Impact of waste water discharge on the plant diversity and community structure of Al‐Marj Plain, Libya

Abstract

AbstractThe present study aims at describing and analyzing the floristic composition and vegetation types, as well as evaluating the impact of waste water pollution on the plant diversity and community structure in Al‐Marj plain, North Libya. Forty‐two stands, distributed among pol‐luted and non‐polluted sites, were selected seasonally for this study. A total of 156 species were recorded (92 in the polluted and 121 in the non‐polluted sites). Eight vegetation groups were resulted after the application of TWINSPAN and DCA as classification and ordi‐nation techniques: four represented the polluted sites, two for the non‐polluted sites and other two were mixed groups. Group II (Sarcopoterium spinosum – Pistacia len‐tiscus), which represents the polluted sites, had the highest values of soil moisture, sa‐linity, sulphate, calcium and potassium; while group VI (Juniperus phoenicea – Olea europaea) inhabiting the non‐polluted site, had the lowest value of organic matter, salinity and magnesium. Group VII (Foeniculum vulgare – Nicotiana glauca), representing the non‐polluted site, was the most diverse, while VG III (Ricinus communis – Chrysanthemum coronarium), characterizing the polluted one, was the least. Heavy metal analysis, in both soil and waste water, indicated that the con‐centrations of Pb, Cd, Cr, Cu and Ni in the polluted sites were significantly higher than that in the non‐polluted ones. The diagram resulting from CCA showed effectiveness of most soil variables, except carbonates, sodium, magnesium and chlorides. The impact of waste water discharge led to the emergence of new invasive species, which may severely affects the plant diversity and community structure of this hot spot of biodiversity in Libya. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)