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EFFECTS OF LARGE FIRES ON BOREAL FORESTS OF CHINA—Historical Reconstruction and Future Prediction through Landscape Modeling ___________________________________ A Dissertation presented to the Faculty of the Graduate School at the University of Missouri-Columbia _______________________________________________________ In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy _____________________________________________________ by Wenru Xu Dr. Hong S. He, Dissertation Supervisor December 2020 © Copyright by Wenru Xu 2020 All Rights Reserved The undersigned, appointed by the Associate Vice Chancellor of the Office of Research and Graduate Studies, have examined the dissertation entitled EFFECTS OF LARGE FIRES ON BOREAL FORESTS OF CHINA — Historical Reconstruction and Future Prediction through Landscape Modeling presented by Wenru Xu, a candidate for the degree of Doctor of Philosophy, and hereby certify that, in their opinion, it is worthy of acceptance. Dr. Hong S. He Dr. Grant P. Elliott Dr. David R. Larsen Dr. Michael C. Stambaugh ACKNOWLEDGEMENTS First I would like to give my sincere thanks to my advisor Dr. Hong S. He for introducing me to the world of science, for guiding me in proceeding research and overcoming difficulties in the research, and for enhancing my abilities in critical thinking and paper writing. His support and advice were indispensable during my Ph.D. study. I would also like to thank my committee members, Dr. David R. Larsen, Dr. Michael C. Stambaugh, and Dr. Grant P. Elliott for their time and effort in attending numerous meetings with me and helping improve my research. I would also like to express my appreciation to Dr. Zhiliang Zhu, Dr. Todd J. Hawbaker, and Dr. Paul D. Henne for their precious time in reviewing my papers and giving recommendations, encouragement, and feedback to my research. I would also acknowledge the financial support from the National Biologic Carbon Sequestration Assessment Program under the U.S. Geological Survey Climate and Land Use Mission Area, and the University of Missouri GIS Mission Enhancement Program. My thanks also goes to the members I met in the GIS Spatial Analysis Lab: Wenjuan Wang, Jacob Fraser, Shengwu Duan and his wife Lu Huang, Yuanyuan Fu, Wenchi Jin, Michael Sunde, and Saaruj Khadka as well as Dr. Benjamin O. Knapp and Dr. John Kabrick for being supportive and making my experience in the forestry department more enjoyable. I would like to extend my thanks to Dr. William Dijak. He is always kindly and generously grants me his time for advice and especially technical support. Finally, I want to say thank you to my parents for all their love and unconditional support throughout my life. ii TABLE OF CONTENTS ACKNOWLEDGEMENTS ......................................................................................................... ii LIST OF FIGURES .................................................................................................................... vii LIST OF TABLES ....................................................................................................................... xi ABSTRACT .................................................................................................................................xiii CHAPTER I. INTRODUCTION ................................................................................................ 1 1. Research background .............................................................................................. 1 2. Research objectives .................................................................................................. 3 3. Chapter outlines ........................................................................................................ 3 Literature cited .............................................................................................................. 6 CHAPTER II. Estimating burn severity and carbon emissions from a historic megafire in boreal forests of China ................................................................................................................ 10 1. Introduction ............................................................................................................. 10 2. Materials and Methods ........................................................................................... 14 2.1. Study area ........................................................................................................... 14 2.2. Data Sets ............................................................................................................. 14 2.3. Quantification of burn severity ........................................................................... 16 2.4. Calculation of aboveground biomass consumption and carbon emission .......... 17 3. Results ...................................................................................................................... 19 iii 4. Discussion ................................................................................................................. 21 4.1. Estimation of carbon emissions from the Black Dragon fire ............................. 21 4.2. Implications for understanding megafire impacts on fire emissions .................. 23 5. Conclusions .............................................................................................................. 25 Figures .......................................................................................................................... 26 Tables............................................................................................................................ 30 Literature cited ............................................................................................................ 35 CHAPTER III. Spatially explicit reconstruction of post-megafire forest recovery through landscape modeling ..................................................................................................................... 46 1. Introduction ............................................................................................................ 46 2. Data and methods ................................................................................................... 50 2.1. Study area ........................................................................................................... 50 2.2. General approach ................................................................................................ 51 2.3. Forest inventory data .......................................................................................... 52 2.4 Remote sensing data ............................................................................................ 53 2.5. Pre-fire forest conditions .................................................................................... 54 2.6 Landscape model parameterization ..................................................................... 55 2.7 Black Dragon fire and its implementation in LANDIS PRO .............................. 57 2.8 Model calibration and results validation ............................................................. 58 iv 2.9. Post-fire tree planting simulation ....................................................................... 60 3. Results ..................................................................................................................... 60 3.1. Results validation ............................................................................................... 60 3.2. The Black Dragon fire effects and post-fire forest recovery trajectories ........... 62 4. Discussion ................................................................................................................. 63 Figures .......................................................................................................................... 66 Tables............................................................................................................................ 77 Literature cited ............................................................................................................ 80 CHAPTER IV. Large fires or small fires, will they differ in affecting shifts in species composition and distribution under climate warming? .......................................................... 93 1. Introduction ............................................................................................................ 93 2. Materials and methods .......................................................................................... 97 2.1 Study area ............................................................................................................ 97 2.2 Model simulation and parameterization .............................................................. 97 2.3 Climate scenarios ................................................................................................. 99 2.4 Fire scenarios ..................................................................................................... 100 2.5 Simulation design and model validation ........................................................... 100 2.6 Data analysis ...................................................................................................... 101 3. Results ................................................................................................................... 102 v 3.1 Model validation ...............................................................................................