The Potsdam Institute for Climate Impact Research (PIK), Germany, is studying causes and effects of land-use change, including externalities such as Nr pollution. It develops and maintains two complementary global simulation models, a bio-physical dynamic global vegetation, hydrology and crop growth model LPJmL and a spatially explicit economic agricultural sector model MAgPIE. Both models can be applied jointly and separately and have a long-standing reputation in global change research. The models have been applied (MAgPIE) and are currently being further developed towards explicit treatment of N dynamics to address the full terrestrial N cycle in natural and managed ecosystems as well as the economic assessment of environmental regulation and market mechanisms. The group is involved in model intercomparison studies (AgMIP, ISI-MIP) and can connect N-specific research questions of INMS with these activities. High spatial detail in simulations and analyses allows for connecting regional studies and mechanisms with global-scale responses in a consistent analysis.
