Vegetation pattern and soil characteristics of the polluted Industrial Area of Karachi

A quantitative phytosociological survey was conducted around the industrial areas of Sindh Industrial Trading Estate (S.I.T.E.) of Karachi. The herbaceous, shrubs vegetation was predominantly disturbed in nature. Fifteen plant communities based on Importance Value Index (IVI) of species were recognized. Eighty plant species were recorded in industrial areas. Abutilon fruticosum L., attained the highest importance value index (823.25) followed by Prosopis juliflora DC. (662.62), Corchorus trilocularis L. (467.20), Aerva javanica Burm.f. (419.97), Amaranthus viridis L. (397.65) and Senna holosericea L. (387.22), respectively. P. juliflora and A. fruticosum showed leading first dominant in five and four stands, respectively. Whereas, A. javanica, A. viridis, S. holosericea, Launaea nudicaulis L., Crochorus depressus L. and Salvadora L., attained the presence class III. Zygophyllum simplex L., Suaeda fruticosa L., Convolvulus glomeratus Choisky, Cressa cretica L., Cleome viscosa L., Calotropis procera Willd, Blepharis sindica T. Anderson, Rhynchosia pulverulenta L., Abutilon pakistanicum Jafri & Ali, Chenopodium album L., Capparis decidua Forssk and Digera muricata L. Mart showed the presence of class II. Whereas, rest of 58 species showed presence of class I. The soil characteristics of the polluted industrial area were also analyzed and related with the vegetation of the polluted areas. The Industrial area soil was coarse in texture and ranged from sandy clay loam to sandy loam. The soil was acidic to alkaline in nature. Maximum water holding capacity, bulk density, porosity, CaCO3, pH, organic matter, total organic carbon, chloride, and electrical conductivity, total dissolved salt, available sulphur contents, exchangeable sodium and potassium were recorded in wide range. It was concluded that certain edaphic factors due to industrial activities and induction of pollutants were responsible for variation in vegetation composition of the study area.