THE DECLINE OF A RIPARIAN GALLERY FOREST IN DEVILS TOWER, WYOMING: CAUSATION AND MANAGEMENT TECHNIQUES FOR RESTORATION by Jacob Michael Anderson A thesis submitted in partial fulfillment of the requirements for the degree of Master of Sciences in Animal and Range Sciences MONTANA STATE UNIVERSITY Bozeman, Montana April 2013 ©COPYRIGHT by Jacob Michael Anderson 2013 All Rights Reserved ii APPROVAL of a thesis submitted by Jacob Michael Anderson This thesis has been read by each member of the thesis committee and has been found to be satisfactory regarding content, English usage, format, citation, bibliographic style, and consistency and is ready for submission to The Graduate School. Dr. Clayton Marlow Approved for the Department of Animal and Range Sciences Dr. Glenn Duff Approved for The Graduate School Dr. Ronald W. Larsen iii STATEMENT OF PERMISSION TO USE In presenting this thesis in partial fulfillment of the requirements for a master’s degree at Montana State University, 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 this thesis in whole or in parts may be granted only by the copyright holder. Jacob Michael Anderson April 2013 iv DEDICATION I dedicate this document to my grandfather, Laurel Anderson, who has always instilled in me a deep appreciation for the natural world, hard work, and dedication for my passions in life. v ACKNOWLEDGEMENTS This project was made possible through funding from Montana State University and the National Park Service. I give my sincere thanks to all of those, named and un-named, who generously donated their time, thoughts, and support to this project from beginning to end. I would like to thank the Devils Tower staff of 2011 and 2012 for their help in the field, the Montana Conservation Corps for helping me plant all of the trees, the Devils Tower Resource Management Department for helping to continually help monitor and care for my project, and the Devils Tower Maintenance Department for providing tools and knowledge for the construction of many of the items used in this study. I would also like to thank my advisor, Dr. Clayton Marlow, and my colleagues, Dustin Anderson, Neto Garcia, and Glenn Owings, for helping me from start to finish with this project. Lastly, I lovingly thank my family (Rhon, Sarah, Matthew, and Elizabeth) and Kristi Boyle for their unfaltering support throughout this entire process. Without them, none of this would have been possible. vi VITA Jacob Michael Anderson was born May 4, 1989 in Sioux Falls, South Dakota. He is the son of Rhon and Sarah Anderson. He attended school in Sioux Falls and graduated Lincoln High School in the spring of 2007. Jacob received a Bachelor’s of Arts in Biology from Augustana College, Sioux Falls, South Dakota in the spring of 2011. vii TABLE OF CONTENTS 1. LITERATURE REVIEW ............................................................................................... 1 Introduction .................................................................................................................... 1 Cottonwood Growth and Requirements ......................................................................... 1 Western Riparian Successional Species ......................................................................... 2 Effects of Dams on Riparian Succession ....................................................................... 4 Purpose ........................................................................................................................... 5 2. INTRODUCTION .......................................................................................................... 6 3. METHODS ................................................................................................................... 11 Study Sites .................................................................................................................... 11 Hypothesis 1: Testing for Residual Herbicide Within Soils at Devils Tower ....................................................................................... 12 Hypothesis 2: Differences Between Regulated and Unregulated Rivers ....................................................................................................... 12 Devils Tower NM Survey ............................................................................................ 13 Devils Tower Age Class Survey .................................................................................. 13 Powder River Survey .................................................................................................... 14 Hypothesis 3: Tree Planting to Determine Species and Treatment Success at Devils Tower National Monument ............................................................. 16 Tree Planting ................................................................................................................ 20 Tree Measurements and Maintenance .......................................................................... 21 Statistics and Data Analysis ......................................................................................... 22 4. RESULTS ..................................................................................................................... 24 Hypothesis 1: Testing for Residual Herbicide Within Soils at Devils Tower NM ................................................................................ 24 Hypothesis 2: Differences Between Regulated and Unregulated Rivers ................................................................................................ 24 Hypothesis 3: Tree Planting to Determine Species and Treatment Success at Devils Tower NM ...................................................................... 26 5. DISCUSSION ............................................................................................................... 31 Hypothesis 1: Residual Herbicide Within Floodplain Soils Limit Cottonwood Regeneration ......................................................................... 31 viii TABLE OF CONTENTS - CONTINUED Hypothesis 2: The Dam Located Upstream of Devils Tower Has No Effect on the Riparian Corridor at Devils Tower. No Difference in Forest Structure Exists Between the Belle Fourche River Riparian Area and the Powder River Riparian Area. ................................................... 33 Hypothesis 3: Trees Planted with Little Care or Soil Preparation Will Perform Best with High Survival and Growth Rates ........................................... 37 6. CONCLUSION ............................................................................................................. 42 7. MANAGEMENT RECOMMENDATIONS ................................................................ 43 LITERATURE CITED ..................................................................................................... 46 APPENDICES .................................................................................................................. 50 APPENDIX A: Devils Tower National Monument Map of Plots Tested for the Tree Growth Study ....................................... 51 APPENDIX B: Soil Profile of Plot C1 ................................................................. 53 APPENDIX C: Soil Profile of Plot C2 ................................................................. 55 APPENDIX D: Soil Profile of Plot C3 ................................................................. 57 APPENDIX E: Soil Profile of Plot C4 ................................................................. 59 APPENDIX F: Soil Profile of Plot P1 .................................................................. 61 APPENDIX G: Soil Profile of Plot P2 ................................................................. 63 APPENDIX H: Soil Profile of Plot P3 ................................................................. 65 APPENDIX I: Irrigation Component Diagram or the Devils Tower NM Tree Planting Study .................................................... 67 APPENDIX J: Datasheet for Campground Measures of Height and Health, 2011 and 2012 at Devils Tower NM ............................................................ 69 APPENDIX K: Datasheet for Primitive Campground Measures of Height and Health, 2011 and 2012 at Devils Tower NM............................................ 73 ix LIST OF TABLES Table Page 1. Treatment Descriptions ......................................................................................11 2. Cottonwood Age Class Structure at Two Locations ..........................................19 3. Soil Data from Two Locations ...........................................................................25 4. Tree Mortality by Species at Devils Tower .......................................................26 5. Tree Mortality by Treatment at Devils Tower ...................................................28 6. Tree Mortality at Devils Tower in 2012 ............................................................29 7. Rainfall by Month for Two Years at Devils Tower ...........................................30 x LIST OF FIGURES Figure Page 1. Devils Tower Study Location ..............................................................................6 2. Plot Design at Devils Tower