Aerial herbicide application to treat downy brome

BLM New Mexico Weeds and  Invasives Program

The diversity of vegetation types represented across the State of New Mexico creates the potential for the occurrence of a wide range of noxious and invasive weeds.  The New Mexico Department of Agriculture has placed 37 species of noxious weeds in three separate management categories on the Noxious Weed List.  They have placed eight additional species on the “watch list” to help determine if any of these species should be listed in the future.

Rather than focusing solely on BLM lands, management actions taken by BLM-New Mexico target noxious weeds in coordination with a multitude of partners to address weed populations across the landscape.

Project Story

Pre treatment view of the project area.
Pre treatment view of the project area.  Photo by Valerie Williams.

Noxious Weeds Management in the Rio Grande Gorge Recreational Area

The Bureau of Land Management (BLM) Rio Grande Gorge Recreation Area (Recreation Area) is approximately 15 miles south of Taos, New Mexico, and includes approximately 5 miles of the Ri­o Grande.

Depending on funding, the BLM initiates control of weeds over 1-5 acres annually.  Small treatment sites mitigate impacts to wildlife habitat and visual resources.  An annual meeting provides an opportunity for the public to sponsor a treatment site in which it can implement treatment using manual methods, where effective, and/or monitor treatments pursuant to an established monitoring protocol.  Vegetation (slash) is removed from the treatment sites by prescribed fire, chipping, hauling, or left on-site to mitigate soil erosion and wildlife habitat.  

The project area is much wider and more open than the upper section of the Rio Grande, and provides a richer riparian environment.  The canyon is about 700 to 800 feet deep in this section and the gradient of the river decreases significantly in contrast to the Upper Gorge.  Wildlife, particularly songbirds, waterfowl, and shorebirds are more abundant in this wider riparian zone, and fishing and other activities increase due to the ease of access.

Approximately 83 acres of riparian area exists in the project area.  The dominant vegetation in the riparian area includes cottonwoods, willows, saltcedar, Siberian elm, New Mexico olive, Apache plume, grasses, rushes, sedges and forbs.  Saltcedar is the most abundant weed in the project area, totaling approximately 25 acres.  

A significant portion of the understory vegetation consists of native riparian species and, as found from monitoring results, once released from the competition of saltcedar and other weeds, reestablishes successfully.  

Success of native vegetation regeneration in the project area comes largely from the existing plant communities found on-site that are in good condition, namely coyote willow.

Post-treatment results have shown an increase in native willow, control of non-native woody species (saltcedar), and in some cases, increase in non-native herbaceous species.  Additional strategies are needed to address increasing introduced understory species after treatment.

The BLM, in coordination with other agencies and project partners, develops an annual project plan that identifies initial and re-treatment sites, methods to be used, monitoring activities required, and educational outreach opportunities.  Regional schools and universities are interested in carrying educational programs on riparian and weed ecology related to the activities taking place in the project area.  Students assist in implementation, monitoring, and conducting further outreach to the community on riparian ecosystem and weed control issues.

The BLM will continue to work in cooperation, consultation, and collaboration with stakeholders, tribal, local, and State governments, interest groups, and the public to support common objectives.

Post treatment view of the project area.
Post treatment view of the project area.  BLM photo.