The Berlin forests suffered severe damage during the course of World War II. Between 1937 and 1944, more than twice as much wood was cut “to strengthen raw material supply” in Berlin than would have been sustainable from the point of view of forestry planning – 150,000 solid cubic meters per year (fm/a) instead of 71,000 fm/a. At the same time, the planting of new trees was neglected, and thus the principle of sustainability abandoned (cf. SenStadtUm 1995a). This systematic depletion increased still more during the last two years of the war: For the defense against the advancing Allies, a large number of trees were indiscriminately felled by the Wehrmacht, leaving behind extensive desolation. However, there was also large-scale theft of firewood, both by the Wehrmacht and by the population, which did great damage to the forest (570,000 fm during 1945-‘46).
With the end of the Second World War, a period of separate development of the forests began in the eastern and western parts of the city, as well as in the districts located outside the city.
West Berlin after the 2nd World War
In West Berlin, after the war’s end and the ensuing blockade (1948-‘49), approx. 45 % of the original wooded areas had been cleared and/or greatly thinned. For lack of other plant material, mainly pines were used for the extensive reforestation of the barren areas. This is the reason for the relatively excessive proportion of 50 to 70 year-old pine monocultures existing today.
Since the beginning of the ’50s, the West Berlin forestry assessments have been using the opportunity to transform the forest and taking a step towards a mixed forest by deciduous undergrowth seeding and planting in clearings in open stands of old trees. The goal has been forestry on the basis of a selection forest, and the development of a permanent forest. At the same time, however, such florally foreign tree species as the larch, the Douglas fir, the Weymouth pine and the red oak were also introduced into the inventory by hurst and cluster. The 1979 State Forest Law and the 1982 Basic Forestry Plan for the Berlin Forests were oriented toward naturally compatible management of the Berlin forests. The most important goals of these operational guidelines were:
- an increase in the deciduous share from 40 % to 60 %;
- the promotion of a richly-structured mixed forest;
- the improvement of the conservation and landscape care;
- a 1-ha limit on clear-cutting;
- the adoption of natural rejuvenation;
- and abandonment of the use of herbicides and melioration measures.
East Berlin after the 2nd World War
The forest lands in East Berlin developed differently. The destruction of the old growth had not been as extensive as in the western part of the city. Those trees which, by the end of the war, had surpassed pole-timber age, but not yet reached felling maturity, were not subjected to harvesting during the ’50s to the same extent as in West Berlin. This affects many areas in the districts south of the Müggel Lake. Thus, the old-growth proportion (stocks over 80 years old) was able to grow to 53 % by 1975. In addition, the rotation age has been raised for pines from 100 to 120 since 1975. The result was a deficit in wood production, which was tolerated out of consideration for the recreational function of the Berlin forests. Thus, the Berlin forests assumed a special place in East Germany. They received a recreational function, in addition to their primary role of raw material production. Due to the staged clear-cutting of the pines, wooded areas were
characterized predominantly by the structures typical of an age-class forest.
Forestry in East Germany was greatly centralized. This was further intensified during the ’70s. The goals were maximum increase in domestic wood production and the transition to industrial production methods. In the Berlin forests, the following measures were to be carried out:
- removal of all low-production stocks;
- no toleration of afforestation delays;
- fertilization and melioration measures; and
- restoration of a normal age structure (i.e., removal of the high old-growth proportion).
Because of the goal of multiple use of the Berlin forests, these guidelines could be somewhat diluted. The forest was broken down into classes of recreational functions. Maximum allowable clear-cut areas were established. For instance clear-cutting was forbidden at key recreational areas, while in recreational park forests, clear-cutting of up to 3 ha was allowed, compared with the up to 10 ha allowed in normal economic-use forests. In the areas of the former city forests outside the city limits, however, work was carried out according to the guidelines of optimal economic use under the direction of the respective locally responsible state-owned forestry operations.
As early as the ’60s, smoke-damage investigations were carried out in the East Berlin forests, and damage to the trees was ascertained. As a result, a smoke-damage area amounting to 36 % of the total area was certified in 1974 (by 1975, it was already 43 %). For “revitalization,” damaged pine forests were fertilized with nitrates. Between 1977 and the cessation of fertilization in 1985, 100 to 800 kg of nitrogen/ha were spread in the Fahlenberg and Müggelheim Districts.
A major problem in the East Berlin forest is the wide dissemination of chee-reed grass (Calamagrostis epigeios), which complicates natural rejuvenation. Its center of dissemination is found particularly in the relatively clear, single-layer pine stands which are devoid of a shrub layer and are of medium age. The spread was encouraged by the former practice the clear-cutting and complete re-plowing, and the fertilization of the forests.
In the northeast of the city, large former sewage-farm areas were transferred to the Berlin Forestry Operation in 1985 and afforested in connection with the 750-year anniversary festival of the founding of Berlin (1987). This was carried out under heavy deadline pressure and without sufficient preliminary examinations, with the goal of the creation a recreational forest. After grading, the sewage farms were planted predominantly mechanically with over 50 different tree and shrub species, such as poplar, mountain ash, birch, alder, European beech, pine and spruce. The site problems, including heavy-metal pollution, the disturbed soil surface and ground-water conditions, and difficulty in the selection and procurement of suitable seed stock (including decorative trees and shrubs) resulted in unsatisfactory growth results and poor stock vitality (cf. SenStadtUm 1995a).
In 1992, the Berlin Forests published the Forestry Guidelines for Greater Berlin, which brings together the interests of forestry, conservation, recreational use and landscape esthetics to form a uniform concept for action. The orientation is toward careful, sustainable and naturally appropriate forestry. To preserve the climatic, hydrological, hydrochemical and public-health effects of forest areas, extensive measures for the protection and development of near-natural forest structures with rich animal and plant life are carried out in the entire wooded area.
The abundant dissemination of the black cherry, which was introduced about 100 years ago from North America, presents a considerable Berlin-wide problem, since it suppresses natural rejuvenation of florally appropriate tree species and the development of a herbaceous layer. In former West Berlin, it has been increasingly cleared since 1985. For financial reasons, removal measures are currently possible only on limited plots, and they need to be supplemented by the establishment of indigenous tree species through natural rejuvenation or plantation, so that areas once cleared cannot be recolonised.
Wood production, still an important function of modern forestry, in view of Germany’s commitment to measures aimed at binding CO2 and the policy of increased use of renewable raw materials, is currently subordinated to the State of Berlin’s cultural and social priorities. Nevertheless, the use fulfills not only the function of the provision of wood, but also provides an important large-scale effective method for the attainment of Berlin’s forestry goals with regard for the creation of a mixed deciduous and coniferous woodland with a variegated structure and a large number of species.
The forests emerging in the future should contain a web of all stages of development, from the rejuvenation through the aged phase. Important structural elements, like standing deadwood or glades, should exist in sufficient quantity and quality and be distributed throughout the entire wooded area, and/or should emerge anew. The essential criteria for natural management of the Berlin forest are:
- Gradual reduction of the florally foreign tree species;
- Promotion of site-appropriate and florally appropriate tree species;
- Stock renewal through promotion of natural rejuvenation;
- Promotion of mixed stands with rich structural and species diversity;
- Abandonment of fixed rotation times while preserving and creating permanent forest structures;
- Selective, tree-by-tree wood harvesting;
- Abandonment of clear-cutting;
- Protection of hollows and nest-trees;
- An increase in the proportion of deadwood;
- No complete replowing of areas; and
- Renunciation of fertilizer and pesticides (cf. SenStadtUm 1992).
The Berlin Forests in 1990 applied to the Trust Agency (which managed former East German government property) for the restoration of approx. 13,000 ha of former Berlin city forest land in Brandenburg. The restoration of this area to the ownership of the state Berlin has now been almost completely concluded. The forest areas adjacent to Berlin to the south, in the Ludwigsfelde/ Grossbeeren/ Königs Wusterhausen area, were managed by the Berlin City Properties through January 1st 2002, and were then taken over by the Berlin Forestry Management. Of the total of approx. 29,000 hectares presently managed by the Berlin Forestry Management, approx. 16,500 hectares are within the State of Berlin, and the other approx. 12,500 hectares in the State of Brandenburg. Besides forested areas, the total area includes approx. 3,000 ha open spaces of diverse quality. They comprise water bodies, wet and dry open country areas, power line routes and many other habitats.
Since June 2002, the Berlin forests have been certified according to the criteria of FSC and Naturland. Thus the preservation of strict forestry standards is annually monitored and confirmed by independent third parties.
Present Structure of the Berlin Forestry Agencies
Since 2004 the Berlin forests have consisted of the four Forestry Agencies Grunewald, Tegel, Pankow and Köpenick with a total of 28 forestry districts. Leaving Kyritz aside, they are spread throughout an area extending over 65 km from north to south and 70 km from east to west.
The average size of the areas is approx. 980 hectares.