Leaf litter ant communities in tropical lowland rain forests in Sabah, Malaysia: effects of forest disturbance and fragmentation Dissertation zur Erlangung des naturwissenschaftlichen Doktorgrades der Bayerischen Julius-Maximilians-Universität Würzburg vorgelegt von Carsten A. Brühl Backnang Würzburg, 2001 Eingereicht am: ....................................................................................................... Mitglieder der Promotionskommission: Vorsitzender: Prof. Dr. Goebel Gutachter : Prof. Dr. K. E. Linsenmair Gutachter: Prof. Dr. B. Hölldobler Tag des Promotionskolloquiums: ........................................................................... Doktorurkunde ausgehändigt am: ................................................................. ‘At last they reached the primeval forest, huge trees swathed in luxuriant creepers, an inextricable tangle, and awe descended upon them. They cut their way through the undergrowth. They walked in twilight and only now and then caught through the dense foliage above them a glimpse of sunshine. They saw neither man nor beast, for the denizens of the jungle are shy and at the first sound of footsteps vanish from sight.’ William Somerset Maugham, Neil MacAdam Für meine Eltern CONTENT 5 1 INTRODUCTION......................................................................................................................................... 9 2 STUDY SITES............................................................................................................................................. 16 2.1 DANUM VALLEY CONSERVATION AREA ............................................................................................... 17 2.1.1 Location......................................................................................................................................... 17 2.1.2 Geology and soils.......................................................................................................................... 17 2.1.3 Climate .......................................................................................................................................... 17 2.1.4 Forest type..................................................................................................................................... 18 2.1.5 Research plots............................................................................................................................... 18 2.2 SEPILOK FOREST RESERVE..................................................................................................................... 19 2.2.1 Location......................................................................................................................................... 19 2.2.2 Geology and soils.......................................................................................................................... 19 2.2.3 Climate .......................................................................................................................................... 20 2.2.4 Forest type..................................................................................................................................... 20 2.2.5 Management history...................................................................................................................... 20 2.2.6 Research plots............................................................................................................................... 21 2.3 KEBUN CINA FOREST RESERVE ............................................................................................................. 22 2.3.1 Location......................................................................................................................................... 22 2.3.2 Research plots............................................................................................................................... 22 2.4 DERAMAKOT FOREST RESERVE ............................................................................................................. 22 2.4.1 Location......................................................................................................................................... 22 2.4.2 Geology and soils.......................................................................................................................... 22 2.4.3 Climate .......................................................................................................................................... 22 2.4.4 Forest type..................................................................................................................................... 23 2.4.5 Management history...................................................................................................................... 23 2.4.6 Research Plots............................................................................................................................... 24 3 GENERAL METHODS.............................................................................................................................. 26 3.1 SAMPLING AND SPECIMEN PROCESSING.................................................................................................. 26 3.1.1 Research plots............................................................................................................................... 26 3.1.2 Transects ....................................................................................................................................... 26 3.1.3 Winkler litter sifting ...................................................................................................................... 27 3.1.4 Sorting of the samples and species identification.......................................................................... 29 3.1.5 Species included in the analysis .................................................................................................... 29 3.1.6 Discussion ..................................................................................................................................... 30 3.2 STATISTICAL METHODS.......................................................................................................................... 31 3.2.1 Data entry...................................................................................................................................... 31 3.2.2 Species richness estimators........................................................................................................... 31 3.2.3 Alpha-diversity indices.................................................................................................................. 32 3.2.4 Beta-diversity index....................................................................................................................... 32 3.2.5 Multidimensional scaling .............................................................................................................. 33 3.2.6 Cluster analysis............................................................................................................................. 33 4 FOREST STRUCTURE ............................................................................................................................. 34 4.1 INTRODUCTION ...................................................................................................................................... 34 4.2 METHODS............................................................................................................................................... 34 4.3 RESULTS ................................................................................................................................................ 34 4.4 DISCUSSION ........................................................................................................................................... 35 5 ENVIRONMENTAL PARAMETERS...................................................................................................... 37 5.1 INTRODUCTION ...................................................................................................................................... 37 5.2 TEMPERATURE ....................................................................................................................................... 37 5.2.1 Air temperature ............................................................................................................................. 37 5.2.1.1 Methods..................................................................................................................................................... 37 5.2.1.2 Results ....................................................................................................................................................... 37 5.2.2 Leaf litter temperature .................................................................................................................. 40 5.2.2.1 Methods..................................................................................................................................................... 40 5.2.2.2 Results ....................................................................................................................................................... 40 5.2.3 Soil temperature ............................................................................................................................ 41 5.2.3.1