The oldest trees on average are the oaks at 102, beeches at 100 and firs at 96 years. The Douglas fir, averaging 45 years, is the “youngest” tree species.
A little less than one fourth of the forest (24 %) is older than 100 years, 14 % is even older than 120 years. The area of old stands over 100 years old grew by 393,000 hectares since 2002
The age structure of the forests in Germany is the result of the extensive reforestation measures after the Second World War. Never have so many forest areas in Germany had to be reforested as they did in the 1950s and 1960s. These forests are now between 40 and 60 years old.
The numbers of large-girth trees are growing in the forest. These thick, old trees can contribute to biological diversity in a special way because they frequently possess special micro-habitats more than young trees do, such as rough bark, crown deadwood and woodpecker cavities. Many rare species need this. Also, old trees are attractive eye catchers for human visitors to the forest.
Large-girth trees are an increasing challenge for the forestry and timber industry. Modern sawmills and chipper canter mills are built for processing small and medium-girth tree trunks. They can produce high-quality timber-based materials of almost any dimensions from these trunks. Therefore large-girth trees are less and less in demand.
If large-girth trees remain in the forest until they decompose, this raises liability risks for the duty to maintain safety and hazards for working in the forest along roads, car parks and hiking trails. Also, the legal requirements for protecting rare species of such trees can result in possible restrictions for management.