Long-term effects of forestry managements on water quality and loading in brooks

The concentration of suspended solids in a meso-eutrophic basin remained unchanged in the years following clear felling (1983–85). The amount of suspended solids increased upon ditching, ploughing and mounting to a mean level of 81.8 mg l–1 in 1986–88, decreased to a level of 7.8 mg l–1 for 1989–91 and 4.5 mg l–1 for 1992–94. Total phosphorus concentration increased four-fold (142 µg l–1) in 1983–85 following clear felling, and remained at three times the reference concentration (95.4 µg l–1) in 1986–88 following ditching and site preparation. Phosphate phosphorus concentration increased more than five-fold after clear felling (97.8 µg l–1) in 1983–85 and was more than two-fold the reference (39.5 µg l–1)…