 The presence of the bear is indicative of healthy forests throughout much of the world. Can we make sure there are forested areas large enough to allow these large species to flourish in the face of human encroachment? |
 Harvesting techniques to produce more useable wood and protect other forest values are being implemented world-wide. Here it is difficult to find the large stump of a harvested tree in the center of the photo. |
Many authors have made the case for wood as the sustainable source of many products needed by the people of the world. The following article is an excerpt from a new book by Patrick Moore, co-founder of Greenpeace (see page 5). He suggests we can have more wood and biodiversity.
There is a tendency among foresters to believe that strategies to increase wood production will automatically result in a loss of biodiversity. As we move from forests that are naturally regenerated to forests that are managed by planting, weeding, fertilizing, thinning and pruning we select in favour of the trees and against other species. Biodiversity certainly is lost when the traditional agricultural model is simply borrowed and adapted to forestry. It is my belief, after many years of field observations around the world, that biodiversity protection and high-yield wood production need not be mutually exclusive.
In the traditional model, wood production is increased by creating a fast growing monoculture over a wide area, eliminating competition through the application of herbicides, and focusing entirely on the trees as an agricultural crop. There is no doubt that this approach works from the perspective of maximizing wood production, but it is nearly always at the expense of biodiversity and the habitat required by many species. By adopting creative strategies, at both the level of the individual stands of trees and at the level of the larger landscape, this apparent conflict between production and biodiversity can be overcome.
In many areas of central Europe, private forest owners have found that planted spruce monocultures provide the best financial return for their families. These forests tend to be very simplified and, in particular, they have few potential nesting sites for birds that need holes in dead trees. In Austria there is a regulation requiring that private forest owners provide 20 wooden birdhouses per hectare, nailed to the sides of the spruce trees. Even though this is a very easy and inexpensive obligation, it results in a tremendous increase in bird populations and breeding success in these forests.
Consider a typical pine plantation such as those found in many regions of the world today. Following harvesting, usually by some form of clearcutting, the site is commonly disc plowed and planted with genetically improved nursery stock in nice neat rows. An herbicide application is often used to reduce competition from herbs and shrubs and at age five to ten, a pre-commercial weeding and thinning establishes the desirable number of stems per acre. Other tree species such as pioneer hardwoods that regenerate from native seed are removed in favour of the pines. If the trees are grown close together to maximize production, not much sunlight gets through to the ground. Not many plants can survive in the deep shade so biodiversity is reduced to those that can. While not all plantation forests are this extreme, there is a tendency to move in this direction with a number of species including pines, spruce, eucalyptus, and poplar.
One of the keys to maintaining a high level of biodiversity is the recognition that in a given ecosystem there are usually some species that have evolved to take advantage of all the successional states in that ecosystem. The best way to make sure that all features are present in an ecosystem at any given time is, in the words of wildlife ecologist Fred Bunnell, "Don't do the same thing everywhere." If forests are managed by blanket prescription some habitats and structures will tend to be lost. This can result in considerable loss of biodiversity at the local or even regional level. There are a number of strategies to avoid the loss of biodiversity that can result from intensive plantation management over large tracts of land. These can be accomplished both at the stand level and at the landscape level.
At the stand level, the key to creating higher biodiversity without much compromise to wood production involves the retention of key structural elements in the stand. Some examples are:
At the landscape level the key to creating higher biodiversity is to treat the landscape so that all elements of the forest are retained at all times. Some examples are:
It is impossible to manage forests intensively for timber production without having some impact on biodiversity. By adopting strategies such as those recommended above, it is possible to minimize negative impacts on biodiversity while maintaining a high level of wood production. To a considerable degree, we can have our cake and eat it when it comes to sustainable forestry.
