부산대학교 도서관

Effects of changes in air pollution and forest cover on the acid atmospheric deposition and runoff were studied in the Jizerka experimental catchment (Czech Republic), a sensitive mountain environment of low buffering capacity. From 1982 to 2015, resident scientists and volunteers measured water quality of precipitation, fog, and stream samples at the watershed level. Archived LANDSAT imagery was used to reconstruct changes in forest composition in the watershed based on a detailed ground inventory done in 2010 to 2012. Spatial interpolation was used to approximate atmospheric deposition of water and SO42−, NO3−, and NH4+ over the watershed area. The open-field load of S peaked in 1987 to 1988 and dropped substantially in the 1990s, but inorganic N did not show a significant trend. The N∶S deposition ratio increased from 0.37 to 2.83. Mean annual stream-water pH increased from 4.2 to 5.9, and concentrations of SO42− and NO3− decreased by 55 and 53%, respectively. Seasonal acidification of stream water was observed during snowmelt (March, April) and episodic summer rainstorms. The relatively rapid response of stream-water quality to reduced deposition corresponded with subsurface runoff generated in a shallow podzolic soil. Relatively high leaching of NO3− in the 1980s followed limited N uptake in damaged spruce stands and clear-cut areas. Recovery of stream-water chemistry followed the drop in the acid atmospheric deposition by ~5 y, and stream biota revived after 10 to 15 y. Removal of spruce forest and reduced air pollution caused faster recovery from acidification than expected from pure air-quality improvement. Reduced atmospheric deposition and fog-drip interactions caused by lower canopy area suggest that modified forestry practices can affect deposition rates and stream-water quality. Deciduous or mixed forests could decrease the acidic atmospheric load by reducing leaf area and surface roughness. [ABSTRACT FROM AUTHOR]