Szintézis a Palaearktikus gyepek biodiverzitásáról és a veszélyeztető tényezőkről

Megjelent az 2020 nyarán publikálásra kerülő az Elsevier kiadó által gondozott 'Encyclopedia of World's Biomes' művésznévre hallgató cikkgyűjtemény Palearktikus gyepekkel és cserjésekkel foglalkozó részének tizenkét cikkét bevezető szintézisfejejezet Jürgen Dengler elsőszerzőségével. A cikk frissíti a 'Grasslands of the World' (Taylor and Francis, CRC Press, 2018, Török & Dengler: Palaearctic Grasslands in Transition: Overarching Patterns and Future Prospects) tanulmánykötetben szereplő cikk adatait, illetve a cikkgyűjtemény kiegészült őshonos cserjések ismertetésével is. A kötet vonatkozó fejezete (és a kelet-európai régióra vonatkozó rész) elérhető lesz a honlapomon is, de letölthető lesz a cikkgyűjtemény oldalán is. Az összefoglalója az alábbiakban olvasható.

Grasslands of the Palaearctic Biogeographic Realm: Introduction and Synthesis

Dengler J.,  Biurrun I., Boch S., Dembicz I., Török P.

Grasslands are spontaneously occurring herbaceous vegetation types that are mostly dominated by grasses or other graminoids and have usually > 10% herb-layer cover, while woody species area absent or have a significantly lower abundance than the herbs. In the Palaearctic biogeographic realm, natural and secondary grasslands (76% and 24% of all grasslands, respectively) cover about 10.0 million km2, i.e., 18% of its territory, which constitute 41% of global grasslands—more than any other biogeographic realm. In “The encyclopedia of the world's biomes,” the Palaearctic grasslands are placed in the section “Grasslands and shrublands,” where we defined 10 regions, which are treated in individual chapters: Western Europe, Northern Europe and Baltic States, Eastern Europe, Mediterranean Region, Middle East and Caucasus, Russia, Kazakhstan and Middle Asia, Mongolia, China, and Japan. These regions cover the huge majority of the realm and about 98% of its grasslands. Each chapter describes the extent, physiogeography, origin, biodiversity and typology of the grasslands in the region, the threats for grassland diversity and extent, as well as grassland management and conservation. Grasslands are important habitats for many groups of taxa. Dry calcareous grasslands and steppes constitute habitat of most of Europe's butterfly and Orthoptera species, and they host significant number of European endemic plants. In small spatial scales (i.e., below 100 m2) Palaearctic grasslands, especially meso-xeric ones, can hold even higher species diversity of plants than tropical rainforests. However, Palaearctic grasslands are also among the most intensively and negatively human-impacted habitats. Changes in grassland management, like overgrazing or other types of intensification as well as abandonment were assessed as the most important recent and future threats. Other important reasons of decline in grassland diversity are habitat loss and altered site conditions. The negative impact of climate change and invasive species is predicted to be stronger in the future. In the last years, various conservation efforts to monitor, maintain and promote grassland extent and diversity were made. However, to counteract the negative trends, these efforts urgently need to be intensified and their efficiency needs to be improved.