Community Disassembly in a Fragmented Tropical Landscape Driven by Both Deterministic and Stochastic Processes

Area of Science:

• Ecology
• Conservation Biology
• Biodiversity Research

Background:

• Deforestation leads to habitat fragmentation, reducing biodiversity.
• Processes driving species loss in fragmented habitats are not fully understood.
• Tropical insectivorous bat communities are vulnerable to habitat changes.

Purpose of the Study:

• To identify community processes driving tropical insectivorous bat community disassembly due to forest fragmentation in Malaysia.
• To assess the impact of fragmentation on species richness and functional diversity.
• To differentiate between deterministic and stochastic processes in fragmented ecosystems.

Main Methods:

• Measured species richness and functional diversity (using eight traits) in continuous forests and forest fragments of varying sizes.
• Analyzed trait-based functional diversity against null expectations.
• Compared community assembly processes in continuous versus fragmented habitats.

Main Results:

• Species loss in fragmented forests was non-random, forming nested subsets.
• Functional trait space collapsed significantly as species richness decreased.
• Continuous forests showed structure from environmental filtering and niche packing; fragments were structured by stochastic processes.

Conclusions:

• Forest fragmentation drives bat community disassembly through a mix of deterministic and stochastic processes.
• Functional diversity is crucial for understanding biodiversity loss and for conservation planning.
• Conservation strategies should integrate functional traits alongside fragment size and species counts for effective landscape-level planning.