One of the results of this study was that around 8 cubic meters (m3) of wood per hectare of forest area grow each year. The annual cutting rate, i.e. the average amount of wood to be cut per year, is only about 5 cubic meters per hectare (Fm/ha).
One of the most important principles is formulated as follows: The character of a mixed forest characterized by oaks is to be preserved, excluding the consequent use of strong deciduous trees in the area close to the city center. Thus, the old trees are to remain standing for the most part.
A renunciation of timber exploitation and harvesting in favor of a recreational forest characterized by old trees!
Nevertheless, the preservation of the oaks requires a lot of intervention by the foresters: especially beeches and hornbeams, which take the light away from the oaks, have to be cut down. Even oaks do not live forever, so the urban forestry takes advantage of opportunities to replant young oak forests in smaller open areas.
For the coniferous forests, on the other hand, the goal is formulated to convert them into mixed deciduous forests in the long term.
The importance of old trees is reflected in a letter to the editor by Heinrich Nordhoff about the cutting down of old oaks in January 1955:
"Many hundreds of years (the oaks) had withstood the storms of time, outlasted countless generations, wet and dry years, wars and revolutions (...) - many hundreds of times they had seen the years come and go and the people. Much love and reverence of many generations had surrounded them. Many times I have sat there by the old oaks in the forest, on the red buck or with no other goal than to be close to the game and the forest and to find there in the silence of nature a counterbalance to worries and hardships of the day, to excessive responsibility and to decisions that determine the fate of tens of thousands. (...) That is all over now. What had endured for centuries had to be ended in these days."