Post-fire decomposition of woody material and post-fire habitat structures in the western Canadian boreal forest.

Regions: Dehcho Region, North Slave Region, South Slave Region

Tags: forest fire, species diversity, boreal forests, post-fire ecosystem, tree ecology

Principal Investigator: Sander, Barbara (1)
Licence Number: 12941
Organization: University of Alberta
Licenced Year(s): 1997
Issued: Aug 21, 1997
Project Team: Ian Nalder, one or two field assistants

Objective(s): Fire has been the main driving force in the western Canadian boreal forest resulting in a vegetation mosaic and diverse habitats. It provides an input of coarse woody material (CWM) into the ecosystem, which is an important structural feature of forest habitats. It provides habitat shelter, food and breeding grounds for a variety of organisms. In addition it is important nutrient and carbon stores. The research objectives are: 1) to evaluate the decomposition over time by testing the following hypothesis-CWM of the pre-fire cohort of trees will be decayed after 30 to 60 years, Trembling Aspen will have the fastest decay rate, Black Spruce will have the slowest decay rate, Jack Pine and White Spruce will have intermediate decay rates, 2) to determine the post-disturbance structural diversity between different stand types and different regions in the boreal forest. The proposed study will provide baseline data on the amount and decay rate of CWM resulting from fire in different stand types. This information is important from an ecological management perspective, due to the requirement that forestry operations mimic natural structural and ecological function as closely as possible.

Project Description: Burned areas of different ages have been identified from fire-history maps and data bases provided by the Forest Management Division of the NWT in Fort Smith. Chosen fires are located along the Highways 1, 2 and 5. Access and transportation will therefore be by car/truck. The exact location of the sites will be documented by using GPS-equipment. A total of three sites (Jack Pine, Black Spruce and Trembling Aspen) will be sampled per selected fire. On the sites a total of 40 to 50 samples of wood will be collected. The wood samples will consists of disks approximately 2-5 cm thick. 30 samples will be collected from dead and downed trees, 10 samples from standing dead trees (if still available) and 10 samples will be collected from trees that regenerated on site or survived the fire (the tree sizes will be below merchantable timber sizes). The sampled trees will be chosen randomly using the line interested method. The disks will be taken using only manual saws. No chainsaws or any other powered equipment will be used on site. The research team will consists of 2-5 people, depending on upcoming budget decisions.