ABSTRACT
This chapter describes the growth of Scots pine stands with respect to different forms of ditch network maintenance. The experimental sites had been drained for forestry purposes a few decades earlier and were considered by the representatives of practical forestry to require immediate measures of ditch network maintenance. In ditch cleaning, the existing ditches were cleaned to their original depth, and in complementary ditching, new ditches were dug between the old ones. In many of the experiments that showed a growth reaction, particularly in the north, basal area growth appeared to increase considerably more by the treatments including complementary ditching than by ditch cleaning. Considering the average of several experiments, the effects of ditch cleaning and complementary ditching on the level of the water table appear to be additive. The growth reaction seemed to concentrate into the trees that are situated far from the old ditches and close to the new, complementary ones.
