I try to apply modern coexistence theory to understand the drivers of coexistence and species richness. While doing this, I try to …
- … incorporate the entire community, not a subset thereof
- … implement complex and/or realistic communities
- … find generalities or concepts and not special cases
1. Modern coexistence theory predominantly focuses on how species from the same trophic level can coexist, while typically assuming that resources or predators are not subject to competitive exclusion. Additionally, even within this trophic level we often take a subsample (usually two species) and ask how these two species can coexist with each other. While our work on these is not complete, I think we have sufficient understanding of these cases, such that we can now move on to more complex communities, including multispecies communities and multi-trophic communities.
2. Similarly, modern coexistence theory focuses often (mainly niche and fitness differences) on phenomenological species interactions (Lotka-Volterra models). Again, we have a gained a reasonable understanding of these models such that we should start to ask the same questions to more complex or realistic community models, which lead to unexpected results.
3. Every now and then, we can loose our selves in special cases that are very intriguing, but how much value do they add? Instead of asking what are all possible mechanisms that could increase species richness, I’d like to ask what are the most important mechanisms affecting species richness? As such I like to work with simulations with many thousands of communities to understand the generalities. I don’t doubt that we can learn a lot from special cases, just out of personal preference I’m not that interested in them and prefer generalities.
Specifically, I’m currently working on a resource-phytoplankton-zooplankton model based on empirical trait measurements. This model allows me to incorporate all the above mentioned points, as we know a lot about how these species interact and we have empirical measurements of their traits.
Specifically, I’m working on understanding which traits are most important for species coexistence? Which fluctuations (nutrients, light, temperature) do affect species richness in general? Are the internal fluctuations generated by the predator-prey cycle essential for coexistence?