An increasing dependence is likely on fast-growing plantations in the tropics to meet the rising world demand for wood and wood products. With the use often of exotic species in pure stands, grown on short rotations, a possible problem will be the maintenance of productivity in successive crops. This subject is reviewed in the light of experience elsewhere, the occurrence of a confirmed second-rotation decline in yield in South Australia, and the author's research in Swaziland. So far there is insufficient evidence for assuming that declining yields will occur in successive rotations of plantations, but the possibility is very real on some sites. This must act as a warning against undue dependence on plantations, and to foresters that greater inputs of improved cultural practice, fertilisers and better genetic varieties may be needed as such forestry practice approaches #x2018;tree farming#x2019;.
展开▼
