The dominant life forms of vegetation types reflect the environmental conditions. The life forms that dominate European vegetation types are defined here by combining various approaches to classifying plant life forms (Du Rietz 1931, Raunkiaer 1934, Klimešová et al. 2017) based on the morphological, physiological, and ecological adaptations of plants to changing environmental conditions. Each vegetation type is characterized by the life form that dominates its stands. If a vegetation type includes stands dominated by different life forms, more than one life form is indicated. For vegetation types with a complex vertical structure, the dominant life form is recorded for each vegetation layer. Bryophytes are recorded for those vegetation types where their presence is important to community structure and their cover exceeds 50% in at least some stands of the vegetation type. The following categories are distinguished:

• Conifer trees – usually evergreen coniferous trees with either needle-like or scale-like leaves
• Broad-leaved deciduous trees – trees that shed all their leaves at the beginning of the cold season
• Sclerophyllous trees – trees with small, leathery evergreen leaves
• Laurophyllous trees – trees with large, evergreen leaves
• Palms – evergreen trees with a straight trunk and a bunch of large leaves on the top
• Conifer shrubs – evergreen coniferous shrubby plants with either needle-like or scale-like leaves
• Broad-leaved deciduous shrubs – shrubby plants that shed all their leaves at the beginning of the cold season
• Sclerophyllous shrubs – shrubby plants with small, leathery evergreen leaves
• Laurophyllous shrubs – shrubby plants with large, evergreen leaves
• Broom-shrubs – shrubby plants that look like a broom and are assimilating primarily through slender green branches; they have sparse, small leaves that drop in summer to reduce water loss; in some species, the leaves are transformed into thorns; examples: Genista benehoavensis, G. corsica, Launaea arborescens, Retama spp., Spartocytisus supranubius, Stauracanthus boivinii, Ulex europaeus
• Microphyllous shrubs – evergreen tall (up to 4 m) shrubby plants with tiny, needle-like leaves; examples: Adenocarpus foliosus, Erica arborea, E. platycodon
• Dwarf shrubs – small woody plants with most of their overwintering buds located up to 25 cm above the soil surface; examples: Artemisia pauciflora, Astragalus siculus, Bruckenthalia spiculifolia, Calluna vulgaris, Daboecia cantabrica, Empetrum nigrum, Ephedra distachya, Erica carnea, Euphorbia spinosa, Genista cupanii, G. pilosa, creeping forms of Juniperus hemisphaerica and J. sabina, Prunus prostrata, Vaccinium myrtillus, V. vitis-idea
• Suffruticose – plants with a woody base and herbaceous (sometimes succulent)
branches; examples: Anabasis aphylla, Artemisia thuscula, Euphorbia lamarckii, E. paralias, E. regis-jubae, Salvia canariensis, Sonchus acaulis
• Perennial graminoids – long-lived grass-like herbaceous plants (Poaceae, Juncaceae, Cyperaceae)
• Perennial non-graminoid herbs – perennial plants with herbaceous shoots and non-graminoid leaves
• Succulents – perennial non-woody plants with succulent leaves or stems; examples: Astydamia spp., Crithmum maritimum, Frankenia laevis, Greenovia spp., Salicornia spp., Sedum spp., Sempervivum spp.
• Annual graminoids – grass-like herbaceous plants that complete their life cycle during one growing season (Poaceae, Juncaceae, Cyperaceae)
• Annual non-graminoid herbs – plants with herbaceous shoots and non-graminoid leaves that complete their life cycle during one growing season
• Aquaphytes – perennial or annual plants that live exclusively in water
• Bryophytes – mosses, liverworts and hornworts
• Lichens – non-vascular plants composed of symbiotic algae and fungi

Categories

• Conifer trees
• Broad-leaved deciduous trees
• Sclerophyllous trees
• Laurophyllous trees
• Palms
• Conifer shrubs
• Broad-leaved deciduous shrubs
• Sclerophyllous shrubs
• Laurophyllous shrubs
• Broom-shrubs
• Microphyllous shrubs
• Dwarf shrubs
• Suffruticose
• Perennial graminoids
• Perennial non-graminoid herbs
• Succulents
• Annual graminoids
• Annual non-graminoid herbs
• Aquaphytes
• Bryophytes
• Lichens

Data source and citation

Preislerová, Z. (2022). Dominant life form. – www.FloraVeg.EU.

Further references

Du Rietz G. E. (1931) Life-forms of terrestrial flowering plants I. Acta Phytogeographica Suecica, 3 (1), 1–95.
Klimešová J., Danihelka J., Chrtek J., de Bello F. & Herben T. (2017) CLO-PLA: a database of clonal and budbank traits of the Central European flora. Ecology, 98, 1179.
Raunkiaer C. (1934) The life forms of plants and statistical plant geography. Clarendon Press, Oxford.

The phenological optimum is defined here as a period when most vascular plants in the community are in flower. This period usually corresponds to the period of the peak biomass of vegetation. For vegetation types that have two or more dominant life forms with different phenological optima, the optimum is considered separately for each dominant life form. Some vegetation types (e.g. annual weed or ruderal vegetation) have two or three groups of species with different phenological optima, even within the same life form, resulting in different spring, summer and autumn aspects. Two or three phenological optima are recorded for these types. In the case of marine, some types of aquatic and monocarpic vegetation that may look similar throughout the year or at least throughout the growing season (e. g., Zosterion, Potamogetonion, Ranunculion aquatilis, Littorellion, Greenovion), the phenological optimum is considered to be the time of flowering of the dominant species or most of the species in the community. Phenological optimum categories have been defined primarily based on Central European phenological patterns and applied to vegetation in other regions of Europe. More than one phenological optimum was reported for vegetation types with an optimum that spans more than one category. Assignments to categories were based on field experience, descriptions in various literature sources, and were partially derived from vegetation-plot data.

Categories

• Early spring – March, April
• Late spring – May
• Summer – June, July, August
• Autumn – August, September, October
• Winter – November, December, January, February

Data source and citation

Preislerová, Z. (2022). Phenological optimum. – www.FloraVeg.EU.

Substrate humidity reflects the soil moisture availability throughout the year.

• Dry substrate is characterized by a low groundwater table, low water-holding capacity and long periods without precipitation
• Mesic substrate holds a moderate amount of soil moisture throughout the year without pronounced drought, waterlogging or flooding
• Wet substrate is characterized by a high water table, waterlogging or occasional flooding
• Water substrate is specified for those vegetation types that occur in water

Categories

• Dry
• Mesic
• Wet
• Water

Data source and citation

Preislerová, Z. (2022). Substrate humidity. – www.FloraVeg.EU.

Substrate reaction expresses soil pH and the content of calcium and other basic cations in the soil or water.

• Acidic substrate has a low pH (usually between 3 and 6) and a low base content
• Slightly acidic to near-neutral substrate has a pH usually between 6 and 7 and moderate base content
• Alkaline substrate has a high pH (above 7) and a high content of calcium or other basic cations

Categories

• Acidic
• Slightly acidic to near-neutral
• Alkaline

Data source and citation

Preislerová, Z. (2022). Substrate reaction. – www.FloraVeg.EU.

Salinity refers to the concentrations of readily soluble salts (especially sodium, potassium, calcium, and magnesium sulphates, chlorides, and carbonates) in soil or water.

• Non-saline substrate has no or very low concentrations of soluble salts
• Slightly saline or brackish substrate has a low to moderate concentration of soluble salts
• Saline substrate has a high concentration of soluble salts

Categories

• Non-saline
• Slightly saline or brackish
• Saline

Data source and citation

Preislerová, Z. (2022). Salinity. – www.FloraVeg.EU.

Nutrient status refers to the concentration of available nitrogen, phosphorus and potassium in soil or water.

• Dystrophic substrate has a low amount of available nutrients, low oxygen concentration and a high amount of dissolved organic matter; it is often associated with mire complexes
• Oligotrophic substrate has low nutrient availability but does not have the other characteristics that define dystrophic conditions
• Mesotrophic substrate has a moderate amount of available nutrients
• Eutrophic substrate has a high amount of available nutrients
• Hypertrophic substrate has a very high amount of available nutrients, often due to anthropogenic eutrophication

Categories

• Dystrophic
• Oligotrophic
• Mesotrophic
• Eutrophic
• Hypertrophic

Data source and citation

Preislerová, Z. (2022). Nutrient status. – www.FloraVeg.EU.

Vegetation zones are large areas of relatively uniform climate and vegetation. These zones often correspond to other land classification units such as biogeographical regions, ecoregions or biomes (Schultz 2005, Rivas-Martínez et al. 2004a, Mucina et al. 2016, Dinerstein et al. 2017, Bruelheide et al. 2018, EEA 2018). However, such classification systems are inconsistent across Europe and differ in the number of units defined and in the position of boundaries between them. Here, we propose a system largely based on a combination of the Biogeographic and Bioclimatic Maps of Europe by Rivas-Martínez (2004a, b) and European Biogeographical Regions (EEA 2018). We found this system optimal for describing the distribution of European phytosociological alliances (Mucina et al. 2016, Preislerová et al. 2022). It includes nine horizontally divided categories (Arctic, Boreal, Hemiboreal, Nemoral, Forest-steppe, Steppe, Submediterranean, Mediterranean and Macaronesian; Fig. 1) and three vertical categories (Oroboreal, Orotemperate and Oromediterranean) for alpine regions.

The assignment of vegetation types to zones is mainly based on the distribution maps of the European alliances (Preislerová et al. 2022). Since these maps do not provide sufficient details such as point distribution, we also used information from various literature and expert knowledge.

We defined the following zones:

• Arctic – Arctic Biogeographical Region of Russia, Greenland, Svalbard
• Boreal – northern part of the Boreal Biogeographical Region of Russia, Finland, Sweden and Norway (except for the southern parts of these three countries), Iceland, Faroe Islands
• Hemiboreal – southern part of the Boreal Biogeographical Region of Russia, Estonia, Latvia, Lithuania, Belarus, the Kaliningrad Region of Russia, the southern part of Sweden except for the Skåne Peninsula and the southernmost parts of Finland and Norway
• Nemoral – Atlantic and partly Continental Biogeographical Regions, including the British Isles, France with the exception of the Mediterranean part, the Atlantic part of the Iberian Peninsula, the Benelux countries, Denmark, Germany, Poland, Czechia, Slovakia, Switzerland, Austria, Alpine part of Italy, Slovenia, the Alpine Biogeograpical Region of Romania and Bulgaria, the Alpine and Continental Biogeographical Regions of Ukraine, the Continental Biogeographical Region of Russia, the higher elevations of the Southern Urals, the Caucasus countries and the Russian part of the Great Caucasus
• Forest-steppe – Hungary, the extra-Carpathian parts of Romania, the Pannonian Biogeographical Region in northern Serbia, northern Moldova, the transition zone between the Continental and Steppic Biogeographical Regions in Ukraine and Russia and the mountain fringes of the Southern Urals
• Steppe – Steppic part of Ukraine and Russia, southern Moldova, northern Crimea, low-lying areas in the Caucasus countries and in the Russian part of the Great Caucasus
• Submediterranean – the northern interior part of Spain and the border areas between the Mediterranean and Continental Biogeographical Regions, including parts of France, Italy, Croatia, Bosnia and Herzegovina, Serbia, Kosovo, Macedonia, Montenegro, Albania, Bulgaria, Turkey and the southern part of Crimea; vegetation types occurring in the Supramediterranean elevation belt within the Mediterranean Biogeographical Region are also included in the Submediterranean zone
• Mediterranean – Portugal, southern parts of Spain, France and Italy, the coastal areas of the Adriatic Sea, Greece and all Mediterranean islands; only vegetation types occurring in the Inframediterranean, Thermomediterranean and Mesomediterranean belts are included in this zone
• Macaronesian – Canary Islands, Madeira and Azores
• Oroboreal – high elevations in the Scandinavian Mountains, Northern and Central Urals; vegetation types from the elevations around or above the timberline are included
• Orotemperate – Cantabrian Mountains, Pyrenees, Massif Central, Alps, Northern and Central Apennines, Vosges, Schwarzwald, Harz, Sudetes, Bohemian Forest, Carpathians, Dinarides, central Balkan mountain systems, Caucasus; vegetation types from the subalpine, alpine and nival elevational belts are included
• Oromediterranean – mountain systems of the Iberian Peninsula south of the Cantabrian Range and the Pyrenees, Cevennes, mountain systems of the Mediterranean islands, Southern Apennines, Greek mountain systems; only vegetation types from the Oromediterranean to Cryomediterranean elevation belts are included

Data source and citation

Preislerová, Z. (2022). Vegetation zone. – www.FloraVeg.EU.

Further references

Bruelheide H., Dengler J., Purschke O., Lenoir J., Jiménez-Alfaro B., Hennekens S.M. ... Jandt U. (2018) Global trait–environment relationships of plant communities. Nature Ecology & Evolution, 2, 1906–1917. https://doi.org/10.1038/s41559-018-0699-8
Dinerstein E., Olson D., Joshi A., Vynne C., Burgess N.D., Wikramanayake E. … Saleem M. (2017) An ecoregion-based approach to protecting half the terrestrial realm. BioScience, 67/6, 534–545. https://doi.org/10.1093/biosci/bix014
EEA (2018) Mapping Europe’s Ecosystems. Copenhagen: European Environment Agency. https://doi.org/10.2800/850732
Mucina L., Bültmann H., Dierßen K., Theurillat J. P., Raus T., Čarni A., … & Tichý L. (2016) Vegetation of Europe: hierarchical floristic classification system of vascular plant, bryophyte, lichen, and algal communities. Applied Vegetation Science, 19 (Suppl. 1), 3-264. https://doi.org/10.1111/avsc.12257
Preislerová Z., Jiménez-Alfaro B., Mucina L., Berg C., Bonari G., Kuzemko A. … Chytrý M. (2022) Distribution maps of vegetation alliances in Europe. Applied Vegetation Science, 25, e12642. https://doi.org/10.1111/avsc.12642
Rivas-Martínez S., Penas A. & Díaz T. E. (2004a). Bioclimatic map of Europe - Bioclimates. Cartographic Service, University of León. https://doi.org/10.5616/gg110001
Rivas-Martínez S., Penas A. & Díaz T.E. (2004b) Biogeographic Map of Europe. Cartographic Service University of León.
Schultz J. (2005) The ecozones of the world. The ecological division of the geosphere, 2nd edition. Berlin, Springer.

The elevational vegetation belts reflect the vertical zonation of vegetation in relation to changes in climatic conditions. In the Arctic and Boreal zones, we distinguish only the Boreo-Arctic lowland and the Boreo-Arctic mountain belts, as the distinction of more belts is often unclear because in maritime and northern areas, the timberline is at low elevations, and the vegetation of the lowland Arctic tundra is very similar and often spatially connected with alpine tundra. In the Hemiboreal, Nemoral, Forest-steppe, Steppe and Submediterranean zone, we use the division into lowland, colline, submontane, montane, subalpine, alpine, and nival belts. In the Mediterranean and Macaronesian zones, we use the division into Inframediterranean, Thermomediterranean, Mesomediterranean, Supramediterranean, Oromediterranean and Cryomediterranean belts. Each elevational belt may shift up or down in a given mountain range or region, depending on local environmental conditions and historical circumstances.

Boreo-Arctic vegetation belts

• Boreo-Arctic lowland – flat landscape with a mixture of deciduous (Betula-Alnus-Acer) and coniferous (Pinus-Larix-Picea) forests or coniferous forests only in the Boreal zone; mixture of shrub vegetation (Salix spp. or Betula pubescens), heathlands (Vaccinium spp., Salix spp., Empetrum spp.), grassy tundra and creeping Salix herbacea and S. polaris snow patches or polar desert tundra in the Arctic zone
• Boreo-Arctic mountain – mountainous landscape with shrubby vegetation or open deciduous woodlands (Salix spp. or Betula pubescens), heathlands and grasslands

Temperate vegetation belts

• Lowland – flat landscape with floodplain forests along rivers and deciduous thermophilous oak forests
• Colline – hilly landscape with broad-leaved deciduous forests or Pinus forests in extreme habitats; agricultural landscape predominates
• Submontane – submontane regions with the dominance of broad-leaved deciduous trees, Pinus forests on rock outcrops, coniferous plantations and agricultural landscapes
• Montane – mountainous regions with mixed coniferous-deciduous forests, with increasing predominance of coniferous forests towards higher elevations
• Subalpine – higher elevations with open coniferous forests, krummholz, heathlands and grasslands around the timberline
• Alpine – grasslands and heathlands above the timberline
• Nival – areas above the snow line and rocky summits with scattered vegetation dominated by bryophytes and lichens

Mediterranean vegetation belts

• Inframediterranean – lowest elevations and latitudes of the Mediterranean with warm and arid climate; this belt is only developed in a small part of the Mediterranean, such as southernmost Spain and the Canary Islands.
• Thermomediterranean – a belt usually located near the coast, with a long period of summer drought, with a potential natural vegetation dominated by evergreen sclerophyllous scrub
• Mesomediterranean – a belt characterized by warm and dry summers and mild winters with almost no frost, suitable for the cultivation of the olive tree; the natural vegetation of this belt is the evergreen oak forest
• Supramediterranean – a belt at middle elevations with less pronounced summer drought and occasional winter frost; the natural vegetation of this belt is broad-leaved deciduous forest; this belt corresponds to the colline belt in the nemoral zone
• Oromediterranean – a belt below the timberline, characterized by heaths and pine and juniper forests; beech forests may occur on humid slopes; this belt corresponds to the montane and subalpine belt in the extra-Mediterranean vegetation zones
• Cryomediterranean – the highest belt of the Mediterranean mountain ranges, located above the timberline; it is characterized by natural grasslands and heathlands; this belt corresponds to the alpine belt in the extra-Mediterranean vegetation zones

Data source and citation

Preislerová, Z. (2022). Elevational vegetation belt. – www.FloraVeg.EU.

Azonality is defined by locally specific abiotic conditions that prevent the development of vegetation types that occupy large areas under similar climatic conditions (zonal vegetation) and promote the development of specific, locally confined vegetation types (azonal vegetation). Some vegetation types may be zonal in some areas but azonal in others, e.g. some types of arctic-alpine or mire vegetation are zonal in northern Europe but azonal in central or southern Europe. Fringe vegetation, which develops at the boundary between forests and herbaceous vegetation on widespread soil types, is zonal but included in the special category of Ecotone because of its patchy occurrence.

The following types of azonality are recognized:

• Marine – sea littoral with sea-grass vegetation
• Coastal wetlands – permanently wet dune slacks affected by saltwater
• Inland aquatic – aquatic vegetation of freshwater lakes and ponds
• Inland wetland – places with a high level of fresh groundwater or near springs; the soil is saturated with water throughout the year or for part of the year
• Riverine – vegetation that develops along streams and in stream beds
• Shallow soil – often dry or rapidly drying, usually with low nutrient availability
• Steep slope – slopes with an inclination greater than 35°, usually affected by erosion, fast water runoff, and in some places in alpine areas, by avalanches
• Rock – outcrops and cliffs without soil, stressed by lack of water and extreme temperatures; develops patchily in crevices, on ledges and terraces
• Scree – unstable mixture of rock fragments that are moved downward by gravity
• Dunes and beaches – coastal or inland sandy habitats with extreme temperature fluctuations, low water storage, low nutrient content, and limited nutrient availability
• Ultramafic and heavy-metal soil – outcrops or shallow soils on peridotite, ophiolite, serpentinite and other rocks that contain high concentrations of heavy metals such as Fe, Mn, Cu, Cr, Ni, Pb, Co, and Cd, which are toxic to many plant species; some heavy-metal soils are also anthropogenic and occur on mining tailing piles
• Gypsum – layers of hydrated calcium sulfate that forms a hard surface crust that is difficult for plants to penetrate; gypsum soils are often deficient in macronutrients and dry out due to heavy water runoff
• Badland – landscape on clay substrate subject to severe erosion during heavy rain storms, resulting in steep slopes; upper soil layers dry out during dry periods and accumulate salt
• Saline – habitats with high concentrations of soluble salt ions (sodium, potassium, calcium and magnesium sulfates, chlorides and carbonates) that are toxic to many plant species
• Mediterranean eroded slope – eroded slopes both at low (usually on lava flows) and high elevations of the Mediterranean mountain ranges, characterized by disturbances combined with summer drought and winter frost
• Snow patch – arctic and alpine habitats where snow melts much later than in the surrounding area, resulting in a short growing season and locally increased moisture
• Alpine, snow-protected – leeward slopes or depressions in high mountains where snow accumulates, protecting vegetation from frost and providing soil with moisture from snowmelt; unlike in snow patches, snow melts early in the season
• Alpine, wind-exposed – high-mountain sites exposed to wind; in winter, wind blows away snow and exposes vegetation to frost; in summer, wind causes desiccation
• Salt-sprayed site – coastal cliffs and slopes affected by horizontal precipitation from the sea, which affects vegetation by salt spray
• Foggy site – wind-facing slopes affected by clouds that bring moisture to otherwise dry sites and reduce direct solar radiation
• Ecotone – linear vegetation types that develop at the transition between two vegetation types of different structure, e.g. forest and grassland
• Zonal – vegetation and habitat types other than those defined above that occur over large areas under the abiotic conditions that prevail in the region

Categories

• Marine
• Coastal wetlands
• Inland aquatic
• Inland wetland
• Riverine
• Shallow soil
• Steep slope
• Rock
• Scree
• Dunes and beaches
• Ultramafic and heavy-metal soil
• Gypsum
• Badland
• Saline
• Mediterranean eroded slope
• Snow patch
• Alpine, snow-protected
• Alpine, wind-exposed
• Solt-sprayed site
• Foggy site
• Ecotone
• Zonal

Data source and citation

Preislerová, Z. (2022). Azonality. – www.FloraVeg.EU.

Successional status reflects the stage of vegetation development either on a new substrate (e.g. volcanic features; primary succession) or following disturbance (e.g. fire; secondary succession). Three successional stages are distinguished. Some vegetation types may be assigned to more than one stage.

• Early-successional – vegetation occurs at recently or frequently disturbed sites (e.g. river bars, exposed pond bottoms, screes, lava fields, dunes, trampled sites, arable fields, heaps, mining sites) or in extreme habitats (rocks, scree, walls); frequently disturbed sites are dominated by short-lived species and undergo a directional vegetation change toward types with a higher proportion of long-lived species; extreme habitats are often dominated by long-lived species
• Mid-successional – vegetation undergoes a directional change (with less intense or frequent disturbance), with early-successional species decreasing and late-successional species increasing
• Late-successional – vegetation undergoes no directional changes unless it is severely disturbed; it is usually dominated by long-lived plant species and is in dynamic equilibrium with the abiotic conditions at the site

Categories

• Early-successional
• Mid-successional
• Late-successional

Data source and citation

Preislerová, Z. (2022). Successional status. – www.FloraVeg.EU.

The origin defines the degree to which vegetation development depends on humans.

• Natural vegetation has developed naturally without human intervention and has not been severely disturbed by humans for a long time
• Semi-natural vegetation is managed by humans, but consists largely of species native to the area, most of which regenerate without direct human intervention. Subcategories include semi-natural forests (tree plantations) , in which the dominant trees have been planted while the herb layer has regenerated spontaneously from the local species pool; and semi-natural grasslands, which have developed at the sites of former forests and are managed as either hay meadows or pastures
• Semi-natural (disturbed, unmanaged) vegetation develops at sites that have been disturbed and altered by human activities (e.g. quarries, sod removal sites, spoil heaps and forest clearings) and then left unmanaged, resulting in secondary succession
• Anthropogenic vegetation is intensively managed or disturbed by humans and is characterized by weeds on arable land or ruderal species at uncultivated ruderal sites; this category also includes stands dominated by alien species and grasslands sown with species-poor commercial seed mixtures

All forest vegetation types are treated as natural, although some forests have been seeded or managed by man for centuries. Only Robinia pseudoacacia forests and Mediterranean plantations of Pinus halepensis and Pinus pinea are classified as Anthropogenic (tree plantations). Pasture is not considered for forests, although grazing has been an important component of management in some regions. Some types of steppe grasslands have been assigned both a natural origin (climatic control combined with grazing by wild animals and a semi-natural origin (through livestock grazing in deforested areas).

Categories

• Natural
• Semi-natural (tree plantation)
• Semi-natural (hay meadow)
• Semi-natural (pasture)
• Semi-natural (disturbed, unmanaged)
• Anthropogenic (arable land)
• Anthropogenic (ruderal)
• Anthropogenic (sown)
• Anthropogenic (alien-dominated)

Data source and citation

Preislerová, Z. (2022). Origin. – www.FloraVeg.EU.