Dynamics of Helichrysum arenarium (L.) Moench populations growing in fallow field on barren soil

The aim of the study was to determine the influence of habitat factors on growth and development dynamics of Helichrysum arenarium individuals growing in extreme and unstable ecosystems. The impact of phytocoenosis type and weather conditions on the population density, biomass, potential fertility, dry mass and the number of shoots per specimen were analyzed in detail. The study was conducted on two Sandy Everlasting populations growing on fallows and representing different succession stages. Measurements and phenological observations were carried out during growing seasons from 2003 to 2005 in four permanent plots, two for each population. The populations remained under a strong influence of habitat factors, which was evidenced by their different phytosociological position. Growth and development processes in these populations were modified by weather conditions. The potential fertility of specimens was significantly correlated with the precipitation amount. Biomass and its seasonal distribution within the populations depended on weather conditions and the number of species building the phytocoenoses.