Decades after fire and tree-cutting devastated the forest in Flin Flon, Man., researchers are trying to solve the mystery of why the forest has not grown back.
"Natural revegetation has been slow, so we want to help speed it up and encourage growth of natural boreal forest species," said Jordan Hamilton, a University of Saskatchewan soil science master's student.
Using the Canadian Light Source synchrotron, Hamilton worked on a key piece of the puzzle by analyzing metals found in the soil. He focused on zinc, the metal most responsible for plant toxicity in the area.
"Jordan used the synchrotron to collect the chemical fingerprint of contaminated soil," said Derek Peak, who co-supervised Hamilton's project with fellow soil scientist Richard Farrell.
"Those detailed measurements help explain the larger landscape."
Hamilton's research is part of a larger ongoing project supported by the Natural Sciences and Engineering Research Council and Hudson Bay Mining and Smelting (Hudbay). The aim is to revegetate the Flin Flon site, which serves as a giant outdoor laboratory covering about 10,000 hectares.
Hudbay has operated a zinc and copper processing facility in Flin Flon since 1930. Several years after the mine opened, a large forest fire destroyed much of the nearby forest. Many other trees were cut for fuel and lumber when the smelter complex and the communities of Flin Flon and Creighton were first established.
The mining and smelting facility has kept up with ever-changing regulatory standards, but soil in the area shows the effects of heavy metals, erosion, and acidity, which hinder the ecosystem's natural recovery. With the loss of plant cover, the thin layer of topsoil became exposed and washed away, making it more difficult for plants to take root.
Hamilton's findings will provide future strategies for faster and more efficient revegetation.
One technique is to add "amendments" - such as fertilizer, compost and peat moss - to improve the soil's ability to support plant life and add nutrients, capture toxins or improve drainage.
Researchers and volunteers with the community's Green Project have been working to revegetate the area for over 10 years. They began by using limestone to raise the soil's pH. This yielded mixed results, deepening the mystery of what was preventing growth.
Researchers then added other amendments including biochar - a type of charcoal made from biological ingredients such as wood and bone - and zeolite, a mineral that can absorb metals.
Using synchrotron analysis, Hamilton examined the forms of zinc present in soils treated with various combinations of amendments and then compared these with samples from untreated soil. He found that whether a particular section of land responded well to the amendments depended on the form of zinc in the soil.
"While others have looked at the resulting plant growth, I'm looking at what those amendments did to the metal in the soil. My goal is to find out whether the metal changed and whether that change made the metal less toxic," Hamilton said.
He will use the synchrotron again during his PhD as part of a larger project aimed at developing bio-char from northern-based resources. He will work on a test site at a former petroleum storage facility in Meadow Lake to find improved methods of managing the effects of petroleum on soil and groundwater.
"I've always been interested in environmental research, and the synchrotron is an ideal facility," Hamilton said.
Lisa Buchanan is a graduate student intern in the U of S Office of Research Communications.
This article first ran as part of the 2012 Young Innovators series, an initiative of the U of S Research Communications office in partnership with the Saskatoon StarPhoenix.