Biodiversity Guidebook Table of Contents]

Biodiversity emphasis options

As natural ecosystems become increasingly modified by human activities, natural patterns of biodiversity become increasingly altered and the risk of losing native species increases (Figure 3). The greatest degree of disruption occurs from extreme habitat modifications such as urbanization and agriculture. Parks and protected areas, on the other hand, if appropriately managed, maintain close to natural levels of biodiversity. Managed forest lands fall between those two extremes, and can support varying levels of natural biodiversity, depending on the management practices. More natural levels of biodiversity will be maintained in managed forests if those forests are managed to mimic important characteristics of natural forest conditions.

Figure 3. The range of management options for maintaining biodiversity.

This guidebook outlines a range of three options for emphasizing biodiversity at the landscape level. Each option is designed to provide a different level of natural biodiversity and a different risk of losing elements of natural biodiversity (Appendix 2):

In reality, these options are points on a continuum, and in between lie a range of options that may be selected depending on the relative priority allocated to biodiversity conservation and timber production in an area.

Applying biodiversity emphasis options to landscape units

Applying biodiversity emphasis options to landscape units across a subregional planning area is a key part of a biodiversity management strategy.

Biodiversity emphasis options can be assigned to landscape units in the following ways:

If no landscape unit has been designated for an area, or an emphasis option has not been assigned for a landscape unit, the default is that the area is managed using the lower biodiversity emphasis option.

To assist with the process of assigning biodiversity emphasis options to landscape units, each unit can be evaluated according to several criteria: topographic and ecosystem complexity, wildlife and fisheries species diversity, significance of key management species and social and economic considerations.

Government has evaluated social and economic impacts against risk to biodiversity on a provincial basis and provided the following policy direction concerning landscape unit biodiversity emphasis assignments within subregional areas. Table 1 illustrates the proportion of the area of a subregional planning unit that should fall under higher, intermediate, or lower biodiversity emphasis. These percentages apply to the provincial forest within the subregional planning unit. For example, approximately 45% (from 30% up to 55%) of the area should fall into the lower biodiversity emphasis category.

Table 1. The distribution of biodiversity emphasis options within a subregional planning area

The intent of this guidance is to limit the impacts of this guidebook, on short-term timber supply, to no more than 4% over the amount specified in the timber supply review, on a province wide basis. If the percentage of area occupied by a biodiversity emphasis option falls within the range shown in Table 1, then it is assumed that the 4% allowable impact will not be exceeded. Subregional planning that results in percentages outside of the ranges specified in Table 1 will have to be evaluated to determine if resultant impacts on short-term timber supply are consistent with government policy direction.

In some cases, large portions of a landscape unit may require a different biodiversity emphasis than the rest of the landscape unit. For example, a low elevation subzone may have a different biodiversity emphasis option assigned than a high elevation subzone. Within a landscape unit, minor areas (up to thousands of hectares in size), may be managed differently from the rest of the unit. For example, a landscape unit assigned a lower biodiversity emphasis option could contain some small protected areas that would contribute to the seral stage and patch size requirements for the landscape unit. Alternatively, stands managed for intensive timber production may be part of any landscape unit, regardless of the biodiversity emphasis option assigned the major portion. (Figure 4).

Concentration of the lower biodiversity emphasis option over extensive, contiguous areas of a subzone or subregional planning area (over several adjacent landscape units, for example) should be avoided as it will greatly impact natural levels of biodiversity in that area. Instead, landscape units with the lower biodiversity emphasis should be distributed across the subregional planning area.

Figure 4. Example of the application and distribution of biodiversity emphasis options for landscape units within a subregional planning area.

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