[Preservation of low fertility calcareous grassland: Pasturing with sheep in a ecosystem-oriented species protection program]

biocenose biocenosis biocoenosis biotope biotopes botanical composition calcareous soils composition botanique comunidades vegetales crianza extensiva ecosistema ecosystems extensive husbandry gazon grazing systems ovin ovinos pastoralism pastoralisme pastoralismo plant animal relations plant communities relaciones planta animal relation plante animal sheep sistemas de pastoreo sol calcaire thuringe thuringia turf turingia