Objective 3: Assessment of links between plant and mammal functional diversity and long-term historical constraints thereon:

The functional diversity of producers and multi-trophic-level consumers is likely to be linked. While many community studies have investigated trophic links between mammals and plants, only a couple of studies have explicitly focused on how mammal and plant species diversity are linked on geographic scales, and none have previously assessed if and how their functional diversities are linked. Notably, historical constraints on one group may indirectly shape the functional diversity of the other group, and historical factors may also affect evolutionary processes behind such functional diversity links; e.g., with greater specialization and co-adaptation in stable areas. This is so far unstudied, but a new study (coauthored by Jens Christian Svenning) provides empirical evidence for a related phenomenon, showing that hummingbird-plant pollination networks are more specialized in areas with low Quaternary climate displacement rates.

The HISTFUNC project will provide a first comprehensive assessment of if and how plant and mammal functional diversity are linked, and whether long-term historical factors influences this linkage. We will address this issue by combining the data from the previous two objectives.

Impact: This first-time assessment of the link between plant and mammal functional diversity across large geographic regions will represent a clear step forward in our understanding of how biotic interactions shape diversity patterns and their links to ecosystem functioning. By assessing the influence of historical constraints on the link between the two groups, it addresses a central component of the historical-constraints hypothesis. Again, this assessment of the plant-mammal functional diversity link will obviously also be important for nature management, much of which has the plant-mammal link as focal point.