Rising CO₂ drives divergence in water use efficiency of evergreen and deciduous plants.

ABSTRACT: Intrinsic water use efficiency (iWUE), defined as the ratio of photosynthesis to stomatal conductance, is a key variable in plant physiology and ecology. Yet, how rising atmospheric CO₂ concentration affects iWUE at broad species and ecosystem scales is poorly understood. In a field-based study of 244 woody angiosperm species across eight biomes over the past 25 years of increasing atmospheric CO₂ (~45 ppm), we show that iWUE in evergreen species has increased more rapidly than in deciduous species. Specifically, the difference in iWUE gain between evergreen and deciduous taxa diverges along a mean annual temperature gradient from tropical to boreal forests and follows similar observed trends in leaf functional traits such as leaf mass per area. Synthesis of multiple

SUBMITTER: Soh WK 

PROVIDER: S-EPMC6905860 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature