Transpiration by oil palm and rubber plantations: refining methods and delineating differences Oil palm (Elaeis guineensis Jacq.) and rubber (Hevea brasiliensis Müll. Arg.) plantations cover large areas in tropical regions and may still expand further. In contrast the area covered by natural forests has strongly declined. From environmental perspectives this raises concerns not only with respect to biodiversity but also regarding the integrity of the hydrological cycle including potential changes in transpiration. For rubber plantations high evapotranspiration rates were reported from mainland Asia and it was indicated that rubber tree transpiration responds sensitively to dynamic...