvestris apple Prunus cerasus Sour cherry Prunus avium Sweet cherry Prunus domestica Plum Cory!us avellana Hazel nut Fagus silvatica hagus Red ed or European beech Hedge maple Quercus pedunculata English oak Syringa vulgaris Lilac Caprinus betulus Hornbeam Ulmus gjabra Wych elm Salix caprea Goat willow Populus tremula European aspen Rhamnus frangula Alder buckthorn Sambucus racemosa European red elder Gingko biloba Gingko ------- TABLE 18. Continued. Most Sensitive Sensitive Less Sensitive Fagus silv. atropurpurea Robinia pseudoacacia Copper beech Locust Quercus rubra Ilex aquifolium Red oak Holly Alnus glutinosa Black alder Populus robusta Poplar (Adapted from van Haut, H. and H. Stratman. 1969. Color-plate atlas of the effects of sulfur dioxide on plants. Verlag W. Gidardet, Essen. 206 pp.) ------- TABLE 19. THE RELATIVE S02 SUSCEPTIBILITY OF EUROPEAN CONIFEROUS WOODY PLANTS (37) Most Sensitive Sensitive Less Sensitive CO Larix europea European larch Larix 1eptolepi s Japanese Larch Picea abies Norway spruce Pseudotsuga menziesii Douglas fir Abies alba Silver fir Picea alba White spruce Abies homo!epis Nikko fir Picea pungens Blue spruce Picea sitchensis Sitka spruce Abies normanniana Nordman's fir Pinus silvestris Scotch pine Pinus ponderosa Ponderosa pine Pinus strobus White pine Pinus m'gra austriaca Austrian pine Pinus concorta var. latifolia Lodgepole pine Pinus mugo Mugho pine Chamaecyparis lawsoniana Lawson cypress Juniperus communis Juniper Thuja occidental is Thuja or white cedar Taxus baccata English yew (Adapted from van Haut, H. and H. Stratman. 1969. Color-plate atlas of the effects of sulfur dioxide on plants. Verlag W. Gidardet, Essen. 206 pp.) ------- have been the major pollutant in many instances, but such emissions in industralized areas also frequently contain fluorides, chlorides, oxides of nitrogens, particulates, etc. Thus, many such reports were not included in this review, since the specific sensitivity or tolerance to SO, was not evaluated. However, certain studies were selected which contain useful listings, based primarily on S02 toxicity. Acatay (1) determined the relative sensitivity of hardwoods growing adjacent to a copper smelter in Turkey and listed them in order of sensitivity. Table 20 is adapted from an abstract of his report. It is assumed that S02 is the major phytotoxic pollutant emitted. Ranft (30) evaluated the S02 susceptibility of a 40-year old planting experiment near a zinc smelter in Germany. The smelter released about 41 tons of S02 daily; maximum ground level concentrations of 1.2 mg S02 per m air were measured 400 m from the smelter. The smelter also released arsenic dust and HC1, but Ranft stated that these did not affect the stand. However, these emissions must be considered when evaluting his report. Sensitivity ratings are given in Table 21. Habj0rg (13) established a number of woody species in containers and maintained them near a source of S02 in Norway. The source was the industrialized area of Sorpsborg, and it was implied that the major air pollutant was S02- His findings are given in Table 22. In the Netherlands, Mooi (24) published preliminary results regarding the sensitivity of woody plants. Vegetation was exposed in chambers located in greenhouses or in the field using a "fumigation gun" or "cannon" which directs a stream of diluted S0? at the desired tree or branch. Table 23 illustrates his findings. Dassler and Enderlein (6) and Enderlein and Vogl (9) summarized two years of data from artificially exposing conifers to 0.8 to 3.0 ppm S02 in chambers. These were presented in a very general form. Table 24 is adapted from the text of the abstracts. In Russia, Nikolayeskiy et al. (27) related various anatomical- morphological and physiological-biochemical characteristics to plant sensitivity to S02. Characteristics such as duration of phenophase, flowering, stomatal characteristics, cuticle and epidermis thickness, accumulation of 35-S02 in various organs, and vascular bundle diameter were studied. These characteristics were correlated with the S02 sensitivity of numerous wild grasses, weeds, higher flowering plants, and woody species. This publication also contained a table which listed the relative sensitivity of woody plants. This modified table is presented as Table 25. 32 ------- TABLE 20. SUSCEPTIBILITY OF HARDWOODS TO "SMOKE" DAMAGE FROM A COPPER SMELTER IN TURKEY3 (1) Juglans regia Ostrya carpinifolia Castanea sativa Cory!us aveil ana Surbus aucupan'a Fraxinus spp. Carpinus spp. Alnus glabra Betula verrucosa Populus tremula Tilia sp. Diospyros lotus Fagus ori entali s Robinia pseudoacacia Ulmus campestris Quercus sessiliflora Buxus sempervirens0 Field observations. Most sensitive. GMost tolerant. (Adapted from Acatay, A. 1968. [Smoke damage from the copper-smelting works in Murgulj. Instanbul Univ. Orman Fak. Derg. Seri A 18:1-17. 1969. For. Abstr. 30:4104 (Turkish). 33 ------- TABLE 21. SUSCEPTIBILITY TO S02 OF 30- TO 40-YEAR OLD WOODY SPECIES PLANTED NEAR A ZINC PLANT EMITTING SO, IN GERMANY3 (30) Trees Shrubs Extremely Sensitive: Larix decidua Very Sensitive: Pi cea abies PTnuT banksiana Pinus silvestris Alnus incana Intermediate: Mai us pumi1 a Prunus avium Tilia platyphyllos Populus alba Pinus strobus Pinus montana Picea pungens Carpinus betulus Populus nigra italica Fagus sylvatica Ulmus glabra Pinus nigra austr. Pinus cembra Larix dahurica Populus marilandica Populus brabantica Populus grandis Betula pendula Sorbus aucuparia Sorbus intermedia Salix caprea Salix alba Viburnum opulus Rhamnus frangula Crataegus monogyna Tolerant: Quercus petraea Acer pseudoplatanus Acer platanoides Populus candicans Populus tremula Robinia pseudoacacia Alnus glIutinosa Quercus boreal is Ligustrum vulgare Salix purpurea Sambucus nigrum Sambucus racemosa Field exposure. (Adapted from Ranft, H. 1966. [Evaluation of a previous planting experiment within the range of the zinc smelter at Freiberg] Int. Symp. Forest Fume Damage Experts Proc. 5:154-165. (Held Janske Lazne, Czech. 11-14 Oct, 1966) (Trans 1. from Slovak). „. ------- TABLE 22. RELATIVE S02 SENSITIVITY OF WOODY PLANTS GROWN IN CONTAINERS AND PLACED IN AN INDUSTRIAL AREA OF NORWAY HAVING HIGH S02 LEVELS3 (13) Sensitive: Alnus incana Cytisus purgans Lonicera morrowii Pinus sylvestris Rosa "Moje Hammarberg" Sorbus aucuparia Intermediate: Amelanchier sp. Betula pubescens Cotoneaster lucidus Crataegus sanguinea Hippophae rhamnoides Picea abies Potentilla "Longacre" Ulrnus glabra Tolerant: Berberis thunbergii Cornus "Sibirica" Elaeagnus comnutata Picea pungens "Glauca" Syringa vulgaris Wei gel a "Eva Rathke" aField exposure. (Adapted from Hobjorg, A. 1973. [Air pollution and vegetation. II. Effects of fertilization on growth and development of twenty woody plants grown in industrial areas] Meld. Nor. Landbrukshoegsk. 52:1-14 (Trans!. from Norwegian) 35 ------- TABLE 23. PRELIMINARY RANKING OF WOODY SPECIES EXPOSED TO S02 IN CHAMBERS OR IN THE FIELD USING THE "FUMIGATION CANNON" IN THE NETHERLANDS3 (24) Sensitive: Alnus incana Corylus avellana Populus canescens (Witte van Haamstede") Sal ix alba (Liempde") Salix caprea Crataegus monogyna Crataegus oxyacantha Alnus glutinosa Sorbus aucuparla Amelanchier canadensis Populus tHchocarpa Betula pendula Tilia cordata Rosa rubiginosa Corpus mas Rosa rugosa Rosa canina Populus euramericana ("ZeelancF) Fraxinus excelsior Intermediate: Ulmus carpinifolia Castanea sativa Ulmus hollandica \cer campestre 'runus padus Prunus spinosa Prunus mahalej) Robinia pseudoacacia Fagus sylvatica Tolerant: Quercus robur Acer pseudoplatanus Jasminurn fruticans Ligustrum ovalifolium Ligustrum vulgare Artificial exposure. (Adapted from Mooi, J. 1972. Investigation of the susceptibility of woody plants to S09 and HF. Inst. Plantenziektenkd. Onderz. Wageningen Meded. 602. 12 PP. * 36 ------- TABLE 24. RELATIVE SUSCEPTIBILITY OF FOREST CONIFERS DETERMINED AFTER TWO YEARS OF FUMIGATIONS IN GERMANY3 (6,9) Spruces Pines Larches Picea abies • b P. omorica P. pungensc P. sitchensis0 Pinus sylvestris P. rigidab P. ponderosa P. strobusb P. montana P. nlgra0 P. peucec P. contorta( Larix decidua L. leptolepis0 aAritficial exposure. Most sensitive within the genus. cLess sensitive. (Adapted from Dassler, H. G. and H. Enderlein. 1965. [Experimental gassing experiments: a possibility for reducing smoke damage to forests in our republic]. Sozial. Forst. 15:367-368 (German) and Enderlein, H. and M. Vogl 1966. [Experimental investigations of S02 sensitivity of the needles of various conifers]. Arch. Forstw. 15:1207-1224 (German)). 37 ------- TABLE 25. PERCENT FOLIAR INJURY PRODUCED BY S02 ON PLANTS, BASED ON THREE YEARS OF EXPERIMENTAL EXPOSURES IN RUSSIA (27) Species Percent Foliar Injury Susceptible: English oak Japanese barberry Prickly rose Hazel nut White willow Juneberry Rugosa rose Aspen Ussurian pear European barberry Siberian peatree Mountain-ash leafed spiraea European mountain ash Small -leafed linden White birch Cranberry-leafed spiraea Moderately Tolerant: Siberian crab apple Forest pear Redhaw hawthorn Common buckthorn White poplar Golden currant European cranberry bush Silver maple European black currant Plum Tatarian maple Norway maple Hedge cotoneaster Goat willow Black chokeberry Shaggy lilac Sweet mockorange - 78.0 66.5 62.5 62.0 61.1 61.1 60.1 59.8 59.3 59.0 56.5 54.6 54.5 51.8 50.6 49.6 49.0 48.6 45.5 44.5 43.3 42.6 42.0 41.2 35.8 35.6 35.0 34.3 33.2 31.0 31.1 31.1 38 ------- TABLE 25. Continued. Percent Species Foliar Injury Tatarian dogwood Balsam poplar Black poplar Black cotoneaster Cherry Birdcherry Common lilac Red-berried elder Common sea buckthorn Snowberry Pennsylvania ash 29.0 29.0 28.6 26.8 26.3 26.2 25.9 24.2 23.0 22.5 21.0 Tolerant: Ash-leaved maple 26.6 European euonymus 11.9 Tatarian honeysuckle 8.2 Common elm 8.2 Artificial exposure. (Adapted from Nikolayevskiy, V. S., V. N. Tsodikova, V. V. Firger, A. T. Miroshnikova, V. V. Suslova and V. P. Galeeva. 1971. [Effect of the anat- omical-morphological structure of leaves and biological features or ornamental plants on the absorption of sulfur-35 dioxide and on the gas stability]. Uch. Zap. Perm. Gos. Uvin. 256:5-23 (Trans!. from Russian)). 39 ------- One of the most comprehensive listings of the S02 sensitivity of woody plants was presented by Ranft and Dassler (31) flable 26). Their report was based on a series of artificial S02 chamber exposures conducted by 1967 to 1969 in Germany. Species were ranRed on a 20-point basis as to their sensitivity or tolerance. Concentrations of SCL during exposures ranged from 0.5-1.2 ppm (authors note 1 ppm = 2.6 mg), 1.5-2.0 ppm, or a higher dose to differentiate the very hardy species (apparently up to at least 4.5 ppm). Exposure durations were not succinctly stated, but examples of damage after 60 hours at 1.5 ppm were given. Table 26 will serve as a summary of the European literature, since many of the various species examined by different researchers were also included in these experiments. Several reports which were not included in this review should be brought to the readers attention. These references (5, 7, 10, 11, 12, 21) are listed in the reference section and provide additional bibliogra- phic material. 40 ------- TABLE 26. SEQUENCE LIST ACCORDING TO LEAF DAMAGE AS A RESULT OF SO, TEST EXPOSURE FROM 1967 TO 1969 IN GERMANY3 (31) Species Points Very Susceptible: Pi nus sylvestri s Hypericum calycinum Pi nus rigida Lan'x decidua Salix purpurea Pinus ponderosa Picea abies 4.3U 4.5 4.7 4.8 4.8 5.0 5.1 Susceptible: Salix fragilis Salix pentandra Berberis vulgaris Amelanchier floribunda Abies concolor Rubus idacus Pinus griffithii Tilia cordata Chenomeles japonica Clemail's montana rubens Picea omorika Pinus Jeffreyi Pinus montana Salix viminalis Vitis vinifera Potentilla fruticosa Salix a Iba7 fragilis Syringa Mrs. E. Harding Cory!us colurna Hydrangea paniculata Pinus nigra Spiraea arguta Cotoneaster bullata Larix leptolepis Physocarpus opulifolius 5.2 5.2 5.3 6.2 6.3 6.4 6.5 6.5 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.8 6.8 6.8 7.0 7.0 7.0 7.0 7.0 7.1 7.1 41 ------- TABLE 26. Continued. Species Points Moderately Tolerant: Cornus stolonifera 7.2 3 Poplar varieties 7.4 Rhus typhina 7.4 Cotoneaster dammeri 7.5 Cotoneaster divaricata 7.7 Kolkwitzia amabilis 7.7 Ribes a1 pinurn 7.7 Caragena arborescens 8.0 Cotoneaster dielsiana 8.0 Rhamnus cathartica 8.0 Lyeium ha1imifo1iurn 8.1 Cory!us aveil. atrop. 8.3 Polygonurn aubertii 8.3 Rosa rubrifolia 8.3 Salix americana/hastala 8.5 Spiraea vanhouttei 8.5 Buddleia alternifolia 8.7 Colutea arborescens 8.7 Cytisus praecox 8.7 Tilia tomentosa 8.7 Vitis vinifera 8.7 Sarothamnus scoparius 8.8 Buddleia variabilis 9.0 Continus coggygria 9.0 Viburnum lantana 9.0 Cornus alba 9.2 Juglans regia 9.3 Rosa Baccus 9.3 Salix caprea 9.4 Juniperus communis hib. 9.5 Kerria japonica 9.5 Ribes sanguinea atr. 9.5 Crataegus monogyna 9.6 Crataegus oxyacantha 9.7 Betula pendula 9.7 Morus alba 9.7 Parthenocissus quinquefolia 9.7 42 ------- TABLE 26. Continued. Species Rosa Gabriele privat Elaeagnus angusti folia Cornus sanguinea Spiraea tnenziesii Syringa vulgaris Picea pungens glauca Coryopteris claudonensis Rosa canina Fraxinus excelsior Hamatnelis jajDonica Laburnum anagyroides Ribes aureum Ulmus campestre Vi burnum rhytidopjiyl 1 um Halesia diptera Hippophae rhamnoides Rhododendron japonicum Rubus fruticosa Sambucus nigra Sorbus aucuparia Alnus glutinosa Acer incana Berberis thunbergi Syringa japonica Chamaecypari s lawsoniana Cory! us avellana Cydonia vulgaris Forsythia intermedia Aesculus hippocastanum Rosa rugosa Philadelphus coronarius Pyracantha cocci nea Fagus silvaticus Deutzia sea bra Cercidiphyllum japom'cum Prunus avium Prunus serrulata Sorbaria chinensis Tamarix tetrandra Cornus mas Pinus peuce Points 9.7 9.9 10.0 10.0 10.0 10.3 10.5 10.5 10.7 10.7 10.7 10.7 10.7 10.7 11.0 11.0 11.0 11.0 11.0 11.3 11.3 11.5 11.7 11.7 12.0 12.0 12.0 12.2 12.3 12.3 12.4 12.5 12.7 12.8 13.0 13.0 13.0 13.0 13.0 13.3 13.3 43 ------- TABLE 26. Continued. Species Points Mahonia aquifoliufn 13.3 Wei gelia fTori da 13.3 Juniperus chinensis pfitz. 13.5 Robinia pseudoacacia 13.5 Wistaria chinensis 13.5 Primus cerasif. Pissardi 13.7 Primus mahaleb 13.8 Rather Tolerant: Amorpha fruticosa 14.0 Berberis gagnepainii 14.0 Ginkgo biloba 14.0 Sambucus nigra 14.0 Thuja plicata 14.0 Quercus boreal is 14.1 Sambucus racemosa 14.2 Symphoricarpus orbiculatus 14.2 Acer rubrum 14.3 Genista tinctoria 14.3 Magnolia obovata 14.3 Prunus padus 14.3 Prunus spinosa 14.3 Symphoricarpus rac. 14.3 Ilex aquifolium 14.5 Li ri odendron tuli pi fera 14.5 Viburnum opulus 14.5 Ailanthus altissima 14.7 Andromeda" floribunda 14.7 Pinus cembra 14.7 Daphne mezereum 15.0 Humulus lupulus 15.0 Juniperus tamariscifolia 15.0 Rhododendron catawb. 15.0 Acer campestre 15.4 Berberis verruculosa 15.5 Taxodium distichum 15.5 Calycanthus floridus 15.7 Chamaecyparis nootkat. 15.7 Hedera helix 15.7 Prunus cerasifera 15.9 44 ------- TABLE 26. Continued. Species Tamarix odessana Taxus baccata Castanea sativa Metasequoia glyptostr. Sorbus aria Catalpa speciosa Prunus serotina Euonymus europaeus Lonicera tatarica Tsuga diver si folia Elaeagnus commute ta Z. Catalpa bignonioides Cryptomeria japonica Erica carnea Halimodendron argent. Rhodotypus scandens Juniperus squama ta meyeri Acer negundo Pinus parvi flora Acer ginnala Erica mediteraneum Thuja occidental is Points 16.0 16.0 16.3 16.3 16.3 16.5 16.5 16.5 16.7 16.8 16.9 17.0 17.0 17.0 17.0 17.0 17.1 17.2 17.3 17.7 17.7 17.7 Very Tolerant: Juniperus sabina 18.0 Lonicera periclymenum 18.0 Ptelea trifoliata 18.0 Quercus petraea 18.0 Celtis austral is 18.2 Aesculus parviflora 18.3 Spiraea bum. A. Waterer 18.3 Juniperus virgineana 18.5 Buxus sempervirens 18.6 Staphylea pinnata 18.7 Ligustrum vulgare atr. 18.9 Jasminum fruticans 19-0 Gleditsia triacanthos 19-3 45 ------- TABLE 26. Continued. Species Points Prunus virgineana Thuja oriental is Chamaecyparis pisifera Celastrus orbicularis Platanus aceri folia Sophora japonica 19.3 19.3 19.9 20.0 20.0 20.0 Artificial exposures. Maximum resistance equals 20 points. (Reprinted from "Smoke-Hardiness Test Carried Out on Woods in an S02 Chamber Test," 1970 by H. Ranft and H. G. Dassler with permission from VEB Gustav Fisher Verlag Jena). 46 ------- SECTION V PHOTOCHEMICAL OXIDANTS INTRODUCTION The most important phytotoxic components of photochemical smog are ozone (Oj, peroxyacetyl nitrate (PAN), and oxides of nitrogen (NO }. Ozone causes significantly more injury to woody plants growing undir ambient environmental conditions than does NO or PAN. Ozone injury has been reported on shrubs, conifers and deciduous trees in rural as well as urban areas. NO causes very little injury to trees and shrubs, except occasionally when they are adjacent to large point sources. Woody plants exposed to PAN have shown a high degree of tolerance. Most of the research regarding the influence of photochemical oxidants on woody vegetation has been conducted in the United States. Therefore, unless otherwise noted, references in this section are from the United States. OZONE In 1958, Richards et^ al_. (23) published the first report specifically identifying ozone as the cause of injury to a woody plant. The plant species was grape and the symptom was referred to as "grape stipple." Hill et al. (15), published a list in 1961, relating the relative sensi- tivity of a number of plant species. The only woody plants included were grape (Vitis vinifera L. var. Mission), and peach (Prunus persica L. var. Elberta), both listed as intermediate in sensitivity. Since these early reports, numerous others have dealt with the ozone sensitivity of trees and shrubs. Ozone injury has been observed in the field in urban areas, downwind from urban centers, and in rural regions. This area of research was reviewed in 1964 (22), 1965 (24), 1968 (11), 1970 (14, 33, 34), and 1974 (12). Wood, Davis, and associates (5, 6, 7,37, 38, 30) exposed numerous woody plant species to ozone in laboratory chambers. Plants were subjected to 0.10 to 0.25 ppm ozone for 2 to 8 hours throughout the growing season. They reported differential sensitivity of coniferous trees (6), deciduous trees (39), and woody ornamentals (38). The information from these reports has been compiled and is presented in Table 27. Treshow and others (10, 33, 34, 35) studied the ozone sensitivity of numerous woody species native to Utah. Their studies included arti- ficial laboratory exposures, field exposures, and field observations. In one study, 70 plant species were exposed in portable field chambers to 0.15 to 0.40 ppm ozone for 2 hours (35). The portion of their report dealing with woody plants is shown in Table 28. Treshow (34) also reported on the results of a study conducted by Harper (unpublished) in which various plant species were exposed to 0.25, 0.40, 0.55, or 0.60 ppm ozone for 4 hours daily during extended time periods up to 2 weeks. 47 ------- TABLE 27. RELATIVE OZONE SUSCEPTIBILITY OF SHRUBS, TREES AND ORNAMENTALS EXPOSED TO OZONE (APPLIED AT BI-WEEKLY INTERVALS THROUGHOUT THE GROWING SEASON IN CHAMBERS3' b' c) (5,6,38,39) Sensitive: Ailanthus, tree-of-heaven Ailanthus altissima, Swingle) Ash, green (Fraxinus pennsylvanica Marsh.) Ash, white (Fraxinus americana L.) Azalea, campfire (Rhododendron kaempheri 'campfire' (Planch) Wils. Hort.) Azalea, Hinodegiri (R. obtubsum Planch. 'Hinodegiri1) Azalea, Korean (R_. poukhanensis Leville) Azalea, snow (IR. kurume 'snow' [Rehd.] Hort.) Cotoneaster, rock (Cotoneaster horizontal is Decne.) Cotoneaster, spreading (C. divaricata Rehd. & Wils.) Honey locust (thornless) (Gleditsia triacanthos inermis [L.] Zabel.) Larch, European (Larix decidua Mill.) Oak, white (Quercus alba L.) Pine, Austrian (Pinus nigra Arnold) 48 ------- TABLE 27. Continued. Sensitive: Pine, jack (Pinus banksiana Lamb.) Pine, ponderosa (Pinus ponderosa Laws.) Pine, Virginia (Pinus virginiana Mi 11.) Poplar, Hybrid - mixed [Populus maximowiczii x trichocarpa Clone #388) [Populus maximowiczii x cv berolinensis Clone #48) Poplar, tulip (Liriodendron tulipifera L.) Sycamore, American (Platanus occidentalis L.) Intermediate: Ash, European mountain (Sorbus aucuparia L.) Elm, Chinese (Ulmus parvifolia Jacq.) Forsythia, Lynwood gold (Forsythia intermedia spectabilis 'Lynwood Gold' Koehn) Gum, sweet (Liquidambar styraciflua L.) Hemlock, eastern (Tsuqa canadensis [L.] Carr.) Larch, Japanese (Larix leptolepis [Sieb. & Fucc.] Gord.) Mock Orange, sweet (Philadelphus coronarius. L.) Oak, pin (Quercus palustris Muenchh.) 49 ------- TABLE 27. Continued. Intermediate: Oak, scarlet (Quercus coccinea Muenchh.) Pine, eastern white (Pinus strobus L.) Pine, pitch (Pinus rigida Mill.) Pine, Scotch (Pinus sylvestris L.) Redbud, eastern (Cereis canadensis L.) Rhododendron (Rhododendron catawbiense album [Michx.] Hort.) Rhododendron (Rhododendron nova zembla Hort.) Rhododendron (Rhododendron roseum elegans Hort.) Viburnum, linden (Viburnum dilatatum Thunb.) Viburnum, Tea (Viburnum setigerum Hance.) Tolerant: Arborvitae (Thuja occidental is L.) Azalea, Chinese (Rhododendron moll is Bl.) Birch, European white (Betula pendula Roth.) Dogwood, gray (Cornus racemosa Lam.) 50 ------- TABLE 27. Continued. Tolerant: Dogwood, white (Cornus fTorida L.) Euonymus, dwarf winged (Euonymus alatus compactus [Sieb.] Bailey) Fir, balsam (Abies balsamea [L.] Mill.) Fir, Douglas (Pseudotsuga menziesii [Mirb.] Franco.) Fir, White (Abies concoloi* [6ord. & Clend.] Lindl.) Firethorne, Laland's (Pyracantha coccinea la_1and_ Depp.) Gum, black (Nyssa sylvatica [Marsh.] Pepperidge) Holly, American (female) (Ilex opaca Ait.) Holly, American (male) (Ilex opaca Ait.) Holly, Hetz Japanese (Ilex crenata Hetzi [Thunb.] Hetzii.) Laurel, mountain (Kalmia latifolia L.) Linden, American (Tilia americana L.) Linden, little-leaf (Tilia cordata Mill.) Maple, Norway (Acer platanoides L.) Maple, sugar (Acer saccharum Marsh.) 51 ------- TABLE 27. Continued. Tolerant: Oak, English (Quercus robur L.) Oak, northern red (Quercus rubra L.) Oak, shingle (Quercus imbricaria Michx.) Pieris, Japanese (Pien's Japonica [Thunb.] D. Don) Pine, red (Pinus resinpsa Ait.) Privet, Amur north (Ligustrum amurense Carr.) Rhododendron, Carolina (Rhododendron carolinianum Redh.) Spruce, Black Hills (Picea glauca var. densata Bailey) Spruce, Colorado blue (Picea pungens Engelm.) Spruce, Norway (Picea abies [L.] Karst.) Spruce, white (Picea glauca [Moench] Voss.) Viburnum, Korean spice (Viburnum carlesi Hems!.) Yew, dense (Taxus densiform's Hort.) Yew, Hatifield's pyramidal (Taxus media hatfieldi Rend.) Artificial exposures. Compilation of several tables. GSome sensitivity ratings were modified based on recent, unpublished research. 52 ------- TABLE 28. THRESHOLD CONCENTRATION OF OZONE NEEDED TO CAUSE INJURY ON PLANTS GROWING IN NATIVE HABITAT IN UTAH3 (35) Concentration (2-hr Exposure) 0.15 ppm Quaking aspen (Populus trenailoides Michx.) 0.20 ppm Saskatoon serviceberry (Amelanchier aim'folia Nutt.) 0.25 ppm Gambel oak (Quercus gambelii Nutt.) White frr (Aibes concolor [Gord. & Glend.] Lindl.) Over 0.25 ppm Boxelder (Acer negundo L.) Blackbead elder (Sambucus melanocarp A. Gray) 0.30 ppm Northern black currant (Ribes hudsonianum Richards.) Snowberry (Symphoricarpos vaccinioides Rydb.) Over 0.30 ppm Pachystima (Pachystima myrsim'tes [Pursh.] Raf.) Poison-ivy (Toxicodendron radicans [L.] Kuntze) Wood's rose (Rosa woodsii Lindl.) 53 ------- TABLE 28. Continued. Concentration (2-hr Exposure) 0.40 ppm Sagebrush (Artemesia tridentata Nutt.) Over 0.40 ppm Big-tooth maple (Acer grandidentatum Nutt. Trailing mahonia (Mahonia repens G. Don.) Artificial exposure. (Reprinted from "Ozone Sensitivity of Plants in Natural Communities," 1973 by M. Treshow and D. Stewart with permission from Applied Science Publishers Ltd), 54 ------- Table 29 is adapted from the text of this report (34). Unfortunately, the exact length of the extended time periods was not given. One of the most extensive studies to determine the impact of ozone on an ecosystem is being conducted in the San Bernardino Mountains of California. Miller and co-workers (19, 20, 21) are studying the influence of ozone on the vegetative compartment of the ecosystem and conducted extensive studies on the high ozone sensitivity of ponderosa pine (21) and other woody plants (19, 20). These reports are based on field observations as well as artificial exposures. Results from these studies are incorporated into Table 30. Other researchers studied the effect of ozone on specific woody species or varieties. Eastern white pine (Pinus strobus L.) populations contain certain individuals which are extremely sensitive to ozone (1, 2, 3, 8, 18) but as a whole, the species population may not be extremely sensitive (6). White ash (Fraxinus americana L.) (27), Virginia pine (Pinus virginiana mill.) (7), slash (Pinus el'liottii engelm.), shortleaf (Pinus echinata mill.), and loblolly pine (Pinus taeda L.) seedlings (2) and certain clones of hybrid poplar (Populus del toides Bartr. x Populus trichocarpa Torr. and Gray) (16) have been shown to be very susceptible. Sugar maple (Acer saceharum marsh.) (13), red maple (Acer rubrum L.) (32), sycamore (Platanus spp.) and American elm (Ulmus americana L.) (25), and grape (Vitis vinifera L.) (26) may also be injured by ozone. In California, both citrus (lemons and oranges) (30) and zinfandel grape (29) yields have declined because of ozone. English holly (Ilex aquifolium) (4) has been reported to be very resistant to ozone. PEROXYACETYL NITRATE (PAN) This secondary, urban air pollutant has been an important problem on leafy vegetables grown in the Los Angeles basin. Also, PAN is a suspected phytotoxicant on vegetables in New Jersey and on tomatoes in southern Canada. However, woody plants are apparently very tolerant of PAN. Drummond (9) exposed numerous woody species to high levels of PAN, but failed to induce symptoms on most species. Kohut (17) and Davis (unpublished) exposed hybrid poplar and ponderosa pine, respectively, to very high levels of PAN, but could not induce symptoms. Table 31 illus- trates these findings. General aspects of PAN phytotoxicity have been reviewed (27, 28). OXIDES OF NITROGEN (NO ) J\ Nitrogen oxide levels in urban air seldom reach phytotoxic concen- trations, but concentrations adjacent to large point sources may cause plant injury. Taylor and MacLean (28) listed the following woody plants and sensitivity classes in their review: Azalea (Rhododendron sp.) (sensitive), brittlewood (Melaleuca leucadendra) (sensitive), orange 'Citrus sinensis osbeck) (intermediate) and heath (Erica sp.) (resistant). very comprehensive listing was presented by Van Haut and Stratmenn 55 ------- TABLE 29. DAILY DOSE OF OZONE NEEDED TO CAUSE INJURY TO VARIOUS PLANT SPECIES, FOR TIME PERIODS UP TO 2 WEEKS3 (34) 0.25 ppm/4 hrs - Very Sensitive: Snowberry (Sytnphoricarpus alba L.) Sumac (Rhus canadensis Marsh.) Aspen (Populus tremuloides Michx.) Bridalwreath (Spireae vanhoutii Zab.) Chinese lilac (Syringa chinensis Willd.) 0.25 ppm/4 hrs - Sensitive: Concord grape (Vitis vinifera L.) Cherry (Prunus avium L. var. Lambert) Privet (Ligustrum vulgare L.) Green ash (Fraxinus pennsylvanica lanceolata Sarg.) Honeylocust (Gleditsia triacanthos L.) English walnut (Juglans regia L.) 56 ------- TABLE 29. Continued. 0.40 ppm/4 hrs. - Fairly Tolerant: Arborvitae (Thuja oriental is L.) Blue spruce (Picea pungens Engelm.) Japanese box (Buxus sjempervirens L.) Red oak (Quercus rubra L.) Japanese pagoda (Sophora japonica L.) 0.55 ppm/4 hrs. - Very Tolerant: Littleleaf linden (Tilia cordata Mi 11.) European beech (Fagus sylvatica L.) European birch (Betula pendula Roth) Pear (Pyrus communis L.) Apricot (Prunus armeniaca L.) Black locust (Robinia pseudoacacia L.) Viburnum (Viburnum burkwoodii Burk) Artificial exposure. (Adapted from Treshow, M. 1970. Ozone damage to plants. Environ. Pollut. 1:155-161). 57 ------- TABLE 30. RELATIVE SENSITIVITY OF WOODY PLANTS GROWN IN NORTH AMERICA TO OZONE3' b SENSITIVE Ailanthus, tree-of-heaven (Ailanthus altissima) Ash, green (Fraxinus pennsylvanica lanceolata) Ash, white (Fraxinus" americanal Aspen, quaking (Populus tremuloides) Azalea, campfire (Rhododendron kaempheri) Azalea, hinodegiri (Rhododendron hinodegiri) Azalea, Korean (Rhododendron poukhanensis) Azalea, snow Rhododendron kurume) Bridalwreath (Spiraea vanhoutii) Cherry, Bing (Prunus avium var. Bing) Cotoneaster, rock (Cotoneaster horizontal is) Cotoneaster, spreading (Cotoneaster divaricata) Grape, concord (Vitis vinifera) Honey 1ocust (Gleditsia triacanthos) Larch, European (Larix d'ecidua) Lilac, Chinese (Syringa chinensis) Mountain-ash, European (Sorbus aucuparia) Oak, Gambel (Quercus gambelii) Oak, white (Quercus alba) Pine, Austrian (Pinus nigra) Pine, Coulter (Pinus coulteri) Pine, Jack (Pinus banksiana) Pine, Jeffery (PTnus jeffreyi) Pine, Loblolly"TPinus taeda) Pine, Monterey (Pinus radiata) Pine, ponderosa (Pinus ponderosa) Pine, Virginia (Pinus virginiana) Poplar, hybrid (Populus maximowiezii x trichocarpa) Poplar, tulip (Liriodendron tulipifera) Privet, londense (Ligustrum'vulgare var. pyramidale) Serviceberry, Saskatoon (Amelanchier alnifolia) Snowberry, alba (Symphoricarpos alba) Sumac, fragrant (Rhus aromatica) Sycamore, AmericanTFlatanus occidental is) Walnut, English (Juglans regial 58 ------- TABLE 30. Continued. INTERMEDIATE Apricot, Chinese (Prunus armeniaca var. Chinese) Boxelder (Acer negundo) Cedar, incense Tlibocedrus decurrens) Cherry, Lambert (Prunus av"iuni var. Lambert) Currant, northern black (RTbes hudsom'anum) Elder, black bead (Sambucus melanocarpa) Elm, Chinese (Ulmus parvifolTa") Forsythia, Lynwood gold (Forsythia intermedia spectabilis) Gum, sweet (Liquidambar styraciflual Honeysuckle, blue-leaf (Lonicera korolkowi) Larch, Japanese (Larix leptolepisl Lilac, common (Syringa vulgarisj" Mock-orange, sweet (Philadelphus coronarius) Oak, black (Quercus velutiniaj Oak, pin ((Quercus palustris) Oak, scarlet (Quercus coccinea) Pine, eastern white (Pinus strubus) Pine, knobcone (Pinus attenuate) Pine, lodgepole (Pinus contorta) Pine, pitch (Pinus rigidal Pine, Scotch IPinus sylvestris) Pine, short!eaf (Pinus echinata) Pine, slash (Pinus elliottii) Pine, sugar (Pinus lambertiana) Pine, Torrey (Pinus torreyana) Privet, common (iTgustrum vulgare) Redbud, eastern (Cercis canadensis) Rhododendron (Rhododendron catawbiense album) Rhododendron (Rhododendron nova zembla) Rhododendron (Rhododendron roseum elegans) Snowberry, vaccinioides (Symphoricarpos vaccinioides) Viburnum, linden (Viburnum dilatatumj Viburnum, tea (Viburnum setigerum) 59 ------- TABLE 30. Continued. TOLERANT (Continued) Spruce, Black Hills (Picea glauca densata) Spruce, Colorado blue (Picea pungenT] Spruce, Norway (Picea abies) Spruce, white (Picea glauca) Viburnum, Korean spice (Viburnum carelsi) Viburnum, burkwoodii (Viburnum burkwoodii) Walnut, black (Juglans nigra) Yew, dense (Taxus dens if prim's) Yew, Hatifield's pyramidal (Taxus media hatfieldi) aCompilation of previously listed species plus new, unpublished data. Sensitivity ratings of some species were modified to reflect new, unpublished results. 60 ------- TABLE 31. RELATIVE SENSITIVITY OF WOODY PLANTS GROWN IN NORTH AMERICA TO PANa>b SENSITIVE None reported INTERMEDIATE None reported TOLERANT Thuja oriental is) Fraxinus pennsylvanica lanceolata) Fraxinus americana) Arborvitae Ash, green Ash, white _= Basswood (Tilia americana) Birch, European white (Be'tula/ pendula) Dogwood, white (Cornus~florida) Fir, balsam (Abies balsamea) Fir, Douglas (Pseudotsuga menziesii) Fir, white (Abies concolorl Gum, sweet (Liquidambar styraciflua) Hemlock, eastern (Tsuga canadensisT Honey locust (Gleditsia triacanthos) Larch, European (Latrix decidua) Larch, Japanese (Larix leptolepis) Lilac, common (Syringia vulgarisT Maple, Norway (Acer pla~tanoides) Maple, silver (Acer saccharinum) Maple, sugar (Acer saccharum) Mountain-ash, American (Sorbus americana) Oak, English (Quercus robur) Oak, northern red (Quercus rubra) Oak, pin (Quercus palustrisl Oak, white (Quercus alba] Pine, Austrian (Pinus nigra) Pine, eastern white (Pinus strobus) Pine, pitch (Pinus rigida) Pine, ponderosa (Pinus ponderosa) Pine, red (Pinus resinosaT) Pine, Scotch (Pfnus sylvestris) Pine, Virginia (Pinus virginiana) Poplar, hybrid (Populus maximowiezii x trichocarpa) Poplar, Tulip (Liriodendron tulipifera) Spruce, Black Hills (Picea glauca densata) Spruce, blue (Picea pungens) Spruce, Norway (PTcea abies) Spruce, white (Picea glauca) Artificial exposures. 61 A Compilation but mainly from (9). ------- (36). They exposed monocots, dicots, and conifers to NOX (NO and NCL) under carefully controlled conditions in small chambers. Table 32 is adapted from their results. In their review, Thompson et al. (31) listed the sensitivity of 14 additional ornamental plants to N02- Woody species from this list are indicated in Table 32. 62 ------- TABLE 32. RELATIVE SUSCEPTIBILITY OF WOODY PLANTS TO NO (PRIMARILY N0ja (36) /\ C. Sensitive: Weeping birch (Betula pendula) Showy apple (Maius specT) Wild pear tree European larch Japanese larch Pyrus spec.) Larix euro pea) Larix leptolepis) Rose (Rosa sp.)~ Azaela (RTTododendron canescens) Pyracantah (Pyracalitha coccinea) Intermediate: Norway map!e (Acer platanoides) Fan maple (Acer palrnatum) Winter 1 ime (Tilia parvifolia) Summer 1ime (Tilia grandifolia) Rhododendron (Rhododendron catawbiense) Blue spruce (Picea pungens glauca) White spruceTPicea alba) Lawson's cypress fChamaecyparis lawsom'ana) Nikko or Japanese fir (Abies homo!epi s) Common silver fir (Abies pectinate) Ligustrum (Ligustrum lucidum) To!erant: Locust (Robinia pseudoacacia) Hornbeam (Carpinus betulus~J~ ' Common beech (Fa'gus sylvatjca) Common elder (Sambucus nigra Gingko tree (Gingko ETloba) '' Mountain elm (Ulmu's' montana^) Purple-leaved beech (Fagus sylvatica atropurpurea) Common oak (Quercus pendunculata) Common yew tree (Taxus baccata) Black pine (Pinus austriaca) Shore juniper Quhiperus conferta) aArtificial exposures. 63 ------- SECTION VI REFERENCES (Reference Section is divided into two sections; the numbering sequence begins at (1) in each section) Sulfur Dioxide 1. Acatay, A. 1968. [Smoke damage from the copper-smelting works in Murgul]. Instanbul Univ. Orman Fak. Derg. Seri A 18:1-17. 1969. For. Abstr. 30:4104 (Turkish). 2. American Institute of Crop Ecology. 1969. AICE survey of USSR air pollution literature. Vol. II. Effects and symptoms of air pollu- tants on vegetation; resistance and susceptibility of different plant species in various habitats, in relation to plant utilization for shelter belts and as biological indicators. AICE Publ. No. 45. M. Y. Nuttonson, ed. Silver Springs, MD. 95 pp. 3. American Institute of Crop Ecology. 1970. AICE survey of USSR air pollution literature. Vol. III. The susceptibility or resistance to gas and smoke of various arboreal species grown under diverse environmental conditions in a number of industrial regions of the Soviet Union. AICE Publ. No. 46. N. Y. Nuttonson, ed. Silver Springs, Md. 114 pp. 4. Barrett, T. W. and H. M. Benedict. 1970. Sulfur dioxide. In: Recognition of Air Pollution Injury to Vegetation. A Pictorial Atlas. J. S. Jacobson and A. C. Hill, eds. Air Pollut. Control Assoc., Pittsburgh, p. C1-C17. 5. Berge, H. 1959. [Injury to fruit and forest trees from sulfur dioxide emission.] Gartenbauwissenschaft 24:220-228. (German). 6. Dassler, H. G. and H. Enderlein. 1965. [Experimental gassing experiments: a possibility for reducing smoke damage to forests in our republic]. Sozial. Forst. 15:367-368 (German). 7. Dochinger, L. S., A. M. Townsend, D. W. Seegrist, and F. W. Bender. 1972. Responses of hybrid poplar trees to sulfur dioxide fumigation. J. Air Pollut. Control Assoc. 22:369-371. 8. Dreisinger, B. R. and P. C. McGovern. 1973. Monitoring atmospheric sulfur dioxide and correlating its effects on crops and forests in the Sudbury area. In: Proc. Impact Air Pollut. Veg. Spec. Conf. (April 7-9, 1970, Toronto). Air Pollut. Control. Assoc., Pittsburgh. 2nd Printing, pp. 11-28. 64 ------- 9. Enderlein, H. and M. Vogl. 1966. [Experimental investigations of S0? sensitivity of the needles of various conifers]. Arch. Forstw. 1571207-1224 (German). 10. Greszta, J., J. Olszowski, and S. Godzik. 1969. The effect of air pollution on wood volume increment in the common pine (Pinus silvestris L.) Ekol. Pol. Ser. A 17:828-846. 11. Guderian, R. and H. Stratmann. 1962. [Field experiments to determine the effects of S02 in vegetation. Part I. Survey of method and evaluation of results] Forschungsber. Landes Nordrhein-Westfalen, No.. 1118, 102 pp. (C. E. Trans. 4369). (German). 12. Guderian, R. and H. Stratmann. 1968. [Field experiments for determining effects of sulfur dioxide on vegetation. Part III. Threshold values of harmful SO, emissions for fruit and forest trees for agricultural and garaen plant species.] Forschungsber. Landes Nordrhein-Westfalen No. 1920. 114 pp. (Trans!. from German). 13. Hobjtfrg, A. 1973. [Air pollution and vegetation. II. 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In: Effect of Sulfur Dioxide on Vegetation. Nat. Res. Council of Canada, N.R.C. No. 815, pp. 244-261. 19. Katz, M. and A. W. McCallum. 1939. Fumigation experiments on conifers in their natural habitat. In: Effect of Sulfur Dioxide on Vegetation. Nat. Res. Council of Canada, N.R.C. No. 815, pp. 218-243. 65 ------- 20. Knabe, W. 1971. Air quality criteria and their importance for forests. Mitt. Forstl. Bundes-Versuchsanst. Wien 92:129-150. 21. Lampadius, F., E. Pelz, and E. Pohl. 1970. The problem of estimating and demonstrating the resistance of forest trees to emissions. Biol. Zentralbl. 89:301-326 (Trans!. from German). 22. Linzon, S. N. 1972. Effects of sulphur oxides on vegetation. For. Chron. 48:182-186. 23. Linzon, S. N., W. D. Mcllveen, and P. J. Temple. 1973. Sulphur dioxide injury to vegetation in the vicinity of a sulphite pulp and paper mill. Water, Air, Soil Pollut. 2:129-134. 24. Mooi, J. 1972. Investigation of the susceptibility of woody plants to S09 and HF. Inst. Plantenziektenkd. Onderz. Wageningen Meded. 602. 12 ppf 25. Nakashima, Y., Y. Hagihara, S. Ogawa, and T. Kawashima. 1970. [Studies on the smoke damage of trees. I. On the acute damage symptoms by the S02] Bull. Fukuoka-ken Forest Exp. Sta. No. 21:23-50 (Japanese). 26. Neger, F. W. 1924. Die Krankheiten unserer WaldbSume und der wichtigsten GartengehOlze. Ferdinand Enke. Stuttgart (2nd edition). 246 pp. (German), 27. Nikolayevskiy, V. S., V. N. Tsodikova, V. V. Firger, A. T. Miroshnikova, V. V. Suslova and V. P. Galeeva. 1971. [Effect of the anatomical- morphological structure of leaves and biological features or ornamental plants on the absorption of sulfur-35 dioxide and on the gas stability]. Uch. Zap. Perm. Gos. Uvin. 256:5-23 (Trans!. from Russian). 28. O'Connor, J. A., D. G. Parbery, and W. Strauss. 1974. The effects of phytotoxic gases on native Australian plant species: Part I. Acute effects of sulphur dioxide. Environ. Pollut. 7:7-23. 29. Pellissier, M. 1972. [Atmospheric pollution and its effects on vege- tation]. Unnumbered pub. of the Queb. Gov't and Univ. of Quebec at Trois-Rivieres, 40 pp. (Transl. from French). 30. Ranft, H. 1966. [Evaluation of a previous planting experiment within the range of the zinc smelter at Freiberg] Int. Symp. Forest Fume Damage Experts Proc. 5:154-165. (Held Janske Lazne, Czech. 11-14 Oct. 1966) (Transl. from Slovak). 31. Ranft, H. and H. G. Dossier. 1970. [Smoke-hardiness test carried out on woods in an SOg chamber test] Flora 159:573-588 (Transl. from German). 66 ------- 32. Scheffer, T. C. and G. C. Hedgcock. 1955. Injury to northwestern trees by sulfur dioxide from smelters. U.S.D.A. Forest Service Tech. Bull. No. 1117, 49 pp. 33. Schroeder, J. von and C. Reuss. 1883. Die BeschMdigung der Vegetation durch Rauch und die Oberharzer Huttenrauchschaden. Paul Parey, Berlin (333 pp) (German). 34. Temple, P. J. 1972. Dose-response of urban trees to sulfur dioxide. J. Air Pollut. Control Assoc. 22:271-274. 35. Thomas, M. D. and R. H. Hendricks. 1956. Air Pollution Handbook (P. L. Magill, F. R. Holden and C. Ackley, ed.) McGraw Hill Book Co., New York, p. 9/1 - 9/44). 36. van Haut, H. and H. Stratman. 1960. [Experimental studies on the effects of sulfur dioxide upon vegetation] Forschungsber. Landes Nordrhein- Westfalen No. 884, 63 pp (German). 37. van Haut, H. and H. Stratman. 1969. Color-plate atlas of the effects of sulfur dioxide on plants. Verlag W. Gidardet, Essen. 206 pp. 38. Wentzel, K. F. 1968. [Sensitivity and differences in the resistance of plants to air pollution.] Forstarchiv 29:189-194 (German). 67 ------- REFERENCES Photochemical Oxidants 1. Berry, C. R. 1971. Relative sensitivity of red, jack, and white pine seedlings to ozone and sulfur dioxide. Phytopathology 61:231- 232. 2. Berry, C. R. 1974. Age of pine seedlings with primary needles affects sensitivity to ozone and sulfur dioxide. Phytopathology 64:207-209. 3. Berry, C. R. and L. A. Ripperton. 1963. Ozone, a possible cause of white pine emergence tipburn. Phytopathology 53:552-557. 4. Brennan, E. and I. Leone. 1970. The response of English holly selections to ozone and sulfur dioxide. Holly Letter 37:6-8. 5. Davis, D. D. and J. B. Coppolino. 1974. Relative ozone suscepti- bility of selected woody ornamentals. HortScience 9:537-539. 6. Davis, D. D. and F. A. Wood. 1972. The relative susceptibility of eighteen coniferous species to ozone. Phytopathology 62:14-19. 7. Davis, D. D. and F. A. Wood. 1973. The influence of environmental factors on the sensitivity of Virginia pine to ozone. Phytopathology 63:371-376. 8. Dochinger, L. S. and C. E. Seliskar. 1970. Air pollution and the chlorotic dwarf disease of eastern White Pine. For. Sci. 16:46- 55. 9. Drummond, D. B. 1971. Influence of high concentrations of peroxy- acetylnitrate on woody plants. Phytopathology 61:128 (Abstract). 10. Harward, M. R. and M. Treshow. 1971. The impact of ozone on understory plants of the aspen zone. Proc. Air Pollut. Control Assoc. Annu. Meet. 64: Paper No. 71-98. 18 pp. 11. Heggestad, H. E. 1968. Diseases of crops and ornamentals incited by air pollutants. Phytopathology 58:1089-1097. 12. Heggestad, H. E., C. E. Anderson and W. A. Feder. 1974. Determining acceptable limits for air pollution dosages and vegetation effects: ozone. Proc. Air Pollut. Control Assoc. Annu. Meet. 67: 68 ------- 13. Hibben, C. R. 1969. Ozone toxicity to sugar maple. Phytopathology 59:1423-1428. 14. Hill, A. C., H. E. Heggestad, and S. N. Linzon. 1970. Ozone. In; Recognition of Air Pollution Injury to Vegetation. A Pictorial Atlas. J. S. Jacobson and A. C. Hill, eds. Air Pollut. Control Assoc., Pittsburgh, pp. B1-B22. 15. Hill, A. C., M. R. Pack, M. Treshow, R. J. Downs and L. G. Transtrum. 1961. Plant injury induced by ozone. Phytopathology 51:356-363. 16. Jensen, K. F. and L. S. Dochinger. 1974. Responses of hybrid poplar cuttings to chronic and acute levels of ozone. Environ. Pollut. 6:289-295. 17. Kohut, R. 1975. The interaction of ozone and PAN on hybrid poplar. Proc. 1974 Annu. Meet. Am. Phytopathol. Soc. 1:76. 18. Linzon, S. N. 1967. Ozone damage and semimature-tissue needle blight of eastern white pine. Can. J. Bot. 45:2047-2061. 19. Miller, P. R. 1973. Oxidant Induced community change in a mixed conifer forest. Adv. Chem. Ser. 122:101-117. 20. Miller, P. R. and A. A. Millecan. 1971. Extent of oxidant air pollution damage to some pines and other conifers in California. Plant Dis. Rep. 55:555-559. 21. Miller, P. R., J. R. Parmeter, 0. C. Taylor, and E. A. Cardiff. 1963. Ozone injury to the foliage of Pinus ponderosa. Phytopathology 53:1072-1076. 22. Rich, S. 1964. Ozone damage to plants. Annu. Rev. Phytopathol. 2:253-266. 23. Richards, B. L., J. T. Middleton, and W. B. Hewitt. 1958. Air pollution with relation to agronomic crops: V. Oxidant stipple of grape. Agron. J. 50:559-561. 24. Richards, B. L, and 0. C. Taylor. 1965. Significance of atmospheric ozone as a phytotoxicant. J. Air Pollut. Control Assoc. 15:191- 193. 25. Santamour, F. S. 1969. Air pollution studies on platanus and American elm seedlings. Plant Dis. Rep. 53:482-484. 69 ------- 26. Shaulis, N. J., W. J. Kender, C. Pratt, and W. A. Sinclair. 1972. Evidence for injury by ozone in New York vineyards. HortScience 7:570-572. 27. Taylor, 0. C. 1969. Importance of peroxyacetyl nitrate (PAN) as a phytotoxic air pollutant. J. Air Pollut. Control Assoc. 19:247- 351. 28. Taylor, 0. C. and D. C. Maclean. 1970. Nitrogen oxides and the peroxyacyl nitrates. In: Recognition of Air Pollution Injury to Vegetation. A Pictorial Atlas. J. S. Jacobson and A. C. Hill, eds. Air Pollut. Control Assoc., Pittsburgh, p. E1-E14. 29. Thompson, C. R., E. Hensel, and G. Kats. 1969. Effects of photo- chemical air pollutants on Zinfandel grapes. HortScience 4:222- 224. 30. Thompson, C. R. and 0. C. Taylor. 1969. Effects of air pollutants on growth, leaf drop, fruit drop, and yield of citrus trees. Environ. Sci. Technol. 3:934-940. 31. Thompson, C. R., D. T. Tingey, and R. A. Reinert. 1974. Acceptable limits for air pollution dosages and vegetation effects: Nitrogen dioxide. Proc. Air Pollut. Control Assoc. Annu. Meet. 67: Paper No. 74-227. 21 pp. 32. Townsend, A. M. and L. S. Dochinger. 1974. Relationship of seed source and developmental stage of the ozone to tolerance of Acer rubrum seedlings. Atmos. Environ. 8:957-964. 33. Treshow, M. 1970. Environment and plant response. McGraw Hill Pub., N.Y. 422 pp. 34. Treshow, M. 1970. Ozone damage to plants. Environ. Pollut. 1:155-161. 35. Treshow, M. and D. Stewart. 1973. Ozone sensitivity of plants in natural communities. Biol. Conserv. 5:209-214. 36. van Haut, H. and H. Stratmann. 1967. Experimental investigation of the effect of nitrogen dioxide on plants. Schriftenr. Landesanst. Immissions Bodennutzungssch. Landes Nordrhein-Westfalen Essen 7:50- 70 (Trans1. from German). 70 ------- 37. Wilhour, R. G. 1970. Influence of ozone on white ash (Fraxlnus amerlcana L.). Pa. State Univ. Center Air Environ. Studies Pub. No. 188-71. 86 pp. 38. Wood, F. A. and J. B. Coppolino. 1971. The influence of ozone on selected woody ornamentals. Phytopathology 61:133 (Abstract). 39. Wood, F. A. and J. B. Coppolino. 1972. The influence of ozone on deciduous forest tree species. Mitt. Forstl. Bundes-Versuchanst. Wien 97:233-253 (Int. Symp. Forest Fume Damage Experts Proc. 7th, Essen, 7-11 Sept 1970). 71 ------- TECHNICAL REPORT DATA (Please read Instructions on the reverse before completing) 1. REPORT NO. EPA-600/3-76-102 3. RECIPIENT'S ACCESSION-NO. 4. TITLE AND SUBTITLE Susceptibility of Woody Plants to Sulfur Dioxide and Photochemical Oxidants 5. REPORT DATE September 1976 6. PERFORMING ORGANIZATION CODE 7. AUTHOR(S) Donald D. Davis and Raymond G. Wilhour 8. PERFORMING ORGANIZATION REPORT NO, 9. PERFORMING ORGANIZATION NAME AND ADDRESS Corvallis Environmental Research Laboratory 200 SW 35th St. Corvallis, Oregon 97330 10. PROGRAM ELEMENT NO. 1AA006 ROAP 21 ALS Task 08 11. CONTRACT/GRANT NO. 12. SPONSORING AGENCY NAME AND ADDRESS 13. TYPE OF REPORT AND PERIOD COVERED final same as above 14. SPONSORING AGENCY CODE EPA/ORD 15. SUPPLEMENTARY NOTES 16. ABSTRACT This report presents the result of a detailed review of European and United States literature regarding the sensitivity of woody vegetation to sulfur dioxide, ozone, peroxyacetyl nitrate (PAN), or nitrogen oxides. Reference is made to Russian, Japanese and Austrian literature only when species examined are commercially important in the United States. The manner in which the original susceptibility data were collected may influence the relative position of a species in a composite susceptibility table. Therefore, many original tables are presented for individual interpretation of susceptibility. Composite summary susceptibility tables are also presented for each pollutant. Relative sensitivity compilations should be used with caution and with an understanding of inherent limitations. The sensitivity categories of "very susceptible" and "very tolerant" should be of great assistance in selecting woody vegetation for planting in areas of high air pollution potential. However, for species found in the "intermediate" sensitivity category, greater emphasis should be placed on local environmental condition and economic factors than on air pollution sensitivity. 17. KEY WORDS AND DOCUMENT ANALYSIS DESCRIPTORS b.lDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group woody plants sulfur dioxide ozone PAN nitrogen oxides woody vegetation and air pollution susceptibility to photochemical oxidants 51 8. DISTRIBUTION STATEMENT Release to public 19. SECURITY CLASS (ThisReport) Unclassified 21. NO. OF PAGES 80 20. SECURITY CLASS (This page) TTnr 22. PRICE EPA Form 2220-1 (9-73) 72 ft U. S. GOVERNMENT PRINTING OPFIC6: 1976-698-165 / H REGION 10 ------- |