Transpiration of trees in a tropical rainforest.
The tritium method was used to measure the transpiration of 20 trees in a rain forest in the Amazon Territory of Venezuela. Transpiration rates ranged from 2.7 litres/day (small understorey trees) to 1180 litres/day (large canopy trees). Transpiration rates were highly correlated (r = 0.96) with the sapwood area of trees. Transpiration rate, as a function of sapwood area, was independent of species and of soil type on which trees were growing. Author's summary.