If the plants die, they could create a landslide hazard, in the case of rain, and they often leave behind dormant seeds that can make the invasive species difficult to eradicate, she said.
“That’s why they call them invasive plants,” Evans-Bye said. “They’re really hard to get rid of.”
By creating the maps, the group hopes to encourage officials to begin eradicating the species, which mostly appear along hiking trails that are clear of other plans and give invasive ones an opportunity to settle in, Evans-Bye said.
But even if invasive plants are removed, the native species could face obstacles of their own, Yeva said.
“Now it’s going to be harder to plant the native plants because studies show that, with global warming, the native plants are having difficulty surviving,” she said, explaining that local species might fare better in the future in moist climates farther north, while species native to more southern regions, like Baja California, might become better fits here.