内蒙古典型草原植被和土壤特性对放牧强度的响应

The Response of Vegetation and Soil Properties to Grazing Intensity in Typical Steppe of Inner Mongolia

在内蒙古温带典型草原放牧控制试验样地,测定不同放牧强度下土壤总有机碳(TSOC)和活性有机碳组分的含量及植物生物量、土壤理化特性。研究结果表明:(1)随放牧强度的增大,地上生物量以及凋落物量逐渐减少,但中度放牧条件下土壤表层根系生物量有所增加,根系生物量会随放牧强度增大而降低。(2)重度放牧导致土壤容重增大,而中度放牧显著升高土壤pH值。(3)试验期不同放牧强度下土壤总有机碳(TSOC)无显著变化,中度放牧增加了微生物量碳(MBC)、颗粒物有机碳(POC)以及潜在可矿化碳(PMC)的含量。

The contents of soil total organic carbon(TSOC)and active organic carbon,plant biomass and soil physical and chemical properties under different grazing intensities were measured in a grazing control experimental plot of temperate grassland in Inner Mongolia.The results showed that:(1)With the increasing of grazing intensity,aboveground biomass and litter biomass gradually decreased,but the root biomass of surfacial soil increased significantly under moderate grazing,and the root biomass also decreased with the increasing of grazing intensity.(2)Heavy grazing increased soil bulk density,while moderate grazing significantly increased soil pH value.(3)There was no significant change in total soil organic carbon(TSOC)content under different grazing intensities during the experimental period.Moderate grazing increased the contents of microbial biomass organic carbon(MBC),particulate organic carbon(POC),and potentially mineralizable carbon(PMC).