Das Projekt "Effect of plant diversity on ecosystem functions in grassland: the role of roots" wird vom Umweltbundesamt gefördert und von Universität Berlin (Humboldt-Univ.), Landwirtschaftlich-Gärtnerische Fakultät, Institut für Pflanzenbauwissenschaften, Fachgebiet Pflanzenernährung durchgeführt. Human activities have led to strong reduction in plant diversity. There is an intensive debate on the consequences of diversity loss on ecosystem functions such as productivity, and cycling of carbon and mineral nutrients, as well as on the plant traits responsible for these ecosystem functions. In this subproject it is tried to assess the effects of plant diversity in experimentally established grassland plots on (a) biomass and nutrient accumulation in roots, (b) acquisition of soil resources by living roots and (c) release of organic carbon and nutrients into the soil by decaying roots. The experimental design allows to differentiate between effects of plant species number per se, and effects of functional attributes associated with specific plant groups on root characteristics. It is expected that the results will improve our knowledge about the processes involved in diversity effects on ecosystem functions, and finally may help to develop recommendations of agricultural measures for sustainable grassland management
Das Projekt "Consumer - interaction webs and the effect of aboveground vertebrates and invertebrates on ecosystem processes" wird vom Umweltbundesamt gefördert und von Universität Jena, Institut für Ökologie durchgeführt. The effects of invertebrate herbivory on ecosystem processes will be tested by excluding above-ground invertebrates from 5 m x 5 m subplots of all experimental plots using biocides. Net primary productivity and other ecosystem processes will be quantified in both treated and unmanipulated parts of the plot to study the relationships between plant diversity, invertebrate herbivory and ecosystem functioning. A second objective of this project is to test the interactions between plant diversity, plant productivity and the structure of the invertebrate community. Above-ground invertebrates will be sampled repeatedly from all grassland plots and allocated to a certain trophic role, i.e. herbivore, predator, parasitoid, or detritivore. Statistical modeling will reveal the influence of plant diversity manipulations on invertebrate density and invertebrate diversity at different trophic