Publications by authors named "James R Runkle"

Terrestrial biomass and soils are a primary global reservoir of mercury (Hg) derived from natural and anthropogenic sources; however, relatively little is known about the fate and stability of Hg in the surface soil reservoir and its susceptibility to change as a result of deforestation and cultivation. In southwest Ohio, we measured Hg concentrations in soils of deciduous old- and new-growth forests, as well as fallow grassland and agricultural soils that had once been forested to examine how, over decadal to century time scales, man-made deforestation and cultivation influence Hg mobility from temperate surface soils. Mercury concentrations in surficial soils were significantly greater in the old-growth than new-growth forest, and both forest soils had greater Hg concentrations than cultivated and fallow fields.

View Article and Find Full Text PDF

Old-growth forests dominated by understory-tolerant tree species are among forest types most likely to be in equilibrium. However, documentation of the degree to which they are in equilibrium over decades-long time periods is lacking. Changes in climate, pathogens, and land use all are likely to impact stand characteristics and species composition, even in these forests.

View Article and Find Full Text PDF

Climate influences butterflies both directly and through impacts on their food plants and habitat. We look at the relationship between climate and butterflies in the Aullwood Audubon Center, west central Ohio, using the weekly Long-Term Butterfly Monitoring (LTBM) surveys (April through October 2000-2006) and the annual fourth of July counts (1989-2006). The 18 annual Fourth of July surveys yielded 20,709 butterflies and 59 species.

View Article and Find Full Text PDF