Forest Ecosystems in Use
Biodiversity Conservation and Timber Management
Endemic Species
Understanding Ecosystem Disturbances
Related Links
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Forest Ecosystems in Use

Forests and woodlands cover nearly 40 percent of the earth's land surface, and they are the most biologically-diverse ecosystems in most parts of the world. The protected-areas network will never expand enough to include the bulk of the world's natural forest areas. Within most regions, some forests will be strictly protected and some managed for such generally low-impact uses as tourism and non-timber forest products. But in many private and public forests extraction of timber will likely remain a dominant use--whether in Canada, Indonesia, or Colombia.

Almost all current logging practices significantly reduce biodiversity, and its is doubtful that more than a fraction of commercial-scale logging operations in the humid tropics are sustainable. Nevertheless, areas dedicated to timber production are part of many bioregions, so the management challenge is to minimize biodiversity loss.

Biodiversity Conservation and Timber Management

If forests managed for timber are to contribute to biodiversity conservation, three steps are especially important.

• First, since many species depend on the complex physical structure of natural forests, some key habitats (including mature trees, snags, and decomposing logs) should be left in place following harvest in production forests. This will help to maintain the "legacy" of the natural forest in the new forest that develops.

• Second, populations of keystone species should be maintained as a high priority. These indispensable species control the structure of the community and help determine which other species are present. In many tropical forests, figs are keystone species. So are trees that provide habitat or food for pollinators and such seed dispersers as bats, fruit-eating birds, and hummingbirds.

• Finally, the fragmentation of natural forest areas that occurs when they are used intensively should be kept to a minimum. In most situations, highly selective logging, careful extraction of trees from large forest blocks, and the use of long rotations (70 years or more) keep the problem within bounds. Logging should be staggered so that various areas are at various stages of succession following disturbance and mature stands lie in close proximity to each other. A rule of thumb, then, is that all of the land covered by a particular forest type should not be logged at the same time and forest corridors should be maintained among unlogged and regenerating blocks. During logging, care should be take to minimize the damage from felling, road-building, and log extraction.

Endemic Species

Native tree species should be given priority over introduced species in forest regeneration, as well as in agroforestry and the restoration of degraded lands. This holds true even in plantation forestry, where indigenous species are most often overlooked on grounds that "exotics" grow faster. Recent work with native species punctures many such myths and shows that indigenous trees can often be more productive than the exotics that replace them. But the myths will live on until information to the contrary is available. Indeed, in many forestry programs the greatest obstacle to the increased use of indigenous trees is lack of information.

Understanding Ecosystem Disturbances

As increasing knowledge on the role of natural disturbances in forest dynamics becomes available, forestry and other human activity can be made to better mimic the disturbances to which forest ecosystems area adapted. Knowledge of the "tree gap dynamics" that govern the natural regeneration of trees in mature tropical forests is especially important. In the Palcazu project in Peru, strip-cutting that mimicked this natural process maintained a high level of natural species diversity. In temperate and boreal forests, such natural disturbances as fires and storms are integral parts of ecological processes in forest areas and should inform silvicultural practices.

Related Links:

• Tropical Forest Species Richness
• In Situ Conservation
• Elements and Dynamics of Bioregional Management
• Regional Coordination in Central America
• Community-Based Forest Management in Orissa, India
• British Columbia's Commission on Resources and the Environment
• Extractive Reserves, Brazilian Amazonia
• Guesselbodi National Forest, Nigeria
• Moving Toward Sustainable Forest Management in Russia
• Balancing Acts: Community-Based Forest Management and National Law in Asia and the Pacific
• Balancing the Scales: Guidelines for Increasing Biodiversity's Chances Through Bioregional Management
• Backs to the Wall in Suriname: Forest Policy in a Country in Crisis
• Breaking the Logjam: Obstacles for Forest Policy Reform in Indonesia and the United States
• Surviving the Cut: Natural Forest Management in the Humid Tropics