Data for: Climate and forest attributes influence aboveground biomass of deciduous broadleaf forests in China

Forests provide a huge carbon pool, a substantial portion of which is
stored in aboveground biomass (AGB). Deciduous broadleaf forests in China
are an essential component of global deciduous broadleaf forests, yet the
impacts of climate and forest attributes on their AGB are not well
understood. Using a comprehensive forest inventory database available from
772 plots distributed across the temperate and subtropical deciduous
broadleaf forests in China (23.51°-42.53° N and 104.24°-128.27° E), we
applied variance partitioning analysis, model selection analysis and
structural equation models to explore how AGB was associated with climate
and forest attributes (species diversity, community-level functional
traits, and stand structures) in different climatic regions (semi-arid
forests, semi-humid forests and humid forests). Community-level functional
traits and stand structures together explained a great portion of the
variance in AGB. The effect of community-level functional traits was
greater than that of stand structures in semi-arid forests and semi-humid
forests, but smaller in humid forests. Further analyses showed that
community-level maximum tree height, stem density and tree size inequality
were the best explanatory variables. Although climate and species
diversity had only minor effects, the direct positive effect of mean
annual precipitation (MAP) was still important, especially in semi-arid
forests. Synthesis. Community-level functional traits but not species
diversity were key drivers of AGB, indicating that tree species diversity
loss may not impair AGB substantially in deciduous broadleaf forests in
China. Moreover, stand structures had also strong effects on AGB in both
semi-arid forests and humid forests, highlighting the importance of
structural complexity. In addition, MAP had a direct positive effect on
AGB in semi-arid forests and semi-humid forests, and a future predicted
increase in drought might potentially reduce carbon storage in these
forests.