Endangered ruderal plant communities of Slovakia and their preservation
Changes in zoo-anthropogenic activities such as abandonment of keeping animals near the house, cessation of stock grazing, reclamation of dung-hills and rubbish tips, and construction of central drainage systems in villages, modern disturbance factors (large-scale building activities, modernization of roads), and changes in water regime of brooks and ponds can be regarded as the main causes of the retreat of the original ruderal vegetation especially in settlements. The most endangered communities are classified within the Onopordion acanthii, Malvion neglectae (both of archaeophytic character) as well as in the Bidention tripartitae, Polygonion avicularis, Lolio-Potentillion and Loto-Trifolion. Measures for the conservation of the endangered ruderal communities are discussed. Open-air museums, reserves of vernacular architecture, and in case of halophilous and sand-dune semiruderal communities, nature reserves appear to be suitable for the preservation of the species pool of the vanish ing ruderals and ruderal communities in Slovakia.