The Amur cork tree is a native of Eastern Asia and was originally planted as an ornamental. Now considered invasive, it has spread into natural areas across the Northeast and is expanding rapidly in Cold Spring Park’s wetland red maple forest. According to Dr. John Regosin, former Deputy Director of Mass. Division of Fisheries & Wildlife, if left unchecked, the Amur cork tree could permanently alter the ecosystem and severely diminish habitat quality.
The tree is recognizable by its deeply furrowed, spongy bark. Despite its name, the tree does not even produce cork.
Massachusetts state law prohibits the sale, import, trade, purchase, distribution, or propagation of the Amur cork. The Amur cork are particularly successful, as local plants and animals have not evolved to benefit from, or to compete with, the Amur cork. Alan Nogee of the Friends of Cold Spring Park spoke of the Amur cork’s vigor, saying, “The tree thrives in sun and shade, and in moist or dry soil.”
The ecological damage is significant and getting worse. The trees cast heavy shade suppressing native plants, while their roots release a chemical that prevents new growth. Unlike native oaks and maples, which support hundreds of caterpillar species essential for bird populations, Amur cork provide little wildlife benefit. Their berries attract birds but offer poor nutrition, and their spread threatens the park’s ability to sustain its 175 bird species.
With City approval, local volunteers have already removed over 150 smaller trees. However, larger trees near trails require professional removal. The removal will result in a closing of the Cold Spring Loop Trail for at least several days in July or August for safety reasons. Two Newton non-profit groups, the Friends of Cold Spring Park and Newton Conservators, have together committed $25,000 to hire contractors to remove the larger trees. Those designated for removal are marked with an “X” as seen in the accompanying photo.