%0 Research Notes
%T Effect of thinning on groundwater table depth in drained peatlands in northern Finland
%A Hökkä, Hannu
%A Penttilä, Timo
%D 1995
%J Suo - Mires and peat
%V 46
%N 1
%U http://suo.fi/article/9743
%X The effect of thinning on the groundwater table level was studied in four stands of Scots pine (Pinus sylvestris) on drained peatlands in northern Finland. Four thinning intensities (0-50% removal of the initial stocking), with three replications arranged using a randomized block design, were used in each experiment. If found to be in an unsatisfactory condition, the ditch networks were repaired at the time of thinning. Data from nine groundwater wells on each plot were used to determine the average depth of the groundwater table. The wells were monitored at two-week intervals during the latter parts of the growing seasons in 1991-1993. The mean groundwater table depth was used as the dependent variable in ANOVA with repeated measurements. In most cases, the groundwater table depth was lowest in the control plots, but significant differences between the treatments were found only in 1993 in two experiments. It was concluded that thinning caused no rise, or only a slight rise, in the groundwater table level.

Keywords: Forest drainage, groundwater table, Pinus sylvestris, thinning