Researchers Examine How Invasive Plants Encourage Wildfires

The past decade has seen 77,951 fires burn about 6.7 million acres in the United States. One condition that facilitates the spread of wildfires is invasive plant species. Nonnative weeds can modify the vegetation of a landscape and provide a source of fuel that did not previously exist.

A special feature in the September issue of the journal Rangeland Ecology & Management focuses on the ecological, economic, and social aspects of the interplay between fire and invasive weeds in the cold desert regions of the western United States. The six papers in this special feature provide a synthesis of the existing literature about the impacts of wildfire and invasive plants on intermountain rangelands in the hope that this knowledge will contribute to management strategies that will minimize the future impacts of wildfire and invasive plants.

In the Great Basin region, invasive cheatgrass has spread among sagebrush sites. As cheatgrass becomes dominant, this fine-textured, early-maturing fuel multiplies, increasing opportunities for igniting fires and bringing about more frequent burning.

One article presents the more human dimensions of these forces of nature within the Great Basin. Invasive plants and subsequent wildfires affect the forage available to ranch animals. For the rancher, this can mean adaptation to other kinds of forage, diversification to other forms of income, or even failure in the form of bankruptcy.

An experience with wildfire can change attitudes and behaviors. Rather than adopt cheatgrass as an early-season forage that reduces hay costs, ranchers might make more effort to eradicate such invasive plants. Alternatively, area residents may not be confident that prescribed burning can be achieved with adequate control and therefore oppose such burning proposals.

On the community level, recovery after a wildfire depends on the social, economic, and infrastructure conditions present before the fire. Such natural hazards do not always hurt local economies, largely because of increased spending by firefighters and government funding that occurs during and after a wildfire. But cohesion or conflict can arise depending on how residents view responses to fire and recovery.