Base de données de recherche des TNO

étiquettes: physical sciences, vegetation, climate change, atmospheric sciences, carbon fluxes, meteorology, carbon dioxide, tundra ecosystems

Objectif(s): To study how carbon dioxide is exchanged between various tundra surfaces and the atmosphere in order to understand how future climate change will impact the land surface and in turn how these impacts might influence the climate.

Description du projet: The specific research objectives are to quantify the variation in CO2 exchange among different tundra types and to explore the potential impacts of climate change on tundra ecosystems. As for the past three summers CO2 exchange and environmental variables (air and soil temperatures, light, precipitation and wind) will be measured at a central monitoring tower. Two satellite towers were added last summer. The equipment runs automatically and is visited a few times a week for data retrieval and maintenance. CO2 exchange from small (0.5m x 0.5m) plots is measured using a portable gas analyzer. The plots are manipulated by clipping the vegetation to simulate the effects of caribou grazing. These measurements are conducted every few days and are confined to a small patch of upland tundra close to the main tower. A series of wood frames for greenhouses is also installed and each spring the houses are covered with plastic sheeting, and temperatures inside and outside the houses are measured. Vegetation surveys are conducted at peak growing season. In addition, the researchers plan to make a visit to the field site in early March 2007 to collect data automatically logged through the fall and winter season and then put the tower in a ready mode for the summer campaign. Copies of any papers that result from the research will be forwarded to the communities and the Aurora Research Institute. The researchers will participate in the 2007 Daring Lake Science Camp and a public information night in Yellowknife in February 2007. Fieldwork will be conducted from March 8 to September 15, 2007 at Daring Lake Terrestrial Ecological Research Station (64.83 N, 111.63 W), specifically at the Main upland tundra tower (64.868 N, 111.575 W), Sedge Meadow tower (64.862 N, 111.571 W), and Island tower (64.81 N, 111.63 W).