Invasive Plant Projects

Exotic plants take a heavy toll on biodiversity around the world. In the United States, exotic plant species invade tens of thousands of hectares every year, outcompeting native species and causing many to become threatened or endangered. Fire, flood, and other natural disturbance regimes can also be altered by exotic plants, broadly affecting land management.

In 2002, the Chihuahuan Desert Network supported a two-year inventory of the vascular plants in Amistad National Recreation Area by the Wildlife Diversity Program of the Texas Parks and Wildlife Department.

National parks, like other publicly managed lands, are deluged by new exotic species arriving through predictable (e.g., road, trail, and riparian corridors), sudden (e.g., long distance dispersal through cargo containers and air freight), and unexpected anthropogenic pathways (e.g., weed seeds mixed in with restoration planting mixes).

Saguaro National Park is located in the scenic southwest Sonoran Desert. Visitors from around the world are drawn to the park’s iconic southwestern landscape, characterized by a wide diversity of plants and animals including the giant saguaro cactus. Today, this desert is becoming increasingly threatened by buffelgrass (Pennisetum ciliare), a perennial grass native to Africa.

Invasive exotic plants represent one of the most significant threats to natural resources in U.S. national parks today. They are a concern because they are able to reproduce prolifically, rapidly colonize new areas, displace native species, and alter ecosystem processes across multiple scales. An invasive non-native plant inventory was conducted at Tumacácori NHP during January and February 2006.