不同放牧制度对荒漠草原植物多样性及土壤理化性状的影响

Effects of Different Grazing Systems on Plant Diversity and Soil Physical and Chemical Properties in Desert Steppe

以宁夏中部荒漠草原为研究对象,通过大样本量野外调查和室内样品分析,研究了禁牧、轮牧和放牧3种不同放牧制度对荒漠草原植物多样性及土壤理化性状的影响,以期为解决荒漠草原面临的生态与生产协调的社会与科学问题提供依据。结果表明:放牧区植物群落的Shannon-Wiener多样性指数、Simpson优势度指数及Margalef丰富度指数最大,分别为2.48、0.80和14,轮牧区植被Pielou均匀度指数为1.42,显著高于禁牧区和放牧区(P<0.05)。轮牧和禁牧区土壤黏粉粒含量显著高于放牧区(P<0.05),轮牧区土壤有机碳和氮含量分别为4.30g·kg^(-1)和0.24g·kg^(-1),显著高于放牧区和禁牧区(P<0.05)。轮牧显著改善了土壤质地,增加了黏粉粒含量,从而改善了土壤理化性状。该研究认为,在禁牧恢复了荒漠草原植物多样性之后,应采用轮牧制度打破禁牧的单优群落结构同时恢复土壤质地。

In this study,an object of the desert grassland in central Ningxia was set,based on the different grazing systems.By field investigation and laboratory analysis,the effects of non-grazing,rotation-grazing and continuous-grazing on plant diversity and soil physicaland chemical characteristic were studied.In order to provide a basis for solving the social and scientific problems of ecological and production coordination in the desert steppe.The results showed that the Shannon-Wiener diversity index,Simpson dominance index and Margalef richness index of plant communities in continuousgrazing areas were 2.48,0.80 and 14,respectively,which were higher than those in the non-grazing and rotation-grazing areas.The Pielou evenness index of vegetation in the pastoral area was 1.42,which was significantly higher than that of the non-grazing and continuous-grazing areas （P〈0.05）.In non-grazing and rotation-grazing area,the content of clay powder was significantly higher than that in grazing area （P〈0.05）.The soil organic carbon and nitrogen contents in the rotational pastoral area were 4.30 g·kg^-1 and 0.24 g·kg^-1,respectively,which were significantly higher than that in the non-grazing area and the continuous-grazing area （P〈0.05）.Rotation-grazing significantly improved the texture of the soil and increased the content of clay powder,thus promoting the improvement of soil physical and chemical characteristic.Grazing had a significant effect on plant diversity improvement.Therefore,after the restoration of vegetation diversity in desert grassland,the rotation system should be adopt to break the single optimal community structure and restore the soil texture.