User:Fluxnet Canada
The Fluxnet-Canada Research Network
[edit]Who We Are:
Nearly the entire industrial capacity of Canada is based on the use of fossil fuels. The resulting CO2 emissions will have an increasingly dramatic effect on the climate, the atmosphere, and the ability of our ecosystems to provide sustainable benefits to Canadians. Furthermore, terrestrial ecosystems also play an important role in the absorption and emission of CO2. The Fluxnet-Canada Research Network (FCRN), established in 2002, is making an important contribution to the study of climate change by examining how management practices (harvesting), disturbance (fire) and climate variability influence carbon cycling in Canadian forest and peatland ecosystems. The network’s mission is to develop a scientific framework for reducing uncertainty in estimating the carbon budget of Canada at hourly to multi-year time scales and to contribute valuable scientific information to the elaboration of greenhouse gas management policies in Canada.
FCRN brings together more than 100 scientists, graduate students and postdoctoral fellows from 15 universities and 9 government laboratories and uses tower-mounted meteorological equipment to measure carbon, water and energy exchange in 20 forested and seven peatland ecosystems in seven different provinces. We are developing and rigorously testing simulation models that will predict how climate change will influence the productivity and sustainability of Canada’s forest and peatland ecosystems.
Key Research Highlights:
Disturbances such as fire, insect infestations, and harvesting change the structure of a forest. This in turn affects how much carbon is absorbed by the forest or released into the atmosphere. FCRN studies reveal that:
-Intermediate-aged forests (35-60 years old) have the highest rate of carbon uptake. Stands younger than 10-20 years old tend to release carbon to the atmosphere, whereas older forests, which contain large stores of carbon, may continue to accumulate carbon under favourable circumstances, but at a slower rate than younger forests.
-In Canada, about one million hectares of forests are cut each year. Recently harvested sites in coastal British Columbia and boreal Quebec released an average of 6 and 1.4 tonnes of carbon/ha per year, respectively. An average Canadian automobile emits ~ 1 tonne of carbon annually.
Determining the factors that govern the time required for a forest to become a net carbon sink following disturbances such as harvest or fire is an important priority for FCRN. For example, our measurements indicate that a Douglas fir forest harvested and planted 17 years ago is on the verge of switching from a net carbon source to a net carbon sink.
-A five-year study showed that the amount of carbon absorbed by Douglas fir forests in British Columbia was influenced ten times more by age since disturbance than it was by year to year differences in climate within a given age class.
-Broadleaved species colonize many coniferous forest sites after fire, changing the amount of sunlight reflected back to the atmosphere by the leaves in summer and causing higher reflection from snow on the ground in winter. This has a cooling effect on the atmosphere.
Northern peatlands contain 25% of the world’s soil carbon and play an important role in global carbon exchange. FCRN work in a variety of wetland systems has indicated that:
-When information from our flux measurements in wetland ecosystems was incorporated into a national-level carbon model, the estimate of annual carbon uptake over the last 20 years increased by about 50 million tonnes.
-Over a six-year measurement period, a bog in eastern Ontario absorbed an average of 0.4 tonnes of carbon per hectare annually and was a carbon sink in all but the driest year.
-During a cool year, an infertile fen, dominated by evergreen moss, absorbed three times as much carbon as a fertile fen containing grass-like plants. However, in a warmer year with better growing conditions, the situation was reversed. The fertile fen was able to produce leaves earlier in the season, photosynthesize for a longer period and, consequently, absorb more carbon than the infertile fen.
Climate change is associated with warmer temperatures, altered precipitation, and elevated atmospheric CO2 concentrations. FCRN research has shown that:
-Greater carbon uptake is associated with warmer spring temperatures.
-Deeper snowpacks insulate the soil and keep it from freezing in winter. Warmer soil temperatures contribute to greater soil respiration and microbial decomposition, thus resulting in greater emissions of carbon from the soil and lower net carbon accumulation by the ecosystem.
-A Saskatchewan aspen forest absorbed carbon at an increased rate in the initial stages of a three-year drought because dry soils limited carbon loss by respiration. However, as the drought progressed, the ability of the aspen forest to accumulate carbon decreased dramatically.
Benefits to Canada:
The greenhouse gases that are altering the Earth’s climate are released into the atmosphere as a result of human activity. Burning of fossil fuels by Canada adds around 140 million tonnes of carbon (as carbon dioxide) to the atmosphere each year. Research being done by Fluxnet-Canada estimates that the Canadian land surface was capable of absorbing around 60 million tonnes of carbon in 2003, or 43% of Canadian fossil fuel CO2 emissions. However, this percentage should vary dramatically from year to year as a result of variability in climate and forest disturbances. Carbon storage might be increased through improved management of forest and peatland ecosystems. Due to its vast land area and natural resource based economy, it is important for Canada to take a leadership role in carbon cycle science. The scientific framework provided by Fluxnet-Canada research will enable policy makers to use improved simulation models to develop strategies for adapting to and mitigating the effects of climate change.
Fluxnet-Canada Research Network
Pavillon Abitibi Price
Université Laval
Québec, QC
G1K 7P4 Canada
Email : fluxnet.canada@sbf.ulaval.ca
Web Site : http://www.fluxnet-canada.ca[1]