Sensitivity of Roadside Trees and Shrubs to Aerial Drift of Deicing Salt1

Abstract

Specific injury symptoms were observed on 75 deciduous and coniferous species growing adjacent (8 to 40 m) to roadways and exposed to aerial drift of deicing salt Susceptible deciduous species (e.g. Cornus stolonifera Michx., Fagus gradifolia Ehrh.) exhibited twig dieback, evidence of previous dieback and inhibition of flowering while damage to conifers (e.g. Pinus strobus L., Thuja occidentalis L.) was evident as needle browning, premature needle abscission and twig dieback. Plants with resinous buds, submerged buds and needle cuticular wax seemed resistant to damage. A distinction between runoff of salty water and aerial salt spray is important when assessing plant damage.