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Invasive Plants - A New Natural Resouce Issue for Alaska

Issue

Invasive plants are a growing problem in Alaska. In the past, many biologists and land managers thought Alaska’s remoteness offered protection from such infestations. In recent years well established infestations of these plants, including white sweetclover, Japanese knotweed, and bird vetch have been documented. These and other invasive species threaten to invade Alaska’s urban and wildland forests, riparian areas, wetlands and drier forest types. For the continental U.S., one study estimates that invasive plants already infest over 100 million acres in the U.S., and this acreage is expected to increase 8 to 20 percent annually. The economic and ecological impacts of these invasive plants can be staggering. If Alaskans act now to prevent, contain, and eradicate these plants, the invasive plant problems that plague the rest of the U.S. may be avoided.

Background

Invasive plants are aggressive non-native plants that have been introduced without the insect predators and plant pathogens that helped keep them in check in their native habitats. Noxious weeds are a legally defined subset of invasive plants within each state.

Invasive plants generally spread from human habitation centers, outward along roads, via machinery, or through the movement of fill material. To stop invasive plants from becoming as widespread as dandelions and to keep them from replacing Alaska’s native flora, prevention and control measures are needed now.

Current Situation

Alaska is just beginning to recognize its invasive plant problems. Because many of Alaska’s existing invasive plant population centers are relatively small, Alaska is in a fortunate position to prevent large-scale weed infestations before they develop into the ecological and management quagmires many other states now have. The costs can be low, if populations are quickly identified, and control efforts are initiated soon.

In 2000, an interagency memorandum of understanding was developed to coordinate cooperative surveys, weed education, prevention, control and eradication measures. Participating agencies include the Alaska Cooperative Extension Service, Alaska Department of Natural Resources, Bureau of Land Management, U.S. Fish and Wildlife Service, National Park Service and the Forest Service.

During the past four years, State and Private Forestry and the Tongass and Chugach Forests have conducted surveys along over 1,000 miles of roads and 100s of miles of trails, trailheads, abandoned canneries and other sites of recent human disturbance. These surveys show that there are more non-native plants growing across Alaska than we thought, but that the serious invasive plants are still relatively manageable. Other species such as reed canary grass, used to stabilize roadsides in the past, is now very extensive and spreading into some wetlands and along streams. One survey in 1999 found Japanese knotweed at a remote cannery site on Baranof Island. The Sitka Ranger District conducted an environmental analysis and has treated the site with herbicides.

Early Detection of the new invaders, such as spotted knapweed and Orange hawkweed is a primary goal of these survey efforts. On Prince of Wales the two districts teamed up to eradicate the spotted knapweed, and work on controling other species such as the white sweet clover and bull thistle.

All of this survey information, plus the survey information from partner agencies and groups is feeding into a state-wide database that serves everyone interested in invasive plant information across Alaska. This database is housed at the Alaska Natural Heritage Program, and now contains over 45,000 records.

To determine which non-native species in Alaska are the real problem species State & Private Forestry initiated a ranking project for invasive plants both in Alaska today, as well as those likely to show up here in the near future. This is a cooperative project with many others, and is also housed on the web at the Alaska Natural heritage Program http://akweeds.uaa.alaska.edu/akweeds_ranking_page.htm.

In cooperation with the Soil and Water Conservation Districts, we have begun to set up Cooperative Weed Management Areas across the state to help control these incipient small infestations.

In 2002 a Tlingit and Haida Central Council employee found Garlic Mustard in central Juneau near the governor’s mansion. This plant is highly invasive in the forests of the Midwest. Several agencies and volunteers assessed the spread of the Juneau invasion and hand-pulled the adult plants before they set seed. This incident highlights the need to establish weed boards or similar entities to facilitate rapid-response multiple-ownership control efforts. Weed infestations are most successfully eradicated or controlled during the early stages following their introduction.

Summary

The increasing impacts of invasive non-native plants on wildland ecosystems require the coordinated actions of all Forest Service programs as well as cooperation with other agencies and the public. Weed prevention strategies include education, information and resource exchange, vigilant monitoring, and prompt control of new infestations.

Multi-agency and other ownership coordination mechanisms are being developed and the Forest Service is providing leadership and financial resources to these efforts. The Alaska Region Invasive Plant Strategy was completed and signed last winter. Invasive plant problems are being addressed on the Tongass National Forest via recently signed invasive plant management plans and on adjacent state and private lands through an increased emphasis in the Alaska Region’s State & Private Forestry Forest Health Protection Program.

More Information

Steve Patterson, Acting Assistant Director Forest Health Programs, State & Private Forestry. Alaska Region (907) 743-9451
Wini Kessler, Director; Wildlife, Fisheries, Ecology, Watershed, and Subsistence; Alaska Region (907) 586-7916

Current as of December 2006

USDA Forest Service - Tongass National Forest Accessibility Statement
Last Modified: February 15, 2007