Distribution of plant communities, ecological strategy types and diversity along a moisture gradient

The influence of water regime on the zonation of wetland communities, distribution patterns of plant species, ecological strategies and biodiversity, was studied in this work. Vegetation of the herbaceous wetland was sampled along a transect, in accordance with the standard central European method. Water level was also measured. The changes in plant species composition, plant functional types (ecological strategies, life forms) and diversity were studied. Classification of vegetation releves enabled the definition of five grassland communities. The same pattern remained in DCA ordination also when the species matrix was replaced with a matrix of ecological strategies. Releves were always segregated into distinct plant communities and distributed along the moisture gradient in the same way. Biodiversity is strongly negatively correlated with moisture-it is decreasing with decreasing ground level. Plant ecological strategy types (C-S-R) change significantly along the transect as well. In communities thriving on the driest sites (Triseto-Centaureetum), there are three times more C- than C-S-strategists, while in the wettest sites (Caricetum elatae) C-S-strategists predominate over C-strategists by almost two times. At the same time Rand C-R-strategists, as well as therophytes, which are present in drier sites almost disappear in the wettest sites. We show that the moisture gradient essentially influences the distribution pattern of plant communities, species diversity, and manifestation of certain ecological strategy types.