Short description of research activities in CRC 990:

Prokaryotes are the most abundant and diverse group of microorganisms in soil. They are important for most nutrient transformations in soil and major drivers of biogeochemical cycles. In this subproject, the impact of lowland rainforest transformation on diversity and ecosystem function of soil prokaryotic communities will be investigated. We identify changes in indigenous taxon-specific patterns accompanying rainforest transformation, and therefore perform comparative phylogenetic and functional profiling of soil microbial communities from lowland rainforest, rubber agroforests (jungle rubber), and intensively managed rubber and oil palm plantations. For this purpose, culture-independent metagenomic and metatranscriptomic approaches are employed. The changes in the species richness, abundance, and distribution of phylogenetic groups and key functions of soil prokaryotic communities along transformation systems will be assessed and compared by barcoded amplicon sequencing of prokaryotic 16S rRNA genes, and deep sequencing of mRNA (cDNA) isolated from the core sites. The functional analysis will include a general functional profile. Special emphasis will be on functions involved in the biogeochemical N cycle. Changes in diversity and abundance of genes encoding known key enzymes of the N cycle are also monitored by PCR-based approaches. All data are correlated with soil attributes, environmental conditions, and biotic data gathered by the other subprojects. Together with joint experiments investigating the effects of gap enrichment of oil palm plantations on biodiversity and ecosystem function, the project will contribute to unravel the composition and functioning of the belowground system along the different landuse types.