Nutrient-poor grasslands
Nutrient-poor grasslands are grassy and mostly frilly vegetation formations which grow on meager substrates and are most often dry (semi-arid grasslands, juniper heath, etc.). Natural grasslands occur in Western Europe more widely in the Alps and above the tree line (see mountains). In the plains they are (were) limited to special locations such as the rearrangement routes of rivers such as the Rhine, Lech etc., heathlands and dry to very steep rocky slopes and possibly clearings caused by grazing of wild animals. Today the grasslands that still can be found outside the Alps are mostly anthropogenic, are thus obtained by sheep grazing or mowing. Grasslands can first be distinguished according to the substrate. On alkaline- or lime-rich underground calcareous grassland sites occur (e.g. in jurassic landscapes), whereas on low-alkaline undergrounds acidophilic grasslands grow (for example the Nardion with Nardus stricta and Arnica montana in the Black Forest or in the central Alps). A second distinction is to be made by the management. Thus, the alkaline-rich grasslands (e.g. Mesobrometum) of the Kaiserstuhl (Southwest Germany) are traditionally mowed, the grove richer of the Swabian Alb (Southern Germany) mostly grazed by sheep (Gentiano-Koelerietum). In the acidic regions, a grazing results most frequent in Nardus grasslands (Nardion) in Central Europe with, for example, arnica and heather. calcareous grasslands are generally more species-rich, especially in botanical terms.

The great species richness on grazed calcareous grasslands is based on the following reasons:
  • Because of low nutrient status and often lower soil moisture due to high water permeability (today, the latter reason is often the more important) no tall, vigorous and nitrogen-loving plants are able to prevail. Thus the soil surface is exposed to the sun and low and slow growing specialists are promoted.
  • Often large differences in slope gradient, exposition, ground cover, stone proportion, shrub cover, etc. generate a large structural diversity
  • Moreover there is the selective grazing (nutrient removal, favoring toxic, bitter or prickly plant species, improved microclimate by short and gappy plant cover) by sheep and goats and soil wounds because of the hooves etc.
  • The result (usually after very long periods of time!) is a highly structured surface with high niche density and biodiversity under microclimate favorable conditions and under extensive grazing conditions also mechanically compatible with the needs of the deloping animal individuals.
  • Nutrient-poor grasslands are endangered by the following factors:
    • Lack of profitability of grazing (transhumance), but also mowing, so-called marginal locations and subsequent succession (bush encroachment, reforestation)
    • Fertilization to obtain rich meadows or redesignation to fields at all not to steep locations
    • Afforestation with conifers
    • Infrastructure development (roads, settlements, industry, allotments)
    • Nutrient deposition from the air due to agricultural and industrial emissions and the traffic
    • Recreational activities such as camps and barbecue places, which threaten especially small-area grasslands
    Although grasslands such as heathlands are now mostly under the protection of various laws, but this only has slowed down the speed of decline - together with dedicated care measures of authorities, organizations and individuals. But there is further decline because in a single case always the so-called public interest is more important than the preservation of the environment, e.g. in the case of new streets and motor ways, new industry or just high-production agricultural pastures. In addition, environmental offenses are rarely punished. Eventually grasslands require an expert care and can not simply be left to itselves, as often happens for reasons of cost.
    Besides reptiles especially many species of insects are found in grasslands, some of southern origin only on particularly warm slopes (known as extrazonale biocenosis).

    In the context of grasslands one should also mention extensive (up to two mowings per year), relatively species-rich, dry or alternating wet and dry meadows, which have already almost vanished. Causes are primarily the fertilization / intensification with up to 4-8 cuttings per year or even including them in pastures and fields, overbuilding and reforestation.

    Finally some pictures (click to enlarge):

    typical, occasionally grazed grassland in a jurassic landscape relativ heavy grazed grassland stony grassland grassland with cripple woods Mediterranean grassland in the Provence grassland in the Haute-Provence grazed grassland in a today dry former fen Stipa-grassland in southern Alps in April Bug species of dry and warm habitats: Jalla dumosa Bee: Rophites algirus

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