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Both harvest removal and leaching losses can deplete nutrient capital in forests, but their combined long-term effects have not been assessed previously. We estimated changes in total soil and biomass N, Ca, K, Mg, and P over 120 years from published data for a spruce-fir site in Maine, two northern hardwood sites in New Hampshire, central hardwood sites in Connecticut and Tennessee, and a loblolly pine site in Tennessee. For N, atmospheric inputs counterbalance the outputs, and there is little long-term change on most sites. For K, Mg, and P, the total pool may decrease by 2%–10% in 120 years depending on site and harvest intensity. For Ca, net leaching loss is 4–16 kg/ha/yr in mature forests, and whole-tree harvest removes 200–1100 kg/ha. Such leaching loss and harvest removal could reduce total soil and biomass Ca by 20%–60% in only 120 years. We estimated unmeasured Ca inputs from rock breakdown, root-zone deepening, and dry deposition; these should not be expected to make up the Ca deficit. Acid precipitation may be the cause of current high leaching of Ca. Although Ca deficiency does not generally occur now in acid forest soils, it seems likely if anthropogenic leaching and intensive harvest removal continue.

Whole‐tree harvesting of a northern hardwood stand in New Hampshire removed an average of 111 dry metric tons/ha of biomass, representing 96% of the aboveground total. Nutrient removal in harvested trees averaged 344, 242, 128, and 19 kg/ha for Ca, N, K, and P, respectively. The nutrients removed were between 2 and 3% of estimated total soil capital for Ca and N, and about 1% of total soil capital for K and P. Of estimated availablenutrient capital, the removals were 30% for Ca and 85% for K. The harvest was carried out on the lower 40% of a 16‐ha watershed. Concentrations of NO3, Ca, and K in soil solution and streamflow of the harvested watershed increased for 1½ to 2 years. Streamflow concentrations increased by a maximum of 3, 1, and 0.2 mg/liter for NO3, Ca, and K, respectively. Increased loss of N and Ca by leaching to streams is estimated at < 40 kg/ha. NO3in soil solution increased from background levels of 1 mg/liter to a maximum of 95 mg/liter. Ca increased from background levels of 2 mg/liter to a maximum of 19 mg/liter. Concentrations of both ions returned to background levels by the third growing season after harvest. The increases in nutrient ions in streams and soil solution are thought to result from increased mineralization and nitrification immediately after harvest. The harvested area has regenerated rapidly with pioneer and commercial species, perhaps partly because of the enriched soil solution. Nutrient removals and leaching losses by themselves do not seem to deplete total nutrient capital significantly. However, the impacts of whole‐tree harvesting upon the processes, mechanisms, and rates by which nutrients are made available for future stands are still of concern.

Dewatered and limed sludge from a primary treatment plant was applied at two rates, 25 and 125 wet metric tons/ha (5.8 and 28.0 dry metric tons/ha), on sandy loam soils in a northern hardwood forest in central New England. Changes in soil water solution were assessed from water samples collected with suction lysimeters at 20‐ and 45‐cm depths below the mineral surface. The light application of 25 metric/ha had little effect, but the heavy application of 125 metric tons/ha caused an increase in the concentration of most ions in soil water. At 20 cm, or just below the B21h horizon, Cl reached a mean maximum of 27.5 mg/liter after heavy application compared to control values of <0.4 mg/liter. Sulfate rose above mean background levels of 5.0 mg/liter to a maximum concentration of 13.5 mg/liter. Mean Ca values rose to over 13.5 mg/liter compared to background concentrations of about 2 mg/liter. Magnesium, Na, K, H, and NO3indicated maximum increases in concentration that averaged two‐ to threefold greater than control values of <0.5 mg/liter. NH4and TOTAL‐P were unchanged. At 45 cm or in the B23 horizon just above a fragipan, the increases in ionic concentrations following the heavy application were less than one‐half the increases that occurred at 20 cm. The concentrations of most ions returned to background levels within 1 year after sludge application. From the time sludge was applied in June 1975 until the end of the growing season in October 1976, leaching losses for calcium were estimated as 18 kg/ha for the control plots, compared to 39 kg/ha from plots receiving the heavy application. Comparable estimates for SO4were 35 kg/ha for the control plots and 64 kg/ha for plots receiving the heavy sludge application. There were no significant differences in basal‐area growth among control and treated plots for the first two growing seasons after sludge application. In the herb and shrub layer only 3 of the 31 commonly occurring species showed statistically significant changes in frequency. All three changes were on plots receiving the heavy application. Sugar maple (Acer saccharumF.) seedlings declined from an average of 22/m2before application to 17/m2in the second summer after application. The shrub Viburnum alnifoliumMarsh, increased from an average of 5/m2before application to 11/m2after and the herb Viola pallensBrainerd increased from 15/m2before to 21/m2after.

The objective of this research was to evaluate the impacts of increasing product removal on biomass and nutrient content of a central hardwood forest ecosystem. Commercial thinning, currently the most common harvesting practice in southern New England, was compared with whole-tree clearcutting or maximum aboveground utilization. Using a paired-watershed approach, we studied three adjacent, first-order streams in Connecticut. During the winter of 1981–82, one was whole-tree clearcut, one was commercially thinned, and one was designated as the untreated reference. Before treatment, living and dead biomass and soil on the whole-tree clearcut site contained 578 Mg ha-1 organic matter, 5 Mg ha-1 nitrogen, 1 Mg ha-1 phosphorus, 5 Mg ha-1 potassium, 4 Mg ha-1 calcium, and 13 Mg ha-1 magnesium. An estimated 158 Mg ha-1 (27% of total organic matter) were removed during the whole-tree harvest. Calcium appeared to be the nutrient most susceptible to depletion with 13% of total site Ca removed in whole-tree clearcut products. In contrast, only 4% (16 Mg ha-1) of the total organic matter and ?2% of the total nutrients were removed from the thinned site. Partial cuts appear to be a reliable management option, in general, for minimizing nutrient depletion and maximizing long-term productivity of central hardwood sites. Additional data are needed to evaluate the long-term impacts of more intensive harvests.

The streams tributary to acidic Cone Pond, pH 4.5–4.8, and circumneutral Black Pond, pH 5.3–6.4, in the White Mountains of New Hampshire, USA, were monitored for a year. The watersheds of these two ponds were characterized in terms of geology and stream hydrology. Chemical gradients and patterns in rock weathering and groundwater discharge explain many of the differences in mineral content and acidity of the streams. The rocks of Black watershed produced an average of ten times the equivalent of basic cations as rocks from Cone watershed. This is on the same order as the difference in acidity of the two streams. Down-stream changes in stream chemistry follow differing patterns, but reflect the same principle of residence time and water path length controlling chemical evolution of streamwater. Watershed and aquatic managers may use these parameters in an inexpensive and simple assessment of the susceptibility of individual streams and ponds to acidification. A method is recommended to determine quickly the potential influence of bedrock type to aquatic chemistry.