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Welcome to the Eastern Forest Environmental Threat Assessment Center!
Message from the Director...
Dr. Danny C. Lee
EFETAC is addressing a variety of complex issues that demand cross-disciplinary integration, collaboration, and creativity. Our work complements ongoing efforts within and outside the Forest Service and builds on a wealth of existing information. Our scientists collaborate with an extensive national and international research community and focus on research that is relevant to rural and urban forest threat issues. More...
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Featured Forest Threat
Salt Injury
Although de-icing salts assist in keeping pavement dry and safe during ice and snow, their extensive use can cause damage to woody species along streets and highways.
What is salt injury? Trees and shrubs can be injured by salt spray and drift, by salt that leaches into the soil, or by a combination of both. The accumulation of salt within plants and soils affects plant nutrition and water absorption.
Why is salt injury a concern? On evergreens, injury from salt spray first appears as browning of the needles facing the road. The browning occurs at the tip of the needle and progresses to the base. Browning is evident in February and March and becomes more prominent through the spring and summer. As injury continues, needles drop prematurely and the branches become bare. As needles die, the photosynthetic capacity of the tree is curtailed. Over several years, the amount of new growth is reduced, causing the tree to weaken, dieback and perhaps die.
On deciduous trees, salt spray affects opening of buds and twigs in the spring, with the flower buds being the most sensitive. Injured buds are slow to open or fail to open. Salt symptoms on deciduous trees include reduced green leaf coloration, smaller leaves with scorched margins, thin crowns with dying twigs and branches, early fall coloration and leaf fall, tufting and clumping of foliage and sparseness of leaves, and small growth rings. The irregularity in foliage thickness from year to year reflects both the growth conditions and differences in the amount of injury each year.
Species do vary in their sensitivity to salt damage. Management prescriptions for roadside plantings should use techniques that minimize salt injury and select trees for planting that are more tolerant to salt.
Source: University of Tennessee Agricultural Extension Service
Photo by USDA Forest Service Northeastern Area Archive, Bugwood.org
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