Collembola (Hexapoda) as quality bioindicators of the hydrocarburans polluted soils in

Abstract

We evaluated invertebrates, with an emphasis on Collembola, as bioindicators of soil quality in hydrocarboncontaminated soils in southeastern Mexico. We carried out 2 sampling periods in summer-fall of 2004 in 4 parcels of 2 hectares each. From each parcel we processed 8 samples using the Berlese-Tullgren funnel technique and 4 using the flotation method. For Collembola we calculated the following ecological indices: abundance, richness, the Shannon index (H’), dominance (λ), equitativity (J’) and the similarity index (S). We also performed the following soil analyses: total petroleum hydrocarbon content (HTP), polycyclic aromatic hydrocarbon content (HAP), porosity, pH, CE, MO, N, P, K, CIC, and texture. In contaminated areas, HTP exceeded the safe limits sets by Mexican environmental legislation. In all studied areas we observed Collembola, mites, and dipteran larvae. The variation in abundance and diversity of these insects can be used as biondicators of the level of contamination and quality of the soil. We found very low abundances of Crustacea, Formicidae, Aranae, Diptera, Pseudoscopionida, and Diplopoda. The Collembola families that were most widely distributed were Sminthurididae and Isotomidae. Our correlation analysis showed that their diversity is affected by HAP level (fl uoranthene, naphfhalene, pyrene, chrysene and phenanthrene).