For the following reasons, it is of great interest to investigate the responses of biological communities to climate change:

• In many cases, ecosystem services are provided by communities rather than by individual species, (e.g. climatic effects of forests, litter decomposition and nutrient cycles of terrestrial ecosystems, functioning of savannahs for grazing, productivity of marine ecosystems).
• Within biological communities single species may occupy such a central position that its extinction may destabilize the entire community (e.g. beech in beech forest, madrepores in tropical coral reefs); in such cases the study of the species level is needed in relation to the target community.
• In most biological communities, however, the key position of individual species and their interactions are not obvious or quite unknown. Accordingly, to study the impact of climate change on the community level is important.
• The community structure may play a great role for the establishment of invasive species.
• It is very likely that changes in species ecosystems will cause changes in ecosystem services.

The project group B2 therefore investigates in close cooperation with group B1:
- Changes in biodiversity on the level of the entire species community to analyze their sensitivity to climate change
- Changes of ecosystem services.
In close collaboration with project area F recommendations for adaptation and mitigation will be provided.