Earthworm community structure under tea plantations (Camellia sinensis) of Tripura (India)

摘要

A study of the community structure of earthworms under the tea plantations (Camellia sinensis) in four districts of Tripura revealed 15 species of earthworms from four families viz. Octochaetidae (Eutyphoeus comillahnus, Eutyphoeus sp. 1, Eutyphoeus orientalis, Lennogaster yeicus, Lennogaster chittagongensis, Dichogaster bolaui, Dichogaster affinis, Octochaetona beatrix), Megascolecidae (Metaphire houlleti, Kanchuria sp. 1, Amynthas alexandri, Polypheretima elongata), Moniligastridae (Drawida assamensis, Drawida papillifer papillifer) and Glossoscolecidae (Pontoscolex corethrurus). These occurred within the top 15 cm of soils with a mean temperature of 26.9 degrees C, moisture content 16.2%, pH 4.92, organic matter content 2.13%, and the bulk density 1.09 g cm(-3). In general, mean density and biomass of earthworms, irrespective of their age groups, were 212 ind. m(-2) and 51.7 g m(-2), respectively. Earthworm community showed co-existence of native species with the exotics, presence of only 2 ecological categories (endogeic and epianecic), low Shannon-Wiener diversity index (0.72), Menhinick species richness (0.43), and a high relative density (36.20%) of the exotic species, Pontoscolex corethrurus.