Fig. 7From: Tree species richness enhances stand productivity while stand structure can have opposite effects, based on forest inventory data from Germany and the United States of AmericaEffects of longitude (a), latitude (b), annual precipitation (c), mean annual temperature (d), tree species richness (e), and stand density (f) on tree size heterogeneity of US inventory plots. Each variable was tested on its own while other variables were set to the meanBack to article page