|Agroforestry In-service Training: A Training Aid for Asia & the Pacific Islands (Peace Corps, 1984)|
|Appendix F: Production of fuelwood and shall timber in community forestry systems¹|
Fuelwood plantations used in small farmer or community forestry systems in the tropics are generally characterized by short rotations of less than 5 years. Cultivation of such plantations is often more intensive and nearly always less extensive than other types of forest plantations. Fast-growing tree species used in such plantations serve as nutrient pumps which remove nutrients from the soil and cycle thee through the mechanisms of litterfall, rainwash from leaves, windthrow and decay of stems, branches and roots. This cycling process is interrupted by the harvest of a plantation just as it is by the harvest of agricultural crops.
In order to sustain production on a single site, the negative effects of harvesting must be minimized. This can be done by attending to:
1. Fertility management. Care must be taken to either retain as many of the nutrients taken up by trees on the site #5 possible, or to replace nutrients which are removed. Nutrient losses might be minimized by allowing harvested trees to dry on the site before removal to allow leaves to dry, fall off and remain on the site. Nitrogen-fixing plants eight be used to improve and maintain soil productivity (Brewbaker, MacDicken and VanDenBelt, 1981; Haines and DeBell, 1979). Where the whole tree is of use off-site, an alternative would be to replace the nutrients removed with the tree by applying fertilizers, animal manures or green manures.
2. Erosion control. Removal of the forest canopy can result in increased danger of erosion, and the further loss of plant nutrients. Soil erosion losses must be minimized by minimizing the risk of exposing soils to the erosive forces of rainfall and runoff. Harvests should be scheduled for periods of little or no rainfall to reduce the risk of exposing bare soil to highly erosive rains. However, this may become risky when regeneration by coppice regrowth is anticipated. A possible solution would be to harvest during periods of light rainfall where adequate moisture is available to support coppicing.
All farming operations run the risks of soil fertility depletion and soil erosion. Short rotation plantations of fast-growing trees are no different. While many soil conservation measures such as contour ditching may be beyond the financial capacity of most farmers or community forestry projects to implement, the proper selection of site and attention to vegetatively covering the soil during periods of heavy rainfall are low-cost means of will greatly reducing the erosion hazard (El-Swaify, Dangler and Armstrong, 1982).