Seven Decades of Calcium Depletion in Organic Horizons of Adirondack Forest Soils

Abstract

We used repeated sampling of the forest floor to determine if there was a net loss of Ca from organic horizons of Adirondack forest soils between 1930 and 2004. In 1984, we established 48 permanent plots in spruce–fir, northern hardwood, and pine stands located in areas sampled by Carl C. Heimburger in the early 1930s. Following Heimburger's protocols and analytical methods, we measured pH and dilute‐HCl‐extractable Ca in Oe and Oa horizons, and determined that there was a statistically significant decrease in Ca concentration during the 1932 to 1984 interval. In the 36 plots that we could locate in 2004, we again sampled organic horizons. During the >70‐yr interval, HCl‐extractable Ca concentrations in the Oe and Oa horizons decreased in each forest type (P < 0.05). We also measured NH4Cl‐extractable Ca and Al in the 1984 and 2004 samples and found a significant decrease in Ca concentration in the pooled Oe horizons. High‐elevation spruce–fir plots showed a Ca loss rate between 1984 and 2004 of 7.6 to 9.8 kg ha−1 yr−1 This compares well with a 4‐yr Ca cycling study conducted in an equivalent spruce–fir forest at Whiteface Mt. in the Adirondacks, which showed an annual forest floor Ca loss of 8.4 kg ha−1 yr−1 Based on uptake and anion flux data from the Whiteface Mt. study, we estimated that about 25 to 30% of the 1984 to 2004 forest floor Ca loss in the spruce–fir plots is attributable to leaching driven by atmospheric SO42− deposition.

A meta-analysis of the effects of nitrogen additions on base cations: Implications for plants, soils, and streams

“…Under these circumstances plant uptake does not represent a net BC loss from the ecosystem, but rather a temporary redistribution into plant biomass and the litter layer and is of minor consequence. But in fast growing ecosystems, such as young forests and those receiving N fertilization, BC uptake and removal from the soil can be large (Akselsson et al, 2007;Johnson et al, 2008) and sometimes permanent in ecosystems actively managed for biomass harvest such as forests where intensive whole-tree harvesting is practiced (Adams et al, 2000;Duchesne and Houle, 2008). The relationship between plant BC uptake and N is straightforward; as plant growth increases with added N, more BC are taken up by plants.…”

A critical evaluation of proxy methods used to estimate the acidity of atmospheric particles

“…Acute and chronic exposures to acidic particles have been linked to deleterious effects in people, although the underlying physiological mechanisms are unclear (Gwynn et al, 2000;Dockery et al, 1996). The deposition of acidic gases and particles has been known for decades to damage freshwater and terrestrial ecosystems (Schindler, 1988;Johnson et al, 2008). While the trends in emissions are promising in the US and western Europe, ecosystem recovery from the effects of acid deposition is a slow process that can take decades (Likens et al, 1996;Stoddard et al, 1999).…”

Wood Decay Fungi Restore Essential Calcium to Acidic Soils in Northern New England

“…Following root uptake, Al is largely precipitated out of solution due to the decreased acidity in the fine root cortex [11], resulting in very low concentrations of Al in wood. Calcium depletion and Al mobilization have caused growth declines and increased mortality in spruce [10,[12][13][14] and maple [15][16][17][18][19].…”