The field of carbon and energy dynamics in forests is a very active area of research, driven by the global need to understand the role of the biosphere in our changing climate. The boreal forest is especially important because it covers such a large area and is very dynamic. Our paper presents data from multiple boreal forest sites that include recently disturbed forests. The treatments included both harvesting and fire, important processes that determine the mosaic of forest ages on the landscape.

“The paper describes comparisons of carbon exchange, as well as energy flow, for several different forests in close proximity to each other.”

The paper describes comparisons of carbon exchange, as well as energy flow, for several different forests in close proximity to each other. Hence, it is a synthesis of multiple sites that allows direct comparison under similar climate conditions.

The paper shows that forests lose carbon for a few years after they have been logged or burned by forest fire. However they can recover quite quickly, so that after about a decade they can be taking up carbon dioxide from the atmosphere.

Actively growing deciduous forests generally take up more carbon from the atmosphere than older coniferous forests. The boreal forest is a mixture of different forest ages and tree species, so that we need to know what is happening in all of these types in order to understand the role of forests in taking up carbon dioxide and slowing climate change.

This is a collaborative research paper, with authors from three Canadian universities, two Canadian government departments, and institutes in Japan and Switzerland. The project began as individual efforts in the Boreal Ecosystem Research and Monitoring Sites (BERMS) area of central Saskatchewan.

Measurements at BERMS continued following the famous Boreal Ecosystem-Atmosphere Study (BOREAS) experiment of the early 1990s. However, the collaboration made the comparison possible, and was further integrated after the establishment of the Fluxnet Canada Research Network. My personal involvement began when I was at the Northern Forestry Centre of the Canadian Forest Service in Edmonton, and has continued since my move to the University of Manitoba.

The Fluxnet Canada Research Network ended this year, but the Canadian Carbon Program has begun. I am involved with this collaboration of scientists, and am currently measuring carbon and energy exchange over forests in northern Manitoba. The international Fluxnet community is also synthesizing much of the global information collected at flux towers, and we are also involved with this collaboration.

The potential impact on policy at several levels of government is important. Our data and those of our colleagues has been showing that the youngest forests following fire and harvesting lose carbon for perhaps about the first decade, but can become strong carbon sinks at ages between about 20 and 40 years. Old forests tend to be close to carbon neutral but can be sources or sinks in any given year, depending on climate conditions.

Boreal forests are very important stores of carbon and disturbances have the potential to release carbon. However, this is also part of the renewal process and is important to maintain the boreal forest and preserve biodiversity. Although forests can help decrease climate change, the problem is still caused by fossil fuel emissions, which need to be reduced drastically.