What are dry grasslands and why are they so interesting?

Dry grasslands are herbaceous vegetation types mostly dominated by grasses but sometimes also by annual or perennial forbs that inhabit climatically or edaphically dry sites, typically on poorly developed soils. Dry grasslands partly belong to natural zonal (steppe biome, alpine zone) or azonal/extrazonal vegetation (e.g. on grey dunes, around rock outcrops), and partly to the semi-natural vegetation. In phytosociological terms, we basically include the following classes:

• Koelerio-Corynephoretea (incl. Sedo- Scleranthetea, Festucetea vaginatae): dry grasslands of sandy and of shallow, skeletal soils
• Festuco-Brometea: dry grasslands and steppes of base-rich soils
• Violetea calaminariae: dry grasslands of soils rich in heavy metals
• Trifolio-Geranietea sanguinei (incl. Melampyro-Holcetea): helio-thermophilous forest-edge and tallherb communities
• Elyno-Seslerietea (Seslerietea albicantis, Kobresio myosuroidis-Seslerietea caeruleae): Alpine and subalpine calcareous grasslands
• Festucetea indigestae: Oro-Iberian siliceous grasslands
• Festuco hystricis-Ononidetea striatae (Ononido-Rosmarinetea): Dry, basiphilous pasture communities of the supra- and oromediterranean zones of the Mediterranean
• Carici-Genistetea lobelii: Cyrno-Sardian supra- and oromediterranean grasslands and phrygana
• Daphno-Festucetea: Greek and Aegean oromediterranean calciphilous grasslands and phrygana
• Thero-Brachypodietea (Tuberarietea guttatae; incl. Poetea bulbosae): Mediterranean low-grown swards, dominated by annual grasses and herbs
• Stipo giganteae-Agrostietea castellanae: Western Mediterranean siliceous perennial grasslands
• Lygeo sparti-Stipetea tenacissimae: Mediterranean steppes, pseudo-steppes and related perennial grasslands
• Onosmo polyphyllae-Ptilostemetea: Crimean mediterranoid macchia and related grasslands over flysch

Of course, the delimitation of these communities towards adjacent classes,such as Carici rupestris-Kobresietea bellardii, Calluno-Ulicetea, Molinio-Arrhenatheretea, Parvo-Caricetea, Puccinellio-Salicornietea, or Artemisietea vulgaris is not always clear and sharp, and thus communities from the latter classes are not  strictly excluded from our activities.

Why are dry grasslands so interesting?

• Dry grasslands are particularly species-rich in many plant and animal groups and they thus host a proportion of
  Europe’s biodiversity that by far exceeds their spatial coverage.
• European dry grasslands are among those plant communities with the highest small-scale species densities ever recorded worldwide.
• Dry grasslands are of high conservation concern as they host many endangered species and they are strongly threatened throughout Europe by many factors, such as destruction for other activities, abandonment of traditional use, afforestation, eutrophication, or invasion of neophytes.
• Most of the dry grassland types fall under the Habitats directive of the European Union.
• Dry grassland species have developed a wide range of interesting adaptations to their harsh environment, such as drought, high solar irradiation, lack of nutrients, instable soils, or grazing pressure.
• Dry grassland are very suitable as model system for biodiversity analyses because: their small-scale richness reaches from low to extremely high; they span very wide latitudinal, altitudinal; and pH ranges; they occur both as natural and anthropogenic communities; they comprise not only vascular plants but also bryophytes, and lichens; and they typically grow in isolated patches.
• Dry grassland could be the first wide-spread vegetation type, for which a relevé-based, consistent vegetation classification at European scale is developed because: they occur in nearly all European countries and they have always attracted botanists/ phytosociologists and thus many data and coworkers are available.  

Edraianthus sp.   © M.Janisova

Last update 01.02.2009
webpage editor: Solvita Rusina