SPECIES COMPOSITION AND RICHNESS OF TERRESTRIAL MOLLUSKS INHABITING LIMESTONE HILL AND LOWLAND FOREST DECLINE MACRO ZONE IN SUB-SAHARAN AFRICA

Ecosystem characteristics affect the composition, richness, diversity of species, and their ability to recolonize disturbed habitats. Here in Nigeria, two localities Mfamosing limestone hills and Odukpani lowland forest with different exposures to human activities were sampled in 2017. The study was aimed at creating inventories, comparing and evaluating the diversity of mollusk species in leaf litters and topsoil sourced from eleven 20x20m plots per locality. Results revealed a total of 593 individuals belonging to 26 species in 18 genera and ten families, and 282 individuals belonging to 18 species from 10 genera in 5 families at Mfamosing and Odukpani respectively. The mollusk composition at Mfamosing was significantly different from those at Odukpani, although they had eleven common species. In further assessing these findings against similar assessments conducted no less than a decade ago in the neighboring Oban hill and Odukpani, previously abundant species were now numerically depauperate species, while some were completely absent. While the key drivers responsible for their population decline remain unknown, how changes in habitats - due to human use over time- impinge on the mollusk species is worthy of further investigation.