Effects of vegetation type and slope position on soil nitrogen transformation rate in Karst regions Effects of understory removal and nitrogen addition on the soil chemical and biological properties of Pinus sylvestris var. mongolica plantation in Keerqin Sandy Land. N Mineralization and Nitrification in a Primary Lithocarpus xylocarpus Forest and Degraded Vegetation in the Ailao Mountain, Yunnan Province Temporal and spatial patterns of soil nitrogen mineralization and nitrification in four temperate forests Nitrification of biological soil crusts and soil system during drought process and its response to temperature and moisture: A case study in the Shapotou region, Northwest China.