Adaptive Management

In the Upper Colorado River Basin, smallmouth bass ( Micropterus dolomieu) are considered the greatest threat to native fishes and have been linked to declines in federally protected humpback chub ( Gila cypha), including one population that was rapidly extirpated in the past. Long-term management efforts have been underway to remove smallmouth bass from rivers in the Upper Basin, but smallmouth...

Land managers face tremendous challenges in the future as drought and climate change alter the abundance, distribution, and interactions of plant species. These challenges will be especially daunting in the southwestern US, which is already experiencing elevated temperatures and prolonged droughts, resulting in reduced soil moisture in an already water-limited environment.

Threatened humpback chub are a native fish found only in the Colorado River Basin. Once found in warm-water canyons in the Basin, the largest population now persists in the Colorado River in Grand Canyon National Park, downstream of Glen Canyon Dam and Lake Powell, the reservoir upstream, created by the dam.

The Rio Grande/Rio Bravo (hereafter referred to as the Rio Grande) in the Big Bend region of Texas, USA, and Chihuahua and Coahuila, Mexico, has substantially narrowed since the early 1900s. This narrowing has been caused by the construction and operation of dams and irrigation diversions in upstream reaches of the Rio Grande in the U.S. and the Rio Conchos in Mexico that has reduced flows without...

River channels and their adjacent floodplains are ever evolving in form and composition in response to changing patterns of streamflow, the quantity and size of supplied sediment, and feedbacks with the riparian and aquatic ecosystems. Changes in channel form affect aquatic and riparian habitats, which are important for plants, animals, and insects. Erosion and deposition of river channels and...

The Southwest Biological Science Center (SBSC) conducts and provides scientific information as part of our mission and Federal Trust Responsibility to strengthen relationships and build partnerships with sovereign tribal nations. Here, we highlight a few examples of projects with tribal partners.

Rainbow trout are a desirable sport fish that have been introduced in many locations around the world, including the Colorado River. Although introductions of rainbow trout and other nonnative fishes provide recreational fishing opportunities, they can also pose threats to native fish populations. The Glen Canyon Dam Adaptive Management Program has tasked scientists and managers with identifying...

The Grand Canyon Monitoring and Research Center, a branch of the Southwest Biological Science Center, conducts scientific assessments of the Colorado River in Grand Canyon, focused primarily on Lake Powell and the river ecosystem downstream of Glen Canyon Dam. On this page, we'd like to share related interactive tools and projects by other USGS Centers that cover science across the upper and lower...

USGS Southwest Biological Science Center's Grand Canyon Monitoring and Research Center provided scientific expertise to evaluate potential effects of reservoir management on various resources in Lake Powell and Grand Canyon. This information, published in a cooperator report, was requested and used by the Bureau of Reclamation for decision-making on water flows from Glen Canyon Dam.

In drylands, chronic reductions in water availability (press-drought) through reduced precipitation and increased temperatures may have profound ecosystem effects, depending on the sensitivities of the dominant plants and plant functional types. In this study, we are examining the impacts of moderate, but long-term chronic drought using a network of 40 drought shelters on the Colorado Plateau...

Renewable energy development is expanding in southwestern deserts, including in Arizona. Energy developers look to resource management agencies to provide siting guidance on public lands where there might be conflicts with wildlife. Often, agency guidance considers species of conservation concern and economic importance, but information on comprehensive vertebrate biodiversity has been hard to...

Approximately 35% of the US and approximately 82% of DOI lands are “drylands” found throughout the western US. These lands contain oil, gas, oil shale, shale oil, and tar sand deposits and the exploration for and extraction of these resources has resulted in hundreds of thousands of operating and abandoned wells across the West. These arid and semi-arid lands have unique soil and plant communities...