Changes of Grassland Vegetation in Surroundings of New Railway Flyover (Eastern Bohemia, Czech Republic). Part I: Plant Communities and Permanent Habitat Plots

Paper shows (1) the results based on vegetation monitoring during the time period 1975-2005 in the grassland segment of undulated landscape along railway corridor close to village Dlouhá Třebová (Ústí nad Orlicí district, Eastern Bohemia, Czech Republic). Survey was focused on the meadow communities, identification of phycenological changes by comparison of historical phytosociological records (1975) with the present ones (2005). (2) Actual relevés taken within transect design showed that there is direct dependence between the meadow species composition and soil moisture gradient. Along the soil moisture gradient different formations can be found: Carex acuta communities occupying the wet sites close to river bank with high groundwater table, followed by wet Calthion meadows with Cirsium rivulare in mosaic with Holcus lanatus formation on drier microsites. Arrhenatherum elatius stands grow in mesic conditions in contact with Calthion wet meadows. Dry sites on high slope are dominated by Festuca rubra. There are also some plant species of semi-thermophilous flora and species that prefer more acid soil reaction as a part of grassland complex. Meadow biotopes which were not affected by site alteration during bridge building, and communities with Carex acuta seem to be relatively stable in time. There are two populations of protected rare plant species in the locality: first an orchid Dactylorhiza majalis and the second Gentianopsis ciliata. (3) The railway reconstruction resulted mainly into degradation processes of grassland sites which is documented by the sown plant mixture or ruderal plant assemblages.