Changes in Water-Use Efficiency of Eucalyptus Plantations and Its Driving Factors in a Small County in South China

Abstract

Ecosystem water-use efficiency ((Formula presented.)) has been central in revealing the variability in terrestrial carbon and water cycles. Short-rotation plantations such as Eucalyptus plantations can simultaneously impact net primary production ((Formula presented.)) and actual evapotranspiration ((Formula presented.)), components of (Formula presented.), resulting in changes in terrestrial carbon and water cycles. However, there are few detailed studies on the changes in the (Formula presented.) of Eucalyptus plantations at the catchment scale with high spatial remote sensing imagery. Here, we present the changes in the (Formula presented.) of Eucalyptus plantations and its driving factors (i.e., (Formula presented.) and (Formula presented.)) using satellite-based models combined with 5-m spatial resolution RapidEye imagery in a small county in South China. The increases in (Formula presented.) of Eucalyptus plantations are primarily the result of climate warming and result in low (Formula presented.) of Eucalyptus plantations. The management practice used (short rotation in this study) can enhance the effect of climate warming on (Formula presented.) by varying the (Formula presented.) of Eucalyptus plantations. A high value of (Formula presented.) leads to a high (Formula presented.) of Eucalyptus plantations at the end of a short rotation, while a low value of (Formula presented.) results in a low (Formula presented.) at the beginning of another short rotation. Changes in the (Formula presented.) of Eucalyptus plantations indicated large spatial and temporal variability, associated with climate warming and short-rotation practices.