RESEARCH GOAL - to understand the effects of non-native species within wilderness ecosystems and to develop, evaluate, and refine strategies and techniques for managing non-native species in wilderness.

INVASIVE AND EXOTIC SPECIES - The introduction and spread of non-native species, commonly referred to as invasives or exotics, is now recognized as one of the most significant threats to natural ecosystems world-wide. Impacts of non-native species range in severity from relatively benign coexistence to the displacement of native species and the disruption of ecological processes. This has lead to new challenges and conflicts in how to manage for and preserve natural conditions. The spread of non-native species into natural areas can lead to changes in populations of native species, shifts in ecological interactions, alteration of large-scale ecosystem processes, and, ultimately, a reduction in native biodiversity. Although wilderness areas are widely valued for their native flora and fauna and intact natural processes, these core aspects of wilderness are susceptible to, and increasingly threatened by, non-native invasions. For most wilderness areas the extent of non-native incursions, and their distribution, density, and rate of spread is poorly known. Non-native species are often associated with disturbances caused by people or livestock, but managers need information on the vectors and environmental factors influencing these incursions and their impacts. In order to understand and quantify the extent of invasions within wilderness and protected areas, standardized inventory and monitoring programs are needed. Research is also needed on the early prediction and detection of non-native species, possibly through remote sensing and predictive statistical models. Finally, cost-effective eradication and control methods specific to wilderness need to be developed and shared with managers. Research at the Leopold Institute has recently begun to addresses some of these needs, especially for plants. In particular, we are working to address invasive plant research in tandem with wildland fire research.

FISH STOCKING IN WILDERNESS AREAS - The introduction of non-native fish into historically fishless lakes in designated wilderness areas is becoming an increasingly controversial issue. Since the 1800's, trout species have been stocked in wilderness lakes in the western United States for recreational fishing purposes. New research suggests that this stocking may compromise some of the ecological and social values of designated wilderness. It has been demonstrated that fish introductions dramatically alter native vertebrate and invertebrate communities, and amphibians, zooplankton, and benthic macroinvertebrates have been extirpated from formally fishless waters.

The concern that aquatic habitats within wilderness are subject to management practices inconsistent with the goal of maintaining natural processes has inspired new research into the effects of these practice on ecosystem structure and function. The Leopold Institute has both completed and ongoing research projects addressing this issue.

In 1998 we sponsored a fish stocking workshop, the proceedings of which have now been published in Ecosystems. 2001. Vol. 4, No. 4.

FURTHER INFORMATION ON OUR INVASIVE SPECIES RESEARCH:

• PRIORITY RESEARCH QUESTIONS

• RESEARCH PROJECTS - Searchable Database

• PUBLICATIONS (Leopold Institute)

OTHER RESOURCES:

• WILDERNESS INVADERS - Surveys and Databases