55 vegetation types are represented in the map. They are arranged according to six general biotope classes or formations: built-up area, open space in settled area, areas used for agricultural, areas used for forests, bogs and bodies of water (cf. Fig. 4). Brief characterizations of each biotope class are followed by one to four typical examples. In addition to the written text profiles clarify the succession of communities for each vegetation type. A complete description of every vegetation type can be found in Seidling 1994.
Vegetation in Built-up Areas
Vegetation is strongly dominated by planted elements. Roadside trees, trees in courtyards and in fringe green spaces between buildings have been planted just as fruit trees in various types of gardens. Shrub-shaped undergrowth is another designing element frequently used for public as well as private greenery. Well-watered and frequently mown grass areas are also a recurring element of vegetation, particularly in areas less densely built-up. These grass areas can be called a half-spontaneous vegetation form. Wild species spontaneously immigrate over time to grass areas, or power shifts occur among sown plant species. Various shrub and summer annual plantations should also be included among the vegetation elements that frequently occur in built-up areas.
Other plants exist near these planted or sown elements. These plants are capable of spontaneously settling in mechanically and chemically stressed urban areas. Species found again and again as so-called weeds in gardens and fields grow between and among cultivated plants. Despite control measures, they reestablish populations. There are also plant types which can survive in extreme habitats, such as pavement cracks. Built-up areas required starting from a mosaic of small interlinked plant life associations (Phytocoenosen), each differentiated according to stress and use. It is not possible to depict each individual community in a 1 : 50,000 scale; but communities can be well described within the composition typical for their area. Figure 4 shows the the most dominant combination and aggregation communities for each vegetation type in built-up areas.
In the following vegetation type 102 is used as an example: Block development with tree inventory with weed communities (5 %) or perennial ryegrass trodden sward (5 %); and shrub plantations with field weed communities (5 %). This vegetation type is encountered in area type “closed-off rear courtyard and courtyard” (cf. Fig. 5). The city area within the inner circle of the City Railway (S-Bahn) is heavily sealed. This highly-sealed area has tree-grids of planted roadside trees (often linden types) which allow space for vegetation in street areas. Non-sealed parts of rear courtyards as well as several long avenues lined with small adjoining front gardens allow additional space for vegetation.
Short-lived trodden sward communities (Polygonium communities), mouse-barley communities (bromo-hordeetum murini), and sometimes even fragmentarily formed tall-forb communities (artemisietalia communities) appear on tree grids. These communities are heavily stressed in varying degrees due to trampling and dog excrement. Alongside the Sagino-bryetum (Silbermoos-Mastkraut) association which regularly appears in pavement cracks, small-area developments all the way up to perennial ryegrass trodden sward (lolio-plantaginion communities) appear on seldomly frequented paved surfaces.
Planted shrubs and hardy perennials are almost always found in shaded rear courtyards. Shade results from building density and/or trees, mostly planted (often chestnuts). Due to more intensive maintenance, field weed communities (chenopodietalia communities) usually appear. Watering in summer and shade create a moist microclimate which allows mesophytic hardy perennials (e.g. fern, hydragenea) to flourish and enables the existence of Epil-obium-marchantia communities. Ornamental lawns have a subordinate role; perennial ryegrass trodden sward are more common.
Occasional spontaneous tree inventories, mostly of plane maples with an undergrowth of wood meadow-grass (Poa nemoralis), in some cases even inventories of robinia or box elder, have been able to develop in inaccessible areas of rear courtyards. Ailanthus (Ailanthus altissima) spontaneously appear repeatedly in cracks, e.g. between building walls and pedestrian areas, because temperatures are higher here than in the surrounding countryside.
Vegetation type 104 is presented more closely as a further example of vegetation in built-up areas: large-scale developments from the 80´s and 90´s with shrub plantations and couch grass communities (20 %); perennial ryegrass trodden sward (15 %); couch grass and ruderal tall-forb communities (15 %) (cf. Fig. 6).
These new residential areas are situated mostly in East Berlin and have a lower degree of sealing than older and larger housing block developments. A unique mosaic of vegetation has developed due to its relative youth and as a result of specific factors. Full-grown trees are not yet present; younger trees are still part of the prevalent shrub plantations. Meanwhile soil in these plantations are often covered with bark mulch, nevertheless, couch grass (Agropyretalia communities) as well as species of ruderal tall-forb communities (Artemisietalia species) and field weed communities are detectable among the woody plant plantations.
Large areas of perennial ryegrass trodden sward are found alongside plantations of woody plants in the enclosed inner yards of the high rises. Ruderal fields (couch grass and tall-forb communities) are more likely to be located in outlying areas e.g. in the space between the street and the buildings.
Attentive horticultural care allows tree growth to make marked progress, and even vegetation is giving way to autonomous developments. It is expected that this vegetation type will develop in the direction of 115 (Row und large-scale developments) or, if intensive use of the inner yards remains constant, in the direction of 110 (redevelopment areas).
Vegetation Types on open spaces in settled areas
Vegetation types described here are found in areas of various use: from sport facilities to cemeteries and parks, up to residual traffic areas and even the extremely varying types of urban vacant areas. Relaxation and sport areas as well as cemeteries are generally more intensively maintained. Land strips running parallel to the railway merely receive enough maintenance to assure traffic security. Fallow lots show that a highly differentiated mosaic of vegetation has finally been able to form that often includes the initial stages of vegetational development as well as pioneer crops. This development depends on the substratum, the disruption regime, and the time period of undisturbed development. Four combined examples should demonstrate more clearly the wide type range of open spaces. Each type has been affected in varying degrees by human activities.
Parks are differentiated based on intensity of maintenance correlated with park size. Small, more ornamental parks with a high portion of ornamental flower beds receive intensive maintenance. Large parks with landscape design receive extensive care. The large, more or less adjacent forest-like parts are considered as a separate vegetation type (205) with wood meadow-grass-plane maple park forests (70 %), shrubs (20 %), and greater celandine-robinia forests (10 %). They are spatially connected with non-forest areas (206). These non-forest areas in parks larger than 50 ha are shown as a separate vegetation type and are characterized by the following combination of basic units: heavily-trampled park lawns (20 %); park meadows (20 %); and plantations of hardy perennials and shrubs with field weed communities (15 %) (cf. Fig. 7).
Park woods with more near-natural composition, e.g. with a high portion of beech, oak or hornbeam, can be found alongside park forests heavily influenced by maintenance. The maintained forests generally contain a high portion of foreign species. Clump-like plantations of various poplar species are found in war damage holes. These plantations are now being removed. Plane maple regenerates remarkably well in park forests as well as in the more near natural park woods. The term “wood meadow-grass and plane maple park forest” is justified even in the general sense.
The woody shrub layer usually consists of planted shrubs such as hazelnut (Corylus avellana), alpine currant (Ribes alpinum) or rhododendron (genus rhododendron). Imported woody shrubs or small woody plants such as pachysandra (Pachysandra torminalis), ivy (Hedera helix) or yellow archangel (Lamiastrum galeobdolon) dominate ground cover over large areas. However, spontaneous undergrowth with wood meadow-grass (Poa nemoralis) or ecotonal species such as parviflorous snapweed (Impatiens parviflora) have settled in these planted stands as well as in unplanted areas. The greater celandine-robinia forest also occurs as a spontaneous type larger role only locally. Its appearance is connected with a higher occurrence of ruderal and nitrophytic species, such as greater celandine (Chelidonium majus) or rough meadow grass (Poa trivialis).
Lawns and meadows in larger parks alternate with park forests and woods in order to create an impression of open countryside. The formation of these green spaces depends mainly on stress and maintenance. The substratum can also play a role. The majority of lawns (Cynosurion communities) in centrally-located parks (e.g. Großer Tiergarten) are fertilized, watered, and frequently mown. Lawns in heavily-trampled areas used for recreation and relaxation turn into perennial ryegrass trodden sward. Smaller, extensively maintained parts of larger parks, or the prevalent part of parks in the periphery (e.g. Pfaueninsel – “Peacock Island”) with little or no trampling contain meadow communities (Arrhenatheretalia communities) that are mown twice a year. Sandy areas show transitions up to sandy dry grasslands (Armerion elongatae communities). Even silver grass (Corynephorion communities) can be found on a small area on Pfaueninsel.
Ornamental decorative plantations play a role only in special, relatively small areas within large parks. These representative areas are intensively maintened and the characteristic field weed communities can be seen with summer annuals, woody shrubs, and small woody plants.
Vegetation on fallow railway property (211) with the unit combination of wheat grass and semi-dry grasslands (25 %); birch pioneer crops (20 %) and robinia pioneer crops (15 %), is another example of open space in settled areas. At railway areas in operation often exist a close neighborhood between glasswort-herbicide vegetation (5 %) and wheat grass (5 %) (212) (cf. Fig. 8).
Fallow railway property was able to develop undisturbed for the relatively long period of time of 40 years due to the special political development of the city. The differences in substrata (i.e. ballast laying, sand and gravel deposits as well as removals) have had an impact just as diversifying as the endogenous processes of vegetational development with its diverse dispersal processes and competitive relationships.
The relatively long period of undisturbed succession allowed woody shrub inventories to take over a larger area. Robinia and birch pioneer crops are dominant in terms of surface area. Other tree species (poplar, sour cherry, ailanthus trees among others) have been able to dominate only in smaller woods. Canada blue grass (Poa compressa) usually forms larger stands under birches, while rough meadow grass and greater celandine always thrive under robinia. A layer of elder bush (Sambucus nigra) is also present. Even wood meadow-grass and plane maple urban forests have established themselves on drift clay sites.
Alongside these woody shrubs, inventories of wood small reed have been able to settle in with Agropyretea communities. Dry grasslands (Festuco-Sedetalia communities) and silver grass (Corynephorion communities) are forming a loose vegetation cover on shallow ballast.
Vegetation-free zones exist near railway lines in current or renewed operation. These zones are vegetation-free due to unavoidable herbicidal applications connected with railway operations and extreme site conditions (ballast). Following this vegetation-free zone is a zone where the herbicide-tolerant glasswort community (Salsola kali community) grows. Normally this community is competitively weak. Other annual species such as Canadian fleabane (Conyza canadensis) or Senecio viscosus also belong to the glasswort community. The zone beyond the glasswort community is less affected by herbicides and consists to a larger extent of ruderal semi-dry grasslands. These grasslands have great species diversity. A few species, however, such as wood small reed (Calamagrostis epigejos) can dominate in this zone. The next zone suffers from herbicidal effects only sporadically. Ruderal tall-forb communities [e.g. inventories of Canadian golden rod (Solidago canadensis)] alternate with woody plant upgrowths which often include robinia. This outer zone belongs to the vegetation of fallow railway property, but its presence depends on the amount of space available.
Vegetation types on agricultural land
In medieval as well as in early modern times, estates and forests made up significant amounts of rural land use. This distribution of land use was also true for the Berlin area. Industrialization reduced the amount of land used for agricultural purposes in the surrounding metropolitan area. The vegetation of arable land, meadows and sewage farms (closed or still in operation) have also been reduced to ever smaller remnants. Sewage farms still in operation are a special feature of conurbation. Two examples of field communities in Lübars provide us with evidence for the vegetation types described here. Lübars is one of the last remaining agricultural areas on the edge of Berlin.
Arable land on principally sandy substrata (302) is distinguished by the community combination of rye crops with wind grass (field parsley-fiert) or Lämmersalat weeds (7 %); and vegetable crops with panic-grass weeds (2 %) (cf. Fig. 9). Most nutrient-poor field habitats have already been transformed into richer substrata through mineral fertilization, and there is rarely spontaneous vegetation of sand fields (acre count ~20), the Setario-amoseridetum association. It appears with the cultivation of rye, a winter grain, as a short-lived community of arable weeds. Sandy substrata with lesser clay are also generally used for rye cultivation. Sand poppy associations occur in its poorest formation with the annual knawel (Papaveretum argemone scleranthetosum). Herbicide use on both types usually results in the formation of a species-poor wind grass fragmented community (Aperion community).
Root crops (potatoes, vegetables) or specialty crops cultivated on these poor soils enable the presence of the smooth crab-grass community (Digitarietum ischaemi), which belongs to the field weed communities.
Field and path edges are significant factors for the wealth and diversity of species in field communities. There are often meadow fragments (Arrhenatheretalia communities), ruderal semi-dry grasslands, and perennial ryegrass trodden sward. However, these are receding greatly.
Moist and wet meadows (307) carry cabbage thistle wet meadows (~ 45 %); large sedge moors (~ 35 %); and reed banks (~ 5 %) (cf. Fig. 10). They have replaced alluvial and swamp forests on low moor habitats located near groundwater (mean groundwater-field distance < 0.5 m) as a result of agriculturally-used grasslands (usually mowing). In small areas, large sedge moors are also often a part of the natural successional pattern of alluviation. The most widespread unit of this vegetation type is the species-rich cabbage thistle meadow (Cirsio-Polygonetum bistortae) which belongs to moist meadows (Molinietalia community). In moister locations, this meadow type turns into the generally species-poor large sedge moor stands (Magnocaricion community), most often represented by the slender-spiked sedge moor (Caricetum gracilis). Also located in flood areas are reed banks of reed grass (Phalaridetum arundinaceae) or reed sweet grass (Glycerietum maximae), the latter belonging to the Phragmition community.
Remnants of molinia meadows (Molinion communities), mostly fragmentally formed, can occasionally be found on poor or moist/wet substrata. Flood meadows (Agropyro-Rumicion communities) appear at compacted sites or in hollows where continuous stream flow remains above ground for longer periods of time. Common reed banks (Phragmition communities), grey willow bushes (Frangulo-Salicetum cinereae) or alder swamps (Alnetum glutinosae) are also bedded in larger wet meadow complexes. Only in the Schildow tufaceous limestone area there are also” flowing springs” with Cratoneurion cummutati communities, a peculiarity for the Berlin area. Transitions to fresh meadows are always found on drier segments as well as perennial plant communities (Artemisietea communities). These perennial plant communities often appear in fallow meadows.
Vegetation on lands used for forests
There are more forest areas left than fields, even if there are no near-natural forests here, rather tree stands stocked for harvesting purposes and accordingly maintained. It can be assumed that the structure and composition of the tree inventories has been heavily modified while the ground cover, aside from weed control measures, reveals the highest degree of characteristic development. Ground cover thus best expresses the potential of the site. In addition to the hemerobiotic degree, younger forest inventories or species of tree inventories foreign to that particular flora have been noted. In general, this information makes possible an estimation of the near-natural state of each forest section.
The widespread community series of Moehringia trinervia-pine-durmast oak forest (Pino-Quercetum moehringietosum) is another example (cf. Fig. 11). It is found at base and nutrient-deficient sites with a poor water supply. However, these sites lie slightly higher than the sites of the community series of the typical pine-durmast oak forest. Flowing transitions exist from the Moehringia trinervia-pine-durmast oak forest to the community series of the typical pine-durmast forest (403 and 402) and the bilberry pine-durmast oak forest due to forest felling operations, such as the removal of the crown layer, which can increase the occurrence of the characteristic species of Moehringia trinervia-pine-durmast forest – the Moehringia trinervia. Other, more hygromorphic species like the parviflorous snapweed (Impatiens parviflora) or Maianthemum bifolium are frequently encountered. However, the generally widespread species of the pine-durmast forest such as wavy hair-grass (Avenella flexuosa) also occur here.
Pine forest communities have to a large extent replaced the near-natural formations of this community series which occupies the greater part of the Berliner Forest. Monospecific ground and shrub cover were formed due to loss of structure and the levelling of the smallest spatial differences in habitats, e.g. through deep ploughing carried out before inventory formation. Wavy hair-grass is an important factor here, although wood small reed can build up even larger communities in these forest stands. Red oak, robinia or even beech and winter linden plantations can be observed next to pure pine forests. Every one of these forest crops is connected with a more or less specific modification of the ground cover.
Vegetation of treeless moors
Treeless moors take up only a very small portion of the total surface area in Berlin. These moors are not utilized in any way, except for occasional peat extraction. This vegetation has consequently been least directly influenced by human activities.
Peat deposits were formed during the alluviation process of nutrient-poor lakes. They offer a habitat to a succession of plant associations which consist mostly of peatmoss (high moor) communities (60 – 100 %); large sedge moors (0 – 40 %); and reed communities (0 – 5 %) (501). A real climate-induced high moor, one solely dependent on precipitation, does not exist in the Berlin area. Nevertheless, the cotton grass-peatmoss community (Eriophoro-Sphagnetum recurvi; Ledo-Spaghnetum maggelanici) is the leading local community and is placed among the high moor hillock communities (Oxycocco-Spagnetea). Peat mosses (in particular Spaghnum recurvum) are highly dominant. Cotton-grass (Eriophorum vaginatum) grows among the peat mosses as well as narrow-leaved cotton-grass (Eriophorum angustifolium) in moister sites. Small cranberries (Vaccinium oxycoccox) are found everywhere. Nowadays this core community often encompasses only small areas. Many areas today are in stages of degradation dominated by marsh meadow grass (Calamagrostis canescens) or purple moor grass (Molinia caerulea). The Caricetum lasiocarpae sedge moor, which belongs to the transitional moor complex (502), the brown bent grass-sedge moor community (Carici-Agrostietum caninae), or the large sedge moor (Magnocaricion) and common reeds (Phragmition) have replaced alder swamps. Eutrophication, moor settling and partial flooding let them appear today in even greater numbers at sites where peatmoss communities once occurred. In the advanced stage of alluviation, peatmoss communities naturally turn into birch or pine bog forests (414).
Macrophytic vegetation of bodies of water
Earthbound vascular plants grow in the riparian zone of bodies of water (litoral). They form reed banks in shallow water and floating aquatic plants in deeper water. Submerged pondweed inventories grow in clear water; they have almost vanished in Berlin.
Reed banks are the most significant representative of this plant formation in terms of surface area. The inventories which appear today in the riparian zone of the Havel, Dahme and adjoining lakes can be summarized with the following combinations: common reed grass (70 %); bullrush reeds (20 %); and sweet flag reeds (5 %) (cf. Fig. 12). The habitats range from mesotrophic to eutrophic with still or slowly flowing surface waters with sandy or muddy bottoms. Reed banks grow in water up to an average depth of 2.5 m (in Berlin up to 1.5 m). The reed stands which used to dominate every bank segment have greatly receded along the shoreline as well as away from it. Remnants are now protected over a wide area by ship and boat traffic restrictions as well as protective wave-dampening structures.
In banks of common reeds (Sciropo-Phragmitetum typicum), only a few other vascular plants (e.g. Rumex hydrolapathum) appear alongside the dominanting reed stand (Phragmites australis). Perennial plant reed banks (Scirpo-Phragmitetum solanetosum), however, are quite different. They settle in protected landing areas where, for example, bitter nightshade (Solanum dulcamara) and marsh woundwort (Stachy palustris) grow. Besides these reed banks, the only other significant reed stands are narrow-leaved bullrush (Thyphetum angustifoliae) and sweet flag (Acoretum calami). Also significant are the reed banks of reed canary grass (Phalaridetum arundinaceae); they grow near the shore followed by common reed banks.
Hemerobiotic degree in areas used for forests
The hemerobiotic degree indicates the total effect of intentional and unintentional human activities on habitat and vegetation in general. Hemerobiotic details especially provide information on the impacts of forestry on inventories. These details overlap forest sections. Young plantations on clear-felled areas (which still existed in East Berlin until recently) show a high degree of human intervention in the forest ecosystem (ß-euhemerobiotic). In general, autonomous development increases with the maturity of the inventory, particularly in inventories with less covering pioneer tree species such as the pine. Forest plantations thus structurally and floristically approach more natural states over time and it is possible to describe mature stands as mesohemerobiotic. Regeneration under shelterwood (composed at least 20 % of shelterwood) has likewise been assigned a lower hemerobiotic degree as a near-natural regeneration complex. Lasting changes in habitat and ecosystem often occur with the cultivation of species foreign to the flora and habitat. As a result, they are described as ß-euhemerobiotic regardless of age. The same applies for areas that are utilized in ways foreign to forests, such as car parks etc.
The map shows the mean hemerobiotic degree for forest areas according to compartments. Sections with mostly near-natural mature forest inventories are mesohemerobiotic and are lightly shaded. Those sections with mostly young inventories or a large portion of tree species foreign to native flora are ß-euhemerobiotic and are shaded in a darker tone. Sections with mostly medium-aged inventories, or inventories with an equal portion of young and mature trees, are given a middle hemerobiotic degree. The Tegler Forst, Bucher Forst and Frohnauer Forst as well as parts of the Spandauer Forst have widespread mature forest inventories that are generally distinguished by a higher portion of deciduous trees (cf. Map 05.04, SenStadt UmTech1996b, 1997c). The Wuhlheide, Königsheide and Dammheide areas also possess an above average number of mature stands. A mosaic of various stages of maturity, however, is found in many forest areas, e.g. in Grunewald. Many areas (e.g. Gatower Heide) have a generally high hemerobiotic degree due to greater amounts of robinia or northern red oaks, or to widespread inventories in sapling or pole stage.