Although ET is a major component of the forest ecohydrological cycle, there is still a large uncertainty in ET estimates due to complex biological (i.e., CO₂ rise) and physical processes, and the dynamic nature of forests (i.e., age, species composition, leaf area index variations). The hydrological impacts of natural or anthropogenic disturbances such as global climate change, land use change (urbanization) and wildland fires on watershed hydrology are reflected in changes in ET. The ET processes are tightly coupled with carbon and nutrient cycles, water supply, and other ecological processes (i.e., biodiversity). Projecting the consequences of recent regional ‘greening up’ and ‘warming up’ of the Earth system requires a close look at the ET processes at the fine scale. We welcome papers on advances of understanding forest ET and associated ecohydrology using field measurements, remote sensing, and computer modeling at multiple scales from tree, stand, small watershed to regional levels.