Ecohydrological process studies and model development to evaluate the impact of land-use change and vegetation dynamics on the hydrological cycle and the biogeochemical cycling

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Many ecosystems around the globe are affected by the impacts of land-use or vegetation change, which have become necessary to comply with food demand, raising crop prices and lately the demand for bioenergy production and the effects of climate change. Extreme land-use changes often lead to manifold adverse effects on the land and water resources such as land degradation and desertification, increased soil erosion, nutrient depletion, pesticide and nutrient contamination of water resources and changes in runoff regimes. For the state Brandenburg in Germany, for example, an intensification of agricultural production is predicted for the near future due to an increased demand for biofuel production, however the impacts of intensive farming methods with e.g. maize and rape monocultures on the water and biogeochemical cycle and land resources are uncertain and potentially lead to increased use of fertilisers, pesticides and nitrification of water resources. The Central parts of Brazil, in the Mato Grosso region within the Amazon Basin, is another example where large areas of natural forests were replaced by cropland for food and bioenergy production, resulting in a major shift in ecosystem stability. A third example of unsustainable land-use change is the south-western part of the United States, where massive overgrazing led to an irreversible, ongoing desertification and land degradation from productive grassland to desert shrubland. The increasing recognition of the importance of ecohydrological processes in understanding the link between the hydrologic cycle and vegetation and land-use change dynamics has enforced the need for future research to consider the interdependence, interactions and feedback mechanisms between ecological and hydrological processes. In this project, ecohydrological process understanding will be derived through detailed temporal and spatially distributed field sampling in different ecosystems around the globe. An integrated ecohydrological modelling tools at the micro- and meso-scale will be developed and applied to vegetation dynamics and land-use change scenarios for study sites in Brandenburg (Germany), Mato Grosso (Brazil) and Jornada (New Mexico, USA). It is expected that the development and application of the novel ecohydrological, process-based modelling tools at the interface between hydrology and ecology will provide valuable insights for the understanding, controlling and water and land-use management of emerging problems and crises related to climate, vegetation and land-use change.