College of Agricultural and Life Sciences
Above ↑This 2003 burn (large photo), the most recent in Gower’s study, shows new green growth, including shoots of willow and fireweed (lower left). The dead trees will remain standing for several years before they tumble over as they did in the 1989 burn shown at upper right.
Fire plays an important role in the forest. The fires that burn 2–3 percent of the boreal forest each year create a patchwork of stands of trees of different ages throughout the region.
Beginning in 2001, Gower identified eight stands that had burned at various times over the last 150 years and measured carbon uptake and release from each site. After three years of data collection, he and his students were able to accurately calculate the net carbon exchange between the forest and the atmosphere.
They found that not all stands perform equally. More recent burns are more productive, says Gower, because the abundance of new growth uses more carbon dioxide. Fire reset the biological clock, he says, and although it releases carbon back to the atmosphere, it ultimately helps increase carbon uptake.