A FLORISTIC SURVEY OF THE TERRESTRIAL VASCULAR PLANTS OF STROUDS RUN STATE PARK, ATHENS COUNTY, OHIO A thesis presented to the faculty of the College of Arts and Sciences of Ohio University In partial fulfillment of the requirements for the degree Master of Science Sarah M. Harrelson March 2005 © 2005 Sarah M. Harrelson All Rights Reserved This thesis entitled A FLORISTIC SURVEY OF THE TERRESTRIAL VASCULAR PLANTS OF STROUDS RUN STATE PARK, ATHENS COUNTY, OHIO BY SARAH M. HARRELSON has been approved for the Program of Environmental Studies and the College of Arts and Sciences by Philip D. Cantino Professor of Environmental and Plant Biology Leslie A. Flemming Dean, College of Arts and Sciences HARRELSON, SARAH M. M.S. March 2005. Program of Environmental Studies Floristic Survey of the Terrestrial Vascular Flora of Strouds Run State Park, Athens County, Ohio. (195pp.) Director of thesis: Philip D. Cantino This study documented the terrestrial vascular flora of Strouds Run State Park (SRSP) in Athens Co., Ohio, and compared it with an earlier flora of the same area completed in 1957. Differences in the species composition of the herb layer between mixed mesic and oak forest and between differently aged stands were analyzed using NMS ordination. Over the course of two growing seasons (2003 and 2004), 624 species in 106 families were found in SRSP. The number and abundance of invasive species increased since 1957, but the percentage of species that are exotic decreased. The abundance of some ant-dispersed species increased, some decreased, and some remained the same. The abundance of most medicinal herb species has changed little since 1957, with the exception of goldenseal (Hydrastis canadensis), which has greatly increased. An NMS ordination of the herb-layer species composition of plots showed a clear separation between mesic and oak forest, and between young and old stands. Separation between mesic and oak forest may be due to moisture differences; however, soil moisture was not measured in this study. A significant difference (p < 0.05) in litter accumulation and the amount of canopy cover may explain the separation of old and young stands in mesic forests, but the age separation in oak forests was not explained by the results of this study. Approved by: Philip D. Cantino Professor of Environmental and Plant Biology Acknowledgements I would like to thank Bob Eichenberg of the Athens County Regional Planning Commission for the preparation of topographic maps of Strouds Run State Park, which were used extensively in my field work. Philip D. Cantino, John Knouse, and Chris Haufler (University of Kansas) helped with some species identifications. Glenn Matlack helped with analyzing statistical data, and Jennifer Gray and Jim Dyer helped produce the maps that are included in this thesis. Finally I thank Cynara M. Medina for editorial comments and technical assistance. I could not have done it without you! 7 Table of Contents Abstract ................................................................................................................ 4 Acknowledgements .............................................................................................. 6 List of Tables ........................................................................................................ 9 List of Figures..................................................................................................... 11 Chapter I Introduction ........................................................................................ 13 Chapter II The Floristic Survey .......................................................................... 17 Introduction...................................................................................................... 17 Study Area....................................................................................................... 18 History of Strouds Run State Park................................................................ 18 Description of the Study Area....................................................................... 20 Methods........................................................................................................... 23 Results and Discussion ................................................................................... 27 Overall Summary.......................................................................................... 27 Community Types......................................................................................... 28 Unusual Habitats .......................................................................................... 36 Potentially Threatened Species .................................................................... 40 Comparison of the 1957 Flora with the Current Flora of Strouds Run State Park................................................................................................................ 44 Chapter III Invasive Species in Strouds Run State Park.................................... 50 Introduction...................................................................................................... 50 Methods........................................................................................................... 53 Results and Discussion ................................................................................... 54 Management Implications................................................................................ 79 Chapter IV Changes in Abundance of Ant-Dispersed Forest Herbs in Strouds Run State Park ................................................................................................... 81 Introduction...................................................................................................... 81 Methods........................................................................................................... 83 Results and Discussion .................................................................................. 83 Chapter V Status of Medicinal Herb Populations in Strouds Run State Park .... 92 Introduction...................................................................................................... 92 Methods........................................................................................................... 97 Results and Discussion ................................................................................... 97 8 Chapter VI Influence of Stand Age and Environmental Factors on Herbaceous Species Composition........................................................................................ 104 Introduction.................................................................................................... 104 Materials and Methods .................................................................................. 107 Field sampling ............................................................................................ 107 Data analysis. ............................................................................................. 109 Results .......................................................................................................... 111 Discussion ..................................................................................................... 129 Conclusion..................................................................................................... 133 Literature Cited................................................................................................. 135 Appendix 1: Terrestrial vascular plant species documented at Strouds Run State Park, Athens County, Ohio ............................................................................... 159 9 List of Tables Table 1. The collecting schedule for the 2003 floristic survey of SRSP.............. 25 Table 2. The scale of abundance as used by Payne (1957)............................... 26 Table 3. Comparison of the number of species, the number of families, and the percent of alien species, both naturalized and casual, between the current floristic survey and Payne’s 1957 floristic survey of SRSP........................... 28 Table 4. The number of species found in each common community type in SRSP, including the number restricted to each community, the number characteristic of each community (of the species restricted to a community type, those that are common or frequent in abundance), and the number and percent of naturalized and casual alien species in each community (excludes Ilex opaca, Pinus strobus, and Liquidambar styraciflua)............................... 30 Table 5. Characteristic species found in the marshes of SRSP, Athens County, Ohio and their wetland status (Reed 1996). OBL = obligate wetland (occurs naturally in wetlands 99% of the time); FACW = facultative wetland (67-99%); FAC = facultative (34-66%); FACU = facultative upland (1-33%). ................ 33 Table 6. The abundance of invasive species in 1957 and their current abundance within SRSP, Athens, Ohio. ....................................................... 54 Table 7. The abundance of ant-dispersed forest herbs in 1957 and theircurrent abundance within SRSP, Athens, Ohio. ....................................................... 84 Table 8. The abundance of medicinal herbs in 1957 and their current abundance within SRSP, Athens, Ohio. ....................................................... 98 Table 9. Mean measurements of litter cover, litter depth, canopy cover, slope, exposed rock, species richness, species