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EDGE EFFECTS IN A FOREST-GRASSLAND MOSAIC IN SOUTHERN INDIA By MILIND BUNYAN A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2009 1 © 2009 Milind Bunyan 2 To, Preethi- no one deserves this more (Proverbs 31: 29-30) 3 ACKNOWLEDGMENTS I would like to thank the chair of my Graduate Committee, Dr. Shibu Jose for giving me the opportunity to pursue a doctoral degree and for his support, encouragement and patience especially when things did not go as planned. I would like to thank my committee members, Dr. Ankila Hiremath, Dr. Kaoru Kitajima, Dr. Alan Long, Dr. Michelle Mack and Dr. George Tanner for their time, guidance and encouragement through my program. I thank Dr. Ankila Hiremath in particular, for help with the logistics of research in India. I am especially grateful to Dr. Robert Fletcher for help with my research and methodology and Aditya Singh without who a large part of this dissertation might not have existed. I am grateful to the Karnataka and Kerala Forest Departments for permission to conduct research in BRT Wildlife Sanctuary and Eravikulam National Park and Pampadum shola National Park respectively. I would like to thank the staff at Ashoka Trust for Research in Ecology and the Environment (ATREE), Bangalore and the ATREE Field station at BRT for their assistance with data collection in BRT. My work in Eravikulam National Park was made possible in no small part by Senthil Kumar, Ancel and Sarvanan and they are gratefully acknowledged. Dr. Ganesan’s (ATREE) assistance was invaluable in the identification of plant specimens. I would like to thank my family in India for their love and support throughout the program. None of this would have been possible without the endless supply of coffee, food and love from my wife Preethi and right near the end, smiles and kisses from my one-year old, Rahael. 4 TABLE OF CONTENTS page ACKNOWLEDGMENTS ...............................................................................................................4 LIST OF TABLES ...........................................................................................................................7 LIST OF FIGURES .........................................................................................................................8 ABSTRACT .....................................................................................................................................9 CHAPTER 1 THE SHOLA-GRASSLAND ECOSYSTEM MOSAIC: A SYNTHESIS OF EXISTING LITERATURE ....................................................................................................11 Introduction .............................................................................................................................11 The Shola-grassland Ecosystem Mosaic ................................................................................12 What is not a Shola? ........................................................................................................13 Flora ........................................................................................................................................13 Fauna .......................................................................................................................................15 Hydrology ...............................................................................................................................16 Soils and Nutrient Cycling ......................................................................................................17 The Shola-grassland Edge ......................................................................................................18 Conclusion ..............................................................................................................................19 2 MICRONENVIRONMENT EDGE EFFECTS IN THE SHOLA GRASSLAND ECOSYSTEM MOSAIC ........................................................................................................25 Introduction .............................................................................................................................25 Methods ..................................................................................................................................29 Study Area .......................................................................................................................29 Sampling Protocol ...........................................................................................................31 Shola Plots .......................................................................................................................31 Grassland Plots ................................................................................................................32 Data Analyses .........................................................................................................................32 Results .....................................................................................................................................34 Comparing Shola and Grassland Plots ............................................................................34 Microenvironment Gradients in Shola Fragments ..........................................................35 Discussion ...............................................................................................................................36 Seasonal and diurnal variation .........................................................................................38 Comparison between One-edge and Multiple Edge Models ...........................................39 Conclusion ..............................................................................................................................40 3 SPECIES DISTRIBUTION PATTERNS IN SHOLA FRAGMENTS ..................................48 Introduction .............................................................................................................................48 5 Methods ..................................................................................................................................51 Study Area .......................................................................................................................51 Sampling Protocol ...........................................................................................................53 Data Analyses .........................................................................................................................54 Vegetation Structure and Composition ...........................................................................54 Edge-interior Gradients in Species Distributions ............................................................55 Results .....................................................................................................................................56 Vegetation Structure and Composition ...........................................................................56 Edge-interior Gradients in Species Distributions ............................................................57 Discussion ...............................................................................................................................58 Conclusion ..............................................................................................................................61 4 EFFECT OF TOPOGRAPHY ON THE DISTRIBUTION OF SHOLA FRAGMENTS: A PREDICTIVE MODELING APPROACH ........................................................................72 Introduction .............................................................................................................................72 Methods ..................................................................................................................................74 Study Area .......................................................................................................................74 Imagery Pre-processing and Data Preparation ................................................................75 Predictive Modeling ........................................................................................................76 Results .....................................................................................................................................77 Combined Model .............................................................................................................77 Data Subsets ....................................................................................................................78 Discussion ...............................................................................................................................78 Comparison of Data Subsets ...........................................................................................80 Implications for the Shola-grassland Edge ......................................................................80 Conclusion ..............................................................................................................................81 5 SUMMARY AND CONCLUSION .......................................................................................91 APPENDIX ....................................................................................................................................95 LIST