THE QUANTITATIVE IMPORTANCE OF STEMFLOW: AN EVALUATION OF PAST RESEARCH AND RESULTS FROM A STUDY IN LODGEPOLE PINE (PINUS CONTORTA VAR. LATIFOLIA) STANDS IN SOUTHERN BRITISH COLUMBIA by Adam Jon McKee B.A. Thompson Rivers University, 2008 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE (ENVIRONMENTAL SCIENCE) Thesis examining committee: Darryl Carlyle-Moses (Ph.D.), Thesis Supervisor, Assistant Professor, Dept. of Geography, Thompson Rivers University Karl Larsen (Ph.D.), Committee Member, Associate Professor, Dept. of Natural Resource Sciences, Thompson Rivers University Rita Winkler (Ph.D., R.P.F.), Committee Member, Adjunct Professor, Dept. of Natural Resource Sciences and Research Hydrologist, BC Ministry of Forests and Range Delphis F. Levia (Ph.D.), External Examiner, Associate Professor, Depts. of Geography & Plant and Soil Science, University of Delaware Spring Convocation 2011 Thompson Rivers University © Adam Jon McKee, 2010 Thesis Supervisory Committee ________________________ Dr. Darryl Carlyle-Moses, Supervisor ________________________ Dr. Karl Larsen, Committee Member ________________________ Dr. Rita Winkler, Committee Member This thesis by Adam Jon McKee was defended successfully in an oral examination on December 9, 2010 by a committee comprising: ________________________ Dr. Delphis F. Levia, External Examiner ________________________ Dr. Darryl Carlyle-Moses, Supervisor ________________________ Dr. Karl Larsen, Committee Member ________________________ Dr. Rita Winkler, Committee Member ii ________________________ Dr. Lauchlan Fraser, Chair/Coordinator of Graduate Program Committee ________________________ Dr. Tom Dickinson, Dean of Science ________________________ Dr. Peter Tsigaris, Chair of the Examining Committee This thesis is accepted in its present form by the Office of the Associate Vice President, Research and Graduate Studies as satisfying the thesis requirements for the degree Master of Science, Environmental Science. ……………………………… Dr. Nancy A. Van Wagoner Associate Vice President, Research and Graduate Studies iii I, Adam Jon McKee, grant non-exclusive permission to the University Librarian of Thompson Rivers University to reproduce, loan or distribute copies of my thesis in microform, paper or electronic formats on a non-profit, royalty-free basis for the full term of copyright protection. I, however, retain the copyright in my thesis. ________________________ Author ________________________ Supervisor ________________________ Date iv ACKNOWLEDGEMENTS I would like to thank my supervisor, Dr. Darryl Carlyle-Moses, for inviting me to join his research program, and for his input, support, and knowledge that made the completion of this thesis possible. Thanks to my thesis committee for their time and guidance: Dr. Rita Winkler, Dr. Karl Larsen, and Dr. Delphis Levia. Special thanks to the entire research team for help with equipment setup, data collection, and for two great summers: Chad Lishman, Pearce Sanders, Andrew Pillar, Jenn Golden, Warren Giesbrecht, and Sarah Ostoforoff. I would like to thank my family for their support over the past two years and everyone that had to listen to me talk about “trees, water, and dirt”. Special thanks to Katie Tallon for her support, editing skills, and field assistance when an extra person was needed. This project would not have been possible without the funding support provided by the NSERC (Natural Sciences and Engineering Research Council of Canada) Discovery Grant and the FIA-FSP (Forest Investment Account – Forest Science Program) funds awarded to Dr. Darryl Carlyle-Moses. v ABSTRACT Stemflow is a focused point source input of precipitation and nutrients at the base of a tree or plant, and can have a significant impact on site hydrology. A review paper examining the quantitative importance of stemflow, and a stemflow modelling paper focused on juvenile lodgepole pine are presented in this thesis. Stemflow production information from 145 different studies is presented in table format with the addition of author-calculated funnelling ratios and plateau funnelling ratios when applicable. Plateau funnelling ratios were calculated to provide an estimation of the rainfall depth required to satisfy the storage capacity of a tree. Reference tables were used to identify inter- climatic, inter-genera, and intra-genera variations in stemflow production. Plateau funnelling ratios were used to identify shortcomings in current canopy interception models. Finally, the reference tables were used to identify areas of the stemflow literature where knowledge remains fairly weak. To date, no known studies have modelled stemflow production for juvenile lodgepole pine (Pinus contorta var. latifolia). Meteorological conditions, tree characteristics, and stemflow were sampled for two juvenile lodgepole pine stands over the course of the 2009 growing season. Step-wise multiple regression was used to assess which meteorological and tree architecture variables influenced stemflow production for each research plot. Once predictor variables were identified, models were produced for each stand and a generic model was produced that applied to both plots. A model employing precipitation depth and crown projection area successfully explained 71.3 % of the variation in stemflow production from sampled trees. Key words: Lodgepole pine (Pinus contorta var. latifolia), stemflow, stemflow funnelling ratio, plateau funnelling ratio, forest hydrology vi TABLE OF CONTENTS ACKNOWLEDGEMENTS ...................................................................................................... v ABSTRACT ............................................................................................................................. vi TABLE OF CONTENTS ........................................................................................................ vii LIST OF TABLES ................................................................................................................... ix LIST OF FIGURES ................................................................................................................. xi LIST OF SYMBOLS .............................................................................................................. xii CHAPTER 1. INTRODUCTION ............................................................................................. 1 LITERATURE CITED ......................................................................................................... 4 CHAPTER 2. A SYNTHESIS AND EVALUATION OF PAST RESEARCH ON THE QUANTITATIVE IMPORTANCE OF STEMFLOW ............................................................. 7 INTRODUCTION ................................................................................................................ 7 METHODS ........................................................................................................................... 9 RESULTS ........................................................................................................................... 12 1. Temperate deciduous .................................................................................................. 12 2. Temperate coniferous and boreal ................................................................................ 14 3. Mixed deciduous and coniferous stands ..................................................................... 15 4. Tropical ....................................................................................................................... 16 5. Mediterranean ............................................................................................................. 16 6. Arid and semi-arid environments................................................................................ 18 7. Agroforestry ................................................................................................................ 19 DISCUSSION ..................................................................................................................... 19 CONCLUSION ................................................................................................................... 22 LITERATURE CITED ....................................................................................................... 23 APPENDIX – REFERENCE TABLES .............................................................................. 39 CHAPTER 3. MODELLING STEMFLOW PRODUCTION BY JUVENILE LODGEPOLE PINE (PINUS CONTORTA VAR. LATIFOLIA) TREES IN SOUTHERN BRITISH COLUMBIA, CANADA........................................................................................ 79 INTRODUCTION .............................................................................................................. 79 MATERIALS AND METHODS ........................................................................................ 81 Site description................................................................................................................ 81 vii Meteorological data ........................................................................................................ 82 Stemflow collection ........................................................................................................ 84 Tree characteristics ......................................................................................................... 86 Statistical analysis ..........................................................................................................