Metapopulations and Metacommunities in a Changing World

Species do not generally occur in continuous space and time, but normally on more or less descrete patches interspaced by a matrix of various degree of hostility. These creates metapopulations, namely a group of populations connected by long-distance dispersal. Seminal theoretical work in metapopulations was pioneered by Levins and further developement was systematically summarized by Ilka Hanski. However, species also do not occurr alone and the same rationale can be applied one ecological level higher - the metacommunity, a field explored and summarized by Mathew Leibold and Jonathan Chase. Various theoretical concepts come into play on metapopulations and metacommunities, such as source-sink dynamics (similar to mainland-island system), multiple equilibria, fragmentation effects, and patch extinction and re-colonization. Studies may have explicit local population dynamics, but metapopulation and metacommunity fields are largely represented by demographically-implicit models that concentrate on the patch colonization and extinction dynamics.

In our working group, we explore how metapopulation and metacommunity dynamics emerge from multi-species, niche-based, spatially-explicit models which are based on individuals and populations.

This topic is currently investigated in three subprojects:

1) Extinction debt in fragmented landscapes: spatio-temporal metacommunity dynamics under environmental change. Performed by PhD student Ludmilla Figueiredo.

2) Eco-evolutionary dynamics on islands. Performed by PhD student Ludwig Leidinger.

3) Invasion dynamics on islands. Performed by MSc student Daniel Vedder.

4) Current and future distribution of aquatic macrophytes in Bavarian lakes (a BLIZ/Bayklif project). Performed by PhD student Anne Lewerentz