5 research outputs found
Significance of soluble p-selectin, von willebrand factor, and other adhesion molecules in hypercholesterolemia and peripheral artery disease [5] (multiple letters)
Declining Acidic Deposition Begins Reversal of Forest-Soil Acidification in the Northeastern U.S. and Eastern Canada
Decreasing
trends in acidic deposition levels over the past several
decades have led to partial chemical recovery of surface waters. However,
depletion of soil Ca from acidic deposition has slowed surface water
recovery and led to the impairment of both aquatic and terrestrial
ecosystems. Nevertheless, documentation of acidic deposition effects
on soils has been limited, and little is known regarding soil responses
to ongoing acidic deposition decreases. In this study, resampling
of soils in eastern Canada and the northeastern U.S. was done at 27
sites exposed to reductions in wet SO<sub>4</sub><sup>2–</sup> deposition of 5.7–76%, over intervals of 8–24 y. Decreases
of exchangeable Al in the O horizon and increases in pH in the O and
B horizons were seen at most sites. Among all sites, reductions in
SO<sub>4</sub><sup>2–</sup> deposition were positively correlated
with ratios (final sampling/initial sampling) of base saturation (<i>P</i> < 0.01) and negatively correlated with exchangeable
Al ratios (<i>P</i> < 0.05) in the O horizon. However,
base saturation in the B horizon decreased at one-third of the sites,
with no increases. These results are unique in showing that the effects
of acidic deposition on North American soils have begun to reverse