Riverine ecosystems are among the most species-rich ecosystems on earth. Furthermore, river networks are important dispersal and invasion corridors for many organisms. For a long time, diversity and ecological process in riverine networks has been studied from a localized perspective, ignoring the inherent dendritic structure of riverine networks.
We study dispersal processes and diversity patterns in dendritic networks, using a wider range of approaches, including simulation models, protist microcosm experiments and field studies. We are using the metapopulation and metacommunity concepts to identify the significance of spatial dynamics on the composition of local populations and communities. More recently, we started to address the role of spatial dynamics on ecosystem functioning. Meta-ecosystem theory gives a conceptual and mathematical framework for studying flow of materials and organisms in spatially explicit systems and subsequent consequences on community dynamics.
We find, for example, that resource flows affect community-dynamics and study how community structure and ecosystem processes (e.g., productivity, decomposition) scale across whole riverine networks. We are testing predictions by meta-ecosystem theory by comparative meta-analyses, experimental field studies and laboratory-based microcosm experiments. Our combined approach aims at a causal understanding of spatial dynamics in complex habitat networks.