Subproject E11

Prof. Dr. Katrin Böhning-Gaese Johannes Gutenberg-University Mainz, Institute of Zoology, Dept. V, Becherweg 13, 55099 Mainz, Germany

Effect of fragmentation on seed dispersal, regeneration and dynamics of an East African rain forest

Background
Destruction and fragmentation of originally extensive tropical forests such as e.g. the Kakamega Forest are the main cause for the decline of biological diversity. As a consequence, important processes in these forests such as e.g. interactions between animals and plants might be disturbed and interupted. Seed dispersal by animals is one of the most important interactions in tropical rainforests where a high percentage of tropical plants depend on animals in the dispersal of their seeds. With seed dispersal playing a major role in seedling establishment, its study is an ideal approach to investigate consequences of fragmentation for diversity as well as for ecosystem processes such as forest regeneration.

Project Summary
In this project we want to document changes in diversity and abundance of important animal dispersers and fruit resources in relation to fragmentation. On the other hand, we want to study the consequences of fragmentation for dispersal, seedling establishment and regeneration of tree populations in a selected tree species. Kakamega Forest is an ideal study site for this investigation due to the fact that it is surrounded by heavily populated areas and disturbed by selective logging and fragmentation.
In the study we want to

•	document fruit diversity and availability and quantify resource use by fruit-eating animals by monitoring fruiting trees using binoculars; describe fruits from the consumers point of view by sampling and describing (e.g. mass, colour);
•	monitor diversity and abundance of fruit-eating animals by systematic observations using binoculars;
•	document the seed dispersal system of a selected bird-dispersed tree species and identify seed dispersers by observing trees from hides (day-& night observations); quantify dispersal rates by monitoring fruit traps under trees; identify seed predators using infra-red cameras and Sherman-traps; quantify seedling establishment, mortality and the spatial patterns of seedlings and trees by systematic mapping of seedlings and trees;
•	characterize the frugivorous birds which might be potential seed dispersers concerning their morphology by catching birds with mist nets, ringing and taking measurements and by keeping birds short-term in aviaries for fruit choice experiments.