B09 - Aboveground biodiversity patterns and processes across rainforest transformation landscapes

Improving ecological and socioeconomic functionality of tropical human-dominated landscapes is a major challenge. In this project, we focus on aboveground animal biodiversity patterns and related ecological functions at local and landscape scales, comparing lowland rainforest, shrubland, rubber plantations and oil palm plantations with variation in local management, biodiversity enrichment with indigenous tree species, and landscape heterogeneity.

Employing extensive field studies in the novel Landscape Assessment, we will test the hypothesis that the heterogeneity of the surrounding landscape has a more pronounced influence on local biodiversity patterns and ecosystem functions than land use and management differences between transformation systems. On the 100 Landscape Assessment plots that are situated along a landscape heterogeneity gradient, we will study bird and bat communities (using sound recordings), predation success (experimental exposure of artificial prey), and colony development and foraging behaviour of stingless bee colonies (colony weight, pollen type identification and DNA metabarcoding of pollen samples). The association of the selected study plots to villages and households surveyed by the socioeconomic subprojects allows for modelling the socioeconomic context of biodiversity patterns and functions across spatial scales.

Using the platform of the B11 Oil Palm Biodiversity Enrichment Experiment (EFForTS-BEE), we will test effects of tree species richness, plot size, and age on biodiversity and ecosystem functions (taxonomic and functional diversity of arthropod, bat and bird communities, predation success, colony development of stingless bees). We expect that the number of additional tree species will promote the diversity of species, collected pollen types and the colony development of stingless bees. These effects will be more pronounced in large rather than small enrichment plots. Regarding the Oil Palm Management Experiment (EFForTS-OPMX), we hypothesize that weed control affects taxonomic and functional diversity of arthropods, birds and bats more than increased levels of fertilization, as species sorting in oil palm plots is driven by non-crop plant communities. Intensity of weed control (mechanical vs. herbicide weed control), but not fertilization, may be reduced without diminishing crop yield, which would allow identifying thresholds with low economic costs and high ecological benefit. Especially, we will focus on the synthesis analyses of data originating from the novel Landscape Assessment. Integrating the data from the ecological and socioeconomic groups will allow the investigation of trade-offs and synergies across local land use management scenarios and landscape heterogeneity gradients. Analyses of multidiversity and multifunctionality of land uses and their dependence on scale, landscape heterogeneity and the socioeconomic context complement the upscaling work. Our project is intimately interlinked with aboveground and belowground subprojects working on the plot level as well as socioeconomic subprojects working at household and village level.