Evidence from nitrogen fertilisation in the forests of Germany

In the first part, this contribution presents German results of nitrogen fertilisation experiments on stand growth, published 1958-1987. Over this period Norway spruce and Scots pine have generally responded positively to nitrogen fertilisation, without showing signs of damage, at levels up to at least 1000 kg N ha(-1). In the second part, growth patterns of forest trees and stands in Southern Germany are presented. Norway spruce in particular is now growing better than in earlier years of this century, starting around 1960. It is plausible that increasing nitrogen deposition, which coincides with the growth increase, is the cause, though this cannot be shown unequivocally. At a few sites with poor soil and management and high acid deposition a deterioration is taking place.