Abstract: Using the gray system analysis method,a study was conducted in Qianguo county,Jilin Province,on the characteristics of several Leymus chinensis communities and their soil environment,as well as the relationship between the two.The result shows:the living root biomass of three communities tended to decrease as the roots penetrated deeper into the earth layer where soil nutrients reduced with the descending depth the roots reached.The nutrients kept a big gray connection to the living root biomass,but remained the same as it in the variation tendency,being an advantage factor.The index of soil alkalinity rose with the depth of the soil layer,but they kept only a slight gray connection to the living root biomass.The variation tendency of the soil alkalinity index was contrary to that of the living root biomass,as the former being a restricted factor.Coupling relation analysis indicated that coupling intensity was the strongest and the coupling relationship the best between the L.chinensis communities and the soil where they grow.The L.chenensis communities yield superior forages and boast high potential productivity.However,in deteriorated grassland caused by excessive grazing,the coupling intensity between vegetation and soil is minimum,the system runs counter,and the communities are degenerating gradually.

Key words: Leymus Chinensis Grassland, Soil environmental factors, Living root biomass, Grey analysis, System coupling

摘要： 采用灰色系统分析法研究羊草草原几种植物群落特征、土壤环境因素以及二者的关系。结果表明:3种群落的活根量随着土层的加深呈下降趋势;土壤营养状况随着土层的加深呈下降趋势,且对活根量的灰色关联度较大,其变化趋势与根量相同,是优势因素;土壤碱化程度随着土层的加深呈上升趋势,对活根量的灰色关联度较小,变化趋势与根量相反,是限制性因素;耦合关系分析结果表明,羊草群落与土壤的耦合度最大,耦合关系最好,是比较优良的群落,具有较高的生产潜力,而过度放牧的退化群落与土壤的耦合度最小,系统相悖最明显,是比较退化的群落。

关键词: 羊草草地, 土壤环境因素, 活根生物量, 灰色分析, 系统耦合