山西历山山地草甸生物多样性、优势种和土壤因素对群落生产力的影响

Effects of biodiversity, dominant species and soil factors on community productivity in Lishan Mountain meadow,Shanxi province

自然生态系统生产力同生物多样性、优势种功能性状和土壤性质等多因素紧密关联,因此,受到多变量过程的综合调控。利用结构方程模型研究了山西历山山地草甸物种多样性、功能多样性、优势种功能性状和土壤等多变量因素对群落生产力的影响。结果表明:除了物种多样性外(γ=0.10,P=0.69),优势种功能性状(γ=0.61,P=0.00)、功能多样性(γ=0.47,P=0.04)和土壤因素(γ=0.34,P=0.02)直接影响群落生产力,并且土壤因素还通过改变优势种功能性状和功能多样性的方式间接影响群落生产力(间接影响系数分别为0.35、0.27)。优势种功能性状是预测群落生产力变化的最佳变量,其次是功能多样性和土壤因素。因此,理解自然生态系统生产力变化应在引入多元方法的前提下,重点考虑优势种功能性状因素。

The productivity of natural ecosystem is closely related to many factors, such as biodiversity, functional traits of dominant species and soil property, thus is controlled by multivariable process. In this paper, the effects of species diversity, functional diversity, functional traits of dominant species and soil factors on community productivity of Lishan Mountain meadow in Shanxi province were studied by using structural equation model. The results showed that species diversity had no effect on productivity(γ=0.10, P=0.69), but the functional traits of dominant species(γ =0.61, P=0.00), functional diversity(γ =0.47, P=0.04) and soil factors(γ =0.34, P=0.02) had a direct impact on productivity, and soil factors had an indirect effect on productivity by the functional traits of the dominant species and functional diversity,with the indirect effect coefficients being 0.35 and 0.27, respectively. The functional traits of dominant species were the best predictors of productivity, followed by functional diversity and soil factors. Therefore, understanding the change of natural ecosystem productivity should be based on the introduction of multiple methods, with emphasis on the functional traits of dominant species.