AN ABSTRACT OF THE THESIS OF Robert John Marquisfor the degree of Master of Arts inBotany and Plant Pathologypresented onDecember 8, 1977 Title: AN INVESTIGATION INTO THE ECOLOGY AND DISTRIBU- TION OF KALMIOPSIS LEACHIANA (HEND. ) ItEHDER Abstract approved: Redacted for Privacy William W. Chilcote Ecological factors associated with the relictual distribution of the endemic shrub Kalmiopsis leachiana (Ericaceae) were investi- gated. A prostrate evergreen species with small coriaceous leaves, K. leachiana is restricted to two disjunct populations in the Siskiyou Mountains and southern Cascade Mountains of southwestern Oregon, USA. Exact distributions of individual populations were mapped and were related to soils, geology, climate, and fire history using these factors to define in part this species' ecological range.Further investigation involved intensive sampling of associated vegetation, pressure chamber studies, seed germination and seedling growth experiments, and preliminary study of herbivore relationships and the heterostylous breeding system. Associated vegetation of Kalmiopsis populations was sampled using a nested plot technique. Analysis showed there to exist three major vegetation units:(1) low elevation Siskiyou stands (300-600 m), characterized by a conifer, broadleaf sclerophyll tree, evergreen shrub, and herb layer; (2) high elevation Siskiyou stands (900 m), differing from low elevation site by the absence of a broadleaf sclerophyll canopy; and (3) Southern Cascades vegetation, having relatively low species diversity associated with a more dense conifer canopy.In the latter stands, Kalmiopsis is found to grow almost invariably only on exposed, silicified rock outcrops.Soil in the Cascades did not prove to be inhibitory to germination and seedling development.Thus it is suggested that competition for light, water, and nutrients plays an important role in the species distribution and especially in its exclusion from surrounding vegetation of Cascades rock outcrops.In turn loss of the broadleaf sclerophyll canopy at high elevations in the Siskiyous, and related decrease in overstory canopy cover, is correlated with the much greater abundance of Kalmiopsis at high elevations there.The nature of the growth form and morphology of this plant and how they appear to be advantageous for establishment and growth in rocky, competition low microhabitats is discussed. Measurements of internal moisture stress were taken in the Siskiyou Mountains on Kalmiopsis and two sympatric sclerophyllous shrub species. Results of predawn and midday measurements at the height of the drought season indicate that Kalmiopsis undergoes higher stress levels than the other two species do in the same location, and appears to shut its stomata early in the day to avoid high stress buildup.In contrast the two sympatric shrubs appear to be able to remain photosynthesizing longer into the day, and this combined with their ability to handle higher stress, might account for theiroccur- rence at more xeric topographic positions where K. leachiana is not found. Germination and growth experiments on natural soils showed that Kalmiopsis seeds can germinate under low light conditions,are, heat sensitive, and resulting seedlings have relatively slow growth rates. The seedlings' small size and slow growth ratesare sug- gested to account for the low reproductive rate observed in the field and to be a contributing factor in the restricted distribution of the species. Kalmiopsis is distylous, this being the first reported case of heterostyly in the Ericaeae.In addition evidence is given that this morphological adaptation for outcrossing is strengthened by genetic self-incompatibility within and between plants of similar morphologi- cal types. Evidence of herbivory was practically absent in all populations. Two seed eating species, a lygaeid bug in the genus Kleidocerys and a species of mite in Trichoribates, were found to be associated with the persistent capsules.These may play an important role in the reproductive output of this plant. An Investigation into the Ecology and Distribution of Kalmiopsis leachiana (Hend.) Rehder by Robert John Marquis A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Master of Arts Completed December 1977 Commencement June 1978 APPROVED: Redacted for Privacy Professor of Botany in charge of major Redacted for Privacy Chaiman of Department of Botany and Plant Pathology Redacted for Privacy Dean of Graduate School Date thesis is presented December 8, 1977 Typed by Mary Jo Stratton forRobert John Marquis ACKNOWLEDGEMENTS I would like to express my appreciation here to those who have helped in the realization of this study.First of all, the advice and encouragement of Dr. William Chilcote were invaluable.Dr. Kenton L. Chambers helped greatly with an initial introduction to the general Siskiyou area and his further technical advice was always present when needed. Greenhouse space for experimental studies was provided through the courtesy of Dr. Chambers.I would like to thank the ladies of the Limpy Rock Committee, and especially Jeanie Moore, for their aid and guidance in location of Kalmiopsis populations in the North Umpqua River area. Many members of the Siskiyou National Forest of the United States Forest Service also aided in numerous ways andare thanked as well. Mr. Len Ramp, through identification of collected rock samples, made possible an important part of this study.Field study of populations in the Big Craggies Botanical Area were made through a grant of the Northwest Scientific Association and through funds provided by Dr. Thomas C. Moore and the Department of Botany and Plant Pathology at Oregon State University.Additional funding was provided by Dr. J. Lattin of the Department of Entomology, OSU. And lastly, I would especially like to thank Cheryl A. Crowder for her valu- able assistance and encouragement in the field, and discussion of ideas which are presented here. TABLE OF CONTENTS Page IN TRODUC TION 1 Systematics of Kalmiopsis leachiana 4 Habitats and Ecology of the Genus Rhodothamnus 9 THE STUDY AREAS 12 General Description 12 Siskiyou Study Area 12 Southern Cascades Study Area 15 Climate 19 Siskiyou Study Area 19 Southern Cascades Study Area 26 Geology and Physiography 28 Siskiyou Mountains Study Area 28 Southern Cascades Study Area 33 Fire History 37 Siskiyou Mountains Study Area 37 Southern Cascades Fire History 43 METHODS Geology and Soils 46 Synecology 47 Vegetation Sampling 47 Vegetation Analysis 54 Autecology 59 Plant Moisture Stress 59 Seed Germination 61 Seedling Growth 69 Phytochemis try 70 RESULTS AND DISCUSSION 71 Geology and Soils 71 Vegetation 76 Introduction 76 Low Elevation Siskiyou Vegetation 81 High Elevation Siskiyou Mountains 94 Southern Cascades Vegetation 108 Table of Contents (Continued) Page Quantitative Similarity Analysis SIMORD) 121 Morphology, Phenology, and Age 136 Morphology and Growth Form in Relation to Environment 136 Phenology 147 Age 150 Plant Moisture Stress Studies 152 Site Description 152 Theoretical Considerations 158 Results and Discussion 160 Seed and Seedling Ecology 171 Adaptive Nature of the Seeds 171 Seed Germination 176 Seedling Growth 189 Heterostyly and Floral Ecology 200 Persistent Style Measurements 201 Flower Measurements 204 Stigma and Style Morphology 212 Pollen Tetrad Shape and Size 213 C ros sing Experiments 214 Pollinator Observations 217 Herbivore Interactions 220 Insects 220 Mite s 221 Phytochemistry 223 SUMMARY AND CONCLUSIONS 225 BIBLIOGRAPHY 238 APPENDICES Appendix I. Location and Relevant Data of Sampled Population of Kalmiopsis leachiana 247 Appendix II. Partial Checklist of Vascular Plant Species Associated with Kalmiopsis leachiana 251 Appendix III.Cover and Constancy Values for Plant Species Associated with Kalmiopsis leachiana 258 Appendix IV.Results of Surface Soil Description of Sampled Sites of Kalmiopsis leachiana 270 LIST OF TABLES Table Page 1 Average precipitation for Siskiyou weather station. 20 2 Temperatures for Siskiyou and Southern Cascades weather stations. 22 3 Growing season for Siskiyou and Southern Cascade stations. 23 4 Mean monthly snowfall for Siskiyou and Southern Cascade stations. 25 5 Average precipitation for Southern Cascade weather stations. 27 6 Snow depths at stations in the Southern Cascades Mountains. 29 7 Summary of the fire history in the Chetco and Lower Illinois River drainages, 1900-1975. 39 8 Rock types associated with sampled sites of Kalmiopsis populations as identified by Len Ramp, Oregon Department of Geology and Mineral Industries. 72 9 Soil analysis results of soils collected from sites of selected Kalmiopsis populations. 75 10 Distribution among sampled vegetation of differ- ential samples which are common to a single vegetation. 79 11 Distribution among sampled vegetation of differ- ential species which are common to two vege- tation units but absent from the third. 80 12 Composition of the three major vegetation units on general life-form basis. 82 13 Relative tree canopy size, conifer representation, species totals, and total herb cover for low elevation Siskiyou Kalmiopsis populations. 84 List of Tables (Continued) Table Page 14 Representation of major tree species by total diameter at breast height of low elevation Siskiyous Kalmiopsis populations for 375 m2 plots. 85 15 Cover distribution of major shrub species of low elevation Siskiyous Kalmiopsis populations for 375 m2 plots. 86 16 Relative tree canopy size, conifer representa- tion, species