Invasive Plants

Surface disturbances ranging from military training, recreation, energy exploration and development, and wildfires impact a large majority of federal lands in the western US, but the ecological and economic impacts are poorly understood. Explore this webpage to learn how Dr. Lesley DeFalco and her research team are currently evaluating and refining conventional approaches for post-fire restoration...

Fuel conditions and fire regimes in western forests and deserts have been altered due to past land management, biological invasions, and recent extreme weather events and climate shifts. These changes have created extreme fire risk to local and regional communities, threatening their economic health related to wildland recreation, forest production, livestock operations, and other uses of public...

The Greater Sage-grouse is a small bird found only in the sagebrush steppe of the Great Basin. Invasions of non-native grasses, evolving wildfire patterns, grazing from livestock, and human land uses are changing this unique ecosystem. WERC’s Dr. Pete Coates studies sage-grouse populations to determine how these influences could affect the bird and other wildlife in the future.

The deserts of the Southwest are under increasing pressure from growing human communities. The spread of cities, agricultural fields, grazing livestock, power plants, and other forms of human development in the past and present have affected the region’s natural resources, including its wildlife. WERC’s Dr. Kristin Berry is studying the response of threatened desert tortoises to changing habitats...

Ecosystems throughout the U.S. face threats from invasive species and rapid changes to the environment. Dr. Kathryn McEachern is studying the long-term effects of invasive plants and animals, and environmental change on the survival and recovery of rare plants across the 18 California Islands and in the Great Lakes.

A requirement for managing a species, be it a common native species, a species of conservation concern, or an invasive species, is having some information on its distribution and potential drivers of distribution. Branch scientists have been tackling the question of where these types of species are and where they might be in the future.

Due to high rates of disturbance and human activity, streamside or “riparian” areas are prone to colonization and spread of invasive plants. In the western United States, hundreds of thousands of riparian acres are occupied by the invasive shrubs/trees tamarisk and Russian olive, as well as numerous exotic herbaceous plants. Our work focuses on understanding the factors driving the distribution...

Formation of arroyos in the late 1800s greatly increased erosion across the southwestern United States. Since the 1930s, however, this erosion has decreased, partly because of bank stabilization by introduced saltcedar. With Isleta Pueblo Indian Nation, the Aquatic Systems Branch developed a new sediment dating method using saltcedar tree rings. We applied the method in a landmark study of arroyo...

Riparian ecologists at the Fort Collins Science Center study interactions among flow, channel change, and vegetation along rivers across the western United States and worldwide. Our work focuses on issues relevant to the management of water and public lands, including dam operation, invasive species, and ecological restoration. Investigations take place on a range of scales. For example...

Beginning in the early twentieth century, non-native trees and shrubs, including tamarisk (also commonly known as saltcedar) and Russian-olive, were introduced to the United States for use as ornamental plants and in erosion-control plantings. These plants spread extensively, becoming the third and fourth most frequently occurring woody riparian plants in the American West.

The foundation for applying science to river and riparian restoration contexts lies in a basic understanding of the factors that drive riparian vegetation dynamics. Much of our research is focused on clarifying relationships between streamflow, fluvial geomorphology, and riparian vegetation, including various feedbacks.

The establishment and proliferation of exotic plants and animals can interfere with native ecological processes and can cause severe stress to sensitive ecosystems.