荒漠草原主导种群与植物群落地上现存量的关系

以内蒙古锡林郭勒盟苏尼特右旗短花针茅荒漠草原为对象,采用随机区组放牧试验设计,结合对比分析、线性回归分析以及结构方程模型等数据分析方法,探讨荒漠草原主要种群与植物群落地上现存量的关系及在放牧条件下的变化特点。结果表明:随放牧强度增大,短花针茅、无芒隐子草和碱韭主导种群地上现存量占植物群落地上现存量的比例下降,且主导种群与植物群落地上现存量的线性关系减弱;不同年度间主导种群占植物群落地上现存量比例以及线性关系会产生变动;短花针茅种群对荒漠草原植物群落的影响强于无芒隐子草种群和碱韭种群,但无芒隐子草种群在降雨较好年份具有补偿作用。

Relationship between Dominant Population and Above-ground Standing Crop of the Plant Communities in the Desert Steppe

In order to study the relationship between dominant population and above-ground standing crop of the plant communities in the desert steppe,and their change characteristics and rules under grazing conditions,we took the Stipa breviflora desert steppe in Sunite Right Banner of Xilinguole league,Inner Mongolia as studied object.The random block grazing experimental design was adopted,and the comparative analysis,linear regression analysis and structural equation model were used to analyzed data.The results showed that with the increase of grazing intensity,the proportion of above-ground standing crop of dominant population(S.breviflora,Cleistogenes songorica and Allium polyrhizum)in the above-ground standing crop of plant communities decreased,and the linear relationship between dominant population and above-ground standing crop of plant community was weakened,the proportion and linear relationship between the dominant population and above-ground standing crop of plant community changed in different years.The effect of S.breviflora population on plant community in desert steppe was stronger than that of C.songorica and A.polyrhizum,but C.songorica population had a compensation effect in years with higher rainfall.