Effect Of Precipitation Variability On Soil Respiration And Net Primary Productivity Of Vegetation On A Semiarid Grassland In The Loess Plateau Of China

As the response of global climate change, it results in extreme precipitation events in the Loess Plateau of China more and more frequent that the total precipitation is steady or increasing while precipitation frequency decreasing. The semiarid grassland of Loess Plateau is sensitive to the climate change and becomes one of the environmental vulnerable areas. As a consequence, it’s severely needed to learn more about the response to the extreme precipitation events in Loess Plateau. We chose one of the semiarid grasslands in the Loess Plateau as the experimental site and studied the impacts of extreme precipitation events on soil respiration and net primary production of vegetation. Treatments include: 1) ambient precipitation; 2) ambient precipitation plus small precipitation; 3) ambient precipitation plus large precipitation. Treatment plots received the large precipitation maintained: 1) net primary productivity may be increased; 2) peak of the soil respiration falled in the July, and Q10 is negatively related to soil temperature while soil respiration is positively related to soil water content; 3) there is no significant relationship between organic carbon, total nitrogen, total phosphorus in soil and extreme precipitation events as well as that in plants and extreme precipitation when compared with other treatments; 4)biodiversity significantly decreased on the condition of extreme precipitation; 5)there is significant difference in soil water content when comparing to that in the other conditions, and seasonal differences existed. It’s demonstrate that it strongly impact the net primary productivity, soil respiration, biodiversity and soil water content by changing the water content under the condition of extreme precipitation. And it will provide more information in the research of Loess Plateau in the response to extreme precipitation in future.