In the topic "Forest Functions" areal information about selected functions of the forest areas in Hamburg is presented. The forest makes a special contribution to the protection of the natural basis of life and to human recreation. The effects and services of the forest and forest management can be described as forest functions, insofar as they generally meet human needs or expectations. Forest functions meet societal requirements on the one hand and contribute to the stabilization of ecosystems on the other. Depending on the purpose, forest functions can be combined. A general distinction is made between the useful function, the protective functions (including nature and biotope protection), the recreational function and other special functions. Forest areas are shown if they fulfill one or more functions beyond the normal extent. The functions are selected for which validated data or definable categories could be obtained. For example, forest areas that are located in flood or water protection areas or in Natura 2000 areas and fulfill a corresponding protective function there are not shown. The data was collected by an expert in 2016 and partially supplemented and adjusted as of 2019. The basis of the expert assessment is the nationwide "Guideline for mapping the protective and recreational functions of the forest" of the Forestry Research and Experimentation Institute Baden-Württemberg, Freiburg 2015. Forest areas are shown that fulfill a function as 1. Recreational forests 2. Protection against erosion 3 . Regional climate protection forest and 4. Privacy forest. Re 1. The forest areas are recorded that were assessed by experts as part of a forest function mapping as important for human recreation. Only the forest that is actually available to the general public was selected. The categories "of very great importance" and "of great importance". Criteria for the designation include accessibility, attractiveness, the range of recreational facilities, low noise and immission levels and restrictions on the right of access. Classification in the category "of very great importance" takes place usually when special forestry efforts and expenses are required to maintain the recreational function. To 2. In principle, the forest offers very good protection for the preservation of the soil and its natural development. Only those forest areas are shown that were assessed as important for protecting the soil from erosion within the framework of a forest function mapping. Forest areas were selected on - soils at risk of wind erosion in correspondingly exposed locations with a high proportion of humus, fine sand and loess, - soils at risk of water erosion with steep slopes and low cohesion or - on artificially raised soils. To 3. All forest areas fulfill a climate protection function. However, depending on the size and structure of the stocks and the topography, the effect on the neighboring built-up or undeveloped areas varies. Shown are the forest areas that protect and improve the climate in densely populated areas through air exchange (regional climate protection forest). Regional climate protection forest is designated taking into account the size of the forest and the size and location of the agglomeration, the relief and the prevailing wind direction. A distinction is made between forest areas, which act as a large-scale source of cold air in summer, and forest areas, which act as brakes on cold air in winter, primarily protecting lower-lying areas from late frosts. On 4. Privacy forest not only hides objects that are perceived as disturbing, but also protects systems or properties from unwanted views from outside. The areas of the forests are shown which, in their horizontal extent, can fulfill the protection purpose all year round and permanently. A distinction is made between forests that - protect against insight into facilities and airports or - provide privacy for recreational or residential areas.
