Study on the Response Mechanism of Soil Nitrogen Mineralization and Enzyme Activity of Typical Vegetation Types in Xinglong Mountain, Gansu Province, China

Climate change is causing the soil environment to change (soil temperature and soil moisture), which affects the soil nitrogen cycling of vegetation. To examine this, the soil of three typical communities (grassland, shrub forests, and Picea wilsonii Mast. forests) was selected and cultured under three different moisture levels (20, 40, and 60% of the field water-holding capacity, referred to as W20, W40, and W60, respectively) and three different temperatures (15, 25, and 35 °C, referred to as T15, T25, and T35, respectively) to evaluate the effects of different vegetation types on soil nitrogen mineralization in the Xinglong Mountains, Gansu Province, China. The results showed that under the three moisture levels, the cumulative mineralization of soil nitrogen in different vegetation types was the largest under the T35 treatment. Under three temperature levels, the cumulative mineralization of soil nitrogen in different vegetation types was the largest under the W60 treatment. Under the three vegetation types, the cumulative mineralization of soil nitrogen in the P. wilsonii Mast. forest was the largest, which was 2.23% and 24.79% higher than those of grasslands and shrub forests, respectively. We concluded that soil nitrogen mineralization in the P. wilsonii Mast. forest was the best option under T35 and W60 in this study.