Plant diversity and ecosystem functioning

Two links are investigated: (1) interactions mediated by changes in plant growth (decomposer - plant - herbivore pathway) and (2) interactions mediated by generalist predators (decomposer - generalist predator - herbivore pathway). In the first three energy channels are distinguished: primary decomposer, bacterial feeder and fungal feeder channel. Focal groups are earthworms as primary decomposers, protozoa and nematodes as bacterial feeders and collembola and oribatid mites as fungal feeders. Focal groups of the second link are spiders, carabid and staphylinid beetles. Methods include microcosm and perturbation experiments, use of radiotracers (14C) and stable isotopes (15N, 13C), analyses of microbial communities (respiration, biomass, nutrient status, bacterial/fungal ratio, in situ catabolic diversity) and analysis of the chemical and genetic response of plants to rhizosphere interactions. Topics investigated include:

  • Relationship between biodiversity and ecosystem functioning (decomposition, mineralization, resilience)
  • The role of soil animals for ecosystem processes, plant growth and herbivore development
  • Rhizosphere interactions
  • Interrelationship between above- and belowground biodiversity
  • The role of decomposer animals as supplementary food for generalist predators above the ground