锡林郭勒草原不同植物群落特征与土壤养分特性研究

Characteristics of Different Plant Communities and Soil Nutrients in Xilingol Grassland

为了揭示不同草原亚型的植被特点和土壤养分特征,探明物种多样性与土壤养分之间的相互关系,本研究以内蒙古锡林郭勒草原为研究区,通过野外采样、室内化验、冗余分析等方法对草甸草原、典型草原和荒漠草原三种草原亚型的植物群落特征、土壤养分特性及其相互关系进行分析。结果表明,(1)植物群落的生物量(W)、丰富度指数(M)、多样性指数(H′)和优势度指数(D)均表现为草甸草原>典型草原>荒漠草原,均匀度指数(J)在荒漠草原数值最高。(2)土壤钾含量在典型草原中最高,其他土壤养分含量均在草甸草原中最高;速效氮、速效钾、有机质和全氮含量在不同草原亚型中差异显著(P<0.05),全磷和全钾含量差异不显著。(3)草甸草原中对植物群落特征影响最大的是速效氮含量,作用最小的是全磷含量;典型草原中对植物群落特征影响较大的是速效氮、速效磷含量,作用较小的是速效钾含量;荒漠草原中全磷含量对植物群落特征影响较大,全钾含量对植物群落特征的作用较小。综上,在草甸草原和典型草原的植被保护中,应注重氮元素的投入,而对荒漠草原,应注重磷元素的控制。

In order to reveal the vegetation characteristics and soil nutrient features of different grasslandsubtypes,and explore the interrelationship between species diversity and soil nutrients,this study was conducted using the Xilingol grassland in Inner Mongolia as research area.The plant community characteristics,soilnutrient characteristics and their interrelationships of three grassland subtypes,namely,meadow grassland,typical grassland and desert grassland,were analyzed by field sampling,indoor assay and redundancy analysis.The results were as follows.①The biomass(W),richness index(M),diversity index(H')and dominanceindex(D)of the plant communities showed meadow grassland>typical grassland>desert grassland,and the uniformity index(J)was the highest in desert grassland.②Soil potassium content was the highest in typicalgrassland,and the contents of other soil nutrients were the highest in meadow grassland.The available nitrogen,available potassium,organic matter and total nitrogen content differed significantly between differentgrassland subtypes(P<0.05),and the difference in total phosphorus and total potassium contents was not significant.③In meadow grassland,the available nitrogen content had the greatest influence on plant communitycharacteristics,and the total phosphorus content had the smallest influence.In typical grassland,the influenceof available nitrogen and phosphorus were higher on plant community characteristics,and that of available potassium was lower.In desert grassland,the total phosphorus content had greater influence on plant communitycharacteristics,while the total potassium had smaller influence.In summary,the intake of nitrogen should beemphasized in the vegetation protection of meadow grassland and typical grassland,and the control of phosphorus should be emphasized for desert grassland.