Forest Biodiversity Conservation Tools
Conservation tools have been developed to enable managers to maintain and improve forest biodiversity. Conservation tools can be used in both natural and intensely managed forest landscapes. In the case of intensely managed landscapes, the key is to use the conservation tools in conjunction with the principles of Adaptive Forest Management.
By examining forest stands from a landscape perspective, forest managers can gain a holistic perspective of how a particular stand relates to the larger regional context. Using this approach, one can examine an entire geographical area and estimate the amount of habitat available for various species. For species requiring large habitat areas, this is an especially important conservation tool. The landscape perspective (at right) also allows for the management of habitat over a larger area, rather than just one particular forested stand (Angelstam and others 2002). The Adaptive Forest Management approach taken in forest management certification systems, which intends to guarantee that management practices conform to performance standards which include biodiversity, and involves an opportunity for stakeholder input in planning and standards formulation by conservation groups and non-governmental agencies, can contribute to successful habitat conservation.
Another technique employed in biodiversity management is the "umbrella" species concept (Angelstam and others 2002). This technique involves wildlife biologists and forest managers choosing one species, such as the red cockaded woodpecker or flying squirrel (at left), that typically requires a relatively large habitat area that includes large trees and standing dead wood. Other species would then be identified that appear to co-occur with the "umbrella" species in the same habitat area. This allows forest managers to manage the landscape for one species, yet maintain habitat for several species at one time.
Stand structure and spatial configuration can also be manipulated in such a way as to conserve biodiversity in the forest landscape. The maintenance of a structurally complex stand is of utmost importance (Lindenmayer and Franklin 2002). There are three main strategies to managing stands for biodiversity. These strategies include:
- Structural retention at the time of regeneration harvest
- Management for creation and/or maintenance of structural complexity
- Long rotation periods
Structural retention at time of regeneration harvest. At the time of harvest, forest managers should decide if certain types and quantities of structures should be retained as potential habitat. These structures include large trees, snags, and dead trees. Other structures, such as trees of varying sizes and ages (at right), would be retained to provide adequate habitat for the conservation of species in the landscape (Lindenmayer and Franklin 2002).
Managing stands for biodiversity. Managing stands for biodiversity includes several different techniques. The most obvious technique is the use of thinning and harvesting to produce stands with a complex structure. According to Lindenmayer and Franklin (2002), other techniques for stand management include creating suitable habitat, installing nest boxes (at left), planting desired plant species, prescribed burning, and introducing or enriching the population of animal species.
Suitable habitat can be created by maintaining buffer zones in intensely managed forest stands. These buffer zones are typically areas that are not harvested and are located in areas between harvested areas. Buffer zones can be along streamsides to protect aquatic life or along forest edge to protect terrestrial species (Russell and others 2004). This has been a proven method of conserving biodiversity in managed stands.
Long rotations. Long rotations allow for the development of structurally complex stands over long periods of time (at right). Lindenmayer and Franklin (2002) define long rotations as rotations significantly longer than the economic rotation of a stand. Rotation times could be extended from 50-300%. This requirement may make this conservation tool less attractive to a large number of forest managers; however it could be applied in streamside management zones and other conservation zones on managed landscapes.
While the same biodiversity conservation tools can be used for both timber operations and bioenergy feedstock production, there are specific challenges with regards to increased utilization of biomass in harvested forests. These challenges include the retention of adequate amounts of dead wood and large and old trees as habitat (Angelstam and others 2002).
Many species are dependent upon deadwood (at right) for their habitat, yet the harvesting of this type of wood might intensify with increased demand for bioenergy and other bio-based products. This could decrease the amount of deadwood in the forests. It will be imperative that forest managers are keenly aware of the amount of deadwood available and retained in the forest for biodiversity conservation. The removal of some deadwood will be acceptable, but total removal will not be a long-term option.
Old and large trees are also desirable habitat for many species. While these trees may be ideal candidates for removal for bioenergy, they should be left on site for the purpose of biodiversity conservation. These trees, which tend to be in short supply, provide suitable habitat for many different species (Angelstam and others 2002).
If standards for bioenergy feedstocks quality prohibit incorporation of rotten wood, this may reduce the potential for habitat loss associated with dead and downed trees in forests that are managed for bioenergy supply.
Using appropriate stand techniques and the principles of Adaptive Forest Management, forest stands can be managed for both biological diversity and biomass production. Careful consideration of habitat conservation will ensure that species are maintained for future generations while providing raw materials for the production of bioenergy and other bio-based products.
Encyclopedia ID: p1285
