The research of Frank Berendse focusses on the long-term dynamics of natural ecosystems. He is fascinated by the question why the species composition of some plant communities seems to be strongly stabilized, while other communities can change rapidly after a slight change in environmental conditions. In his vision plant-plant and plant-soil interactions are key to the understanding of these phenomena. He developed a mathematical theory for plant competition in non-uniform environments that explains how plant species can coexist in stochastically fluctuating environments. His concept of the relative nutrient requirement of plants enabled us to determine at what level of nutrient supply a given plant species will be replaced by another species. This approach allowed - amongst others - the calculation of critical nitrogen loads which provided a firm basis for environmental policy in Western Europe.
More recently, Berendse studied the impacts of biodiversity loss on crucial ecosystem services. We showed that biodiversity loss does not only lead to lower productivity, but also to reduced erosion resistance of sloping grasslands, amongst others on embankements that protect densely populated areas against flooding.
Berendse's earlier studies on the feedbacks between plant and soil were expanded to the interaction between the expansion of dwarf birch (Betula nana) and large scale permafrost thawing in arctic Siberia. The dwarf birches were found to have important negative impacts on the warming of the soil during early summer. Removal of birches resulted in accelerated thawing and the development of ponds with strongly increased methane emissions.
It is exciting to investigate beautiful ecosystems such as North-European bogs or Arctic tundra, but the most important part of Europe consists of farmland. In these agricultural landscapes biodiversity has declined dramatically during the last decades. The European Commission attempts to develop new agricultural policy to halt this decline and to restore biodiversity. We showed that earlier measures were not really effective, since the key factors were not addressed. The pressing question is how we can develop a new sustainable agriculture that can coexist with the wild plant and animal species that live on farmland.
Our study on vegetation-permafrost feedbacks on cover of Nature Climate Change