Upland Forest Soils Research Articles

Methane fluxes in a northern hardwood forest ecosystem in relation to acid precipitation

Methane fluxes were measured periodically in 1990 and 1991 in upland forest and peatland soils of a northern hardwood forest in the Adirondack region of New York State. A portion of the study area received lime (10 Mg CaCO 3 ha -1) in October 1989 to mitigate several decades of chronic acid precipitation (H + deposition in 1981 = 653 eq ha −1 yr −1). Consumption of atmospheric methane by forest soils averaged −0.60 mg CH 4 m −2 d −1 and showed no difference between treatments (unlimed versus limed soils). Eliminating root growth and removing leaf litter from the soil seemed to decrease rates of methane consumption. Related responses of soil nitrogen transformations to the lime indicated lower nitrification rates and higher net nitrogen mineralization rates compared to unlimed soils, yet rates of methane consumption were unaffected by these changes in soil nitrogen transformations. Methane efflux from the peatland soils into the atmosphere averaged 12.1 mg CH 4 m −2 d −1, with no significant difference in rates between treatments. Laboratory measurements revealed that liming resulted in less consumption of atmospheric methane (measured with atmospheres amended with methane) and potentially more methane production. Overall, methane efflux from these peatland soils is much lower than that for more northern counterparts that currently experience cooler climate but less acid precipitation. This suggests that several decades of acid precipitation may play a role in limiting methane emissions from northern peatlands.

Sulfate dynamics in upland forest soils, central and southern Ontario, Canada: stable isotope evidence

In a Podzol (central Ontario) and a Brunisol-Luvisol (southern Ontario), SO 4 in soil seepage is buffered by various mechanisms including microbial cycling and sorption-desorption. A large portion of the water-soluble SO 4 in these soils is not derived from soil water, but is apparently desorbed from soil matrix. A HCO 3-exchange procedure extracts even more sorbed SO 4, especially from the acidic Podzol B horizon. The SO 4 in these soils has a range in δ 34S values similar to that of atmospheric SO 4 input. In contrast, the δ 18O (avg. + 4 to + 8.5) values of the soil SO 4 are depleted by 2–9% relative to atmospheric SO 4 input (δ 18O = + 11 to + 13) due to rapid biological cycling of soil S. This cycling includes biological assimilation of SO 4 and production of secondary SO 4, which is depleted in 18O. Calculations based on δ 18O data of litter leaching experiments indicate that approximately 50–100% of seepage SO 4 in the LFH and B horizons at Plastic Lake, central Ontario, is secondary. Biological cycling apparently exerts an important control on net release or retention of S by oils. Seasonal variations in soil water evaporation and litterfall may be important factors affecting the δ 18O of soil SO 4, and may be partly responsible for the 10% seasonal shift in δ 18O of LFH horizon SO 4.

Relations Among Sulfate, Aluminum, Iron, Dissolved Organic Carbon, and pH in Upland Forest Soils of Northwestern Massachusetts

Relations Among Sulfate, Aluminum, Iron, Dissolved Organic Carbon, and pH in Upland Forest Soils of Northwestern Massachusetts

Seasonal Variation in Nutrients of Floodplain and Upland Forest Soils of Central Illinois

AbstractVariation in nutrients was studied over a two‐year period in adjacent floodplain and upland forest soils in central Illinois. Nutrient pools of all elements except Na were greater in floodplain soils than in upland soils and were in the following order at both study sites: exchangeable Ca > exchangeable Mg > exchangeable K > available P. Seasonal variation in nutrient content of soils was the result of several environmental factors. Available P in floodplain soils was highly dependent on pH, which was in turn influenced by flooding, but there was no evidence of seasonal variation in available P for upland soils. Soil pH was positively correlated with the concentration of exchangeable bases in both soils, especially Ca and Mg in upland soils. Exchangeable Na was highly variable at both floodplain and upland sites and may have been influenced by leaching and variation in tree root exudation. The seasonal variation in nutrient pools of forest soils in this study has implications for tree growth, site evaluation, and nutrient cycling in forest stands.

Surface Soil Textural and Potential Erodibility Characteristics of Some Southern Sierra Nevada Forest Sites

AbstractAnalyses of texture and potential erodibility were made on 208 samples of residual, upland forest soils collected at elevations from 6,500 to 8,000 feet in the southern Sierra Nevada in California. Multiple regression tests showed that soil texture and erodibility indexes were significantly related to variation in parent rock type, vegetative cover type, aspect, slope, and elevation. Prediction equations implied that granitic forest soils at high elevations may be twice as erodible as soils developed under similar soil forming conditions at low elevations.