Soil Associations 2015

Map Description

Soils vary greatly in their ecological properties, depending on parent material, grain size, composition, humus contents, relief profiles and depth to groundwater.

Important parameters that characterize the ecological properties of soils are: usable field capacity, aeration, cation exchange capacity, pH values, effective rooting depth, and summer moisture.

Usable field capacity is a measure for the amount of water in soil available to plants. This includes slowly moving seepage water and retained water in the coarse and medium pores of soil. Soil water in the fine pores (dead water) is subject to high water tension and cannot be absorbed by plants. The amount of water stored in the soil is determined by pore volume, pore size distribution, grain size composition, and humus levels.

Aeration of the soil includes gas exchange by diffusion between the atmosphere and soil. Aeration is critical for the growth of plant roots and the existence and activity of soil organisms. The intensity of gas exchange depends on pore volume, particularly the number of coarse pores, as well as their continuity. Other factors are grain size composition, structure, and the water content of the soil.

Cation exchange capacity is the number of exchangeable cations bound to clay minerals and humus materials in the soil; e.g. Ca2+, Mg2+, K+, Na+, NH4+, H+. Cation exchange capacity gives indications of the soil’s ability to bind and store nutrients. This binding capacity, or nutrient storage capacity, depends on the type and amount of clay minerals, humus amounts, and pH values. Current actual nutrient levels in the soil can thus be lower than potential nutrient levels. The potential (i. e. maximum) cation exchange capacity for soil is given as a pH value of 8.2, and the effective cation exchange capacity for the current actual pH value of the soil is determined. Effective cation exchange capacity, air and water conditions, biological activity, and redox properties, etc. are important factors for an evaluation of nutrient levels actually available in the soil.

The pH value allows for direct and indirect determinations of various processes and properties of soils, including weathering processes; soil formation processes, such as podzolization or clay translocation; species range and activity of soil organisms; humic material formation; structural stability; soil acidification; and the silting (mud filling) process.

Summer moisture represents the water supply useable for the effective root area in critical dry periods during the main vegetation growth period. The figure takes into consideration usable field capacity, climate, relief, and groundwater.

Effective rooting depth is the depth in the soil where plants can draw water. Anthrosols can restrict rooting by impenetrable layers, e.g. concrete, lack of air, or the formation of methane, for example in waste disposal site soils.

Soil Types

The near-natural soils in Berlin with a long developmental history and relatively uninfluenced by use are: luvisols (para-brown soils), podzoluvisols (leached soils), cambisols (brown soils), dystric cambisols (rusty-brown soils), spodo-dystric cambisols (podzol brown soils), podzols, gleysols, and histosols (bog soils). Histosols (bog soils) appear almost only in the less densely populated and unpopulated outer edges of the city.

Luvisols (para-brown) and podzoluvisols (leached soils) are the most predominant soils in the sandy overlayered Barnim and Teltow boulder marl plateaus. They are dealkalized to a depth of 1 – 2 m. Podzoluvisols (leached soils) occur mainly in forest areas. The greater humus and clay contents in the topsoil give luvisols (para-brown soils) a distinctively greater nutrient supply than podzoluvisols (leached soils). Luvisols have a medium to high storage capacity for water and nutrients and are well aerated. The pH values of topsoils in forest plantation areas are usually low at 3 – 4; with soil acidification by humic acid, fulvic acid and “acid rain”. The pH values of agricultural soils are higher because of fertilizers and liming. The nutrient supply of forest plantation soils in the shallow root zone down to 0.3 m depth is very low to moderate; on farmland it is low to elevated. The nutrient supply in the deep root zone down to 1.5 m depth is medium to high because of the increase in pH (Grenzius 1987). Podzoluvisols (leached soils) have a greater nutrient supply in the subsoil – Bt horizon – than topsoils with little clay. Water storage capacity and aeration are sufficient. Luvisols (para-brown soils) are good locations for agricultural plants, particularly in Rudow, Mariendorf, Lichtenrade (Teltow plateau), Kladow (Nauen plate), Hohenschönhausen, Hellersdorf, Weißensee, and Pankow (Barnim pleateau).

Cambisols (brown soils) develop on the sandy areas of the Barnim and Teltow boulder marl plateaus, on the lower slope of plateaus, moraine hills, and end moraines. Cambisols develop particularly well as colluvial (transported) formations in the sometimes silty medium and fine sands of the Berlin glacial spillway, the Panke-Tal, and in the sinks of dune landscapes. Stagno-gleyed and residual stagno-gleyed cambisols, and eutro-gleyic cambisols occur mainly in the glacial spillway, depending on earlier and current groundwater levels.

Cambisols are deeply rootable and well aerated. They have a low, sometimes medium water storage capacity at lower slopes of end moraines through water inputs and deposits of clay. They are dry locations for shallow-rooted plants and fresh locations for deep-rooted plants. The stagno-gleyed and eutro-gleyic cambisols of the glacial spillway, however, were moist locations before the groundwater level sank. Cambisols usually have a moderate nutrient storage capacity, but the actual nutrient supply of cambisols with low pH values used for forests and grain production is very low to moderate. The nutrient supply is higher with greater humus contents and pH values, such as found in vegetable crop and horticultural areas.

Dystric cambisols (rusty brown soils) are found on the glacial sands of the Nauen plate (Gatow-Kladow), and the Barnim and Teltow plateaus. Dystric cambisols are also the predominant soils of the end moraines in the Düppeler Forst, in Grunewald (Havelberge), in the Köpenicker Forst (Müggelberge), the Gosenberge, and the Seddinberg. Dystric cambisols are also formed in valley sands remote from groundwater, such as in the Forst Jungfernheide, and dystric cambisols, along with spodo-dystric cambisols (podzol brown soils). They are the predominant soils in dunes in the Spandau, Tegel, and Köpenick forests.

Both dystric and spodo-dystric cambisols are deeply rootable and well aerated. They possess a low to moderate usable field capacity and a medium nutrient storage capacity. They are very dry to dry and are very nutrient-poor locations. Their water and nutrient storage capacities are increased by interstratifications of silt in the subsoil, and by horticultural use, or in the vicinity of bogs (gleyed spodo-dystric cambisols or stagno-gleyed dystric cambisols, and dystric gleysols or spodo-dystric cambic gleysols).

The formation of podzol soils requires special climatic conditions, such as low temperatures and high precipitation. Podzol soils develop on fine-grained, lime-free and sandy substrates. They only appear at a few locations in Berlin forests; mainly at the northeast slopes of dunes in the Tegel Forst (cf. Grenzius 1987), the Püttberge in the Köpenicker Forst (cf. Smettan 1995), and in part of the end moraine formation of the Seddinberg.

Podzol soils are usually deeply rootable and well aerated, but in spite of their medium to high water and nutrient storage capacity, they are nutrient-poor and dry soils.

Gleysols form from sandy or silty substrate at locations with high groundwater levels. Gleysols appear in sinks of valley sand levels in the Spandau Forst. They are dependent on relief profiles and are often associated with stagnic gleysols (wet gleys), histo-humic gleysols (turfy moulder gleys) and histosols (bogs). Together, they form the soils of the sinks in the dunes in the Spandau Forst and in the Forstrevier Schmöckwitz south of Seddinsee; the meltwater channels such as the Kuhlake, Breite Fenn, Rudower Fließ, Tegeler Fließ, Wuhle, Neuenhagener Mühlenfließ, and the Krumme Laake; the dead ice sinks of the Großer Rohrpfuhl and the Teufelsbruch in Spandau, and the dead ice sink Teufelssee in Köpenick.

The ecological properties of gleysols differ greatly depending on the parent material, humus contents, groundwater level, and the nutrient supply in the groundwater. Residual gleysols are also found in Berlin in areas of lesser depth to groundwater where groundwater levels have sunk. The residual gleysols have typical gley characteristics in profile structure, but their ecological properties differ very greatly from gleysols.

Gleysols are usually moist topsoil locations for shallow-rooted plants, and wet subsoil locations for deep-rooted plants. The available air supply is inversely proportional to the water level of the soil. This results in poorly aerated subsoil and, depending on water levels, a well to poorly aerated topsoil (sometimes alternately dry to wet), and medium rootability. Gleysols have a large to high nutrient storage capacity and a moderate to high nutrient supply, depending on humus contents. The nutrient supply is higher if additional nutrient inputs occur by way of the capillary uptake of eutrophied groundwater.

Residual gleysols are dry to very dry, well aerated into the subsoil, deeply rootable locations with generally medium to higher water capacities. The nutrient supply is low to medium, depending on humus contents and pH values. Nutrient input from groundwater is usually lacking.

Histosols (bog soils) have a high water level, are very poorly aerated, and only shallowly rootable. Histosols have a very high water storage capacity and a medium to higher nutrient storage capacity. They are undrained, near-natural locations with varying nutrient supplies.

Bog soils are subject to drying and mineralization when groundwater levels sink. Their properties relevant for plants are thus changeable. Dried boggy (histosols) and peaty moulder soils (histo-humic soils) that appear in the glacial spillway, such as in allotment garden areas along the Teltow and Neukölln canals, and in Treptow along the edge of the Teltow plateau, are deeply rootable, well aerated, and moist locations, in contrast to intact bog soils.

Loose lithosols (raw soils of loose material), regosols, and calcaric regosols (para-rendzinas) are relatively young soil formations, compared to soils that have developed for hundreds or thousands of years. They develop on young aggraded areas of eroded natural rocks, and at areas of anthropogenically aggraded materials.

Natural soil erosion occurs naturally, for example, by the action of wind or water on the slopes of dunes, as well as on kames (short moraines crosswise to the flowing direction of the ice), and moraine hills. Anthropogenic soil erosion is caused by human use of soil. Soil inputs can occur both through natural translocation processes and through anthropogenic aggradations. Aggradations are differentiated into aggradations of natural material, such as soil excavation and gravel, and aggradations of artificial substrates such as war debris, construction debris, slags and cinders, etc.

Loose lithosols, regosols and calcaric regosols (para-rendzinas) of anthropogenically aggraded material undergo the same soil development as natural rock. The various parent material is described by the soil form, e.g. regosol of glacial sand, regosol of war debris, etc. (Grenzius 1987).

The soils of the Berlin urban area are characterized by intensive anthropogenic interventions resulting from settlement, demolition of buildings, damage incurred during the Second World War, as well as construction. There are large-area aggradations of war debris, slag and cinders, and building materials, as well as eroded areas due to construction of streets and railway lines, and the surface mining of gravel, sand, and clay. This has led to the wide distribution of loose lithosols, regosols, and calcaric regosols in the Berlin urban area.

Loose lithosols (raw soils of loose material) appear mainly on eroded areas of natural rock in the outer urban area. They develop where dystric cambisols (rusty-brown soils) and cambisols (brown soils) of glacial, valley, and drift sands have been removed by use, such as at military training areas and surface mining sites. Near-natural soils can still be found in small parts of areas impaired to a lesser degree.

Larger military training areas are located in Heiligensee at Baumberge, in the Grunewald, and in the Köpenick Forst at Jagen 161. Surface mines in the Berlin urban area are located at Kaulsdorfer Seen, the Kiessee Arkenberge in Pankow, the Tegeler Flughafensee, and the Laszinssee in Spandau.

Ecological properties are marked by natural undersoil and groundwater levels, e.g., loose lithosols created by erosion of dystic cambisols are well-aerated, usually dry, and nutrient-poor soils.

Loose lithosols (raw soils of loose material) at aggradation areas of anthropogenically transported rock (war debris, construction debris, railway track crushed rock, industrial crushed rock) are found at open areas throughout the entire densely-populated urban area, such as the inner city; at all areas greatly damaged or destroyed during the Second World War (soil association 52); and at industrial, and commercial locations. Loose lithosols also appear at war and construction debris disposal sites like the Eichberge in Köpenick, Arkenberge in Pankow, Teufelsberg in Grunewald, Trümmerberg in Friedrichshain, Volkspark Prenzlauer Berg, and at railway tracks throughout the entire urban area. Loose lithosols are less common at aggraded or translocated natural rock, such as landfill bulwarks at military training areas, including firing ranges.

The ecological properties of these loose lithosols are determined by the aggraded material. Loose lithosols of sands and artificial substrates form very dry to dry locations; tar or concrete layers in the undersoil form locations of periodic moisture. Aeration and thus oxygen supply are good; rootability is restricted by high stone contents; rootability is deep in rock-free, sandy soils. Nutrient supply and storage capacity is low to high, according to basis rock and use.

The formation of regosols (cf. Grenzius 1987) is a result of natural erosion (water and wind) and anthropogenic induced erosion (in Berlin often a high pedestrian load on slopes) of the loose lithosols on kames, moraines, or dune sands. The soil formation process is continuous. Humus accumulation in the Ah horizon results finally in regosols. These regosols appear, for example, on the steeper slopes along river Havel in Grunewald, in the Düppeler Forst, and on the slopes of the Müggelberge. Soil aggradation and erosion by the construction and closing (levelling) of sewage farms in the north of the boroughs Pankow, Weißensee, and Hohenschönhausen also influenced the formation of regosols from natural materials. These are soil associations 2560 [60], 2580 [62], 2590 [63].

Regosols of sandy, lime-free aggradations develop mainly in more densely built-up urban areas, including smaller green areas and park facilities. They are usually poor in nutrients. Humus accumulation in the topsoil improves the nutrient supply. They often have a low water storage capacity, good aeration, and a deep to medium rootability, depending on the stone content.

Calcaric regosols (para-rendzinas) develop from loose lithosols of limey substrate. Calcaric regosols of natural origin develop on eroded areas of marl pits which have been left open, on translocated marl, such as at foundation excavations, and on eroded slopes of bodies of water and channels of boulder marl plateaus.

Calcaric regosols developed in the bottomland of the Bäke at the Landgut Eule, and at Albrechts Teerofen from lime mud or disturbed shallow water sediments. This material was excavated for the Teltow canal and redeposited (cf. Grenzius 1987).

Calcaric regosols of anthropogenic aggradation material occur all throughout the entire densely built-up urban area at sites filled with war debris or construction debris; at all areas of heavy war damage with debris aggradations; and at railway facilities. Calcaric regosols are also found along the many landfill banks and bottomlands of the Havel and Spree rivers and their lake-like broadenings.

The higher clay levels of boulder marl calcaric regosols show an increased nutrient storage capacity, and a medium to high usable field capacity. Calcaric regosols of war debris are nutrient-poor and dry. Aeration is good, the rootability of war debris calcaric regosols is shallow because of the stone content. Calcaric regosols of lime muds are fresh, well to poorly aerated locations that are rich in nutrients, depending on the groundwater level.

Selected Soil Associations

Currently, there are 78 distinct soil associations. In the following, some characteristic soil associations (SA) will be described. A more detailed description of soil associations was developed by Grenzius (1987). The depicted landscape segments originate from Grenzius’ dissertation (1987).

Soil association and its characteristic soil types, use/ formation and frequency

Tab. 7: Soil association and its characteristic soil types, use/ formation and frequency. The frequency for collective associations 3020, 3030 and 3040, cannot be directly compared with others, as it encompasses several soil associations.

Near-natural Soil Associations

SA 1010 [1] Luvisol (para-brown soil) – arenic cambisol (wedged sand-pit brown soil)
(ground moraine flat upland area of boulder marl)

This soil association combines soil types with plateaus withboulder clay or marl as parent material. Shrinkage created wedges filled with sand; this was then overlaid with drift sand. A mixture of drift sand with boulder marl led to the formation of the glacial cover sand. Luvisols developed on the 1 – 3 m deep wedged sand-pits of arenic cambisols (wedged sand-pit brown soils) where the boulder clay and marl was covered with a thin glacial sand cover.

This soil association is particularly found at the Teltow and Barnim boulder marl plateaus.

soil association of the ground moraine flat upland area of boulder marl

Fig. 2: Luvisol (para-brown soil) - arenic cambisol (wedged sand-pit brown soil) (soil association of the ground moraine plateau of boulder marl)

SA 1070 [6] Dystric cambisol (rusty brown soil) – colluvial cambisol (colluvial brown soil)
(outwash plain over) moraine area of glacial sands

This soil association comprises dystric cambisols on the sandy, morphologically relatively flat area of the boulder marl plateaus and the ground moraines of the Teltow (Grunewald, Düppler forest) and Barnim plateau. The upper 2 metres of glacial sand do not contain boulder clay or marl.

soil association of moraine areas (outwash plain) of glacial load sand

Fig. 3: Dystric cambisol (rusty brown soil) - colluvial cambisol (colluvial brown soil) (soil association of moraine areas (outwash plain) of glacial sands)

Dystric cambisols also appear at the kames formations of the Grunewald forest, from Lübars to Arkenberge, and in the end moraine formations in Gatow and Müggelberge, where they have a different spatial relationship (geomorphological unit). This is why, this geomorphological unit was included with another soil type in another soil association, SA 1040 [4]).

Another soil association, SA 1020 [2] or 1030 [3], is of dystric cambisols on relatively higher moraine hills of glacial sands with some boulder marl or boulder clay remainders within the first two metres of the glacial sands.

SA 1090 [9] Spodo-dystric cambisol (podzol brown soil) – podzol – colluvial dystric cambisol (colluvial rusty brown soil)
(dunes of fine sand)

SA 1100 [10] Spodo-dystric cambisol (podzol brown soil) – dystric cambisol (rusty brown soil) – colluvial dystric cambisol (colluvial rusty brown soil)
(dunes of fine sand)

Soil associations 1090 [9] and 1100 [10] are dunes several metres thick, remote from groundwater, as well as larger dune areas with terrain heights of over 40 m above sea level. They differ primarily in the presence of podzols. They appear mainly in the Tegel and Frohnau forests, but in the Köpenicker Forst as well. No statements can be made about the presence of podzols without soil profile studies. These two soil associations in East Berlin were partially listed as collective soil associations, unless maps were available (Standortskarten des Forstbetriebes Ost-Berlin, Smettan 1995) (Site Maps of East Berlin Forest Management), in which case they were listed separately.

soil association of dunes of fine sand

Fig. 4: Spodo-dystric cambisol (podzol-brown soils) - podzols - colluvial Dystric cambisols (colluvial rusty brown soil) (soil association of dunes of fine sand)

SA 1160 [15] Dystric cambisol (rusty brown soil) – stagno-gleyed cambisol (gleyed brown soil) – eutro-gleyic cambisol
(valley sand areas of medium and fine sand)

This soil association is widely distributed in the Berlin glacial spillway (Urstromtal). The Berlin Urstromtal is the last meltwater valley of the Frankfurt phase of the Weichselian glaciation. The medium and fine sands transported and deposited in the valley by meltwater formed the parent material for the formation of cambisols and dystric cambisols. Varying groundwater levels caused the formation of gley properties, such as rusty spots, in various depths. These are represented by the soil types stagno-gleyic cambisol and eutro-gleyic cambisol. Groundwater levels sank in this century because of groundwater removals by the Berlin Waterworks. Gley properties are often only residuals today, i.e. groundwater levels today are deeper than the gley characteristics they once produced. This soil association is present particularly in the Spreetal in Köpenick, and in the valley sand areas of forests in Spandau, Tegel and Jungfernheide.

soil association of valley sand areas of medium and fine sand in the Spandau Forest

Fig. 5: Stagno-gleyed cambisol (gleyed brown soil) - eutro-gleyic cambisol (gleyic brown soil) (soil association of valley sand areas of medium and fine sand in the Spandauer Forst)

SA 1231 [22a] Eutro-gleyic cambisol (gleyic brown soil) – gleysol – eutric histosol (lower bog)
(meltwater channels in valley sand areas without dunes)

The great pressure from the weight of the glaciers melted ice at their bottom layers. The runoff of this meltwater produced subglacial meltwater. Great amounts of meltwater produced in the warm periods between ice ages flowed into the valleys and with their erosive force created – at times deep – subglacial meltwater channels. The channels in the vicinity of groundwater bogged or silted up after the last ice age. Many of these channels, particularly in the Berlin inner city, were landfilled and/or built upon, and are not visible today.

Such fluvioglacial meltwater channels within valley sand areas are found in parts of the Wuhle, the Neuenhagener Mühlenfließ, Spekte-Lake, the Egelpfuhlwiesen, and the Breite Fenn. Histo-humic gleysols (peatymoulder gleys) and valley bog peat formed directly in the middle of these channels, depending on groundwater levels. Also depending on groundwater levels, eutro-gleyic, eutro-gleyic dystric, stagno-gleyed and stagno-gleyed dystric cambisols were formed towards the channel edges.

meltwater channels in valley sand areas without dunes

Fig. 6: Eutro-gleyic cambisol (gleyic brown soil) - gleysol - eutric histosol (lower bog) (meltwater channels in valley sand areas without dunes)

Anthropogenic Soil Associations

SA 2420 [41] Necrosol + eutro-gleyic cambic hortisol (gleyic brown horticultural soil) + gleysol
(cemetery on valley sand areas of medium and fine sands)

This soil association is comprised of valley sand soils. The use as cemeteries brings certain anthropogenic influences. Necrosols are defined as soils resulting from excavations for graves. The unused cemetery areas of valley sands still retain residual eutro-gleyic cambisols and gleysols. The long-term input of humus develops humic regosols, horti-gleyic cambisols, and hortisols (horticultural soils).

soils of cemeteries on valley sand areas of fine and medium sands

Fig. 7: Necrosols + eutro-gleyic cambic hortisol (gley brown horticultural soil) + gleysol (soils of cemeteries on valley sand areas of fine and medium sands)

Other anthropogenic uses have extremely altered soils so that once natural soils were extensively destroyed, or covered by other materials.

SA 2470 [49] Lithosol + calcic regosol + calcaric regosol (para-rendzina)
(railway tracks on aggraded and eroded surfaces)

This soil association includes soils used for railway facilities and railway stations. The trackbeds are of coarse gravel of various materials; the embankments are of sand, war and industrial debris are also used as fill. Lithosols, loose lithosols, calcaric and calcic regosols are mainly formed, depending on the soil substrate.

soils of rail facilities on aggraded or eroded surfaces

Fig. 8: Lithosol + calcic regosol + calcaric regosol (soils of railway facilities on aggraded or eroded surfaces; Potsdamer Güterbahnhof (freight station))

SA 2490 [51] Loose lithosol (raw soil of loose material) + humic regosol + calcaric regosol (para-rendzina)
(dense inner city construction; not destroyed during the Second World War ; on aggraded surfaces)

This soil association characterizes soils within areas of uniform construction built before the Second World War, undestroyed or only lightly damaged. The degree of impervious soil coverage is high. Soils in the rear courtyards used currently or previously as yards are characterized by humic topsoils and were able to develop into humic regosols, hortisols, and humic calcaric regosols. Other back courtyard areas lightly covered by debris formed loose lithosols (raw soils of loose material) and regosols.

soils of dense inner city construction

Fig. 9: Loose lithosol (raw soil of loose material) + humic regosol + calcaric regosol (soils of dense inner city construction; not destroyed in the Second World War; on aggraded surfaces)

SA 2500 [52] Loose lithosol (raw soil of loose material) + regosol + calcaric regosol (para-rendzina)
(inner city on aggradation/landfill)

This soil association describes soils of the previously densely constructed inner city, completely destroyed in the Second World War. Most war debris remained where it fell. Many surfaces without buildings have a soil layer composed partially or completely of war debris and/ or construction sand. This thickness of this layer is from a few tenths of a metre up to 2 metres deep (cf. Grenzius 1987). Fig. 10 shows how these surfaces develop lithosols and calcaric regosols. Surfaces without war debris develop lithosols and regosols.

soils of the inner city on aggradations

Fig. 10: Loose lithosol (raw soil of loose material) + regosol + calcaric regosol (para-rendzina) (soils of the inner city on aggradations)

The Map of Soil Associations was prepared from existing data of the most various kinds. The map gives an overview of the near-natural and anthropogenic soil associations to be expected, depending on the parent material, geomorphology or landscape segment, groundwater level, and use. The soil association category allows the derivation of main soil types, as well as site characteristics such as aeration, rootability, field capacity, usable field capacity, nutrient storage capacity, and potential and effective cation exchange capacity as a measure for nutrient storage capacity (cf. Grenzius 1987).

Soil types and ecological properties may be derived with a certain probability using additional information, such as topographic maps and the current groundwater level, as well as the soil association in a terrain without a map. Using this method, statements about gleysols or residual gleysols, and thus of moist or dry locations, can be made only under consideration of current groundwater levels.

Soils are a basic natural element and co-determinants of the diversity of flora and fauna at the site. Seldom, unaltered, and only slightly altered soils are considered in the demarcation of protected areas.

The Map of Soil Associations is suitable for deriving site characteristics, and for making evaluations regarding soil protection and soil functions. Environmental Atlas Maps 01.06 document soil-scientific characteristic values, Maps 01.12 present an analysis of soil functions and Maps 01.11 outline criteria to derive these functions.

Tab. 8: List of soil type abbreviations used in figures 2 - 10 (according to Grenzius 1987)

Tab. 8: List of soil type abbreviations used in figures 2 - 10 (according to Grenzius 1987)