This study was carried out at Otofure, Asoro, Ikhueniro and Iguomo municipal dumpsites while the control was a parcel of land located in Obe in Edo state, Nigeria. Species population and biodiversity studies were carried out using quadrat method and Shannon-Wiener diversity index respectively. Plant growth parameters were measured and analyzed using inferential statistics. Soil physicochemical, microbial, heavy metal as well as plant heavy metal analyses were carried out using standard methods. Results showed that the control was more species diverse than all the dumpsites except Ikhueniro dumpsite. Amaranthus spinosus, Chromolaena odorata and Panicum maximum were common to all the dumpsites. Growth studies revealed that these plants grew better in the dumpsites than in the control. The results of physicochemical analyses revealed that the dumpsites contained C, N, P, Ca, Mg, Na and K within the ranges of 2.67% – 5.81%, 0.15% – 0.22%, 5.10% – 6.48%, 1.78 meq/100g – 3.07 meq/100g, 0.63 meq/100g – 1.74meq/100g, 0.31 meq/100g – 0.68 meq/100g and 0.34 meq/100g – 0.87 meq/100g respectively. The control site had lesser values as follows; N (0.08%), P (1.90%), Ca (0.83 meq/100g), Mg (0.45 meq/100g) Na (0.18 meq/100g) and K (0.22 meq/100g). The results of soil microbial analysis revealed that the control site recorded more microorganisms than the dumpsites. Amaranthus spinosus growing on the dumpsites were found to contain heavy metals within WHO limits except Fe. It was concluded that though the plants on the dumpsites grew better, the presence of heavy metals even at low concentrations may bio-accumulate and pose public health hazard.
Key Words: Dumpsite, Biodiversity, Heavy metal, Edo State, Nigeria