Leaves and Crowns

The Chemical Landscape of Leaf Surfaces and Its Interaction with the Atmosphere

“…229 Last, the chemistry of wet-deposited material strongly influences its fate. In general, radionuclides in particulate forms (>3 to 100 μm) and cations (e.g., 7 Be 2+ ) are retained on leaf surfaces, whereas dissolved anions (e.g., 131 I − or 34 ) are washed off as efficiently as water. 224,225,227,233 For example, in the same simulated rain event, Hoffman et al 224 measured an average interception fraction of 0.08 for 131 I − , 0.28 for 7 Be 2+ , and 0.30−0.37 for radionuclides embedded in polystyrene microspheres (3−25 μm in diameter).…”

“…The leaves of almost all vascular plants share a similar microscopic structure consisting of an external layer of cells, the epidermis, that encloses the mesophyll, the inner leaf region (Figure ). − Stomata, pores that allow gas exchange between the atmosphere and the mesophyll, are also located within the epidermis, either on one or both sides of the leaf depending on the species. The entire epidermis, including eventual surface structures, is covered by a thin waxy layer (0.03 to 30 μm) , called the cuticle.…”