The Alaska Division of Agriculture has issued a statewide quarantine on two invasive tree species—Prunus padus, known as the European Bird Cherry or Mayday tree, and Prunus virginiana, commonly called the Canada Red or Chokecherry tree.
Effective Sept. 1, the order prohibits the importation, transport, and sale of both species and their parts. State officials say the trees are rapidly spreading in Alaska’s riparian zones and forests, creating monocultures that displace native vegetation and threaten fish and wildlife habitat.
The trees have established themselves across multiple regions, including the Fairbanks North Star Borough, Matanuska-Susitna Borough, Anchorage, the Kenai Peninsula, and Juneau.
These species have been documented along creeks and streams, where they reduce insect biomass critical to juvenile salmon, said Bryan Scoresby, Director of the Division of Agriculture. “Many agencies continue to pursue control measures with the goal of eliminating these invasive trees. With this quarantine, the flow of trees into Alaska will stop, making this goal more attainable.”
The invasive Prunus species not only compete with native plants but also pose direct risks to Alaska’s wildlife. They contain a cyanogenic glycoside that is toxic to ruminants such as moose when consumed, reducing the availability of safe winter forage.
In addition, researchers recently detected the fungal disease “Black Knot” (Apiosporina morbosa) on European Bird Cherry trees at the University of Alaska Anchorage campus. Black Knot is a serious threat to fruit tree cultivation, especially plums and cherries, and invasive Prunus trees are a potential vector for its spread.
Over the past five years, the Department of Natural Resources’ Division of Forestry & Fire Protection has invested more than $400,000 in control measures across Alaska’s largest boroughs. The agency has also led public outreach campaigns through community meetings, media coverage, and radio ads to warn Alaskans about the risks of invasive Prunus trees. An additional $250,000 has been committed to current projects aimed at eradication.
The Department of Natural Resources said that protecting native ecosystems aligns with its mission to develop, conserve, and maximize the use of Alaska’s natural resources in the public interest.