Soil Associations 2020

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 characterise the ecological properties of soils are available water capacity , aeration, cation exchange capacity, pH values, effective rooting depth, and summer moisture.

*Available water capacity * is a measure for the amount of water in soil available to plants. This includes slowly moving seepage water and water retained in the coarse and medium pores of the 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 the 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 the 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⁺. The 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 levels, and pH values. Actual nutrient levels present in the soil may thus be lower than the potential maximum nutrient levels. The potential (i.e. maximum) cation exchange capacity for soil is determined based on a pH value of 8.2, and the effective cation exchange capacity on the current pH value of the soil. Effective cation exchange capacity, air and water conditions, biological activity, and redox properties, are important factors in assessing the actual nutrient availability of the soil.

The pH value plays an important role in shaping the soil, influencing both directly and indirectly a range of processes and properties, including weathering processes; soil formation processes, such as podzolisation or clay translocation; diversity and activity of soil organisms; humic material formation; structural stability; soil acidification; and the silting (mud filling) process.

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.

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 available water capacity, climate, relief, and groundwater.

Soil Types

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) are near-natural soils that occur in the Berlin area. They have a long developmental history and have been minimally influenced by human activity. 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 sand-covered Barnim and Teltow boulder marl plateaus. They are decalcified down to depths of 1 to 2 m. Podzoluvisols (leached soils) occur mainly in forest areas. The higher humus and clay contents in the topsoil offer luvisols (para-brown soils) a distinctively greater nutrient supply compared to podzoluvisols (leached soils). Luvisols have a medium to high capacity for storing water and nutrients and are well aerated. As a result, luvisols provide ideal planting conditions for agriculture, particularly in Rudow, Mariendorf, Lichtenrade (Teltow plateau), Kladow (Nauen plate) as well as Hohenschönhausen, Hellersdorf, Weißensee, and Pankow (Barnim plateau). In forest areas, topsoil pH values are typically low (pH 3 to 4, due to soil acidification from humic and fulvic acids as well as ‘acid rain’). Farmland, however, has higher pH levels due to fertilisation and liming practices. The nutrient supply of forest 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 topsoil with little clay. Water storage capacity and aeration are sufficient.

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 Valley, 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 previous and current groundwater levels.

Cambisols are well aerated and allow for deep root development. They have a low, sometimes medium water storage capacity at lower slopes of end moraines through water inputs and deposits of clay. They provide a dry environment for shallow-rooted plants and provide adequate moisture for deep-rooted plants. The stagno-gleyed and eutro-gleyic cambisols of the glacial spillway, however, were once moist locations until the groundwater level receded. Cambisols generally exhibit a moderate nutrient storage capacity However, in practice, cambisols with low pH values used for forestry and grain production often have very low to moderate nutrient availability. The nutrient supply increases with higher humus content and pH values, such as found in areas used for vegetable crops and horticulture.

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 soil type in the push moraines of Pichelsberg in Charlottenburg-Wilmersdorf. Additionally, they develop on valley sands without groundwater, such as in the Forst Jungfernheide, and, along with spodo-dystric cambisols (podzol brown soils), serve as the predominant soils in the dunes of the Spandau, Tegel, and Köpenick forests. Both dystric and spodo-dystric cambisols allow for deep root development and are well aerated. They possess a low to moderate available water capacity and a medium nutrient storage capacity. They are very dry to dry environments and extremely poor in nutrients. The capacity to store water and nutrients is increased in these soils if there are silt deposits in the subsoil, if they are used for horticulture, or if they are located 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 specific 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 the Berlin forests; mainly on the northeast slopes of dunes in the Tegeler Forst (cf. Grenzius 1987), and the Püttberge in the Köpenicker Forst (cf. Smettan 1995).
Podzol soils usually allow for deep root development and are well aerated, but in spite of their medium to high water and nutrient storage capacity, they are nutrient-poor and dry.

Gleysols develop in locations with high groundwater levels from sandy or silty substrates. They occur in sinks within the sand plains in the Spandau Forst. Due to the relief, they are often associated with stagnic gleysols (wet gleys), histo-humic gleysols (peaty half-bog 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 kettle holes of the Großer Rohrpfuhl and the Teufelsbruch in Spandau as well as the kettle hole Teufelssee in Köpenick.

The ecological properties of gleysols vary greatly, depending on the parent material, humus contents, groundwater level, and the availability of nutrients in the groundwater. In Berlin, relict gleysols can also be found in areas with a low depth to groundwater, where the groundwater level has decreased. While these relict gleysols exhibit typical gley characteristics in their profile structure, their ecological properties differ significantly from gleysols.

Gleysols usually provide moist topsoil locations for shallow-rooted plants, and wet subsoil locations for deep-rooted plants. The available air supply is therefore inversely proportional to the water level of the soil. This results in a poorly aerated subsoil and, depending on water levels, a topsoil that ranges from well to poorly aerated. The topsoil may sometimes be wet or periodically dry with a medium level of rootability. Gleysols have a relatively high to high nutrient storage capacity and a moderate to high nutrient supply, depending on humus levels. The nutrient supply increases if eutrophied groundwater introduces additional nutrients through capillary uptake.

Relict gleysols are dry to very dry locations that are well aerated into the subsoil and allow for plants to form deep roots. They usually exhibit a medium to high capacity to store water. The nutrient supply is low to medium, depending on humus contents and pH values. Nutrient input from groundwater is usually lacking.

Histosols (bogs) have a high water level, are very poorly aerated, and only allow for shallow roots. Histosols have a very high water storage capacity and a medium to high nutrient storage capacity. They are undrained, near-natural sites with varying nutrient levels.

Bog soils often undergo peat humification and mineralisation due to groundwater lowering, resulting in altered conditions for plant growth.

In contrast to intact bog soils, earthy bog soils (histosols) and half bog soils (histo-humic soils) are relatively well aerated and moist locations that allow for plants to grow deep roots. They occur 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.

The soil types loose lithosols (raw soils of loose material), regosols, and calcaric regosols (para-rendzinas) are relatively young soil formations, compared to soils with development periods of hundreds or thousands of years. They develop on both young erosion surfaces from naturally occurring rocks, and areas composed of anthropogenically aggraded materials.

Natural soil erosion occurs as a result of natural processes, such as wind or water erosion on dune slopes, as well as on kames (short moraines perpendicular to the flow direction of the ice), and moraine hills. Anthropogenic soil erosion is a result of human activity on the soil. Soil inputs can occur both through natural translocation processes and through anthropogenic aggradations. Aggradations can be classified into those involving natural materials, such as soil excavation and gravel, and those involving artificial substrates such as war debris, construction debris, slags and cinders.

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

The soils of the Berlin urban area bear the marks of extensive human activity caused by settlement, the demolition of buildings, damage incurred during the Second World War as well as construction. On the one hand, there are large-scale aggradations of war debris, slag and cinders, and building materials, while on the other hand, there are areas eroded due to the construction of roads and railway lines as well as surface mining of gravel, sand, and clay. As a result, loose lithosols, regosols, and calcaric regosols are common in the Berlin urban area.

Loose lithosols (raw soils of loose material) on eroded areas of natural rock are mainly found 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 eroded due to specific land uses, such as is the case for military training areas and surface mining sites. Near-natural soils can still be found in small, less impacted military training areas.

Larger military training areas are located in Heiligensee at Baumberge, in the Grunewald, and in the Köpenicker 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 depend on the natural undersoil and groundwater levels, e.g., loose lithosols created by erosion of dystric cambisols are well-aerated, usually dry, and nutrient-poor.

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 in 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 2500); and at industrial, and commercial locations (Soil Association 2540). 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 as well as along railway tracks running throughout the entire urban area. Loose lithosols are less common on aggraded or transported natural rock, such as embankments 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 technogenic 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, however in rock-free, sandy soils. Nutrient supply and storage capacity is low to high, according to parent material and use.

Regosols develop from the loose lithosols found in areas where erosion occurs naturally or due to human activity, such as on kame, moraine, or dune sands and form due to humus accumulating in the Ah horizon (cf. Grenzius 1987). These regosols are commonly found on the steeper slopes of Grunewald along the Havel, 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 of Pankow, Weißensee, and Hohenschönhausen also influenced the formation of regosols from natural materials. These are represented by soil associations 2560 [60], 2580 [62], 2590 [63].

Regosols of sandy, lime-free aggradations develop mainly in 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 availability of nutrients. Regosols often have a low water storage capacity, good aeration, and allow for deep to medium root development, 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 relocated marl, such as at excavation sites, and on eroded slopes of bodies of water and channels of boulder marl plateaus.

In the Bäke lowland near Landgut Eule and Albrechts Teerofen, calcaric regosols developed from lime mud that was dredged up and then redeposited during the building of the Teltow Canal, or from disturbed shallow water sediments (cf. Grenzius 1987).

Calcaric regosols formed by anthropogenic aggradation develop on areas filled with war or construction debris. This includes the entire densely built-up urban area, areas that suffered extensive destruction during the War and were subsequently filled with debris, as well as railway areas. Calcaric regosols are also found along the many landfill banks and lowlands of the Havel and Spree rivers and their lake-like broadenings.

The higher clay levels of calcaric regosols of boulder marl exhibit an increased capacity to store nutrients, and a medium to high available water 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).

Tab. 7: Soil associations and their characteristic soil types, use/ formation and frequency. The frequency for Collective Associations 3020, 3030 and 3040, cannot be directly compared with each other, as they contain multiple soil associations.

Near-natural Soil Associations

SA 1010 [1] Luvisol (para-brown soil) – arenic cambisol (wedged sandpit brown soil)
(Ground moraine plateau of boulder marl)

This soil association combines soil types with plateaus with boulder 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 to 3 m deep wedged sandpits of arenic cambisols (wedged sandpit brown soils) where the boulder clay and marl was covered with a thin layer of glacial sand.

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

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

SA1070 [6] Dystric cambisol (rusty brown soil) – colluvial cambisol (colluvial brown soil)
(Meltwater sand on glacial sand)

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, Düppeler Forst) and scattered across the Barnim plateau. The upper 2 metres of glacial sand do not contain boulder clay or marl.

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 occur in the push moraine formation in Pichelsberg. Here, they have a different spatial reference (geomorphological unit), however. For this specific geomorphological unit, dystric cambisols were therefore incorporated into other soil associations (SA 1040 [4] and 1060 [5]) along with another occurring soil type.

Dystric cambisols have their own soil associations, designated as SA 1020 [2] and 1030 [3]. These soils also occur on moraine hills consisting of glacial sands of varying heights. Sometimes, remnants of boulder marl or boulder clay can be found within the upper two metres of the glacial sand.

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, with some occurrences in the Köpenicker Forst. Soil profile studies would be required to determine the presence of podzols. In East Berlin, these two soil associations were sometimes grouped together in 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.

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, which 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 served as the parent material for the formation of cambisols and dystric cambisols. Varying groundwater levels contributed to the development of gley properties, such as rusty spots, at various depths. These properties are represented by the soil types stagno-gleyic cambisol and eutro-gleyic cambisol. Since the 20^th century, groundwater levels have been lowered due to the groundwater extraction by the Berlin Waterworks. As a result, gley properties are often only remnants today, meaning that groundwater levels today are deeper than the gley features they once produced. This soil association is primarily found in the Spreetal in Köpenick, and in the valley sand areas of the forests in Spandau, Tegel and Jungfernheide.

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 (low-moor bog)
(Meltwater channels in valley sand areas without dunes)

The subglacial meltwaters formed during the glacial period due to the high pressure of the glacier on its bed as well as the meltwaters formed during interglacial periods as a result of climate warming, flowed into the large glacial spillways. They created, at times deep, (subglacial) meltwater channels through their erosive force. Channels close to groundwater filled with sediment and peat after the last Ice Age. Many of these channels, especially in the area of Berlin’s inner city, were anthropogenically filled and built upon and are therefore no longer visible today.

Such fluvioglacial meltwater channels within valley sand areas occur in parts of the Wuhle, the Neuenhagener Mühlenfließ, Spektelake, the Egelpfuhlwiesen, and the Breite Fenn. Depending on the groundwater level, Histo-humic gleysols (peaty half-bog gleys) and low-moor bog soils formed directly in the middle of these channels. Also depending on groundwater levels, eutro-gleyic, eutro-gleyic dystric, stagno-gleyed and stagno-gleyed dystric cambisols were formed towards the edges of the channels.

Fig. 6: Eutro-gleyic cambisol (gleyic brown soil) - gleysol - eutric histosol (low-moor 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 consists of soils found in valley sand areas, which have been influenced by humas due to their use as cemeteries. Soils resulting from deep excavation during grave digging are termed necrosols. In the unused sections of the cemetery that are located on valley sand, remnants of eutro-gleyic cambisols and gleysols can still be observed. Over time, continuous organic matter input has led to the development of humic regosols, horti-gleyic cambisols, and hortisols (horticultural soils).

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

Soils subjected to other anthropogenic uses have been significantly altered by human influence, leading to the extensive destruction or covering of natural soils with 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 composed of coarse gravel of various materials; railway embankments consist of sand or were filled with war and industrial debris. Depending on the soil substrate, lithosols, loose lithosols, calcaric and calcic regosols have primarily formed.

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 refers to soils within the urban area characterised by closed development, constructed prior to the Second World War and largely preserved or minimally damaged. The degree of impervious soil coverage is high. Soils found in the rear courtyards, which were or are still used for gardening, are characterised by humic topsoil and have evolved into humic regosols, hortisols, and humic calcaric regosols. In other areas of the rear courtyards, which may be covered with debris in individual cases, loose lithosols (raw soils of loose material) and regosols form.

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. The thickness of this layer ranges from a few decimetres up to 2 metres (cf. Grenzius 1987). Figure 10 shows how lithosols and calcaric regosols develop on these surfaces. On areas without war debris, lithosols and regosols form.

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 compiled from various existing data sources. The map provides an overview of the near-natural and anthropogenic soil associations likely to be present, based on factors such as parent material, geomorphology or landscape segment, groundwater level, and land use. From the soil associations, the main soil types and additional site characteristics may be inferred. This includes aeration, rootability, (available) water capacity, and nutrient storage capacity as well as potential and effective cation exchange capacity as an indicator of the nutrient storage capacity (cf. Grenzius 1987).

With additional information, such as topographic maps and current groundwater levels as well as information on the soil associations, it is possible to deduce the soil type and ecological properties of a location with relative certainty, even in the absence of a map. Information about (remnants of) gleyed soils and therefore wet or dry sites, can only be inferred based on current groundwater levels.

As essential components of the landscape, soils significantly influence the diversity of flora and fauna of an area. Therefore, rare or minimally altered soils are prioritised in the designation of protected areas.

In addition to deriving site properties, Soil Association Map 01.01 is also useful for gaining insight into soil protection and soil functions. Maps 01.06 of the Environmental Atlas document soil-scientific characteristic values, Maps 01.11 outline criteria for deriving soil functions, and Maps 01.12 present an analysis of soil functions, from which Map 01.13 of ‘Planning Advice for Soil Protection’ is derived.

Tab. 8: List of soil type abbreviations used in figures 2 - 10