Base de données de recherche des TNO

Régions: Inuvialuit Settlement Region

étiquettes: physical sciences, environmental assessment, permafrost, climate change, limnology

Description du projet: Climate change is expected to have the greatest impacts in northern regions. Permafrost degradation is a likely outcome of warming temperatures. As temperatures increase and permafrost begins to melt, there is likely to be significant impacts on aquatic communities as nutrients and contaminants accumulated in permafrost are released into lakes. This study will examine the impact of permafrost degradation on lake ecosystems through the analysis of diatom communities living in the lakes. Lake sites will be sampled in the winter of 2006. At each site, a small auger hole will be cut through the ice and sediment cores will be extracted from the lake bottom. A sample from the top 40 cm of sediment from each lake basin will be taken. The sites will be accessed by snowmobile and helicopter. Another part of this research will focus on the forests of the Mackenzie Delta. A number of studies to examine the impacts of climate change on forest ecosystems are proposed. Previous dendrochronology work indicates that some trees are growing slower. During the summer of 2006, the relations between tree growth and climate will be examined using manual and automatic band dendrometers. Sampling will be focused at the site referred to as Blueberry. Six automatic dendrometers and twenty manual dendrometers will be attached to trees at the site. These will be monitored throughout the summer. The growth of the trees will be monitored every fifteen minutes by the automatic dendrometers. These growth records will be compared with climate data collected at the Inuvik airport. Two small cores (diameter of ~4 mm) will be removed from each tree using an increment tree borer. The dendrometers will be removed at the end of the growing season. The recent establishment of white spruce along a north-south transect in the Mackenzie Delta will also be examined. The sites lie along the East Channel. At each site a number of 20 x 20 m plots will be established and the number of white spruce saplings counted. Year of establishment for each sapling will also be determined. Some larger saplings may be cored to accurately determine their age of establishment. Access to field sites will be by boat. Publications and theses arising from this research will be shared with community organizations through the Aurora Research Institute. This study will be conducted from June 8 to December 22, 2006 at the following locations: Lake sites: Lake 4A (68° 30’ 58”N 133° 39’ 36”W), Lake 4B (68° 30’ 52”N 133° 39’ 08”W), Lake 5A (68° 33' 04"N 133° 38' 24"W), Lake 5B (68° 32’ 15”N 133° 39’ 28”W), Lake 7A (68° 36’ 18”N 133° 35’ 26”W), Lake 7B (68° 36' 31" N 133° 35' 13"W), Lake 10A (69° 07’ 07”N 134° 10’ 07”W), Lake 10B (69° 07' 13"N 134° 10' 49"W); Tree ring sites: Blueberry (68° 25’00”N 133° 50’05”W), Timber (68° 24’00”N 133° 48’40”W), Bombardier Channel (68° 24’30”N 133° 50’00”W), Delta Hill (68° 24’20”N 133° 49’00”W), East Channel (68 °22’30”N 133° 47’00”W), Airport site (68° 18’00”N 132° 18’00”W ).