Simulated effects of precipitation and nitrogen on Serengeti grassland productivity

摘要: In the Serengeti National Park, Tanzania, precipitation and soil nitrogen vary greatly between northwestern tallgrass areas southeastern shortgrass areas, with having higher total lower fertility. We used a model of grassland productivity, carbon/nitrogen cycling, abiotic factors to test hypothesis that productivity is limited primarily by availability while water. Under observed grazing intensities ungrazed conditions, exerted primary control over for both regions, differences in texture mediating water grasses. Mineral interacted influence at levels ⩾ 130% mean. Nitrogen mineralization were positively related each type, however, nitrification varied types grazed conditions. Combined could not maintain mineral face plant uptake stimulated increased precipitation, thus providing mechanism which becomes secondary limiting factor grasslands. Model experiments indicated pattern limitation was robust assumptions concerning ungulate deposition urine dung soil.