February 7th, 2014 by

By John-Miguel Dalbey

Stands of Douglas-fir, commonly referred to as “Christmas trees,” across the Pacific Northwest have been fighting off root rotting fungus for millennia; however in recent years, the rot, combined with other tree diseases, has been killing Douglas-fir at an alarmingly increasing rate. Scientists have begun to suspect that climate change’s effect on the area has led to an increase of these infestations. This effect could possibly be due to increases in temperature, moisture and humidity in the area, combined with decreases in snow and cold weather, all environmental factors in which these fungi thrive. In fact, many worry that this increase in disease could turn the Northwest’s forests from carbon sinks — systems which absorb carbon dioxide — into carbon emitters as the dead trees rot and release their sequestered carbon dioxide back into the atmosphere. Timber companies are worried as well, as the decrease in forest productivity has already begun to drastically decrease profits in the area, by millions of dollars in lost revenue annually.

Douglas-Fir, the species threatened by root rot.

Douglas-Fir, the species threatened by root rot. Credit: Homer Edward Price

One strain of root rot, known as “laminated root rot,” has single-handedly reduced timber harvests between five to 15 percent, a Washington State Academy of Sciences study found. While weakened trees are more likely to be killed by fungus, an infected healthy tree is still left more vulnerable to other threats such as beetle infestation, fire or strong winds. As fungus-infected trees decompose more rapidly than trees killed by other means, they release carbon dioxide and methane into the atmosphere much more rapidly. And as climate change leads to extreme weather events, infected trees will be doubly threatened by storms, wind and flooding. Furthermore, such a large amount of dead, decaying trees in a forest leaves the entire ecosystem vulnerable to fire.

American Forests conducts several Douglas-fir replanting efforts[SL2]  across the Pacific Northwest, whether the cause of deforestation was logging, fire or disease. The Tumblebug Fire Restoration project in particular is one of the larger Douglas-fir restoration projects in effect. This project aims to preserve the delicate Oregon forest system by planting 60,000 Douglas-fir trees across an area in excess of 8,000 acres, damaged by the lightning-induced Tumblebug Fire.