Impact of Backcountry Campsite Use on Forest Structure, Within Yellowstone National Park, U.S.A
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Impact of backcountry campsite use on forest structure, within Yellowstone National Park, U.S.A. by James Y Taylor A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Earth Sciences Montana State University © Copyright by James Y Taylor (1995) Abstract: This study investigated how backcountry campsite use impacts the surrounding forest structure. Forest structure included the occurrence and distribution of trees around campsites, species composition of trees, forest canopy density, and understory composition. Additional elements considered were mode of user travel, annual number of users, and shoreline topography. It was hypothesized that as distance from the campsite increased, more tree saplings would occur, and that the more resistant species such as Pinus contorts (lodgepole pine) would occur in greater abundance nearer campsites than the less resistant species of Picea engelmannii (Engelmann spruce) and Abies Iasiocarpa (subalpine fir). Other hypotheses were that more annual campsite users would positively correlate with a greater impact, and that there would be measurable differences in the forest structure around campsites with differing user types (backpack, canoe, and motorboat use). Thirty campsites and three control sites on Yellowstone and Shoshone Lakes were studied. Transects with quadrats were used to sample the vegetation outward from each campsite. Within each quadrat all vegetation was classified and counted. Abiotic variables were also noted. There was a significant difference (P = .00002) between the forest structure surrounding backcountry campsites and that surrounding control sites. The number of saplings, forest canopy, conifer species composition and percent bare area were all found to be significantly different between campsites and control sites. There were also differences in the number of saplings per quadrat between campsites with differing user types, and a decrease in saplings around campsites with increasing user numbers. There were positive correlations between distance from the campsites and the number of conifer trees within all size classes (r = .96, .98, .95, and .80 for trees within the <30 cm, 30-90 cm, 90-140 cm and > 140 cm height size classes respectively), and positive correlations between percent understory (r = .78) and percent canopy cover (r = .31) with distance. There were significant correlations between distance from the control sites and the number of saplings. These measured differences between the campsites and control sites are essential components to sound resource management plans and provide greater understanding of the forest structure and understory vegetation surrounding the backcountry campsites in Yellowstone National Park. IMPACT OF BACKCOUNTRY CAMPSITE USE ON FOREST STRUCTURE, WITHIN YELLOWSTONE NATIONAL PARK, U.S.A. by James Y. Taylor 6 A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Earth Sciences Montana State University Bozeman, Montana November, 1995 MS')? T a W Il APPROVAL of a thesis submitted by James Y. Taylor This thesis has been read by each member of the thesis committee and has been found to be satisfactory regarding content, english usage, format, citations, bibliographic style, and consistency, and is ready for submission to the College of Graduate Studies. iV Date Chairperson, aduate Committee Approved for the Major Department /zwf Date Approved for the College of Graduate Studies Date Graduate Dean Ni STATEMENT OF PERMISSION TO USE In presenting this thesis in partial fulfillment of the requirements for a master's degree at Montana State University-Bozeman, I agree that the Library shall make it available to borrowers under rules of the Library. If I. have indicated my intention to copyright this thesis by including a copyright notice page, copying is allowable only for scholarly purposes, consistent with "fair use" as prescribed in the U.S: Copyright Law. Requests for . permission for extended quotation from or reproduction of the thesis in whole or in parts may be granted only by the copyright holder. ) IV ACKNOWLEDGEMENTS I wish to express my sincere appreciation to Dr. Kathy Hansen for the patient and persistent encouragement during my thesis work. Her knowledge and field research experience were invaluable to completing this project. I also wish to thank Dr. Andrew Marcus for his guidance and continued support. Dr. Ward McCaughey also provided much needed advice and field experience and was of great assistance during the development of the field methods. Tom Olliff of the Backcountry Rangers Office in Yellowstone National Park also provided logistical and technical support which was greatly appreciated. Funding for this project was provided by the Yellowstone Center for Mountain Environments at Montana State University. David Cole, of the Aldo Leopold Center for Wilderness Research, Intermountain Research Station, United States Forest Service, also provided financial and technical support which proved invaluable. I also wish to acknowledge the continual support of family members and friends who provided great technical and emotional assistance. In particular I wish to thank Nancy Taylor for her patience and her encouragement. V ) TABLE OF CONTENTS Page APPROVAL . , ......... .......................................................................... ii STATEMENT OF PERMISSION TO USE................................................ Hi ACKNOWLEDGEMENTS........................................................................ iv CONTENTS............................................................................................... v LIST OF TABLES...................................................................................... vii LIST OF FIGURES.................................................................................... viii ABSTRACT.................................... .......................................................... xi 1. INTRODUCTION.................................................................................... 1 Introduction............................................. ...................................... 1 Previous Research . : .....................................................................3 Study A rea..................................................................................... 5 2. METHODOLOGY........... .................................... ........................... 12 Campsite Selection........... ............................................................ 12 Sampling Techniques............................................. ..............14 3. RESULTS................................................................................................17 Sapling Occurrence Around Campsites and Control Sites........... 17 Sapling Numbers and Direction from the Campsite Centers.........18 Impact Associated with Differing Types of Campsite U se............. 23 Impact Associated with Increasing User Numbers....................... 25 Analysis of Differing Conifer Size Classes.................................... 28 Differences in Impact within Campsites of Differing Topography . 31 Difference in Measured Impact Between Conifer Species........... 32 Changes in Percent Forest Canopy due to Campsite U se......... 35 Impact of Campsite Use on Percent Bare Area and Percent Understory Vegetation................................................... 37 Average Percent Bare Area by User Type.................................... 38 Average Percent Understory Vegetation...................................... 39 \ vi 4. DISCUSSION, CONCLUSIONS, AND MANAGEMENT IMPLICATIONS, AND RECOMMENDATIONS.................................. 45 Discussion.................................................................................... 45 Conclusions................................................................. 48 Management Implications........................................................... 50 Management Recommendations...................................................... 51 APPENDICES...................................................... 54 Appendix A - List of Vegetation Species Identified..................... 55 Appendix B - Study Site Data by Campsite................................ 56 Appendix C - Complete Listing of All Statistical Tests.............. 73 REFERENCES CITED............................................................................. 77 vii LIST OF TABLES Tables Page 1 Diagnostic Characteristics of Lodgepole Pine Forest Cover Types.....................................................12 2 Study Site Characteristics....................................................13 3 Comparison of the Number of Saplings per Quadrat between the Campsites and the Control Sites for each Transect................................................................. 19 4 Correlation and Slope between Distance and Sapling Numbers for the Campsites and the Control Sites for each Transect.................................................................... 19 5 Occurrence of Numbers of Tree Saplings within Various Size Classes within the Campsites and the Control Sites......................................................................................28 6 Correlation between Increasing Distance and Average Number of Saplings for the Campsites and the Control Sites.........................................................................29 7 Comparison of the Average Percent Moss, Grass, Sedge, Forb, and Shrub Cover between the Campsites