The Structure and Function of Subalpine Ecosystems in the Face of Climate Change
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The Structure and Function of Subalpine Ecosystems in the Face of Climate Change Item Type text; Electronic Dissertation Authors Lamanna, Christine Anne Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 05/10/2021 15:50:54 Link to Item http://hdl.handle.net/10150/228495 THE STRUCTURE AND FUNCTION OF SUBALPINE ECOSYSTEMS IN THE FACE OF CLIMATE CHANGE By Christine A. Lamanna ________________________ A Dissertation Submitted to the Faculty of the DEPARTMENT OF ECOLOGY AND EVOLUTIONARY BIOLOGY In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 2012 ! "! THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE As members of the Dissertation Committee, we certify that we have read the dissertation prepared by Christine Lamanna entitled “Subalpine ecosystem responses to climate change”, and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of Doctor of Philosophy ______________________________________________________ Date: March 1, 2012 Brian Enquist ______________________________________________________ Date: March 1, 2012 Scott Saleska ______________________________________________________ Date: March 1, 2012 Judith Bronstein ______________________________________________________ Date: March 1, 2012 Steve Archer ______________________________________________________ Date: March 1, 2012 Lara Kueppers Final approval and acceptance of this dissertation is contingent upon the candidate's submission of the final copies of the dissertation to the Graduate College. I hereby certify that I have read this dissertation prepared under my direction and recommend that it be accepted as fulfilling the dissertation requirement. ______________________________________________________ Date: March 1, 2012 Dissertation Director: Brian Enquist ! #! STATEMENT BY AUTHOR This dissertation has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgement of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED: Christine A. Lamanna ! $! ACKNOWLEDGEMENTS I would like to thank my advisor, Brian Enquist, who took a chance on a graduate student with no background in biology, and helped me to become the ecologist that I am today. Brian showed me how to take a love of natural history and transform it into a research science and conservation career. I am also indebted to all of the members of the Enquist lab, past and present, who supported me as mentors, colleagues and friends throughout my time at the University of Arizona. I would also like to thank my committee members for their feedback and support. Scott Saleska taught me how to do ecophysiological measurements and introduced me to the Rocky Mountain Biological Lab, which became the stage for my dissertation. He also showed me how to bring together science and environmental activism, and is my role model for what science activism can look like. Judie Bronstein was particularly helpful in designing my field experiments, her expertise in species interactions, and her wisdom in dealing with personal struggles. Lara Kueppers provided expertise in ecosystem functioning and sagebrush encroachment, and Steve Archer provided expertise in the physiology and ecology of sagebrush encroachment. Special thanks goes to the entire staff of Rocky Mountain Biological Laboratory who enabled me to do research there. Ian Billick, Jennie Reithel, Dan Jones and billy barr helped with permitting, site selection, data depositing and climate data. Jennie Reithel, John Harte, Nick Waser, Mary Price and David Inouye provided invaluable guidance on my research and showed me how important a love and knowledge of place is for an ecologist. My heartfelt thanks goes to the researchers and graduate students of the RMBL, who were my “other” department during my dissertation, and provided support, guidance and many wonderful memories. Rocky Mountain Biological Laboratory, founded 1928. We do science over there. ! %! DEDICATION This work is dedicated to my parents, Richard and Nancy Lamanna, who became the first in their families to go to college, and enabled me to become the first person in our family to earn a Ph.D. ! &! TABLE OF CONTENTS ABSTRACT………………………………………………………………………………9 INTRODUCTION...........................................................................................................11 An explanation of the problem and a review of the literature ......................................11 An explanation of the dissertation format .....................................................................14 PRESENT STUDY..........................................................................................................16 REFERENCES.................................................................................................................20 APPENDIX A- ASSESSING THE DIFFERENTIAL EFFECTS OF TEMPERATURE AND PRECIPITATION ON SUBALPINE ECOSYSTEM FUNCTIONING ………………………………………….…………….………………22 Abstract………..……………………………………………………...…………………………24 Introduction…………………………………………………………..…………………………26 Materials and Methods……………………………………………………………………..…29 Results…………….……………………..………………………………………………………35 Discussion………….……………………………………………………………………………39 Acknowledgements …………………………………………………………………………….45 References ………………………………………………………………………………………46 Tables ……...……………………………………………………………………………………50 Figure Captions …..…………………………………………………………………………...51 Figures ……………..…………………………………………………………………………..54 ! 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TABLE OF CONTENTS – CONTINUED APPENDIX B- MICROBES ON MOUNTAINSIDES: CONTRASTING ELEVATIONAL PATTERNS OF BACTERIAL AND PLANT DIVERSITY ……60 Abstract………..…………………………………………………………………..…………… 62 Introduction………………………………………………………………..……………………63 Results and Discussion.………………………………………………………..……………..69 Materials and Methods………………………………………………………………………..77 List of Supplementary Information…………………………………………………………..86 Acknowledgements …………………………………………………………………………….87 References …………………………………………………………………………………,…..88 Tables …... ……………………………………………………………………………….….…94 Figure Captions...……………………………………………………………………………...95 Figures …...……………………………………………………………………………………..97 Supplementary Information…………………………………………………………………100 APPENDIX C- DISENTANGLING DIFFERENTIAL TRAIT DRIVERS OF PHYLOGENETIC COMMUNITY ASSEMBLY ACROSS AN ELEVATIONAL GRADIENT……..……………………...……………………114 Abstract………..…………………………………………...………………………………….116 Introduction………………………………………………..………………………………….117 Methods..………………………………..……………………………………………………..122 ! 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TABLE OF CONTENTS – CONTINUED Results…………….…………………………………………………………….………..........128 Discussion………….………………………………………………………………………….131 Acknowledgements …………………………………………………………..………………136 References ………………………………………………………………………………….....137 Tables …... ……………………………………………………………………………………141 Figure Captions..…………………………………………………………………….….……146 Figures ...…..……………………………………………………………………………..…..148 APPENDIX D- FACILITATION IS CRITICAL TO THE SURVIVAL OF SAGEBRUSH SEEDLINGS AT THEIR ELEVATIONAL RANGE LIMIT…….152 Abstract………..…………………………………………………………………..…………..154 Introduction………………………………………………………………..………………….155 Materials and Methods………….…………………………………………………………...159 Results…………….……………………………………………………………..……………..162 Discussion………….………………………………………………………………………….164 Acknowledgements …………………………………………………………………………..167 References …………………………………………………………………………………….168 Tables …... ……………………………………………………………………………………172 Figure Captions...…………………………………………………………………………….173 Figures …...……………………………………………………………………………………175 ! )! ABSTRACT Subalpine ecosystems are experiencing rapid changes in snow pack, temperature, and precipitation regime as a result of anthropogenic climate forcing. These changes in climate can have a profound effect on subalpine ecosystem structure and functioning, which may ultimately feed back to climate change. In this study, I examined the response of the subalpine meadow plant communities at the Rocky Mountain Biological Laboratory to natural and simulated climate change. First, I looked at whether changes in growing season precipitation or temperature regime would have the larger effect on subalpine ecosystem carbon flux. In a simulated warming experiment, changes in growing season precipitation had a tenfold larger effect on cumulative carbon flux than did the warming treatment. Along a natural climatic and elevational gradient, precipitation stimulates carbon uptake, particularly at higher elevations. Given projected decreases in summer precipitation in the high elevation Rockies, we predict a 20% decrease in carbon uptake from subalpine meadows. Second, I compared the taxonomic, phylogenetic and functional structure of plant communities along an elevational gradient to infer