NATURALNE UWARUNKOWANIA PRZYRODNICZO-GOSPODARCZO- -SIEDLISKOWE ZBIOROWISK ŁĄKOWYCH NA POLDERZE PÓŁNOCNYM W PARKU NARODOWYM „UJŚCIE WARTY”

Abstract

Research on natural and functional values of grassy and reed phytocenoses in the “Ujście Warty” National Park in the Northern Polder, was carried out in 2013–2019. They showed that the formation of grass communities, their richness and floristic diversity, as well as natural and agricultural values, is mainly influenced by moisture, which results from the mosaic of habitats and the intensity of use. The aim of the study was to assess the floristic diversity, natural values and utility of grass communities in leasehold complexes in the “Ujście Warty” National Park in the Northern Polder in the Natura 2000 area. One of the methods of protection and renaturation of naturally valuable meadow communities is the introduction of extensive forms of mowing and pasture use. The aim of such activities is, among others, to improve floristic diversity and prevent unfavorable transformations of protocoenoses, especially in relation to areas covered by the Natura 2000 area. Single, annual mowing during the growing season, through the implementation of agri-environmental programs, does not cause significant changes in the botanical composition of the sward, but it is conducive to restoring the most valuable natural habitats as a potential habitat for bird species endangered on a national and European scale. The distinguished communities have a diversified economic and use value of Lwu ranging from 1.1 to 7.4, and some are wastelands. The calculated floristic diversity (H’) is varied and ranges from 1.3 to 3.9, and the obtained yields are sm. range from 2.8 to 14.8 t∙ha−1 .