In addition to a survey of the distribution and heterogeneity of the particular soil associations in the municipal area (cf. Map 01.01), data on their ecological properties are of great importance for statements regarding the qualities, sensitivity and pollution of the soil. This involves primarily characteristic values regarding the chemistry, the physical state and the water balance of the soil. The quality of these characteristic quanta is determined primarily by the soil associations, but it is substantially influenced by current land use.
The soil-scientific characteristic quanta described here have been derived from the soil associations, taking land use into account (cf. Maps 06.01 and 06.02). The assumption was that the quality of the characteristic soil values for certain soil associations with a certain land use would be identical for all lots of such a combination, in the context of the required precision of statements.
The characteristic quanta for every combination of land use and soil associations were determined as representative values from existing documents. The data were primarily taken from the assistance manual for the maps of soil associations (Dissertation, Grenzius 1987), in which landscape segments and sample profiles on particular soil associations are documented, based largely on measurements by the Institute for Soil Science at the Berlin University of Technology. In addition, various other soil-scientific maps were evaluated. Moreover, it was possible to access the results of the extensive soil analyses of the heavy-metal investigation programme for humus content and pH values.
If no measurements were available for certain combinations, the values were assessed by expert evaluations, using data on comparable uses or comparable soil associations. Due to the often very different number of measurements available per combination and the great variety of analogical evaluations, the precision of the values given varies greatly.
For most characteristic quanta, the data refer to the topsoil (0 – 10 cm) and the subsoil (90 – 100 cm) separately.
Due to the map scale, the units given in the legend of the soil map refer to soil associations which are in many cases have very heterogeneous soil-ecological qualities. The complexity of the ecological conditions, with the assigned typical values which refer to a single characteristic soil type of the respective soil associations, is represented in greatly simplified terms. Therefore, the soil-scientific database contains, in addition to the representative value (e.g. typical pH value), the maximum and minimum values available from the respective evaluations.
For these reasons, the maps are therefore designed only as general maps in a scale of 1:50,000, and cannot replace site-specific investigations in particular cases.