Predicting water-use efficiency at canopy level under climatic change

摘要

A simple water-use efficiency (WUE) model, derived originally for single leaves, was directly applied to canopies without explicitly upscaling. Fluxes and concentrations of CO_2 and water vapor in a cotton field and sweet corn field were measured with a Bowen ratio/energy balance/CO_2 gradient (BREB+) system and a multiport air-sampling apparatus. Those data were used to test the validity of the model at canopy level in open fields. Results showed that predicted WUE was remarkably close to measured WUE for cotton and reasonably close for sweet corn.