Adaptive Management Projects

Project Summary: Donna Creek Biodiversity Project

The Testing of Alternative Timber-harvesting techniques designed to benefit cavity-nesting birds and mammals

Peace/Williston Wildlife Compensation Program

Contacts:
Mari Wood (Peace/Williston Wildlife Compensation Program)
Fraser Corbould (Peace/Williston Wildlife Compensation Program)

Background:
The Donna Creek Biodiversity Project was initiated in 1990 as a cooperative venture of the Peace/Williston Fish and Wildlife Compensation Program (a joint initiative of B.C. Hydro and B.C. Environment) and Fletcher Challenge Canada Ltd. This project was designed to test whether maintenance of 3-m tall high stumps (stubs) and small residual tree islands benefit cavity-using animals within clearcuts.

Objective:
The Program's mandate is to protect and enhance fish and wildlife resources affected by the construction of the W.A.C. Bennett dam, and the subsequent creation of the Williston Reservoir.

The aim of the project is to develop and test alternative timber-harvesting techniques designed to benefit tree-cavity-nesting birds and mammals.

The primary objectives of the project are:

• To test for differences in use by cavity nesters and by other breeding birds between conventionally clearcut blocks, old growth control areas and blocks cut with three modified techniques.
• To test for differences in use by furbearers between conventionally clearcut blocks, old growth control areas and blocks cut with three modified techniques.
• To document the deterioration of various species and sizes of snags over time.
• To document the characteristics of nesting and feeding trees preferred by cavity nesters.

Cavity nesting birds - The primary objectives of this portion of the Donna Creek Biodiversity Project was to determine breeding bird responses to two alternative forest harvesting techniques -- the retention of residual tree islands and creation of 3-m stubs within clearcuts. By comparing breeding bird densities (numbers of detections per unit area) between these experimental timber-harvest treatments, and between the treatments and Old-Growth control forests, the responses could be measured. Cavity-nesting birds were the focus group for this study since the alternative harvesting techniques have been proposed to mitigate the effects of clearcutting on them in particular, but data were also collected for breeding passerines.

Experimental Design:
There are three clearcut study areas, each measuring 100 ha in size. The areas are divided into 4 sections of 25 ha each. Each of the 4 sections contains a different harvesting treatment. The four treatments are:

1. Clearcut (CC) - No stubs-no tree islands
2. Stub (SB) - Stubs but no tree islands
3. Tree-Island (TI) - Tree islands but no stubs
4. Stub-and-Island (SI) - Stubs and tree islands

In addition, there are three areas of clearcuts with a section of 25 ha of clearcut only, no other treatments are present in the 100 ha area. This is to prevent any effect the other treatments may have on the results measured in the other 3 clearcut study areas.

In order to determine the affect/benefit of alternative harvesting methods for wildlife, a number of different monitoring phases are being studied (birds, furbearers, decay rate of 3-m snags - at what point do they become useful to wildlife?). Within these plots (3 of each treatment) bird surveys, furbearer surveys and snag decay wildlife interactions are being monitored to detemine which treatments are the most beneficial.

Monitoring:
Bird Surveys - Bird surveys are done in the spring (breeding bird surveys). Doing point counts instead of transects as in the past for the spring 1995 and spring 1996 bird surveys.

Furbearers - Surveys take place in the winter (track surveys).

Snag Surveys - The marked snags will be periodically re-examined - Attributes sampled included: species, site position, D.B.H., height, decay stage (based on a 9 class system developed by the Wildlife Tree Committee of B.C. which takes into account the heartwood, sapwood and root conditions), top condition, and % bark remaining. In addition, data was also collected on the use of these trees by wildlife species (cavity nesters, feeding signs, perching etc..).

Time Frame:
Minimum 10 year project

Current Status:
Bird Surveys - Preliminary studies in 1993. Will sample again in spring of 1995 and 1996. Need two year data toaccount for annual variation, then not again for 5-10 years. Improvements will be made on methodology each year (i.e. transect surveys changed to point counts).

Furbearer Surveys - Furbearer track surveys were conducted in January and March 1994. They were sampled by a BC Hydro crew. Next year they will use a local trapper.

Snag decay Surveys - In the summer of 1994, vegetation, snag and island assessments were conducted. Mari and Fraser Corbould will resample snags and snag use in August, 1995. Last year, the program tried to get P.G. Naturalist Club involved in snag monitoring - may work out this year.

References:

Gyug, Les and Ken Summers. 1995. Donna Crk. Biodiversity Project: Preliminary Breeding Bird Surveys (1993) - Technical Report. Peace/Williston Compensation Program, Prince George, B.C.

The Peace/Williston Nature Line (Newsletter). No. 3, October, 1992 and No. 6, Winter, 1994/1995.

Murray, L.J. 1992. Cavity Nester Habitat Selection Project Phase 3 Report: Map Preparation and Transect Layout (Status Report). Peace/Williston Compensation Wildlife Program. Prince George, B.C.

Wood, M.D. 1992. Donna Creek Biodiversity Project (Cavity Nester Habitat Selection) 1992/93 Progress Report. Peace/Williston Compensation Wildlife Program. Prince George, B.C.

Dawson, R.; L.J. Murray; and M.D. Wood. 1992. Wildlife Tree Maintenance and Creation in Managed ESSF Forests in the Mackenzie District (Working Plan). Peace/Williston Compensation Wildlife Program. Prince George, B.C.

Murray, L.J. 1992. Cavity Nester Habitat Selection Project Phase 1 Report: Snag Deterioration (Status Report). Peace/Williston Compensation Wildlife Program. Prince George, B.C.

Corbould, F.B. 1994. Donna Creek Winter Furbearer Survey (Status Report). Peace/Williston Compensation Wildlife Program. Prince George, B.C.

Wood, M.D. 1994. Donna Creek Biodiversity Project (Progress Report: 1993/94 and 1994/95). Peace/Williston Compensation Wildlife Program. Prince George, B.C.