Biomass-density relationship varies with water use efficiency across an aridity gradient

Accumulating evidence has shown that the scaling exponent (alpha) of the aboveground biomass-density relationship is not a constant value. Debate continues over what determines the variation in alpha. By measuring foliar stable carbon isotope, plant morphological traits and alpha along an aridity gradient from eastern to western China, we confirmed that the variation in alpha was accounted for by changes in plant morphological traits which are adaptive strategies for enhancing water use efficiency during drought stress. This information can be crucial for understanding and predicting community and ecosystem processes.