Short description of research activities in CRC 990:

Soil fungi are present in every terrestrial ecosystem and strongly influence biochemical cycles and soil biology. A good example for this are plant-root associated mycorrhizal fungi which can be found in around 80% of all land plants. They play a major role in nutrient, water and carbon transfer. Furthermore, they are known to enhance plant health and performance by suppression of soil pathogens and uptake of heavy metals. Despite of the great importance of soil fungi in nearly all ecosystem processes, little is known on their functional diversity, effects on root traits and drivers of community structure. This is especially true for tropical habitats. The currently ongoing land transformation from tropical rain forest to oil palm and rubber plantations is known to cause a massive loss of biodiversity and ecosystem functions above ground. However, knowledge about effects on soil biota is limited. In phase 1 a decline in root health and accumulation of potentially toxic compounds in oil palm plantations compared to jungle forest was observed. Furthermore, diversity of arbuscular mycorrhizal fungi (AM) decreased in oil and rubber plantations compared to forest sites.
In the current phase we address the question whether diversity of the root-associated fungal microbiome is increased by increasing plant diversity and furthermore, how root community traits respond to changes in the fungal microbiome. Additionally, we would like to investigate whether for AM host preferences exist and whether plant species richness affects AM root communities at the level of host identity. Also we will investigate the impact of different land use systems on the temporal variation of the fungal microbial communities by resampling the sites already investigated in the first phase. We expect that our results will contribute to a better understanding how land transformation affects the soil fungal community.