Plumes of black smoke billowing west of Salt Lake City caused a stir Monday as state officials worked to remove stands of phragmites.
Phragmites are a noxious reed that popped up after the record-flood years of the 1980s and quickly began invading wetlands around the Great Salt Lake. The plants are problematic because they drink up vast quantities of water. At their peak, they slurped up 71,000 acre-feet from the Great Salt Lake each year, the equivalent of the Jordan River’s flow for nine months. They also crowd out native plant species, ruin habitat for shorebirds and pose a risk to waterfowl hunters, who can become disoriented in their towering monoculture stands.
The Utah Department of Natural Resources began trying to wipe out phragmites in earnest in 2014. While it’s unlikely resource managers will eradicate them completely, state officials say controlled fires are one of the quickest and most cost-effective tools to keep them at bay.
“We can remove thousands of acres of biomass in a single day for a fraction of the cost of mowing that same site, which can take a month or more to complete,” a spokesperson for the Division of Forestry, Fire and State Lands wrote in an email Tuesday.
There is a limited window to burn phragmites. Winter is too cold and wet to ignite them. Summer is wildfire season, and state officials don’t want to overextend firefighting resources. That leaves spring and fall for burning phragmites, but the state also tries to avoid disrupting migrating birds and their nesting season.
“However, many areas we burn have incredibly dense phragmites,” the spokesperson wrote. “In that case, we may burn during nesting after we have confirmed there is minimal to no nesting activity.”
The Department of Natural Resources only burns individual phragmites patches once per year, but because they are so widespread, that usually means multiple controlled fires each year. The department planned on burning six sites this season, but have only completed five due to nesting birds flying in.
Phragmites spread aggressively via a rhizome root system and by seeds traveling in the wind. Burning helps destroy those seeds. State resource managers also combine burning with herbicide treatments to ensure roots don’t spread.
Some wetland areas use cattle grazing to keep the phragmites down as well, which is useful for opening up bird habitat. But ungulate munching doesn’t permanently remove the reeds.
“Cattle prefer to graze on live phragmites,” the division spokesperson said, “so we cannot use cattle grazing as a method for removing dead phragmites biomass.”
Lawmakers budget $800,000 each year for phragmites removal. This year, the Legislature appropriated an additional $2.2 million toward tackling the invasive reeds. The nonprofit Ducks Unlimited also announced an initiative last fall to raise $100 million for Great Salt Lake conservation projects, including phragmites mapping, alongside Gov. Spencer Cox’s Great Salt Lake Charter 2034.