nonnative

Livestock not native to the desert have grazed and trampled the plants tortoises like to eat, spreading unpalatable nonnative grasses in their wake.

Once a nonnative species gets into an environment, it is often too late to get rid of it, and the focus shifts to containment or long-term management.

Their woes have also been compounded by disease and predation by nonnative trout.

Others blame the nonnative trees for lifting sidewalks and clogging sewer lines with their roots, or are willing to sacrifice the trees to break ground on a project they believe will bring economic vitality.

Additionally, they wrote, some nutrients exist in the lake bed’s sediment and are mixed into the water by waves and nonnative carp.