Invasive plants are harmful non-native trees, shrubs, and herbaceous plants that are spread by global trade, human and animal transport, and gardening. They invade forests and prevent native plants from growing, which can have negative impacts on how ecosystems function, on native vegetation, and native wildlife. 

Many invasive plants cannot be used by wildlife for food which puts grazing pressure on the few native plants that remain. Invasive plants also pose threats to agriculture due to their ability to spread quickly, out-compete crop and forest plants, and deteriorate soil quality. Once they have taken hold, the thick spread of invasive plants makes them costly and time-consuming to remove.