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Sunday, December 14, 2008

Pulpwood,Monocultures,Acacia mangium,forest fires, tornadoes, hurricanes

Pulpwood refers to timber grown with the principal purpose of making wood pulp for paper production. However, pulpwood is also used as the raw material for some wood products, such as oriented strand board (OSB), and there is an increasing demand for pulpwood as a source of 'green energy' by the bio-energy sector. Trees raised specifically for pulp production account for 16% of world pulp production, old growth forests 9% and second- and third- and more generation forests account for the balance. Reforestation is practiced in most areas, so trees are a renewable resource.

In the logging of mixed forest stands, the better trees are usually used for sawlogs for lumber production, while the inferior trees and components are harvested for pulpwood production. Pulpwood usually derives from four types of woody materials in a mixed logging operation. First are open-grown trees, that are heavily branched low on the trunk, and so make poor sawlogs. Second are dead or diseased trees. Third are tops cut from trees harvested for sawlogs (branches are rarely used since they contain little useable wood after the bark has been removed). And fourth are trees too small to harvest for sawlogs.
Harvesting a stand of eucalyptus pulpwood, Australia

Pulpwood is also harvested from plantations/tree farms established for the specific purpose of growing pulpwood, with little or minimal sawlog production. Monocultures of species intended specifically for pulpwood include loblolly/slash pine in the southern USA; various species of eucalyptus (most commonly Eucalyptus globulus and Eucalyptus grandis) in Latin America, Iberian Peninsula, Australia, south-east Asia and southern Africa and acacia (most commonly Acacia mangium) in south-east Asia and southern Africa.

Natural forest stands may also be harvested solely for pulpwood where, for various reasons, the value of the trees as sawlogs is low. This may be due to the predominant species in the forest stand (for example, some aspen forests in northern North America), or to the relative proximity of the nearest sawmill or pulp mill.

Salvage cuts after forest fires, tornadoes, hurricanes, or other natural disasters are often also for pulpwood. An alternative source of wood for use in kraft pulping is recovered lumber from demolition, industrial processing of wood and wooden pallets

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