Steppe ecosystems and climate and land-use changes—vulnerability, feedbacks and possibilities for adaptation

Abstract

In temperate zones, grasslands such as steppe cover approximately 20% (~10 km) of the land surfaces and are widely used as pasture (Graetz 1994). Grassland soils are one of the most significant stocks for organic carbon. The degradation of grasslands due to changes in management, intensification of rangeland use or climate changes may significantly affect biosphere-atmosphere exchange for carbon and nitrogen due to the volatilization and dislocation by erosion of huge amounts of C and N previously stored in the soil (White et al. 2000, Schlesinger et al. 1990, Ojima et al. 1993). This is in turn associated with soil fertility decline and reduced productivity. In the recent past temperate grassland research was largely dominated by work carried out in North America (Schlesinger et al. 1990, Goodrich et al. 1994, Hernandez et al. 2000, Frank and Dugas 2001). However, due to the increasing extent of degradation and desertification of grasslands e.g. in China, public awareness on the vulnerability of grassland ecosystems to changes in rangeland management or climate has risen. This was accompanied by an increasing number of research activities on grassland degradation in several regions worldwide with a strong regional focus on grasslands in China and Mongolia. Most of the contributions summarized in this special issue are reporting on results as obtained from the SinoGerman Research Group MAGIM “Matter Fluxes in Grassland Ecosystems of Inner Mongolia”. The MAGIM project, funded by the German Science Foundation (Deutsche Forschungsgemeinschaft, DFG, Research Group 536) with additional support being given by the National Science Foundation of China (NSFC), brought together an interdisciplinary team of scientists from Germany and China with specific expertises in soil science, plant ecology and animal production, micro-meteorology, and biogeochemistry. The regional focus of the project was on steppe systems in the Xilin river catchment of Inner Mongolia (Fig. 1), with Inner Mongolia—besides Tibet—being the most important province in China for grassland based Plant Soil (2011) 340:1–6 DOI 10.1007/s11104-010-0651-4