Assemblage and distribution of pill millipedes and earthworms in relation to soil edaphic features in the Western Ghats and the west coast of India

Abstract

Abundance and biomass of pill millipedes (Arthrosphaera) and earthworms in the forests and plantations of nine study sites in the southwestern India (Western Ghats, foothill of the Western Ghats and the west coast) were surveyed. Out of 10 morphospecies of pill millipedes (Arthrosphaera) recovered, four were identified, and the rest did not match with morphological and taxonomic descriptions. A maximum of five species of Arthrosphaera were recovered from the Western Ghat forests. In forests, the biomass of pill millipedes was higher than earthworms but lower in abundance. In plantations, both biomass and abundance of millipedes were higher than those of earthworms. None of the 12 soil edaphic features (moisture, bulk density, water-holding capacity, temperature, pH, conductivity, organic carbon, P, K, Ca, Mg and litter depth) significantly correlated with millipede biomass in the Western Ghat forests, nor were any soil features correlated with earthworm biomass in the west coast plantations. While all, except for soil moisture, were significantly correlated with earthworm biomass in the Western Ghat forests. In the Western Ghat plantations, the biomass of millipedes was significantly correlated with soil moisture, pH, organic carbon and minerals (P, K and Ca). In the west coast plantations, the biomass of millipedes was significantly correlated with moisture, water-holding capacity, organic carbon, Ca, and Mg, while, in the foothill plantations, only with temperature.