Effects of Nutrient Addition and Altered Precipitation on Soil Respiration on the Leymus secalinus Grassland in Northern Shanxi
Soil respiration is the second largest ecosystems carbon flux in terrestrial ecosystems,which affects the carbon balance of ecosystems.However,the effects of nutrient addition,precipitation alteration and their interactions on soil autotrophic respiration(Ra)and soil heterotrophic respiration(Rh)are still unclear.In order to explore the influencing mechanism of nutrient addition and precipitation-altering interactions on soil res-piration,we set up an experimental platform with nitrogen,phosphorus and potassium+altered precipitation in the typical agro-pastoral ecotone grassland of Shanxi.The deep-shallow ring method was used to distinguish Ra and Rh,and the biotic and abiotic factors was also measured.The results showed that nutrient addition com-bined increase of 50% precipitation significantly increased soil total respiration(Rs),soil autotrophic respiration and the cumulative CO2 emissions.There was a positive correlation between Ra and plant productivity and soil temperature.Rh was positively correlated with oil temperature,while negatively with microbial biomass nitro-gen.The result of structural equation model showed that soil pH and soil NO3--N indirectly regulate the effects of nutrient addition and precipitation alteration on soil respiration.In conclusion,with the global climate change,we should not only consider the individual effects of nutrient addition or precipitation changes,but also integrate the effects of multiple factors of global change.
万方数据
维普
