Contributions to the Knowledge of Synanthropic Flora from The Pitesti Area

Abstract

The research of the synanthropic plant species characteristics from the urban environment offers information about their relation with the anthropic environment, on one hand, and on the other hand, they can be used as indicators of the pollution level. The research was performed in the city of Pitesti from June 2008 to may 2009, to compile an inventory of the flora, to establish the biological and ecological spectrum, the phytogeographic elements and their economic importance. The fresh above ground phytomass of the synanthropic species from 22 sample locations, was determined. The dry matter, the total nitrogen and phosphorus content, for six species of the dominant synanthropic plants, were also determined. It was identified 214 species of 38 families. The biological and ecological spectra show the high percentages of hemicryptophytes (35%), eutrophic species (54%), xeromesophilous-mesophilous species (29%) as well as eurytherm (20%) and euryacide species. The phytogeographic spectrum shows a high number of species from Eurasia (96 species). From the total number of identified species, 54% are polyploid and 27% present economic importance. It was found that the phytomass from stationaries varies between 281.7 g m-2 and 21.5 g m-2, for a number of 35 species. The highest dry matter content (64.01%) was recorded in Conyza canadensis, the highest value of N (8,200 ppm) in Lactuca serriola and the highest total P content (301.5 ppm) in Erigeron annuus. The results enable us to estimate the value of the synanthropic plants as ecologic indicators in the Pitesti area.