(This page is still under construction but still contains useful information)

The protection and maintenance of biodiversity is of global concern. Pack Forest is too small an area to have a significant impact on regional or even many landscape-level biodiversity issues which do not recognize lines of ownership. Until a larger-scale planning approach is developed that involves adjacent landowners and their land uses, Pack Forest will strive to address biodiversity issues within its own limited sphere.

As applied to forest ecosystems in general (and to Pack Forest in particular) managing for biodiversity consists of four distinct yet complementary approaches:

1. Maintaining amounts of all habitats at all times (coarse filter approach, Hunter 1990):

The five stand structures shown below are used as surrogates for habitat types (Oliver and Larson 1996):

For each time period, each stand is classified as one of these structures using the following criteria:

Measurable criteria: Sufficient amounts of each structure are considered as follows:

Savanna structure: 5% of the forest area (217 acres)
Open (stand initiation) structure: 5% of the forest area (217 acres)
Dense (stem exclusion) structure 10% of the forest area (433 acres)
Understory (understory reinitiation) structure: 10% of the forest area (433 acres)
Complex (old growth) structure: 10% of the forest area (433 acres)

(Less area in savanna and open structures is targeted because of the presence of significant areas of open fields, yards, and roadsides in and around the Pack Forest that contain many components of the open structure.)

For example, during one time period, the targets for savanna and open structures are shown by the dashed line and for dense, understory, and complex structures are shown by the solid line. Note that the objective (minimum amount of structure) was met for only two of the five structures.

The objective is to maintain biodiversity over time; therefore, the measurable criteria are the number of 5-year management cycles that the target amounts of each structure are met. In the example below, the savanna target was met during 9 out of 11 cycles. All structures were met in 47 out of 55 cases.

Summary Value: The summary value will be defined as the proportion of times that a structural goal is reached relative to the maximum possible, normalized to a scale of 10. (I.e., 10 = maximum possible amount).

For the example above, in the above chart, the summary value would be:

Caution: Because this algorithm uses cutoff values (5% or 10%) to determine whether a landscape is considered to have a particular structural type, it is possible to have extremely divergent summary values when the relative percent of each structural type is almost identical. For example, if Landscape A, had 4.5%, 4.5%, 9.5%, 9.5%, 72% of each of the structures, respectively, over all years, the summary value would be 2 (a relatively low value for coarse filter biodiversity); whereas if the same Landscape A had 5%, 5%, 10%, 10%, 70% of each of the structures, respectively, over all years, the summary value would be 10 (the highest possible value). It is important to know what the threshold value is and to check the output in light of these issues.

2. Maintaining critical habitats for key species (fine filter approach):
The critical habitats are the "late succession and old growth habitats" and the riparian habitats. Riparian habitats will be addressed by establishing "riparian zones" in which management practices follow state laws. Riparian zones along the major rivers will not be actively managed. (This passive management is because of unique features of the Pack Forest situation.)

The complex structure is used as a measure of the old growth habitat, and both the understory and complex structures are used as measures of "late succession and old growth" habitat.

Measurable criteria: Sufficient amounts of late succession and old growth habitats are considered as follows:

Late succession: 10% of the forest area in understory or complex structure (433 acres)
Old growth: 10% of the forest area in complex structure (433 acres)

For example, during one time period, the targets late succession and old growth structures are shown by the solid line. Note that the objective (minimum amount of structure) was not met for the Old growth, but was met for the Late Succession.

The objective is to maintain these habitats over time; therefore, the measurable criteria are the number of 5-year management cycles that the target amounts of each structure are met. In the example below, the old growth structure target was met in 10 out of 11 cases, and the late successional structure target was met in 21 out of 22 cases.

Summary Value: The summary value will be defined as the proportion of times that a structural goal is reached relative to the maximum possible, normalized to a scale of 10. (I.e., 10 = maximum possible amount).

For the example above, in the above chart, the summary values would be:

Alternative Summary Values: If Pack Forest were expected to maintain "Late successional" and "Old growth" habitats at all times, it may be inappropriate to give credit for providing the habitat for some times, but allowing it to disappear at other times.
In this case, a summary value o "0" would be given if, once the target 20% habitat was achieved, the habitat declined to less than 20%. However, a "0" summary value would not be given if there was less than the 20% target habitat at present, as long as management was increasing the habitat toward the target through time.

If this alternative criterion were applied to the "Old growth" habitat value, the summary values would be calculated as follows:

3. Maintaining Reserve Areas

Reserve areas are typically addressed at a regional scale. For example, there are large "reserves" in the nearby Mt. Rainier National Park; therefore, this issue may not be considered important for Pack Forest. There are several types of reserves:

• Old forest reserves are forests which are already old (>81 years) in which no silvicultural operations are done during the 50-year planning period;
  
• All reserve areas are forests of any age in which no silvicultural operations are done during the 50-year planning period;
  
• Quiet areas, where roads would be closed for one or two decades during the planning period, with silvicultural operations being performed before and after the quiet period. Quiet periods are important for species which are directly or indirectly affected by frequent human activities.

Measurable criteria: Sufficient amounts of reserves will be as follows:

Old forest reserves: 10% of the forest which is currently (2000) 81 years or older and have no active management planned between now and 2050.

All reserve areas: 20% of the total Pack Forest area (including old forest areas) which has no active management planned between now and 2050.

Quiet areas will not be considered as a possible objective because the demonstration and other needs of Pack Forest necessitate continuous access to all parts of the forest.

For example, the target for old forest reserves is met because the forests over 81 years exceeded the solid line, below. The target for all reserves is met because all reserves exceed the dashed line, below.

Summary values: The summary values would be highest (10) if the goals of 10% or 20% were reached. They would be proportionately less if the goals were not reached. They would be calculated by the following formulas:

4. Corridors for Species Movement

Corridors for open species will be satisfied by the road network providing roadside habitats (ref); and corridors for closed forest species will be provided by the forest being in a shifting mosaic of conditions (Oliver et al. 199_)--and not isolated by permanent fields and/or populated areas.

Prof. Chadwick Oliver, College of Forest Resources - content, layout.