Abstract: Species diversity pattern is closely related to selected scales. By using additive partition approach, this paper analyzed the species diversity patterns in tree, shrub, and herb layers of Pinus tabulaeformis f. shekannesis community at three scales (quadrat, slope position, and slope). When using species richness as the indicator, slope scale contributed most to regional diversity, being the critical scale for species composition and maintenance within a region. When measured with Shannon and Simpson diversity indices, the highest diversity was found at quadrat scale, because these two indices not only considered species number, but also considered the species abundance in a quadrat and the influence and roles of common and rare species. When using Shannon diversity as the indicator, the contribution of β diversity at betweenquadrat, between-slope position, and between-slope scales to regional diversity was higher than that of Simpson diversity, which was mainly decided by the distribution pattern of rare species among the scales. The order of β diversity existed differences among between-quadrat, between-slope position, and between-slope scales, which was closely related to the species composition and distribution in the tree, shrub, and herb layers of the community, and the environmental heterogeneity among different scales.

Key words: Crop residue, Soil respiration, Soil microbial biomass