Variation of stomatal traits from cold-temperate to tropical forests and association with water use efficiency

1.Stomata control carbon and water vapor exchange between leaves and the atmosphere, thus it can influence water use efficiency and reflect plant adaptation to climate. However, the spatial patterns of leaf stomatal traits and relationships between stomatal trait and water use efficiency across natural communities remain unclear.

2.We measured stomatal density, stomatal size, and stomatal area fraction for 737 plant species from nine forests ranging from tropical to cold-temperate forests.

3.Stomatal density, stomatal size, and stomatal area fraction were all log-normally distributed, and different across species, plant functional groups (trees, shrubs, and herbs), and communities. At the regional scale, variation in stomatal traits was primarily related to species, followed by climate and soil types.

4.The community-weighted mean of stomatal size increased linearly with latitude, whereas those of stomatal density and stomatal area fraction showed humpbacked relationship. The c...