Fig. 7From: Changes in soil organic carbon contents and fractionations of forests along a climatic gradient in ChinaVariations in (a) annual litterfall; (b) soil microbial respiration (MR); and (c) clay content, clay content with mean annual temperature (MAT). Values are averages across forest types within climatic zones. Vertical bars indicate standard errors of means (n = 3 for the cool temperate and subtropical sites, and 2 for the warm temperate sites)Back to article page