Move this drama to St. Francis Xavier’s University’s Environmental Sciences Research Centre (ESRC) in Antigonish, Nova Scotia. The patient is the planet Earth. Dr Lisa Kellman, the newly appointed Canada Research Chair in Environmental Sciences, is the attending doctor. She’s keeping tabs on the temperature of the soils of Atlantic Canada forests to measure greenhouse gas emissions and to co-relate them with the changing activity of forest management practices.
“Basically, if you increase the temperature of the soil, you increase the rate at which dead organic matter in soils is converted to CO2 and returned to the atmosphere,” Kellman explains. “When you cut the trees, the soil warms up.”
Other important controls of the decomposition rate in soils include the amount of moisture, quality of the organic matter, and nutrient status. Researchers analyze how these various factors operate together to control rates of decomposition, and therefore the rate at which CO2 is emitted to the atmosphere.
Kellman’s group is particularly interested in measuring and analyzing these vital signs of the soil. Instead of relying on surface readings, the group probes into the soil to detect any changes in the quantities, qualities, and distribution of organic carbon, as well as the associated variances in the release of greenhouse gases. The work will also involve the testing of samples in the laboratory to link these findings with what is being done above ground.
So why does any of this matter? With so much CO2 spewed by automobiles and factories in the world today, surely a little gas from forest-decaying material can’t be all that bad. Isn’t composting a good thing?
Not necessarily. First of all, soils hold approximately twice the mass of carbon than the atmosphere. Depending on variables such as temperature, moisture level, and type and quantity of dead material, the soils can hold several times the mass of carbon that is stored in aboveground vegetation. So when we talk about CO2 levels, we must consider the balance between the carbon stored in soils versus the atmosphere.
The giant forest ecosystem that covers roughly 35 percent of Canada has been dubbed North America’s “giant lung,” inhaling CO2 and exhaling oxygen. Carbon naturally accumulates in forest soil. As long as the forest cover keeps the soil cool with vegetation, the area collects more carbon than it emits.
If the vegetation is severely disturbed however, the soil loses that protection. As it warms up, the CO2 and other greenhouse gasses are released into the air. In fact, forest soils that have been disturbed by bad forestry practices, fires, or disease are the largest source of human-induced emissions. That’s why Kellman and her students focus on the soil, its temperature, and other decomposition controls. It tells them if and how human activities alter the exchanges between the soils and the atmosphere.
“By measuring and quantifying these changes, we are in a better position to make predictions and therefore make decisions that will minimize disruptions to natural systems,” says Kellman.
Benefits
This year for the first time, climate change has taken centre stage at a G8 summit. World leaders have committed to “act with resolve and urgency to reduce greenhouse gas emissions, improve the global environment, enhance energy security, and cut air pollution.”
Kellman’s research supports Canada’s contribution toward this action. Important advanced scientific knowledge about carbon storage in forest soils in the Atlantic Provinces will be a resource for negotiating land-use changes and forestry provisions of the Kyoto Protocol and will help in the implementation of the government’s Climate Change Plan for Canada.
“We need to develop a good scientific-based understanding of the complex processes that contribute to the release of greenhouse gases from terrestrial ecosystems,” Kellman advises. “By investigating how human activities alter the biogeochemical cycling of carbon and nitrogen in these systems along with the consequences for the release of greenhouse gases, we will be in a better position to make future predictions and implement mitigation measures.”
Dr Mike Lavigne of the Canadian Forestry Service agrees. “In the short term, the knowledge that we gain from research such as Dr Kellman`s will help the nation decide how to meet its Kyoto commitments. In the longer term, it will contribute to a better understanding of the role of forests in controlling the rate of climate change.”
Partners
Currently, the forest industry is uncertain whether the short-term supply of wood will increase or decrease with the changes in climate due to greenhouse gasses. However, it recognizes the need to respond to the changing biogeochemistry of the soil and to adapt the forestry management practices accordingly in order to sustain a wood supply and a forest industry in the future. Kellman’s research will lead to more accurate predictions of the impact of climate change on managed forests and on the supply of wood for forest industries.
This is why the industry has been extremely cooperative with Kellman’s research. Stora-Enso and Kimberly-Clark, two of the leaders in the Atlantic scene, consistently provide Kellman’s students with access to field sites and computerized models. In one anticipated project, a Master’s level student will be involved in testing and evaluating an industry model for maximizing carbon storage in forest soils. The quest for sustainable forest practices is what joins these students of the environment to the industrial giants.
In a collaborative effort with Dr. Hugo Beltrami, also of the ESRC, Kellman is involved in the operation of a network of climate monitoring stations around Nova Scotia, collecting above and below-ground climatic data. Using state-of-the-art equipment, they can examine the chemical elements (isotopes) of the data collected, which may provide a clearer insight into the processes that contribute greenhouse gases to the atmosphere.
All in all, Kellman’s prognosis is good, “as long as we take the time to understand and manage the process,” she cautions.
Learn More
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