CLOUD PEAK ENERGY TACKLES CHEATGRASS IN RECLAMATION
Domestic mine article by Harold Hough
It might seem that in the big picture of mine reclamation the type of grass used to reseed reclaimed land is only a small part. That, however, is not the case in the Great Basin and Cloud Peak Energy’s Antelope Mine is at the forefront of a war against a major invasive grass – cheatgrass.
In June, Cloud Peak Energy’s Antelope Mine, located near Douglas, Wyoming, received the prestigious 2013 State of Wyoming Reclamation Award from the Wyoming Department of Environmental Quality, Land Quality Division. The reclamation award was received for the controlling cheatgrass. The Antelope Mine restored 400 acres of reclaimed mining areas dominated by cheatgrass to native plant communities.
Ranchers, farmers, and biologists have been fighting a losing battle against cheatgrass for over 100 years. It came from the Russian steppes and was first found in the US about the time of the Civil War. It moved west, often in bags of grain and has slowly crowded out native grasses in the Great Basin and West.
Although cheatgrass has some nutritional value, it is disliked by farmers, ranchers, and biologists alike. First, it has a dense root system that crowds out and chokes other native grasses. Second, it can germinate either in the fall or spring, which doubles its chances during droughts. Third, it can destroy the native ecosystem and wildlife, while making it hard to graze cattle. Forth, cattle prefer natural species for food.
The major problem is that cheatgrass grows and dies quickly. By dying early in the growing season, it dries out and becomes a threat for wildfires. Grassland that has native grasses is usually liable to be overrun once every 35 – 40 years by wildfire. Cheatgrass lowers that number to 5 years and prevents the reestablishment of the native ecosystem before the next fire. It also makes it that much easier for the next generation of cheatgrass to establish itself over native plants.
Cheatgrass also cheats the local wildlife nutritionally. The natural mix of native grasses grows throughout the growing season and provides wildlife with a constant source of food. Cheatgrass dies earlier, leaving wildlife without food.
Given the hardiness of cheatgrass, it wasn’t an easy task for the Antelope Mine to destroy it and revegetate its lands with native species. It required a combination of animal husbandry and reseeding to accomplish it.
Although overgrazing did originally contribute to the growth of cheatgrass in the West, merely getting rid of the cattle will not help. In fact, studies show that reduced grazing will actually help the cheatgrass because it will leave more dead, uneaten grass and encourage more wildfires – which will give cheatgrass a greater foothold.
The key has been to increase the number of native grasses so that the cheatgrass doesn’t develop the critical mass that allows it to take over. This is what the Antelope Mine has done. They focused on planting grasses that are more resistant to cheatgrass invasion than others.
A key to successful reclamation that inhibits cheatgrass is buying higher quality seed that is less likely to have cheatgrass seeds in it to begin with. When buying seed, mines must pay attention to “Pure Live Seed” (PLS). This is a measure used by the seed industry to describe the purity and percentage of seed that will germinate from that product. For instance, a seed product that is only 75% pure and only has a 60% germination factor has a PLS of 45% while a product with a 95% purity and 80% germination will have a 76% PLS. That means that if former product costs $3 a pound and the latter product costs $4.50, the latter product is still the better buy. This purity is critical because the seed can contain cheatgrass seeds, which will take over and choke the grasses the mine is trying to grow.
Carrying out the reclamation at the right time was also critical for the Antelope Mine. Cheatgrass is most vulnerable in the spring, so this is the best time to try to destroy it and reclaim the ground with native grasses.
Despite the Antelope Mine’s successes, cheatgrass still remains a major threat to the Great Basin grasslands. One technique that is being considered by scientists is a fungus that specifically targets cheatgrass. It also attacks during the spring when the grass is most vulnerable and allows the reintroduction of native species which start germination a bit later. Other molds may also fight cheatgrass at other times of the year. However, at the moment, the work done by the Antelope Mine and Cloud Peak Energy has set the standard for controlling cheatgrass and reintroducing native grasses to the Great Basin.