Related Topics (module 3, p. 8)

Related Topics

A fundamental premise for maintaining biological diversity is to implement strategies at both the landscape and stand scales. There is a linkage between

  1. How much retention of stand structure is required at the stand scale;
  2. How much should be retained at the landscape scale

There are two tables that are used to calculate the percentage required as wildlife tree patches.

Table 1-A — When landscape units are designated and landscape level biodiversity objectives are established, then the requirement for maintaining biodiversity in individual stands can be reduced and the appropriate retention levels determined from Table 1-A.

Table 1-B — When no landscape unit biodiversity objectives is established, then appropriate retention levels are determined from Table 1-B.

The use of Table 1-A is a one-time calculation (within a harvest rotation length) for each biogeoclimatic subzone within the landscape unit unless the landscape unit objectives change, a new landscape unit is designated, or operability limits change (changing the area available for harvest).

A separate objective is made for each subzone within the landscape unit.

Explanation for Tables

Columns: The proportion of the subzone within the landscape unit (or forest development plan) that is identified as available for harvest. The Y-axis.

Rows: The proportion of the available landscape (by subzone) that has already been harvested without application of the Landscape Unit Planning Guidebook (LUPG) and/or Provincial Wildlife Tree Policy and Management recommendations or similar prescriptions. The X-axis.

For each biogeoclimatic subzone in the landscape unit (Table 1-A), calculate the area available for harvest (the X-axis).

An example using Table 1-A

For example:

If 30% of the SBSmc subzone area* is available for harvest, then, using the 30% column, the recommended minimum proportion of each cutblock to be managed for wildlife trees is between 1 and 9%.
* SBSmc subzone area — Sub Boreal Spruce (moist continental)

If 50% of the available area in the subzone were already harvested without application of these or similar guidelines (Y-axis), then 5% of each new cutblock would need to be left for wildlife tree patches.

Where landscape units have not been designated, the same calculation can be done using Table 1-B.

The purpose of a no-work zone is to protect workers from tree hazards in situations where the danger tree or parts thereof have not been removed. NWZs are generally 1.5 times the height of the danger tree length. This length can be modified (larger or smaller) depending on site-specific conditions.

When the decision has been made to retain a valuable wildlife tree that has been assessed as dangerous to workers, a no-work zone must be clearly identified and marked on site. The no-work zone must include all the area on the ground that could be reached by any dislodged portion of the tree.

No-work zones will take into account the nature of the hazard and the lean of the tree. On steep ground, the no-work zone will be extended downhill to protect workers. No-work zones can be adjusted in size depending on the size of surrounding live timber (e.g., a small tree surrounded by much larger trees that shield the adjacent area have a NWZ radius less than 1.5 defect lengths. A kickback area should be included for semicircular no-work zones. The size and shape of this area is determined by tree lean, condition, and form (branching). 

See the Wildlife/Danger Tree Assessor's Course (No-Work Zones (NWZ) for detailed information.


The Wildlife Tree Committee (WTC) is a multi-agency committee composed of representatives from the government ministries as well as the BC Workers' Compensation Board, industry and labour, and public interest groups from across the province. Formed in 1985, the WTC is the advisory body acting on behalf of the three signatory agencies and representing all wildlife matters in British Columbia.

The Wildlife Tree Committee mandate is:

To promote the conservation of wildlife trees and associated stand-level biodiversity in a safe and operationally efficient manner, in forest, park, and urban environments.

Two major objectives of the WTC are:

  1. To ensure the maintenance and enhancement of wildlife trees in order to sustain the species dependent on them (about 80 species, or 15% of the province's birds, mammals, and amphibians 
  2. To foster cooperation and understanding between the various interest groups

The WTC believes that managed forests, high standards of worker safety, and maintenance of valuable habitat for wildlife tree-dependent species are mutually compatible if cooperative action is taken to integrate these goals.


There are two parts to recall — modifying the mind map and answering the set of questions some which are listed at the beginning of the module. Begin by returning to the mind map that you started at the beginning of this module and using a different colored pen add what you have learned during this module. This may mean that you add facts or ideas, modify some, or correct others. This is an important step in your learning process. You need to recognize what you learned, what you have modified, and what you had to correct because of misinformation.

  1. Do you now better understand the role that the six stand level components play in forest biodiversity? If not, what do you have to do to assist in your understanding?
  2. Are you able to list and describe the six stand level components of forest biodiversity? If not, what do you have to do so that you can?
  3. Are you able to identify several forest management applications for each of the six stand level components? If not, what do you have to do so that you can?
  4. Are you able to describe the role of stand level in forest biodiversity? If not, what do you have to do, so that you can?
  5. Do you now recognize the management strategies used within forest biodiversity — stand level components? If not, what do you have to help you to recognize them?
  6. Are you able to list several recommendations for the two management strategies of wildlife trees? If not, what do you have to do so that you can?
  7. Will you be able to utilize the applications to forest management as a forest manager? If not, what else do you need to do so that you can?

If you completed the three application assignments (or fewer), answer these questions:

  1. How successful were you in assessing an old growth forest using the stand level components tools?

  • If you need more practice, when will you get it?
  • If you need help, where will you go for it?
  1. Were you able to formulate recommendations for managing a harvest site?
  • If not, where will you go for assistance?
  1. How successful were you in preparing a plan for harvesting a future logging site using good forest management practices?
  • Did you give it to someone for assessment?
  • What else do you need to know before preparing another plan?
  • Where will you go for this help?

Transfer of Learning

  1. Think of 3 – 5 ideas or concepts discussed here that you could use in your work. 
  2. If you are a forest manager, how will you incorporate the ideas in this module into your role as manager? (List  3 – 5 ideas.)
  3. If you and a five-year old child were walking in a forest and you had to explain to him or her about creating wildlife trees, what you would say?
  •  About worker safety
  • About standing dead trees


  1. What topics do you need to learn more about? Where can you locate them? 
  2. How are you now thinking about six stand level components that may be different or modified from before?
  3. Think about how the six stand level components of forest biodiversity are like music.
  • Think about music in it many forms-notes, how it is played, with what instruments, how it is written, uses of music including medical, functions of music, etc. 
  • Think about how the six stand level components of forest biodiversity are not like music.