Impact of pollution on weeds phytosociology

Abstract

THE ASSOCIATED vegetation to some Assiut province farmlands was investigated between two years (2015 and 2016). The recorded flora (82 species belonging to 25 families) revealed general dominance of the annuals (65% of the total flora). Cluster analysis as a classification method yielded two distinct groups (A and B). Stands of group “A” were restricted to the polluted areas and those of group “B” were confined to the non-polluted areas. Fifteen species were confined to the polluted areas (group A), 31 species were in the non-polluted areas (group B) and 36 species were represented in both. Presence (P %) of species within the different groups was used as monitor of ecological success and habitat performance. Those species represented in both areas but with high presence percentages in polluted area (eurytopic species), in addition to species confined to this area can be checked for their potential use in phytoremediation. Urtica urens was the most abundant invasive species tolerating serious pollution level. Therefore, it can be considered as an indicator species for polluted areas. The application of DCA and CCA as ordination techniques on the collected data revealed the dependence of group “A” vegetation on heavy metals and group “B” on major nutrients. Preliminary phytosociological studies, however, can provide useful information on the species of potential use in phytoremediation. Keywords: CCA, DCA, Heavy metals, Phytosociology