15Very few comparative studies of nitrogen (N) deposition in agroecosystems have been 16 conducted along landuse and altitude gradients. In an effort to fill this gap of 17 knowledge we selected three typical, interconnected landuse systems (cropland, 18 mountain grassland and plain grassland)at six sampling sites in the transboundary China had 72% higher N deposition than in Mongolia whereas the reverse was true 40 for mountain grasslands which received 31% more Nin Mongolia. 41