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.