A study on the distribution of vascular epiphytes in a secondary cloud forest, Central Cordillera, Colombia. Maaike Bader A study on the distribution of vascular epiphytes in a secondary cloud forest, Central Cordillera, Colombia. Oktober 1999 Thesis tropical nature management (H300-762) Maaike Bader (Wageningen University) Main tutor: Drs. Frans van Dunné (Hugo de Vries Laboratory, University of Amsterdam) Other tutors: Prof. Dr. Antoine M. Cleef (Hugo de Vries Laboratory, UvA & Vertebrate Ecology & Tropical Nature Management, Wageningen University) Dr. Pieter Ketner (Vertebrate Ecology & Tropical Nature Management, Wageningen University) John Stuiver (Laboratory of Geographical Information Science and Remote Sensing, Wageningen University) Internal Report no. 326 Wageningen University and Research Centre (Formerly ‘Wageningen Agricultural University)’ THE DATA IN THIS REPORT ARE MEANT FOR INTERNAL USE ONLY. NO COPYING PERMITTED WITHOUT PERMISSION FROM THE AUTHOR OR TUTOR(S). Contents `CONTENTS.................................................................................................................................... 1 PREFACE........................................................................................................................................ 3 ABSTRACT ..................................................................................................................................... 4 SAMENVATTING............................................................................................................................ 5 RESUMEN....................................................................................................................................... 6 1 EPIPHYTISM............................................................................................................................ 7 1.1 DEFINITION ......................................................................................................................... 7 1.2 ECOLOGY AND EVOLUTION ................................................................................................... 7 1.3 DISTRIBUTION AND TAXONOMY ........................................................................................... 10 1.4 BROMELIACEAE ................................................................................................................ 11 1.5 ORCHIDACEAE .................................................................................................................. 13 1.6 LORANTHACEAE ................................................................................................................ 14 2 INTRODUCTION TO THE STUDY ........................................................................................ 18 3 STUDY AREA ........................................................................................................................ 22 4 METHOD................................................................................................................................ 25 4.1 FIELDWORK ........................................................................................................................... 25 4.2 DATA ANALYSIS ................................................................................................................ 26 4.2.1 GIS ........................................................................................................................... 26 GIS pre-processing ........................................................................................................................... 27 GIS-analysis ...................................................................................................................................... 29 4.2.2 Spatial point pattern .............................................................................................. 29 4.2.3 Climatic data ........................................................................................................... 30 4.2.4 Height distribution ................................................................................................. 30 4.2.5 Other environmental factors ................................................................................. 31 4.2.6 Plant appearance ................................................................................................... 31 5 RESULTS............................................................................................................................... 32 5.1 CLIMATE ........................................................................................................................... 32 5.2 EPIPHYTE SPECIES ............................................................................................................ 35 Bromeliaceae ......................................................................................................................... 35 Orchidaceae ........................................................................................................................... 35 Loranthaceae ......................................................................................................................... 36 5.3 EPIPHYTE ABUNDANCE ...................................................................................................... 36 5.4 HEIGHT DISTRIBUTION ........................................................................................................ 38 5.5 SPATIAL POINT PATTERN ................................................................................................... 40 5.6 PHOROPHYTES .................................................................................................................. 40 5.7 PLOTS .............................................................................................................................. 42 5.8 GROWING SITES ................................................................................................................ 42 5.9 PLANT APPEARANCE ......................................................................................................... 43 6 DISCUSSION ......................................................................................................................... 45 6.1 CLIMATE ................................................................................................................................ 45 6.2 EPIPHYTE SPECIES AND ABUNDANCE .................................................................................. 45 1 6.3 POPULATION STRUCTURE .................................................................................................. 46 6.4 HEIGHT DISTRIBUTION ........................................................................................................ 48 Height of the epiphytes ........................................................................................................... 48 Ecological equivalence and coexistence ................................................................................ 49 Defining the vertical position .................................................................................................. 51 6.5 SPATIAL PATTERN ............................................................................................................. 51 Clustering of the epiphytes ..................................................................................................... 51 Describing spatial patterns ..................................................................................................... 52 6.6 PHOROPHYTES .................................................................................................................. 53 6.7 PLOTS .............................................................................................................................. 54 6.8 GROWING SITES ................................................................................................................ 55 6.9 PLANT APPEARANCE ......................................................................................................... 56 6.10 GIS .................................................................................................................................. 57 7 CONCLUSION ....................................................................................................................... 59 REFERENCES .............................................................................................................................. 60 APPENDIX I : EVALUATION OF SOME METHODS................................................................... 68 Field methods ....................................................................................................................... 68 Analysis ................................................................................................................................. 69 APPENDIX II-1: MAPS OF THE PLOTS: SOME GRAPHICS ..................................................... 71 APPENDIX III-1: HEIGHT DISTRIBUTION OF ALL EPIPHYTES. .............................................. 83 APPENDIX IV : DIFFERENT HEIGHT MEASURES PER PLOT ................................................. 90 APPENDIX V : DIFFERENT HEIGHT MEASURES PER SPECIES............................................ 91 APPENDIX VI-1: L 2-GRAPHS ...................................................................................................... 92 APPENDIX VII-1 : DISTRIBUTION ON PHOROPHYTES.......................................................... 108 APPENDIX VIII: