invasive plants

Wildfire is a continual threat in the West, but researchers say an invasive species of grass that’s taking hold in states like Colorado, Wyoming, Nevada could make things worse.

A new species of tumbleweed is more vigorous and invasive than ones we've seen in the past. Its range could spread throughout the Mountain West. 

Matt Lavin / Flickr

According to the Western Governors Association, species like the Canada thistle and common carp aren’t just nuisances -- they’re a matter of western biosecurity.

Jose Hernandez / USDA-NRCS PLANTS Database

In an open field in Longmont, Colorado, about a dozen people crouched in the tall grass, moving slowly and deliberately through mud that squelched underfoot. Some carried huge, serrated knives called hori-hori, a Japanese tool made specifically for gutting weeds. Others wielded gardening shears, saws or chemical sprays as their weapons of choice.

J. N. Stuart / Flickr

The tamarisk plant, also called saltcedar, is infesting waterways across the West. The scaly-leafed shrub can grow taller than a person. It sucks up a lot of water and spits out salt, making the soil around it too salty for other plants to grow.

“It’s very bad, yes,” says Alex Gaffke, a graduate student in land resources and environmental science at Montana State University.