摘要 : Compositional and edaphic gradients were studied in montane forestsof the Bavarian AIps(Germany), in which natural mixed deciduous-coniferous tree layers have been aiteredby past management in favour of Picea abies. Data on specie... 展开 Compositional and edaphic gradients were studied in montane forestsof the Bavarian AIps(Germany), in which natural mixed deciduous-coniferous tree layers have been aiteredby past management in favour of Picea abies. Data on species composition and ecological factors were collectedin a stratified random sample of 84 quadrats comprising a gradient from pure Picea to pure Fagus sylvatica stands. Data about the understorey complsition were subjected to indirect(DCA)and direct gradient analysis(RDA)withthe proportion of Picea in the canopy as a comstraining variable. Three principal components of a matrix containing seven descriptors of mineral soil, relief and tree layer cover were included as covariables describing the variability of primary ecological factors. Gradients of organic topsoil morphology and chemistry were extracted correspondingly. Responses of individual species, species group and topsoil attributes were studied by simple and partial correlation analysis. Mosses were significantly more abundant and diverse under Picea stands.Few graminoid and herb species were partially associated with picea, and total understorey richness and cover did not differ systematically by stand type. No relationship between tree layer and understorey diversity was detected at the studied scale. Juvenile Fagus sylvatica was the only woody species significantly less abundant under picea. In the topsoil lower base saturation, lower pH and larger C/Nratios in the litter layer were partially attributable to the proprtion of Picea, only for base saturation a relationship was detected in greater soil depth also. The frequency of broad humus from types did not differ by tree species, nor was overall depth of organic forest floor attributable to canopy compositio 收起