Vom Fachbereich Biologie der Universität Kaiserslautern zur
Verleihung des akademischen Grades
„Doktor der Naturwissenschaften“
genehmigte Dissertation








Long-term changes of vascular epiphyte
assemblages in the tropical lowlands of
Panama




by

STEFAN LAUBE






D 386

Kaiserslautern 2006





Tag der wissenschaftlichen Aussprache: 25. Juli 2006

Vorsitzender der Prüfungskommission: Prof. Dr. Joachim W. Deitmer
1. Gutachter: Prof. Dr. Burkhard Büdel
2. Gutachter: PD Dr. Gerhard Zotz List of papers




This thesis is based on the following papers:

Paper I: Laube, S. and G. Zotz (2006) “Long-term changes of the vascular epiphyte
assemblage on the palm Socratea exorrhiza in a lowland forest in Panama.”
Journal of Vegetation Science 17: 307-314

Paper II: Laube, S. and G. Zotz (2006) “Neither host specific nor random: vascular
epiphytes on three tree species in a Panamanian rainforest.” Annals of Botany
97: 1103-1114

Paper III: Laube, S. and G. Zotz, “A metapopulation approach to the analysis of long-
term changes in the epiphyte vegetation of Annona glabra.” (manuscript) My contribution to the papers




Paper I: We used data collected for another research project (Zotz and Vollrath, 2003). I
collected the data of the 2004 epiphyte census. Further I conducted all analyses
and wrote the text. Zotz provided helpful comments and discussion on the text.

Paper II: I am responsible for the idea, conducting most of the analyses and writing the
text. Zotz provided the data from an earlier work (Zotz and Vollrath, 2003),
performed the Canonical Correspondence Analysis, and made helpful
comments on the text.

Paper III: This study builds on a previous study by Zotz et al. (1999). Zotz suggested the
study and provided helpful comments on the text. I conducted the data
sampling. Further, I suggested the analysis approach, conducted the analyses
and wrote the text.
Contents

ABSTRACT .................................................................................................................................. XI
LIST OF FIGURES......................................................................................................................XII
LIST OF TABLES ..................................................................................................................... XIV
LIST OF ABBREVIATIONS ......................................................................................................XV
CHAPTER 1 - INTRODUCTION .................................................................................................. 1
DYNAMICS IN PLANT COMMUNITIES ............................................................................................. 1
CURRENT KNOWLEDGE................................................................................................................. 2
AIMS............................................................................................................................................. 5
CHAPTER 2 – GENERAL METHODS AND STUDY SITES ..................................................... 6
SAN LORENZO CRANE SITE........................................................................................................... 6
Study species ........................................................................................................................... 6
BARRO COLORADO ISLAND .......................................................................................................... 7
Study species ........................................................................................................................... 8
Epiphyte Census ...................................................................................................................... 9
CHAPTER 3 - LONG-TERM CHANGES OF THE VASCULAR EPIPHYTE
ASSEMBLAGE ON THE PALM SOCRATEA EXORRHIZA IN A LOWLAND FOREST IN
PANAMA...................................................................................................................................... 11
INTRODUCTION........................................................................................................................... 11
MATERIAL AND METHODS.......................................................................................................... 13
Study site and species............................................................................................................ 13
Data analysis.......................................................................................................................... 14
RESULTS..................................................................................................................................... 15
Host trees ............................................................................................................................... 15
Epiphyte vegetation ............................................................................................................... 15
DISCUSSION................................................................................................................................ 22
CHAPTER 4 - NEITHER HOST SPECIFIC NOR RANDOM: VASCULAR EPIPHYTES
ON THREE TREE SPECIES IN A PANAMANIAN RAINFOREST......................................... 25
INTRODUCTION........................................................................................................................... 25
MATERIAL AND METHODS.......................................................................................................... 27
Study site and species............................................................................................................ 27
Data analysis.......................................................................................................................... 27
RESULTS..................................................................................................................................... 29
Socratea exorrhiza................................................................................................................. 29
Marila laxiflora ..................................................................................................................... 31
Perebea xanthochyma............................................................................................................ 32
Spatial patchiness .................................................................................................................. 32
Ordination.............................................................................................................................. 33
DISCUSSION................................................................................................................................ 36


IX
CHAPTER 5 - A METAPOPULATION APPROACH TO THE ANALYSIS OF LONG-
TERM CHANGES IN THE EPIPHYTE VEGETATION OF ANNONA GLABRA .....................39
INTRODUCTION ...........................................................................................................................39
MATERIAL AND METHODS ..........................................................................................................41
Study area and epiphyte census .............................................................................................41
Data analysis ..........................................................................................................................42
RESULTS .....................................................................................................................................45
Epiphyte vegetation................................................................................................................45
Species composition...............................................................................................................45
Population change..................................................................................................................45
Species-area relationship, distribution-abundance relationship, regional patch frequency
distribution .............................................................................................................................47
Subset of 725 Annona glabra trees........................................................................................50
DISCUSSION ................................................................................................................................58
CHAPTER 6 - CONCLUSION .....................................................................................................62
ACKNOWLEDGEMENTS...........................................................................................................64
REFERENCES...............................................................................................................................66
APPENDICES ...............................................................................................................................77

X