Diversity, abundance and tissue mineral composition of indigenous earthworm species of sawmills of Abeokuta, South-Western Nigeria

The influence of earthworm’s environment on its biology needs to be well understood. This study investigated the impact of sawmilling activities on the diversity, abundance and mineral composition of the tissues of earthworm species in Lafenwa, Sapon, Isale-Ake and Kotopo sawmills of Abeokuta (7^o9’12’’N-3^o19’35’’E). The arboretum of the Federal University of Agriculture, Abeokuta was used as control. Earthworms were sampled in the morning hours from four random samples of 25x25x30cm and carefully counted. Weight of the earthworms was taken and tissues mineral composition determined using Atomic Absorption Spectrophotometer. Average population of earthworms were significantly higher (P<0.05) (140–516 earthworms/m²) in the sawmill soils than in the soil of the control site (96 earthworms/m²). A total of five earthworm species were identified from the study locations. Mean weight of adult E. eugeniae from Sapon (1.18g) and Kotopo (1.21g) sawmills were significantly higher than that of the control site (0.92g). K and Na were higher in the tissues of earthworms from Sapon sawmill. Significantly lower (P<0.05) Ca and Mg concentrations were recorded in the tissues of E. eugeniae from the control site compared to those of Kotopo and Sapon sawmills. Sawmilling activities is therefore not totally detrimental to earthworms’ habitation

Earthworm species, population density, sawmill, tissue minerals, diversity, soil, environment