Response of soil enzyme activity to warming and nitrogen addition in a meadow steppe

Soil enzymes play vital roles in the decomposition of soil organic matter and soil nutrient mineralisation. The activity of soil enzymes may be influenced by climate change. In the present study we measured soil enzyme activity, soil microclimate and soil nutrients to investigate the response of soil enzyme activity to N addition and experimental warming. Warming enhanced phosphatase activity (35.8%), but inhibited the cellulase activity (30%). N addition significantly enhanced the activities of urease (34.5%) and phosphatase (33.5%), but had no effect on cellulase activity. Significant interactive effects of warming and N addition on soil enzyme activity were observed. In addition, warming reduced soil C (7.2%) and available P (20.5%), whereas N addition increased soil total N (17.3%) and available N (19.8%) but reduced soil C (7.3%), total P (14.9%) and available P (23.5%). Cellulase and phosphatase activity was highly correlated with soil temperature and water content, whereas urease activity was determined primarily by soil N availability. The results show that climate change not only significantly affects soil enzyme activity, but also affects the mineralisation of soil nutrients. These findings suggest that global change may alter grassland ecosystem C, N and P cycling by influencing soil enzyme activity. Additional keyword: climate change.
Introduction Soil enzymes are important biological activators of underground energy flow and material circulation and play a crucial role in carbon (C) and nutrient transformation in grassland soil (Gorissen and [...]