P10

Chemodiversity as part of the plant trait space and economics spectrum

The fascination for biodiversity is paralleled by the appeal of chemodiversity, which is an underexplored but important property of the plants’ phenotypes. In the first funding period, we have introduced the R package chemodiv to quantify chemodiversity of mixtures of metabolites. This statistical pipeline allows researchers not only to quantify the richness and evenness component of chemodiversity, but also the disparity component. Considering biochemical disparity provides a more complete understanding of the ecological and evolutionary importance of chemodiversity. Accordingly, several projects of the RU used or will use our R package chemodiv to analyse their data. Additionally, we worked on a review article that addresses a number of topics related to chemodiversity, including information on its statistical quantification, its use in the literature, as well as future directions. As a central component of this work, we are providing a decision tree to determine which chemodiversity indices should be used to test various hypotheses in different biological contexts. Importantly, all members of the RU contributed ideas and perspectives about the role of different aspects of chemodiversity, which is reflected in the manuscript.

The major goals of the second funding period are 1) to understand the global distribution of plant chemodiversity as well as the biotic and abiotic factors influencing it, which will serve as an important reference for the empirically working projects (P1-P7). This global analysis will allow conclusions about plant strategies in coping with environmental stresses. 2) P10 will also provide a framework to relate chemodiversity to plant strategies and functions by adding chemodiversity as an additional dimension of the plant economics spectrum. This analysis will reveal whether chemodiversity represents a complementary or redundant part in the plants’ phenotypes and functions and thus their ecological strategy. This framework will elucidate trade-offs and constrains in the ecology and evolution of the chemical phenotype. 3) Furthermore, by using the data of P1-P7 as well as the chemodiversity-plasticity experiment (COR project) on phytochemical responses to drought and herbivory, intraspecific variability in chemodiversity will be mapped onto the plant economics spectrum to test whether responses are species- and/or stressor-specific. Likewise, the intraspecific variability of virtual plants as simulated in P9 can be mapped onto the trait space to explore their responses in relation to “real” plants and in a multi-species context.