Vegetation succession on fallows in Podyjí National Park - small-area management of abandoned sites

The main aim of the thesis was to describe the succession of several abandoned fields under ploughing and discuss ploughing as a possible management for establishing and maintaining species-rich communities of fallows. Actual vegetation, its development over time and soil seed bank were studied. Experimental small-area ploughing was established at five abandoned fields in the southeastern part of the Podyjí National Park. Three strips with different types of management were founded: A) strip ploughed each year, B) strip ploughed once at the beginning of the experiment, C) control meadow without intervention. Vegetation development was evaluated through a series of relèves recorded during the years 2009-2012. The species composition of the seed bank was described using the seedling-emergence method and subsequent elutriation of soil samples. Similarity indexes, Longevity index (LI) and concept of RCS strategies were used. The vegetation of each-year plowed sites (A) consisted mostly of annual weeds and ruderal species with R-strategy and high LI. Grassland vegetation (C) consisted mostly of grasses and perennial herbs with C-strategy and lower LI. The vegetation of older fallows (B) was at first most similar to one-year fallow (A), but during the 4 years of succession has moved closer to the meadow..