Efficiency of Water Use by Eucalyptus Spp. for Water Conservation and Sustainable Forest Production

Forestry plantations have been expanded to meet the increasing demand for tree products, impacting evapotranspiration rates and hydrology. We explore how three Eucalyptus spp. respond to environmental resources using productivity and water use efficiency as indicators. Environmental variables, tree transpiration, soil physical properties, soil water content, and plant productivity were monitored. Eucalyptus saligna was the most productive, with higher volume, basal area and average annual increment compared to E. benthamii and E. dunnii. Transpiration of E. saligna (1249 mm year(-1)) was also higher than that of E. benthamii (928 mm year(-1)) and E. dunnii (733 mm year(-1)). The highest water use efficiency was evident for E. dunnii. Soil water rarely limited plant growth. Nevertheless, annual transpiration for E. saligna exceeded annual rainfall. Eucalyptus species with high water use should be avoided in areas of limited water availability, while species with low water use can provide productivity without depleting water resources.