Das Projekt "The organisation of ecological networks in time and space" wird vom Umweltbundesamt gefördert und von Universität Freiburg, Institut für Biologie II durchgeführt. Current global changes put pressure on natural communities. Understanding how these communities are organized in time and space is crucial to predict how they will react to more variable meteorological conditions, increased temperature, or fragmentation of habitats. We will tackle the question of the organization, functioning, and evolution of communities by considering the trophic (who eats whom) and non-trophic (e.g., pollination, nest provisioning...) relations between species, thus considering communities as interaction networks. A 'large-scale' and a 'small-scale' system will be studied. The former consists of sown wildflower strips in agroecosystems, the latter of urn-like leaves (pitchers) of Sarracenia purpurea, a North American plant species introduced in Europe and inhabiting bogs. The ecological networks in the wildflower strips will be used to test several models of community organization and notably how the spatial arrangement of communities influences their composition and structure (metacommunity models). The small size of pitchers allows recording the evolution of the abundances of the species inhabiting the leaves, notably with molecular techniques for bacteria. The network in pitchers will be used in two lines of research: firstly, we will manipulate the presence/absence of key species (e.g., top predators) and of environmental conditions (e.g., temperature) and follow the dynamical response of the communities. Secondly, we will perform reciprocal transplant experiments to explore the question of 'local adaptation' at a network level.