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Exotic and Invasive Plants

Exotic or invasive plants grow quickly and will crowd out other plants.  Often they have long roots that consume the water native plants depend upon and they have limited nutritional value for wildlife.  With no natural predators, exotic and invasive plants can be very damaging and very hard to control.   

Exotic & Invasive Plants:  

The Lower Rio Grande Valley National Wildlife Refuge is actively involved in restoration through the control of invasive plant species. All control efforts conducted on refuge are designed to improve the native habitat, therefore improving conditions for wildlife.

Many species of plants have been introduced into the area, some of which are beneficial as ornamental plants, as food crops, for erosion control, or other purposes. However, some of these introduced plants readily escape and become invasive in the native landscape. These species spread in many ways including; wind, water, animal movement, or through human and vehicle movement. Due to many dispersal methods and the need to understand species distribution and population, the refuge is actively involved in mapping and inventorying all invasive species on refuge lands.  

The refuge maintains all mapping data in a Geographic Information System and then prioritizes how to manage these invasive plants on these sites based on species present, size of population, potential to spread to surrounding areas, and proximity to native, undisturbed habitat. Currently, species that the refuge maps and controls are:

Brazilian Peppertree (Schinus terebinthifolius)
Shrub morning glory (Ipomoea carnea)
Tree tobacco (Nicotiana glauca)
Chinaberry (Melia azedarach)
Chandelier plant (Kalanchoe delagoensis)
Chinese tallow (Triadica sebifera)
Salt cedar (Tamarix spp.)
Athel salt cedar (Tamarix aphylla)
Guineagrass (Urochloa maxima)
Bufflegrass (Pennisetum ciliare)
Kleberg bluestem (Dichanthium annulatum)
Bermuda grass (Cynodon dactylon)

The refuge controls these species by implementing integrated pest management, including a variety of treatment methods such as mechanical removal and herbicide. The refuge chooses treatment techniques based on what is most effective, the least detrimental to the environment, and least the  inhibiting to restoration efforts.

Currently, the refuge has a strong focus on controlling salt cedar and Athel salt cedar along the Rio Grande. This species spread rapidly following a flooding disturbance and has a high potential to continue to spread as well as a high potential to outcompete native species, thus both decreasing native plant diversity and native wildlife diversity. These control efforts are supported by both staff and volunteers at the refuge.

Many volunteer opportunities exist in the mapping, control, and follow-up monitoring of invasive species on the Lower Rio Grande Valley National Wildlife Refuge. If interested in volunteering or to learn more about the program, please contact the refuge.

Please follow these links to learn more about invasive species:

Helpful Links 

What Are Invasive Species? 

The National Invasives Species Council  



Last Updated: Jul 06, 2012
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