Shooting ranges polluted by antimony (Sb), lead (Pb), copper (Cu) and zinc (Zn) are used for animal grazing, thus pose a risk of contaminants entering the food chain. Many of these sites are subject to waterlogging of poorly drained soils. Using field lysimeter experiments, we compared Sb, Pb, Cu and Zn uptake by four common pasture plant species (Lolium perenne, Trifolium repens, Plantago lanceolata and Rumex obtusifolius) growing on a calcareous shooting range soil under waterlogged and drained conditions. To monitor seasonal trends, the same plants were collected at three times over the growing season. Additionally, variations in soil solution concentrations were monitored at three depths over the experiment. Under reducing conditions, soluble Sb concentrations dropped from ∼50 μg L−1 to ∼10 μg L−1, which was attributed to the reduction of Sb(V) to Sb(III) and the higher retention of the trivalent species by the soil matrix. Shoot Sb concentrations differed by a factor of 60 between plant species, but remained at levels <0.3 μg g−1. Despite the difference in soil solution concentrations between treatments, total Sb accumulation in shoots for plants collected on the waterlogged soil did not change, suggesting that Sb(III) was much more available for plant uptake than Sb(V), as only 10% of the total Sb was present as Sb(III). In contrast to Sb, Pb, Cu and Zn soil solution concentrations remained unaffected by waterlogging, and shoot concentrations were significantly higher in the drained treatment for many plant species. Although showing an increasing trend over the season, shoot metal concentrations generally remained below regulatory values for fodder plants (40 μg g−1 Pb, 150 μg g−1 Zn, 15–35 μg g−1 Cu), indicating a low risk of contaminant transfer into the food chain under both oxic and anoxic conditions for the type of shooting range soil investigated in this study.

Most previous studies investigating controls on nitrous oxide (N2O) emissions have relied on plot-scale experiments and focused on relative homogeneous biotic and abiotic factors such as soil, vegetation, and moisture. We studied soil N2O flux at 11 chamber sites along a 620 m topographic gradient in upstate New York, USA, aiming at identifying patterns of N2O flux and correlating them to hydrological factors and soil substrate properties along the gradient. The topographic gradient is a complex slope with an overall gradient of 8%, covering plant communities of pasture, forest, alfalfa field, and riparian area from the top to the bottom. Mean fluxes of N2O measured from late March to May ranged from 4.45 to 343 μg N m−2 h−1, and these fluxes were not significantly different among chamber sites located in different communities. With the descending of the slope, N2O fluxes increased with the increase of soil water content, except for the riparian site. Statistically, N2O fluxes were not strongly correlated with soil temperature, soil bulk density, and water filled pore space (p > 0.05). Instead, strong correlations (p < 0.05) were found between N2O fluxes and soil C and N content including NO 3 − , NH 4 + , total organic carbon, and C/N ratio. Multiple linear regression analyses including both soil physical and substrate properties highlighted the significance of soil NO 3 − content and C/N ratio in regulating N2O fluxes along the gradient.