Carbon and water dynamics in Canadian boreal and mixedwood forests: Jack pine in Saskatchewan and mixedwood in Ontario

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Over the next five years, the proposed work will examine the processes that control the exchange of carbon dioxide, water, and energy from selected sites in the Canadian boreal forest zone. A particular emphasis of the work is to study the impact of disturbance and silvicultural practices on the ability of the forest to sequester (capture and store) carbon dioxide. We will measure the fluxes (exchange rates) of carbon, water, and energy (CWE) between the atmosphere and the forest, examine how these fluxes change with season and from year-to-year, and develop a scheme to scale the flux of carbon dioxide from the site to the regional level. The work will contribute to the development of ecosystem models of carbon exchange and to models used to simulate the impact of climate change. Such work is basic to our ability to understand how the likely future climate change will impact our forests. Experiments will be conducted at sites in northern Ontario and northern Saskatchewan. In Ontario, the work will focus on the mixedwood forests located near Timmins. Three sites will be studied: a logged site, a juvenile, improved mixedwood site (17 years old), and an old, fully mature site (76 years old). In Saskatchewan, the experimental work will be conducted on a range of jack pine forest sites that are part of the Boreal Ecosystem Research and Monitoring Sites (BERMS) project. The selected sites are part of a chronosequence representing a series of stages of tree growth from juvenile (12 years old) to mature (31 years old) to old (90 years old). In studying a chronosequence we assume that we can recreate the trajectory of the changing CWE fluxes as the forest regrows after a disturbance. Effectively, we substitute space for time.