Nonnative Species

Buddleja davidii, an invasive flowering species.

National Invasive Species Information Center
U.S. Department of Agriculture

Invasive exotic plants pose a serious threat to the health of ecosystems in protected areas around the globe. These plants can spread quickly, taking over spaces and pushing out native species that are more beneficial. They can lead to a decrease in the variety and number of species by destroying essential resources like food, shelter, and nesting sites for animals, birds, and insects. Additionally, they can affect water supply and soil quality, leading to major economic impacts. Research indicates that extreme climate changes might give certain invasive plants an edge over native ones, especially during severe droughts, which can wipe out some native species while allowing invasive plants that thrive in hot, dry conditions to flourish and reproduce rapidly.

The Southwest Invasive Plant Management Team (SW IPMT) plays a vital role in bringing back damaged native ecosystems and habitats in the Southwest. They collaborate with park staff, National Park Service programs, local communities, and various state and federal agencies to help restore natural ecosystems across 46 NPS units and nearby regions in Arizona, Colorado, New Mexico, Oklahoma, Texas, and Utah. Additionally, the SW IPMT backs global efforts aimed at tackling invasive species, ecological fragmentation, and habitat restoration.

The research conducted by the USGS on invasive species plays a crucial role in assessing risks, preventing invasions, detecting them early, responding quickly, monitoring their spread, and controlling their impact. In the Southwest region, the combination of Mediterranean, montane, and desert climates creates special conditions and habitats that can be taken over by invasive plants, diseases, insects, and animals. Climate changes affect the vegetation in various ways across the dry Southwest, where small thunderstorms during the monsoon season can either provide much-needed moisture or lead to severe flooding, which helps invasive species thrive. Additionally, long-term climate shifts driven by ocean currents can lead to wet or dry periods lasting decades, influencing the growth or decline of these species on a large scale.