Conservation tools and strategies
Society’s most familiar approach to forest conservation has been to set aside no-harvest reserves. Even on private commercial forestlands, forests of exceptional conservation value are sometimes set aside, but they usually represent only a fraction of a percent of the land base. Strict reserves are much more common on public lands. Reserves where a high density of older forest attributes is maintained by limited harvesting probably have the widest appeal for public and private land managers.
Set-aside reserves can be integrated with other management approaches. In the Northeast, an ambitious forest conservation proposal for Massachusetts is known as “Wildlands and Woodlands.” It would put about 50% of Massachusetts’ 5 million acres into either “wildlands”—reserves with no harvesting—or working forest “woodlands” with sustainable harvesting. Forestry would be promoted and enhanced in the working forest areas and throughout local communities. About 10% of the 2.5 million acres in the program (about 5% of the state) would be allocated to wildlands destined to grow into older forest. This long-term vision won’t become reality overnight. It will be expensive because many landowners will require fair compensation, through the purchase of no-development easements on their land, to give up their future rights to convert their forestland into some other more lucrative land use. Nevertheless, this may be the scale of vision that our society needs to achieve true forest sustainability.
But forests are dynamic living organisms, and even a set-aside reserve can’t preserve an older forest intact like a prehistoric fly in amber. In the Pacific Northwest, for example, where current federal policies emphasize protecting older forests, about 80% of federal land is in reserves where exis¬ing old growth is protected from logging. These forests are constantly changing, and natural disturbances, fire suppression, invasive species, insect and disease outbreaks, forest succession, and global warming will continue to bring change. Even though the forests are protected, managers face many decisions about the compatibility of changes with their long-term goals and the need to take action when undesirable ones appear.
Restoration, retention, and rotation length
In addition to reserves, potential conservation tools for older forests include restoration, retention, and rotation length. These tools are applicable primarily to lands where owners also seek some level of financial return from wood production.
Restoration provides the opportunity to promote long-lived tree species and to accelerate growth rates to produce older forest conditions sooner than they would have developed without management intervention. In most situations, restoration will cost the landowner in terms of lost revenue, as trees more than 100 years old generally are beyond the age of maximum commercial value. Moreover, promotion of large dead standing trees and fallen wood, which are more abundant in older forest, is not a typical goal for timber managers. Nevertheless, restoration is a tool that is an option for interested forest managers, and it may be of special interest to conservation forest owners such as the Nature Conservancy and the Appalachian Mountain Club.
Retention refers to leaving some trees standing during harvesting and allowing them to mature beyond the age of maximum commercial value. They can be selected to retain older-forest features such as large trees and old trees that host particular epiphytes (plants that grow upon another plant but don’t derive any nourishment from it). Retaining decadent or inferior quality trees often represents only a small opportunity cost to the landowner. Foresters and loggers must be knowledgeable about which trees make the best candidates for retention. Retention has become an increasingly popular management strategy for commercial forest landowners, but it’s not clear that old trees are always being targeted for retention or that retention represents a long-term strategy for providing older-forest features on commercially managed forests.
Extending rotation length is problematic for commercial forest owners. For example, the commercial value of a tree in the Northeast peaks at an age of 50 to 80 years for many forest products, and older forest conditions start to emerge at 90+ years of age, depending on forest type and latitude. However, it may be realistic for some private forest managers to place part of the harvestable acreage, for example 10 percent, in a long-rotation management regime. “Rotation easements” similar to conservation easements that purchase development rights could be used to “buy” rotation length—that is, pay landowners the opportunity cost of longer rotation periods. Extending rotation length is more common on public lands where forest products represent one of many values to be sustained.
Proposed strategies for protecting older forest on private lands include tax incentives and forest conservation easements (voluntary legal agreements by property owners to restrict development on their land, usually in return for financial compensation).
Another potential incentive may be forest-based carbon credits—tradable credits that represent the amount of carbon sequestered by a tract of forestland. These credits are sold to organizations such as utility companies that operate coal-burning electric-generating plants to offset the carbon dioxide emissions that they generate. Forest-based and other carbon credits are now traded independently as well as through the Chicago Climate Exchange, a voluntary but legally binding emissions-trading market. Growing forests over longer times allows them to absorb and retain more carbon, providing more potential for carbon credits. Some organizations, such as the Pacific Forest Trust, have established programs that provide revenue to private forestland owners from carbon credit sale. Larger forestland owners have sold carbon credits on the open market. In addition to finding a buyer, the seller must demonstrate that the forestland will actually sequester additional carbon and define the amount and method.
The cost of keeping timber past its maximum economic value and investing in restoration can be partly offset by the value of high-quality timber products and the potential of older forests for wildlife management and recreation. Comprehensive economic models that explicitly evaluate such tradeoffs and incentives are needed, especially for protection, restoration, and development of older forests on private land.
In the [[Great Lakes]] region, many of the few existing old-growth stands on public and private lands have no protection. The region has so few stands with trees more than 120 years old that many people feel that all of them should be protected without question, on private as well as public lands. Mature stands that are nearly old growth also deserve protection. The next step after protecting existing stands of older forest should be to select second-growth areas that can be managed for extended rotation in even-aged forest or older cohorts (groups of trees of similar age) in multi-aged forest. In many of these stands, thinning and fire may hasten the development of older forest characteristics. The percentage of the forest that is managed for extended rotation needs to be determined by a public process with scientific input. Active restoration is useful and necessary for restoring old growth conditions faster on certain sites, but simulations suggest that such efforts should be focused on even-aged stands, uneven-aged stands with few large trees, or former plantations. Heavy thinning may actually delay the onset of old-growth structure in older uneven-aged stands with numerous legacy trees (old trees that have been spared during harvest or have survived stand-replacing natural disturbances).
In the Southwest, ecological restoration appears to be the best strategy for conserving old-growth forests. It aims to restore forest structure, processes, and composition within their natural range of variability. The basic strategy is first to facilitate the partial recovery of the ecosystem structure through thinning and then to return the key ecosystem process—low-intensity fire—to set the stage for more natural rates of decomposition, nutrient cycling, and net primary productivity while at the same time helping to reestablish the system’s plant and animal communities. In some cases it may be necessary to reseed or transplant missing plant species, rake around old trees before burning to prevent damage, control invasive plants, and defer or regulate grazing. Monitoring is required to make sure that the restoration is meeting the project’s goals and objectives. It will be important to interact with people who are affected by the restoration.
This is a chapter from Beyond Old Growth (report).
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