NWT RESEARCH DATABASE

Regions: Sahtu Settlement Area

Tags: environmental assessment, biology, vegetation, traditional knowledge, forestry, topography, rare plants, environment

Objective(s): Investigations were conducted in summer 2001 to 2004 to classify vegetation and soils along the proposed pipeline corridor. Further classification of terrestrial resources in 2005 will occur at potential infrastructure and facility sites, access roads, water source sites, and borrow pits as well as along the pipeline where further information is still required. The primary goals for the terrestrial studies are to: classify and map vegetation, landforms, soils, and permafrost in the project area; assess timber volumes for each vegetation type; identify locations of rare plants and uncommon plant communities in the project area; and, conduct soil sampling. Detailed rare plant surveys will occur where the project footprint is reasonably well defined. This information is required to assess the potential impacts of the project to terrestrial resources on a site specific bases, and plan strategies to minimize or avoid impacts to sensitive or valued terrestrial features.

Project Description: During this study, activities conducted will include vegetation mapping, rare plant surveys, rare plant mitigation planning, timber cruising, and landform, soil and permafrost investigations. Vegetation mapping surveys will consist of visual observations from a helicopter to confirm vegetation types for mapping. These surveys will be conducted in conjuction with rare plant surveys. Sampling equipment will include items such as GPS units and cameras. During rare plant surveys, rare plant specialists will survey each site and describe the vegetation community and search for and record rare plant species. Where plants cannot be identified, a sample of the plant will be collected to be identified at a later time. Rare plants will only be collected if the population is sufficiently large enough to allow sampling (i.e., at least 20 plants). A field timber cruise will be undertaken to determine average timber volumes for each mapped vegetation type that supports trees. Tree height and density will be measured for each type of tree at each 20m x 20m site. Sampling equipment will include hand-held items such as: chain saws, hand saws, tree corers, clinometers, prisms, measuring tapes, GPS units, cameras and collecting bags. Soil samples may be collected at select sites where a 15 cm x 15 cm soil pit will be excavated with a spade/auger to a depth of about 0.5, or to the top of the permafrost. The exposed soil profile will be described. The soil pit will then be backfilled with the excavated material and the sod replaced. At some locations, soil samples will be collected for analysis (approx.. 500-1000g). At some locations hand probes will be used to determine the depth of the active layer and to characterize the permafrost immediately beneath the active layer. A local assistant will be hired as part of each terrestrial survey team to assist in observing and recording data taken at survey sites, informing the study team of sensitive or important areas and, if necessary, searching for and recording occurrences of rare plants and helping to identify plants of cultural or traditional importance.