Effects Of Different Moving Intensities On Soil Respiration In Grassland Ecosystem Of Northern Agro-pastoral Ecotone

The grassland ecosystem of the northern agro-pastoral ecotone is an important part of the semi-arid grassland ecosystem in China.Castration is one of the main ways of grassland management and utilization,and plays an important role in the carbon cycle of grassland ecosystem.Soil respiration is an important part of the carbon cycle process and an important way to export carbon to the atmosphere.Subtle changes will cause dramatic changes in atmospheric CO2.Therefore,studying the response of soil respiration to castration in the grassland ecosystem of the northern agro-pastoral ecotone is of great significance for the accurate evaluation of the carbon budget of the ecosystem.Based on the moving experimental platform of the Farmland-Agricultural Pastoral Zone Grassland Ecosystem Field Observation and Research Station(Youyu),four different moving intensities were set: no castration,mild castration,moderate castration and severe castration.In the 2017,2018 growing season(May-September),soil respiration,soil temperature,soil water content,and above-ground and underground biomass were monitored simultaneously.The results showed that soil respiration and its components responded differently to different moving intensities.Mild castration reduced soil respiration rates by 12.72% and 11.68% in 2017 and 2018,respectively,while severe castration resulted in total soil respiration and dissimilarity.Respiratory rate increased by 5% and 14%,respectively.Moderate castration had no significant effect,and different castration intensity had no significant effect on soil temperature sensitivity.Rainfall in the 2018 growing season increased significantly by 63.4% compared to 2017,resulting in significant interannual variations in soil respiration in 2017 and 2018.Soil respiration has an exponential and linear relationship with soil temperature and soil water content.Soil heterotrophic respiration is more sensitive to changes in soil temperature,while soil autotrophic respiration is more sensitive to changes in soil water content.