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Thousands of trees are struck by lightning every year. These trees will have varying degrees of damage ranging from complete shattering and destruction of the tree, to a slow lingering death, to virtually no apparent damage at all (Figure 1).
Conifers are commonly planted in North America to provide year-round screening, as windbreaks or as focal trees in the landscape.
Nate Siegert, Ph.D., USDA Forest Service, discusses the latest information pertaining to the Emerald Ash Borer (EAB) and its continued spread across the urban forests of the U.S. and Canada.
Oak decline is a slow-acting disease complex that involves the interaction of biotic and abiotic factors such as climate, site quality and advancing tree age.
Iconic tree species include those native trees that once dominated the typical American city landscape. The American elm and chestnut are the first two that come to mind, and now ash trees are similarly under significant threat of loss.
Tree defects such as co-dominant leaders, girding roots and buried trunk flares, present at time of planting, cause failures and decline long after the warrantee period has expired. Landscape architects may go to nurseries to tag trees; but often inspe
Ice or snow loads can cause branch breakage or failure of entire trees and shrubs. Branches or entire trees that fall in storms can impact homes, vehicles, power lines and block roads.
ManagementEmerald ash borer (Agrilus planipennis) was first discovered in southeastern Michigan in 2002.
Insect and disease infestations pose major threats to several North American forest tree species.
North American forests and forest management institutions are experiencing a wide range of significant ecological disturbances and socioeconomic changes, which point to the need for enhanced resilience.