Tongass National Forest

Prior to the completion of the Forest Plan Revision in 1997, many wildlife species habitats were modeled, usually using GIS tools. The Tongass was administered as 3 Forests at that time, and was somewhat different in GIS structure and coding. Projects on the Forest were transitioning to the use of polygon-based analyses at that time while the Forest Plan was done using grid analyses tools. The accuracy of the volume class mapping was also questioned at that time, which led to the use of volume strata for much of the analyses. These and other factors brought into question how the models were being used, as well as, contributing to them being used in slightly different methodologies. The practical application of wildlife habitat models can be a very useful tool at the Forest Plan scale. However, its application at the project scale may be limited or misleading. The models are often based on conversion of old growth habitats to early successional vegetation. Appropriate values for other than old growth habitat are often not considered, nor very capable of factoring into structure retention or other mitigation measures. (See also, page 3-352 in volume 1 of the 1997 Forest Plan Revision Final EIS for more information regarding use and limitations of habitat models.)

Work to refine or develop wildlife habitat models is ongoing. However, this should be focused primarily for use at the Forest Plan scale. For project planning and management uses, more site specific approaches are needed. Mapping of habitat types or wildlife use areas and how these areas function on that portion of the landscape will be useful for project design, developing treatment prescriptions that are easier to consider short and long term functions, displaying effects including cumulative effects, and in supporting the best reasoned decision making. Models can be applied at the project scale to help identify initial mapping of various habitats, but local knowledge of the project area usually will be needed to provide the best habitat mapping.

For example, deer winter range can initially be mapped in GIS using the deer model. However, this is often limited to the high value deer habitats while the many other areas used by deer in the winter across most project areas are not likely to be mapped very well from the model. Local knowledge will help complete the deer winter range map. From a project design and analysis standpoint, the deer winter range map needs to be further refined to be most usable. In addition to the localized climatic related components like south-facing slopes, lower elevations and maritime influence zones, winter range vegetative components such as types of forage areas, types of cover areas, and types of connectivity zones can be mapped relatively easily. Once they are mapped, they can then be described in terms of how they function across the landscape currently as well as into the future. This information can then be used to help describe current conditions, desired future conditions, and as appropriate in project design and decision making.

A small group made up of biologists, GIS specialists, silviculturists, ecologists, and planners needs to assess the current status and uses of the various habitat models. Representation from PNW will also need to be part of the initial assessment and ongoing model design adjustments where needed.

This assessment needs to address the models for use at the Forest Plan scale and the project scale separately. The project scale assessment needs to take a hard look at the applicability and appropriateness of the models for use at the project or local scale. Biologists from other agencies should be part of this process after the initial assessment. If the models are not appropriate for project scale, the group needs to recommend appropriate and consistent approaches to identify and assess habitats, and to support project design and informed decision making.

A specific assessment of the deer model needs to be made that looks at the clearcut and second growth coefficients based on G. DeGayner’s studies. Other PNW studies that look at forage production in various second growth situations need to be included. Additionally, there appears to be a lack of information on snow interception related to various forest canopy conditions in Southeast Alaska. Obtaining such information could influence the overall operation of the deer model, and such information could also be influential in how deer winter range is managed through time.

• Forest Wildlife Biologist
• PNW Biologists
• Forest Silviculturist
• Forest Ecologist
• Forest Planner

• Assess of the current status of the models and uses of the various Forest Plan old-growth related species models.
• Assessment of the appropriateness of Forest Plan models for use at the project or local scale to support informed decision making.
• Science needs update relative to deer and old-growth related species habitat.