Saline desertic steppe vegetation of the Northern Caspian region
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:
Preislerová, Z. (2022). Dominant life form. – www.FloraVeg.EU.
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.
Preislerová, Z. (2022). Phenological optimum. – www.FloraVeg.EU.
Substrate humidity reflects the soil moisture availability throughout the year.
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.
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.
Preislerová, Z. (2022). Salinity. – www.FloraVeg.EU.
Nutrient status refers to the concentration of available nitrogen, phosphorus and potassium in soil or water.
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.
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:
Preislerová, Z. (2022). Vegetation zone. – www.FloraVeg.EU.
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
Temperate vegetation belts
Mediterranean vegetation belts
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:
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.
Preislerová, Z. (2022). Successional status. – www.FloraVeg.EU.
The origin defines the degree to which vegetation development depends on humans.
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).
Preislerová, Z. (2022). Origin. – www.FloraVeg.EU.