Base de données de recherche des TNO

Régions: Inuvialuit Settlement Region, Gwich'in Settlement Area

étiquettes: physical sciences, vegetation, forestry, monitoring

Objectif(s): To determine what conditions facilitate tree range expansion across the western Canadian boreal-tundra ecotone.

Description du projet: The overarching research goal of this project is to determine what conditions facilitate tree range expansion across the western Canadian boreal-tundra ecotone. Using a biogeographical, multi-trophic level approach, the research team aim to determine: 1. how multi-trophic level species composition changes across the tundra and which conditions dictate these changes; and, 2. the constraints, driven by community structure, trophic interactions, and disturbance, on tree establishment for boreal-tundra ecotone tree species (Picea mariana and Larix laricina) at different latitudes. The research team will employ a large-scale, multi-factorial sampling effort by establishing three latitudinal transects that cover low, mid and high latitudes respectively (Transect 1: Dawson City to Eagle Plains, YT; T2: Eagle Plains, YT to Fort MacPherson, NT; T3: Fort MacPherson to Tuktoyaktuk, NT). Within each transect, the team will sample sites across high and low elevation, as well sites that are dominated by both forest or tundra vegetation. To gain an understanding of community composition and diversity throughout the boreal-tundra ecotone, the research team will assess community composition, species diversity, and species abundance at five trophic levels (invertebrates, vertebrates, vascular plants, non-vascular plants, and soil microbiota). All sites will be instrumented with pit-fall traps, track tubes, and animal trap cameras to provide quantitative data on invertebrate and vertebrate communities. Vascular and non-vascular plants will be identified in five 1m2 quadrats at each site. Soil samples will be taken next to each quadrat. The research team will obtain a quantitative measure of microbial groups within the soil samples using Phospholipid Fatty Acid Analysis at Memorial University. At each site, the team will measure active layer depth (ALD), air and soil temperature, snow depth, and soil properties. ALD will be measured yearly in late summer to ensure maximum thaw depth. Soil properties to be assessed include organic layer thickness, soil pH, soil moisture, and soil nutrients. Stations measuring snow depth and air and soil temperature will be installed at each site. Through assessing community composition and diversity and measuring site-specific variables, the team will be able to determine the physical site factor(s) that dictate(s) species composition and diversity as well as how the driving factor changes with latitude. To test the constraints on tree seedling establishment, thus informing treeline range expansion, at different latitudes, the team will establish a seeding experiment using Picea mariana, Larix laricina seeds, and Picea glauca and will measure the same physical site conditions as above. The research team will individually test the role of seed limitation, herbivory, and disturbance in a multi-factorial seeding experiment. The role of herbivory will be tested with exclosure cages. The team will test the role of disturbance in two ways. First, the team will sow seeds at sites that burned in 2017. Second, in sites that have not been naturally disturbed, the team will manually scarify the substrate. The team will also use paired burned-scarified plots to test how well scarification treatments represent burned conditions. The research team are interested in having Aurora Research Institute (ARI) students or community members join the team out in the field to learn about what the team are doing and to share knowledge. Incorporating a traditional ecological knowledge component and learning from community Elders is something that the team would like to incorporate into the project. The team will use the following approaches to engage with community members. Local communities and Band’s will be contacted prior to arrival in the NWT to find out if and how the team can work in and around their community and to what level they would like to be involved. Additionally, the team will aim to be actively involved with ARI throughout the time in the Inuvik region and will be interested in participating in any ARI research events or workshops. Given the field methodology that the team are planning to implement, a continuing commitment to northern capacity building would be to establish these sites as long-term monitoring sites. The research team would train community members in methods of ecology and environmental science, while providing critically needed long-term data on northern ecosystem change. Sites close to communities would provide knowledge on ecosystem change in systems that are directly affecting community members by examining changes in biodiversity and community composition over time. The research team will make yearly presentations in the communities near where the work is taking place (i.e., Inuvik, Fort McPherson, Tsiigehtchic). The team will seek to inform community members of what is being studied and how the team expect the results to be applicable and of interest to them. For previous work that the team has completed throughout the NWT and Yukon, these community presentations have involved showing pictures of sites and explaining our methodology and what the team hope to learn as a result of the project. Additionally, the research team would like to make connections with the Gwich’in Renewable Resource Board and ARI. The team would plan to be actively involved with these stakeholder groups and would work with them to create meaningful results for communities in the NWT and to share and communicate the results. The research team will be cognisant of meeting any requirements that are held by Bands or communities in exchange for working on their land. At the conclusion of our project (2021), the team will provide a written report to all NWT and Yukon stakeholders in the research. Finally, the team will provide copies of all peer-reviewed scientific publications that arise as a result of this research. The fieldwork for this study will be conducted from June 1, 2019 to September 1, 2019.