Responses of above- and belowground food webs to the conversion of tropical rainforest to plantation systems

• Applicants: Dr. Anton Potapov; Professor Dr. Stefan Scheu
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 532846413

The proposed project forms part of the bundle of projects “Conversion of rainforests: Biodiversity and landscape-scale perspectives”. It is grouped into five work packages, each of them heavily building on the previous work done in the framework of projects B08 (Structure and functioning of the decomposer system in lowland rainforest transformation systems) and Z02 (Central Scientific Service Project) of the CRC 990 “Ecological and socioeconomic functions of tropical lowland rainforest transformation systems, Sumatra (Indonesia)” (EFForTS). Three of the work packages aim at continuing and finalizing work, which had been anticipated to be done during the current phase of EFForTS, but could not be achieved due to a moratorium on research permits issued by the Indonesian government during the Corona-virus pandemic. During Phase 3 of EFForTS, two main field campaigns were conducted. The first campaign targeted ca. 100 field sites in addition to the 24 core sites of EFForTS, allowing us to scale up our findings to the landscape level. The second campaign aimed at evaluating the response of ecological and socioeconomic functions to the enrichment planting of oil palm plantations more than 10 years after initial planting. In the framework of the EFForTS Landscape Assessment (EFForTS-LA) and Biodiversity Enrichment Experiment (EFForTS-BEE) we took soil samples for the extraction of soil animals (meso-and macrofauna) and collected leaf litter and canopy arthropod samples in 2021. The proposed project aims at finalizing (the delayed) sorting of these samples to taxonomic groups, for focal soil (Collembola, Oribatida) and canopy taxa (Formicidae, Araneae, Coleoptera) to (morpho)species level, document them in Ecotaxonomy.org and measure body length for calculating biomass and energy fluxes (WPs 1-3). The proposed work in WP4 & WP5 goes beyond what we planned to finish in Phase 3 of EFForTS. In WP4 we aim at using a novel technique for analysing the channelling of energy through food webs, i.e. compound-specific stable isotope analysis of amino acids (CSIA-AA). The study will identify and quantify the basal resources used (higher plants, algae, bacteria, fungi) and the channelling of these resources through below- and aboveground food webs of tropical rainforests as well as rainforest transformation systems. The work proposed in WP5 aims at using community phylogenetics combined with traits of species to get more detailed insight into community assembly processes of focal arthropod groups in soil (Collembola, Oribatida) and tree canopies (Formicidae, Araneae, Coleoptera). Overall, the proposed project will analyse in a comprehensive way the response of above- and belowground invertebrate communities to the conversion of rainforest into agricultural production systems of rubber and oil palm including shrubland. Both structural and functional changes will be investigated and scaled up from the plot to the landscape scale.

• DFG Programme: Research Grants
• International Connection: Indonesia
• Cooperation Partners: Professorin Dr. Damayanti Buchori; Dr. Purnama Hidayat; Dr. Rahayu Widyastuti