Recovery of boreal caribou habitat after forest fires

Regions: South Slave Region

Tags: physical sciences, lichen, climate change, caribou, habitat, forest fire

Principal Investigator: d'Entremont, Marc (3)
Licence Number: 16367
Organization: LGL Limited environmental research associates
Licenced Year(s): 2018
Issued: Jul 13, 2018
Project Team: Rosy Bjornson (Resource Management Coordinator, Deninu Kue First Nation)

Objective(s): To measure changes in lichen abundance across habitats impacted by recent and historic forest fires; to predict when habitat disturbed by forest fires becomes functioning again for boreal caribou; and to predict potential implications of climate change on processes affecting boreal caribou habitat supply.

Project Description: In 2015-2016, the Deninu Kue First Nation (DKFN) and LGL (Lewis, Gunn, Livingston) Limited completed a traditional use study on boreal caribou habitat and habitat use that incorporated traditional knowledge and scientific information in the identification of foraging habitat for boreal caribou in the South Slave region of the Northwest Territories (NWT). One outcome of the study was the DKFN elders and harvesters perceive forest fires as a threat to the local boreal caribou population. To expand upon the previous work by DKFN, the purpose of this project is to understand the temporal impacts of forest fires on boreal caribou foraging habitat, and terrestrial lichens in particular, which are an important food source for caribou.

Specific objectives of the project are:
1) to measure changes in lichen abundance across habitats impacted by recent and historic forest fires;
2) to predict when habitat disturbed by forest fires becomes functioning again for boreal caribou; and,
3) to predict potential implications of climate change on processes affecting boreal caribou habitat supply.

The research question will be addressed by measuring the abundance of forage lichens in experimental (burned) and control sites (unburned) in the study area. Data on forest stand attributes associated with these areas will also be collected.

Sampling units for data collection will be a macroplot (30 m x 30 m. Seven transects (30 m) will be spaced within each macroplot at 5 m intervals. One random location per transect will be selected for quadrat sampling, where a 50 cm x 50 cm point frame on adjustable legs with 16 pins (i.e., divided into 25 squares) will be used to collect data on terrestrial lichens. The team are proposing to conduct non-destructive sampling of lichens. At each pin the species or genus and height of lichens will be recorded by lowering a metal ruler perpendicular to the frame. The mean height from the 16 points will be used as the measure of height estimation for each quadrat. Percent cover of lichens at each quadrat will also be measured through several methods: 1) the per cent of squares (out of 25) in the quadrat with the presence of lichen; 2) the per cent of squares with at least 50% cover of lichens; 3) the per cent of squares with 100% cover of lichens; and 4) visual estimation of cover.

Data on forest stand attributes will include crown closure (spherical densiometer), basal area (prism), stand height (measuring tape and clinometer), stand age (tree rings), percent cover of trees and shrubs and vegetation species composition. We will use equations to estimate biomass of lichens at each site. Lichen species presence and abundance will be compared across the treatment areas. Lichen data will be correlated with other forest stand attributes and environmental variables (e.g., fire characteristics – age, severity). Forest stand data will be correlated with the Earths Observation for Sustainable Development (EOSD) land cover descriptions.

The five fire-age categories are distributed across the study area. An ad hoc power analysis indicated that between 125-150 sample plots are required to achieve power of ~0.90, which should be sufficient to detect a moderate effect. Therefore, 20-25 marcoplots will be targeted in each treatment area (5 burned; 1 unburned). Macroplot locations will be randomly selected within each treatment area using GIS. Data collection will be spread across three years and will be completed by two field teams comprised on one LGL biologist/ecologist and two DKFN technicians (six people total). Both teams will work in close proximity to each other. Data collection in year 1 will be at plots that are accessible by road. Access to randomly selected sites that are further from roads will be assessed and access requirements (e.g., foot access, ATV requirements) for years 2 and 3 will be confirmed. Refinements to data collection techniques will also occur at the conclusion of the year 1 field season, with the goal of building efficiencies into the program. Prior to data collection, a safety management plan will be prepared that will include personnel responsibilities, required safety training, a hazard assessment and safe work practices. All field staff will be required to understand all aspects of the safety management plan.

The project is fully supported by the Deninu Kue First Nation, who will be involved in the data collection and will provide logistical support throughout the project. LGL will provide training to DKFN technicians on the fundamentals of field sampling protocols for terrestrial ecosystems.

A final report will be prepared at the conclusion of the multi-year data collection that will be submitted to the NWT Cumulative Impacts Monitoring and the NWT Discovery Portal. It is the intention that this report will be prepared as a manuscript for peer-reviewed publication.

The fieldwork for this study will be conducted from August 1, 2018 August 31, 2018.