Weeds and Fire
Exotic Grasses and Weeds
Exotic grasses and weeds spell trouble for sage grouse and healthy sagebrush and grassland country. Cheatgrass is particularly problematic- a non-native grass that spreads easily, dries out early in the season and can lead to hot, big fires that kill sagebrush. The best practice is to keep rangelands as healthy as possible to prevent cheatgrass spread to the point it’s extremely difficult to control.
Cheatgrass- native to the Eurasian steppe- has now become one of the dominant grasses across much of the Intermountain West. The problem? The highly flammable grass leads to frequent and very hot fires that kill sagebrush. This grass changes natural fire conditions in the west, because its’ life cycle differs from most native grasses. Seeds germinate in the fall or early winter, so that the plants grow rapidly in early spring and seeds are produced by early summer. By the time cheatgrass dries out, native bunchgrasses are still green and working on producing their seedheads. Dry cheatgrass not only burns easily, it is carried along a continuous layer of fuel. The natives that have not produced seeds are in trouble, while cheatgrass flourishes after fires. With every fire, cheatgrass becomes more dominant. The fires are so hot that sagebrush often cannot survive them.
When cheatgrass takes over native grasslands and sagebrush, wildlife suffers. Sage grouse have no food or shelter. The pygmy rabbit, too, relies on sagebrush vegetation. The sharp awns (bristles) of cheatgrass seeds are unpalatable to grazers. The seeds attach easily to wildlife (and people’s socks-as westerners know from hiking in cheatgrass!) and spread. Once established, cheatgrass is hard to eradicate.
Effective practices today to keep cheatgrass from spreading include:
- managing rangelands to encourage native species that can compete with cheatgrass;
- managing human disturbances, such as off-highway vehicle use (that spread seeds);
- and replanting to native species following fires.
Early Detection: Best Practice to Prevent Weed Invasions
Invasive and noxious weeds degrade rangelands and habitat for sage grouse. The weeds compete with native and desirable plant species. They increase soil erosion, reduce water quality, and often increase fire frequency. Invasive weeds that are causing problems in the West for sage grouse habitat include cheatgrass, medusahead rye, white-top, leafy spurge, various thistles, and knapweed. Once rangelands are taken over by certain weeds like cheatgrass and medusahead rye, they are extremely hard to eradicate. The best hope for sage grouse is to prevent or hinder the spread of noxious weeds – through early detection and removal, and grazing practices that keep native plants healthy.
Science on the Subject:
Davies, Kirk W., et al, Saving the Sagebrush Sea: An ecosystem conservation plan for big sagebrush plant communities.
Johnson, Dustin D., and Kirk W. Davies, Medusahead Management in Sagebrush–Steppe Rangelands: Prevention, Control, and Revegetation.
Wildfire Poses High Risks to Sagebrush-Steppe:
Accelerated Efforts Underway to Reduce Wildfire impacts
Protection of sage grouse habitat now ranks among the highest priorities driving fire and fuels management approaches in the west, yet large scale wildfires in sagebrush country continue to challenge managers.
Today, you’ll find bird biologists and lead firefighting managers on the same team—sharing maps of priority habitats to save from the flames. While fire is a natural part of the ecology of the sagebrush-steppe, today we have unnatural forces at work, like cheatgrass that fuels fast fires that kill sagebrush and destroy sagebrush habitat in the short-term.
The good news is that more than 95 percent of all wildfires are contained within a day of starting, but the five percent of fires that escape can wreak havoc as the 2012 wildfire season showed. Then, about 2.7 million acres of priority sage grouse habitat burned, killing large areas of sagebrush that the birds depend upon for survival.
In 2015, the U.S. Fish and Wildlife Service will decide whether sage grouse will be listed under the Endangered Species Act. That decision will be based on how well proactive conservation to reduce threats is working.
Slowing the pace and scale of habitat loss to wildfire is not out of reach but will take more hands on deck, working strategically on multiple fronts to come up with both short and long term solutions.
The U.S. Fish and Wildlife Service recently tapped state partners through the Western Association of Fish and Wildlife Agencies to compile existing information on efforts underway and develop a list of actions land managers and policy makers can take to reduce fire impacts — an interdisciplinary team of experts convened in late June, 2013.
For an analysis of how BLM policies have changed dramatically to improve our abilities to save sage grouse habitat, combined with a call to arms for accelerated collaboration, please see the 2013 paper Trial by Fire by Murphy et al.