Samir Ghannem

Assessment of heavy metal contamination in soil and Chlaenius (Chlaeniellus) olivieri (Coleoptera, Carabidae) in the vicinity of a textile factory near Ras Jbel (Bizerte, Tunisia)

In this study, data on several metals (Cd, Zn, Cu, Ni and Pb) in soil and carabids Chlaenius (Chlaeniellus) olivieri sampled from northeastern Tunisia were presented. Samples were taken at six sites S1, S2, S3, S4, S5 and S6 alongside Kantra River close to three jeans fading industries: Lee Cooper, Denim authority and CRJ. Elemental compositions were assessed through the estimation of geochemical accumulation indices, pollution load index, the contamination factor and bioaccumulation factor (BAF), determined to reveal any potential toxic effects on biota. Significant enrichment of the soil with Cd, Zn, Cu, Ni and Pb was observed in all considered sites and shows a veritable metallic polluted state. The highest concentrations of metals recorded in soil were found at S1. In addition, negative correlation was observed between concentrations of heavy metals in the soil and the species. The BAF values show that C. olivieri is a macro-concentrator for Cd and a micro-concentrator for Zn. The finding provides a rich dataset of metals in several biotas and had operational significance for coexistence of heavy metals in both soil and ground beetles. C. olivieri can be used as a bioindicator in monitoring metals pollution of terrestrial ecosystem. Results can be useful for mitigating the impact of metallic pollution on environmental health and required strategies to prevent such effect.

Beetles (Insecta: Coleoptera) as bioindicators of the assessment of environmental pollution

ABSTRACT Bioindicators have been generating great interest in environmental pollution research. Insects and especially arthropod are useful to assess the effects of anthropogenic activities on the terrestrial ecosystem, because they are inclose contact with toxic elements present in soil and in leaf litter. Beetles are extremely sensitive to several ecological parameters, react quickly to environmental modifications and can be easily and cost-effectively sampled by various methods. These criteria make beetles excellent indicators of terrestrial ecosystem. In order to evaluate the environmental impact of human activities on different ecosystems, the use of Coleoptera in ecological studies has been largely increased in recent years. This review presents the results obtained by researchers when using beetles as bioindicators of metallic pollution and forest disturbance.

Assessment of trace metals contamination in soil, leaf litter and leaf beetles (Coleoptera, Chrysomelidae) in the vicinity of a metallurgical factory near Menzel Bourguiba (Tunisia)

ABSTRACT Metal pollution is a major environmental danger owing to the rapid increase of urbanization and anthropogenic activities, which may damage the fauna and flora. Insects are often used as bioindicators of the accumulation of toxic elements. We measured concentrations of Cu, Fe, Mn, Zn, Al, and Pb in soil, litter and leaf beetles: Oulema gallaeciana (Heyden, 1879) and Lachnaia paradoxa (Olivier, 1808) at four sampling sites at different distances from metallurgical factory near Menzel Bourguiba (Tunisia). Metal concentrations did not extend beyond a distance of 4 km and were restricted to the immediate surroundings. Significant difference between sites was found for Cu, Fe, Al, and Mn concentrations in leaf litter and only for Pb in soil. In the case of Lachnaia paradoxa, no significant differences were found in the contaminant, except for Cu. The concentrations of Fe and Cu were high in Oulema gallaeciana. Positive correlations were detected for metals in the soil, leaf beetles and leaf litter. Our study confirms that the contaminants can transfer from plants to species.

Biodiversity of Ground Beetles (Coleoptera: Carabidae) from Northern Tunisia

ABSTRACT:  The family Carabidae is an important group of mostly terrestrial predators in the order of Coleoptera. Their diversity and assemblage structure were analyzed using samples obtained from six localities in northern Tunisia using pitfall traps. Species richness and abundance of carabids in different habitat types (forests, parks and cultivated fields), and their relationship with the environment were discussed. A total of 840 carabid beetles belonging to 39 species were collected. An analysis of site similarity based on species richness showed spatial variation. The Shannon-Wiener diversity and evenness indexes were calculated. The most abundant taxa were Chlaenius chrysocephalus (Rossi, 1790), Carterus rotundicollis (Rambur, 1842) and Amara aenea (De Geer, 1774). Non-metric multidimensional scaling (NMDS) ordination highlighted the faunistic affinities among sites revealing three main groups. Temperature, rainfall, soil organic matter content, altitude and abundance of vegetation seem to be the major drivers structuring beetle assemblages and influencing species abundance and richness. These results suggest that habitat heterogeneity was the predictor of beetle assemblages, while species richness could be expected at a landscape scale using abiotic features.