Consequences of nitrate leaching following stem-only harvesting of Swedish forests are dependent on spatial scale.
Short-term increases in soil solution nitrate (NO(3)(-)) concentration are often observed after forest harvest, even in N-limited systems. We model NO(3)(-) leaching below the rooting zone as a function of site productivity. Using national forest inventories and published estimates of N attenuation in rivers and the riparian zone, we estimate effects of stem-only harvesting on NO(3)(-) leaching to groundwater, surface waters and the marine environment. Stem-only harvesting is a minor contributor to NO(3)(-) pollution of Swedish waters. Effects in surface waters are rapidly diluted downstream, but can be locally important for shallow well-waters as well as for the total amount of N reaching the sea. Harvesting adds approximately 8 Gg NO(3)-N to soil waters in Sweden, with local concentrations up to 7 mg NO(3)-N l(-1). Of that, ∼3.3 Gg reaches the marine environment. This is ∼3% of the overall Swedish N load to the Baltic.
Futter
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MN
Swedish University of Agricultural Sciences, Department of Environmental Assessment, SE 750 07 Uppsala, Sweden. martyn.futter@vatten.slu.se
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Högbom
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Entenmann
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Bishop
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D004784:Environmental Monitoring; D016468:Forestry / Q000379:methods*; D009566:Nitrates / Q000032:analysis*; D018547:Plant Stems / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis; D013548:Sweden; D014197:Trees / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000032:analysis
D009566:Nitrates; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical