The transformation of rainforest to rubber and oil palm plantations may have severe ecohydrological consequences. Monitoring water fluxes or relevant ecohydrological indicators on sites with such different land-uses is important to describe the impacts of land-use transformations. A central water flux in the hydrological cycle is transpiration. Thermal screening of canopy leaf temperatures is potentially a great indicator for transpiration of vegetation as well as palm and tree water use characteristics such as stomatal closure and drought response. Changes of fluxes regarding their temporal variability and spatial heterogeneity will be addressed as well as mechanisms controlling tree and palm water use. Research sites will comprise the main land use systems (forest, rubber and oil palm plantations) and enable a comparison of periodically wet, riparian sites with upland sites in the Harapan region. A rapid assessment tool is being developed based on an unmanned aerial vehicle carrying a radiometric camera to record thermal infrared radiation from canopy leaves. The results of this study may help to evaluate and understand changes in tree and palm water use characteristics as a consequence of rainforest transformation.

Florian Ellsäßer is Doctoral Speaker of Group A