Age and Inventory Structure of the Forests 2005
Tree Species Distribution, Total Area of the Berlin Forests
The distribution of tree species groups in the main stock of the Berlin forests shows the pine with 65 % and the oak with 13 %, while 11 % of the areas are stocked with birch and 4 % with beech. Hornbeam, maple, elm and other deciduous hardwoods account for 3 %, while fir, Douglas fir, larch and other conifers make up 4 % of the total area. Figure 2 and the corresponding Table show an overview of the distribution of tree species in the Berlin forests and the differences between the Forestry Agencies.
In the inventory layers Undergrowth and Secondary Growth, the distribution of tree species is completely different. Here, the area shares shift away from Pine (only 3 %) and Other Coniferous (2 %) to Deciduous Hardwoods (14 %), Oak and Beech (21 % each) and Deciduous Softwoods (39 %). The major share of the latter is accounted for by the black cherry, the common birch and the mountain ash. Among the Deciduous Hardwoods, the Norway maple and the sycamore dominate.
With a total of 10,500 hectares of undergrowth and secondary growth, as well as the staged character of the main stock which has been achieved to some extent, 50 % of the area of the Berlin forests now has a two or multi-layered inventory.
Age-Class Distribution, Total Area of the Berlin Forests
The age-class distribution shows a picture characteristic for the North German Plain. There is a clear excess of the third and fourth age-classes, which is due to over-exploitation during and after World War II. Except for these two age-classes, the age-class structure of the Berlin forests is quite well-balanced.
Clearly, the pine is the dominant tree species in all age-classes. Fortunately, there is also a share of oak in almost every age class.
An evaluation included all inventory layers in an age-class confirms the impression already obtained from the tree-species distribution that an extensive transformation in the inventory, involving a shift of considerable proportion away from pine monoculture and toward a mixed inventory with a major share of deciduous species, is occurring. In particular, the high proportion of oak and beech should be noted here. Less heartening is the large area share occupied by the Aln category (Other Deciduous with Low Rotation Times), since this essentially involves the black cherry.
Tree Species and Age-Class Distribution in the Single Forestry Agencies
The inventory of tree species differs due to location and historical conditions in the individual Forestry Agencies.
Tegel Forestry Agency
In the Tegel Forestry Agency, the pine is still the characteristic species of tree, although the overall tree-species structure is distorted in favor of the pine by the very high pine share in the Wansdorf and Stolpe forestry districts. The oak has a relatively high share, with 21 %, particularly in the inner-city forest areas. The beech is often the characteristic tree species in these inner-city areas; however, it accounts for only a small share of overall tree-species distribution.
The age-class distribution in the Tegel Forestry Agency also shows a typical peak in the third and fourth age classes. At the same time, however, there is also a considerable share of older stock of oak. The amount of older beech is not particularly large, contrary to the visual impression in the inner-city forest areas.
Grunewald Forestry Agency
The share of oak is even more considerable in the Grunewald Forestry Agency, largely due to the lack of large pure-pine districts. The share of beech is roughly comparable to that of the Tegel Forestry Agency.
A not atypical distribution for Berlin forests, though the high share of oak in the fourth age-class is conspicuous. The oaks here are predominantly present as mixed-tree species in pine stocks. The very low area share of the youngest age-class in the main stock is also conspicuous. The reason for that is that in recent decades, large-area uses were not carried out. Secondary growth does however exist in sufficient quantity in the areas of the Grunewald Forestry Agency.
Köpenick Forestry Agency
Two thirds of the forest areas of the Köpenick Forestry Agency are pine areas, mainly single-layered pure stock covering large areas. Forestry management measures during the coming decade are to bring about an extensive change of tree species by means of a change of the light-exposure conditions. The oak stock is to a large extent very near-natural. The large share of deciduous softwoods (Aln) involves largely alder stocks in major wetlands as well as along the numerous lakes, as well as the birch stands, which can be found everywhere. The beech share is low due to climatic and site conditions.
Köpenick differs markedly from the two previous Forestry Agencies. The very balanced distribution, with a high share of older stock is notable. Historically, this is due to the relatively low amount of reparations logging after the war, and to restrained use because of the special significance of this area for recreation.
Pankow Forestry Agency
The tree species distribution in the Pankow Forestry Agency is also strongly characterized by the pine. However, due to site and climatic conditions, there is a higher share of Aln-category trees, as well as of beech. North of the Berlin city limits runs the boundary between two climatically delimited zones, the dry lowlands climate to the south of the city limits, and the temperate humid lowlands climate to the north. North of the Berlin city limits, a characteristic beech area thus begins, of which the Pankow forest areas constitute a considerable share. The largest coherent old beech complexes in the Berlin forests are located here. They have considerable significance for conservation as well as favorable conditions for the gradual development of a richly structured, near-natural inventory.
The distribution of the Pankow Forestry Agency shows clearly that oak species are considerably less frequently represented, with the beech taking its place. The high share of Aln-category trees is dominated by species from the former sewage farms, with the poplar occupying the largest areas. Another significant species of this category is the alder, which occurs along the numerous ditches, creeks, lakes and wetlands.