Natural Forest Management

Natural forest management has been defined as "controlled and regulated harvesting, combined with silvicultural and protective measures, to sustain or increase the commercial value of future stands, all relying on natural regeneration of native species" (Schmidt 1991). Compared to plantations and agro-forestry, natural forest management systems are less intensive, with relatively lower short-term yields, but also requiring lower capital inputs. There is a long history of management of natural forests by indigenous peoples. For example, recent archaeological research in the Upper Xingú region of Brazil has revealed that a complex settlement pattern existed in the Amazon long before the arrival of European colonizers (years 1200-1600 a.d.). These settlements apparently greatly transformed the local landscape and sustained human populations without destroying biodiversity (Heckenberger et al. 2003; Stok-stad 2003). Another recent study has shown a history of human occupation in other regions that otherwise were considered to be pristine, such as the Solomon Islands (Bayliss-Smith et al. 2003).

It appears that several cultures have been able to use the forest in a sustainable manner to their benefit. Even today, large areas of tropical forests are used by indigenous peoples. Such forests can be considered "humandominated ecosystems", since many forests are actually used for gardening, agroforestry, hunting and gathering (Noble and Dirzo 1997). The key to using tropical forests to sustain human populations in indigenous societies has been to conserve the basic forest structure and function. Natural forest management of today is based on this same principle.

Modern natural forest management is often not sustainable, and has been criticized on a number of grounds (Buschbacher 1990; Bruenig 1996; Reid and Rice 1997; Pereira et al. 2002; Frederiksen and Putz 2003):

• It is based on a few valuable species including Swietenia spp. (mahogany) in Latin America, Khaya in Africa, and Shorea in Asia. Selective logging can reduce or extinguish local populations of these species.

• Other species are not used, because existing markets are often not sufficient to warrant their extraction.

• Selective logging practices cause a certain degree of damage to the forest, especially when felling and transportation of logs is carried out on steep slopes. Damage to the forest is highly dependent on the intensity of logging and therefore sustained forest management techniques necessarily restrict the amount of timber harvested.

• Due to the damage caused to the forest by selective logging, there is often not enough natural regeneration.

• Selective logging opens up areas that local people can use for shifting agriculture.

• Logging roads increase access to wildlife hunting.

• Opening of the canopy by logging increases risk of damage by fire.

In the following sections we explain how some of these negative effects can be avoided or counteracted, using knowledge of the basic ecology of natural forests to design sustainable management systems.

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