Summary:
Published in International Peat Journal 9: 21-37
A comprehensive study was initiated in a black spruce (Picea mariana (Mill.) B.S.P.) peatland of eastern Québec, Canada, to evaluate the effects of drainage on substrate conditions, tree growth, streamflow and water quality. Considering the drawdown due to drainage during periods of highest and lowest water table as well as average seasonal values, the 20- and 30-m spacing showed lower water table than the 40-, 50- and 60-m spacing, which were efficient at midpoint between the ditches only during dry periods. Water table lowering was substantial in the first 5 m from the ditches and minimal beyond 15 m. Peat moisture content was reduced by 20-29% and maximum summer soil temperatures increased by 1.5 to 3.5°C at 10-cm depth, while rates of decomposition were accelerated mainly at the 30-cm depth. Drainage increased nutrient content of the soil water solution proportionally to ditch closeness. Base flow was increased by at least 0.7 L s-1, while total runoff was increased by 0.9 L s-1 which represents a 25% increase due to drainage. The concentration of suspended sediments significantly increased only during ditching and the following four weeks. Streamflow temperature fluctuations were increased after drainage, by lowering of the average weekly minimum and increasing the average weekly maximum, by 2 and 7°C, respectively. The treatment increased electric conductivity of surface water, which was clearly related to increases in mineral N (NH4 + NOx), Ca, Mg, Na and S concentrations.
Sector(s):
Forests
Catégorie(s):
Scientific Article
Theme(s):
Ecosystems and Environment, Forest Ecology, Forestry Research, Forests
Departmental author(s):
Author(s):
PRÉVOST, Marcel and André P. PLAMONDON
Year of publication:
1999
How to get the publication:
Keyword(s):
forest drainage, water table, soil water, streamflow, water quality, nutrient leaching, ecosystems and environment, écosystèmes et environnement, écologie écosystèmes et environnement, drainage forestier, nappe phréatique, eau du sol, ruissellement de surface, qualité de l'eau, lessivage de nutriments