Medium protection level
The category of the soils deserving protection is based on their medium-level fulfillment of the function both for the water balance and for the filtration and buffering fortune.
The pervious or slightly impervious share (0 – 5 %) of this category is a large contiguous area, the Grunewald Forest and the Düppel Forest. The dominant soil associations include acidic dystric cambisols with colluvial cambisols of detritial sands. Scattered areas of detritial sands, but over marl, are located in the Gatow Heath, and in Bohnsdorf, with colluvial cambisol – dystric cambisol – luvisol. In Heiligensee, soils of drifting sands with loose lithosols, cambisol/dystric cambisol – stagno-gleyed cambisol – gleysol, too, are characteristic soils in this protection category.
The share with a medium level of imperviousness (> 5 – < 30 %) is small, and consists of very small, non-contiguous areas. Examples are sections in the valley sands, such as the East Berlin Zoo, shore areas on the Spree in Köpenick, and Tegel Airport with dystric cambisol – stagno-gleyed cambisol – gleyic cambisol. In residential sections with more loosely-built single-family homes in Frohnau, the soils of drifting sand with spodo-dystric cambisol – dystric cambisol – colluvial dystric cambisol are deserving of protection. In the residential sections of Zehlendorf and Dahlem and the Hasenheide Park, the dystric cambisol – regosol-cambisol – colluvial cambisol soil association of detritial sand fulfill these prerequisites. In the loosely-built areas in Kladow and to some extent in Gatow, luvisol – colluvial cambisol is present. Groundwater-affected associations of this protection category exist in the residential sections of
Müggelheim and Rahnsdorf with dystric cambisol – stagno-gleyed cambisol – eutro-gleyic cambisol on valley sand, to some extent linked with podzol (coniferous-forest) soil associations of drifting sand. On the Barnim Plateau, in Wittenau and Pankow, there is primarily dystric cambisol – luvisol associated with dystric cambisol – colluvial cambisol or gleyic cambisol of detritial sands (mixed with Ice-Age material).
The highly impervious sections (30 – 100 %) account for the major share of this protection category. They are concentrated on the Barnim and Teltow Plateaus, in the south and north of the city. These locations are chiefly located in such densely built-up areas as Steglitz, Prenzlauer Berg, Pankow, Lichtenberg or the Märkisches Viertel in Reinickendorf. The soil associations are anthropogenically characterized, and sandy deposits are frequently the basic material for their soil formation. The dominant soil types are therefore little developed A – C soils, such as loose lithosols, regosols, calcaric regosols and hortisols.
The total area of this protection category amounts to 17,151 ha. Of these, 3,084 ha (18 %) are up to 5 % impervious, 4,144 ha (24 %) > 5 – < 30 % and 9,923 ha (58 %) 30 % and more impervious.
This category accounts for the second-largest area among the protection categories, with 23 %. Of the total area, 11,401 ha (66 %) are pervious (cf. Fig. 7). Where in the other protection categories, sections with degrees of imperviousness of less than 30 % predominated, this category is primarily characterized by sections with a high degree of imperviousness, of 30 – 100 %. These are largely located on the residential sections of the plateaus, some even within the urban-rail ring line. Sections with a low degree of imperviousness of < 5 % are negligible (cf. Fig. 6 and Tab. 1).
The sections of this protection category are found predominantly in the residential sections, but also in forests (Fig. 8).