Meteorological drivers of vineyard water vapour loss and water use efficiency during dry days

Detailed monitoring of agroecosystem water vapour losses is essential for improving water management schemes. In this study, a combination of eddy covariance and sap flow sensors was used to examine the responses of evapotranspirative components and water use efficiency of a grassed vineyard to meteorological drivers during a dry spell. Results showed that the grapevines dominated the ecosystem fluxes of carbon and water in the mornings, after which they closed their stomata to limit transpiration. The grasses continued transpiring throughout the day, decreasing overall water use efficiency of the vineyard. Our findings emphasise the importance of short-timescale response monitoring in understanding vineyard water fluxes.