Spatial and Temporal Patterns of Lead Accumulation in the Forest Floor in the Northeastern United States

Abstract

Abstract In light of the relatively large amounts of anthropogenic Pb deposition from the atmosphere, a regional study of forest floor Pb was undertaken. The current Pb content averages 1.1 ± 0.1 g m −2 and 148 ± 5 µ g g −1 of forest floor. Factors that control forest floor Pb levels include precipitation rate, distance from the urban corridor, elevation, proximity to Pb‐emitting industries, forest floor age, and nature of the underlying mineral horizon. Analysis of buried organic horizons from windthrow mounds indicates that the Pb content of the forest floor may have increased five‐ to 10‐fold in the past century.