Abstract: Most research on carbon storage in forests has focused on qualitative studies of carbon storage and influencing factors rather than on quantifying the effect of the spatial distribution of carbon storage and of its influencing factors at different scales. Here we described the spatial distribution of aboveground carbon storage (ACS) in a 20-ha plot in a subtropical evergreen broad-leaved forest to evaluate and quantify the relative effects of biotic factors (species diversity and structural diversity) and abiotic factors (soil and topographic factors) on ACS at different scales. Scale effects of the spatial distribution of ACS were significant, with higher variability at smaller scales, but less at larger scales. The distribution was also spatially heterogeneous, with more carbon storage on north- and east-facing slopes than on south- and west-facing slopes. At a smaller scale, species diversity and structural diversity each had a direct positive impact on ACS, but soil factors had no significant direct impact. At increasing scales, topographic and soil factors gradually had a greater direct influence, whereas the influence of species diversity gradually decreased. Structural diversity had the greatest impact, followed by topographic factors and soil factors, while species diversity had a relatively smaller impact. These findings suggest studies on ACS in subtropical evergreen broadleaf forests in southern China should consider scale effects, specifically on the heterogeneity of ACS distribution at small scales. Studies and conservation efforts need to focus on smaller habitat types with particular emphasis on habitat factors such as aspect and soil conditions, which have significant influences on community species diversity, structural diversity, and ACS distribution.

Key words: Aboveground carbon storage (ACS), Scale, Diversity, Soil factors, Topographical factors