Latitudinal variation of leaf stomatal traits from species to community level in forests: linkage with ecosystem productivity

Abstract

To explore the latitudinal variation of stomatal traits from species to community level and their linkage with net primary productivity (NPP), we investigated leaf stomatal density (SD _L) and stomatal length (SL _L) across 760 species from nine forest ecosystems in eastern China, and calculated the community-level SD (SD _C) and SL (SL _C) through species-specific leaf area index (LAI). Our results showed that latitudinal variation in species-level SD _L and SL _L was minimal, but community-level SD _C and SL _C decreased clearly with increasing latitude. The relationship between SD and SL was negative across species and different plant functional types (PFTs), but positive at the community level. Furthermore, community-level SD _C correlated positively with forest NPP, and explained 51% of the variation in NPP. These findings indicate that the trade-off by regulating SD _L and SL _L may be an important strategy for plant individuals to adapt to environmental changes, and temperature acts as the main factor influencing community-level stomatal traits through alteration of species composition. Importantly, our findings provide new insight into the relationship between plant traits and ecosystem function.