An investigation of the leaf anatomy, foliar mineral levels, and water relations of trees of a Sarawak Forest [Malaysia]

Trees and shrubs of the heath forests of Southeast Asia have leaves which appear to be structurally adapted to drought, despite the occurrence of this vegetation within the continuously wet lowland tropics. Results of investigations of the anatomy of the leaves and some mineral analyses thereon are presented and discussed. Experiments show that the rate of water loss from cut shoots, the water deficits required to induce stomatal closure in cut shoots, and the sublethal water deficits of detached leaves of heath forest species are all within the range recorded for lowland rain forest species. The significance of these results is discussed in the light of previous investigations of the climate physiognomy and ecology of heath forests.