Effect of clear-cutting and the amount of logging residue on chemical composition of percolation water in spruce stands on glaciofluvial sandy soils in southern Finland

The relationship between the amount of logging residue and element leaching from forest ecosystems to watercourses is not fully understood.We hypothesized that if the amount of logging residue in slash piles increases, this will be reflected as elevated N, DOC, base cation and PO 4 -P concentrations in soil percolation water after clear-cut of spruce stands at site types with homogenous sandy material.Percolation water (depth 40 cm) was collected from small experimental sample plots by soil column lysimeters at two sites.The treatments were 0, 10 and 40 kg m -2 of logging residue.The highest NO 3 -N concentrations (mean > 15 mg l -1 ) were associated with the highest amount of logging residue left at the site.The NO 3 -N concentrations were < 1 mg l -1 in the third year after clear-cut in the treatments 0 and 10 kg m -2 of logging residue.DON, DOC and PO 4 did not leach markedly, but higher base cation concentrations were associated with the highest amount of logging residue.