After rainfall, evaporation is the largest component of the water balance. Depending on the location on earth, 50 to 80% of the rainfall can easily evaporate on annual basis. Although the importance of evaporation is clear, determination of the evaporation flux remains difficult, as energy, moisture, and vegetation are highly variable in time and space. Especially, vegetation is an uncertain key factor when one wants to upscale evaporation both in time and space, and is the scope of this session.

Vegetation influences evaporation in many ways: directly through transpiration and interception, but also indirectly by feedback mechanisms. Especially, when a forest consists of multiple vegetation layers with e.g., mature trees, sub-canopy vegetation, and a forest floor layer, feedback mechanisms and interactions between the different evaporation processes become more important. Furthermore, the re-distribution of the different water stores (canopy-, stem-, forest floor-interception) as well as their seasonal variability determine evaporation.

Since nowadays effect studies of land use change and climate change on the water budget are very relevant, further knowledge on the evaporation process is essential. This session aims at new insights into the effect of vegetation on evaporation estimates.


For this session we are looking for new methods to measure and/or model forest evaporation both at the small and large scale. We solicit contributions related but not limited to the following topics:
- Advances in transpiration and interception studies;
- Methods to study interaction between transpiration and interception;
- New insights in vegetation feedback mechanisms;
- Energy balance studies;
- New remote sensing applications for forest evaporation;
- Ways to upscale forest evaporation from point to catchment scale

Invited talks are by Alexander Zimmermann on optimum throughfall sampling strategies and Scott Mackay on spatial patterns of transpiration.