Assessment of management-dependent nutrient losses in tropical industrial tree plantations.
Industrial tree plantations in the tropics usually follow short rotations and intensive site management including slash and burn, and the use of heavy machinery. We attempt to quantify the implied nutrient losses (harvest export, erosion, slash and burn, leaching) in order to give plantation managers a chance to understand the significance of their planning and decisions. We used the scarce globally available information and a case study plantation in East Kalimantan, Indonesia (Acacia mangium and Eucalyptus deglupta). Adaptation involves problems and is discussed in some detail. Results are approximate only. Assuming a harvest volume of 200 m3 ha(-1), we assessed a loss of 427-680 kg ha(-1) N, 12-13 kg ha(-1) P, 178-252 kg ha(-1) Ca, 276-370 kg ha(-1) K, and 45-57 kg ha(-1) Mg per rotation. Of this overall loss, stand harvest accounted for 18-29% (N), 21-30% (P), 56-26% (K), 48-64% (Ca) and 22-37% (Mg). This means that the cumulative loss by erosion, slash and burn, and leaching exceeds that of the harvest. These losses can be influenced by management.
United Nations Environmental Program, Nairobi, Kenya. Jens.Mackensen@unep.org
Jens
J
Mackensen
Rudolf
R
Klinge
Daddy
D
Ruhiyat
Horst
H
Fölster
D000045:Acacia / Q000254:growth & development; D003247:Conservation of Natural Resources; D005052:Eucalyptus / Q000254:growth & development; D005390:Fires; D016468:Forestry; D009584:Nitrogen / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis*; D012987:Soil; D014197:Trees; D014329:Tropical Climate
D012987:Soil; D010758:Phosphorus; D009584:Nitrogen