草原土壤微生物受放牧的影响及其季节变化

Steppe Soil Microorganisms Is Impacted by the Grazing and Their Seasonal Changes

以内蒙古克什克腾旗西部的典型草原为对象,研究轻度放牧区(LG)、中度放牧区(MG)、重度放牧区(HG)土壤中的微生物数量、微生物生物量和土壤呼吸强度的季节变化以及放牧强度对它们的影响。结果表明,微生物数量、微生物生物量以及土壤的呼吸作用强度均有较明显的季节性变化,峰值均出现在8月份,而且三者之间具有极显著的正相关关系;轻度和中度放牧有利于土壤中的微生物数量、生物量的增加,而重度放牧则导致土壤中微生物数量和生物量的减少。

In the paper,we took the typical steppe in the west of Keshiketeng County in Inner Mongolia as the sample.We studied the seasonal changes of the quantity of soil microorganisms,soil microbial biomass of microorganism and the soil respiration intensity in light grazing district（LG）,moderate grazing district（MG） and heavy grazing district（HG）.We also observed the impact on these changes of different grazing intensity.The results show that the quantity of micro-organisms,the soil microbial biomass of microorganism and the soil respiration intensity are obviously changed with season,their highest values all appear in the August.There is obvious correlation between the three;light and middle grazing were beneficial to soil microorganisms,soil microbial biomass of microorganism increased,but heavy grazing have resulted in the quantity of soil micro-organisms and soil microbial biomass of microorganism reduction.