Soil microorganisms and enzyme activity of grassland ecosystem affected by changes in precipitation pattern and increase in nitrogen deposition-a review
Changes in precipitation pattern and increase in regional nitrogen deposition have turned to be two hot issues in the study on global change in recent years. As grassland ecosystems are widely distributed over the globe and mostly in the ecological fragile zones, they are very sensitive and susceptible to the interference of global change and then lose balance. Soil microorganisms and soil enzyme activity are sensitive indicators of soil quality in natural ecosystems, They can be used to monitor changes of grassland ecosystems in structure and function under the grand background of changes in water and nitrogen. Based on this, a review is presented of progresses of the study on impacts of changes in precipitation pattern and increase in nitrogen deposition, and their interaction on number, biomass and diversity of soil microbes and enzyme activity, so as to provide a scientific basis for better prediction, evaluation and eventual control and maintenance of the stability of grassland ecosystems. At the same time, problems and shortcomings existing in the current work are analyzed and key scientific issues in future research are also discussed and previewed.