A 200-year paleoecological record of Pinus virginiana ,t race metals, sedimentation, and mining disturbance in a Maryland

) when the area fell under state management and pine forest expanded. Metal concentrations were highest for Cr and Ni, followed in decreasing order by V, Zn, Cu, and Pb. Results from this study suggest that 1) while Pinus virginiana was present in the early 1800s in sheltered lowland sites chromite-mining and its erosive effects on soil development may have been a factor in suppressing pine expansion in the Chimney Branch watershed between 1820 and 1920. Hence, pine expansion may be a natural stage in the succession of serpentine vegetation related directly to increasing soil depth, with the pace of expansion influenced by fire or mining disturbance; and 2) variation in Cr concentrations combined with mining history and macrofossils, in conjunction with aerial photos and recent studies, can provide useful stratigraphic dates to establish ecosystem development within the past 200 years in a serpentine environment.