Appendix C. Description of the management schemes distinguished in this study.
Age-class forest: Following a clear cut are other stand replacing disturbance a new generation of trees establishes itself or is planted. With aging, stand regeneration contains increasingly more trees with dbh > 7 cm and with growing stem diameter the self-thinning line is eventually reached. At this point an increasing number of trees will start to die and only the dominant individuals will continue to grow. The tree population will continue to increase in diameter at the expense of a decreasing stem population. At a certain diameter initial thinning by management will decrease the stem population, and the remaining trees will continue to grow at constant density. The process of thinning may be repeated until a final age or diameter is reached and the whole stand is harvested.
Continuous cover forest: This management scheme resembles age-class forest. The main difference is that before the final harvest, tree density is decreased such that the canopy is no longer closed and regeneration can be established. This approach ensures that there is never a clear-cut, nevertheless, the diameter distribution across the whole rotation is similar to an age-class forest.
Selectively cut forest: ideally, a single tall tree or a group of big trees, which have reached a desired diameter is harvested. The gap in the canopy then allows regeneration at gap scale, subsequently density increases and the stand grows up again to the initial desired diameter.
Unmanaged forest: This forest type exists in Germany as national park (i.e., Hainich) or as protected nature reserves. In the region under study unmanaged forests were forests that have not been thinned or cut during the past 40 to 100 years. Despite this fairly long period of no management, they still remain in a transition between their former management type, i.e., coppice with standards and a tall forest.
Coppice forest: This forest type is a remnant of an historic management system, which was practiced throughout Germany about 200 to 300 years ago, but has now been largely abandoned. Coppicing requires tree species that can re-sprout after cutting, i.e., most temperate broad-leaved species. In a coppice forest, coppicing took place with a 15 to 30 year frequency. As the system was abandoned, formerly coppiced forest developed dense canopies, which are considerably older than they would be under active coppicing. This management type may become more popular in the near future as it resembles the system used in wood-based bio-energy plantations.
Coppice with standards: This forest formerly served two purposes: to provide wood for fuel, by using the coppiced under-story, and wood for construction, by maintaining an over-story of canopy trees to be used as saw-timber. This forest type was widely distributed about 200 years ago on land owned by the state, communities, and by private owners. This management type has also now been largely abandoned.
Farmers’ forest: This forest type is the result of handing forest to peasants after the French and German revolutions in the early 19th Century. These forests had been effectively used by these farmers for centuries, but the land was originally owned by the nobility or collectives. Once property rights were granted to the farmers, the land was consecutively split among the heirs of subsequent generations of farmers. As a result, very narrow (1 to 5 m) and long (up to 100 m) stretches of forest emerged which were managed by cutting individual trees on demand or for specific purposes, such as making tools or furniture. The main problem of farmers’ forests is identifying the owner of a given tree. For this reason, these forests developed as an almost unmanaged forest type.