Factors determining species diversity and species composition of abandoned fields

6 Abstract Factors determining plant species composition and species diversity of former fields in Slavkovský les The secondary succesion is relatively thoroughly examined phenomenon, but quite little is known about wet secondary grasslands developed on the former farmland. There is a large number of abandoned fields in the Slavkovský les protected landscape area, western Bohemia, which occuring on mesic to wet soil. For this study an area surrounding Ovesné Kladruby hamlet was chosen. The aim of this thesis is to explore, which plant species can occur on the former fields and how the species composition and species diversity is effected by environmental and historical factors, such as soil properties, distance from an old grassland and the age of the field. I made 190 phytosociological relevés and noted 215 species of vascular plants. Some rare species were also present, e.g. an orchid Dactylorhiza majalis and state protected species Triglochin palustre. Species composition data were explored using multivariate analyses and species diversity data using linear regression. Species composition was effected mainly by soil properties. The effect of soil nitrogen and phosphorus content was the strongest one. Soil nitrogen content was positively correlated with soil moisture and on such localities mainly wetland..