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.

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.

The organic component of soil consists of plant and animal detritus in various stages of decomposition. Two categories are defined according to the predominant mineral or organic component. Aquatic vegetation types that do not root in soil are not classified.

• Mineral soil – the mineral soil component predominates over the organic component
• Organic soil – the organic soil component predominates over the mineral component

Categories

• Mineral soil
• Organic soil

Data source and citation

Preislerová, Z. (2022). Soil organic matter. – 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.

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.