Leaf Cuticles as Potential Markers of Air Pollutant Exposure in Trees : Biologic Markers of Air-Pollution Stress and Damage in Forests. Workshop Papers

1989

S. 333-339

36 Lit. Ang.

Unselbständiges Werk

200069352

Biologic Markers of Air-Pollution Stress and Damage in Forests : Workshop Papers : Biologic Markers of Air-Pollution Stress and Damage in Forests. Workshop Papers, S. 333-339

Because leaf cuticle covers a large area and is continually exposed to the environment, it might serve as a sensitive and early indicator of exposure to air pollutants. Some investigations have shown alterations of the ultrastructure of surface waxes with field or laboratory exposure to air pollutants, while others have not detected significant differences. It is possible that the changes in the surface structure are largely a product of pollutantinduced stress, rather than a direct consequence of exposure of the cuticle itself. The healthiest trees in polluted zones may show less alteration of cuticle than the least healthy trees of less polluted zones. Laboratory studies have demonstrated that prolonged exposure of isolated cuticle to acid can increase the permeability of the cuticle to the acid, but such studies have not yet been carried out on intact leaves. Because the changes seen for cuticles are nonspecific, resembling an acceleration of natural aging processes or exposure to other stresses, it is currently difficult to use them as specific markers of air pollution exposure, especially if the object is to distinguish air pollution from other sources of stress.