Diversity and distribution of earthworms in a natural reserved and disturbed sub-tropical forest ecosystem of Imphal-West, Manipur, India.
Keywords:
Native species, natural forest, disturbed forest, population density, diversity.Abstract
A comparative analysis of earthworm communities was carried out in sub-tropical forest ecosystem to understand the impact of biotic disturbances. Three sites selected were: natural mixed reserved forest, disturbed oak dominated sub-tropical forest ecosystem and managed oak plantation sector. We evaluated the presence and diversity of various earthworm genera and species in selected forests sites. Our investigation revealed the presence of at least 7 species of earthworms belonging to 5 genera and 4 families: Megascolecidae (Metaphire houlleti, Metaphire anomala, Amynthas corticis, and Amynthas morrisi.), Glossoscolecidae (Pontoscolex corethrurus) and Moniligastridae (Drawida sp.), Octochaetidae (Eutyphoeus sp.). Glossoscolecidae and Megascolecidae were generally found in disturbed forest ecosystem. Drawida sp. had a mean density of 65 ind. m-2 in a natural reserved forest whereas in the disturbed oak dominated forest it showed maximum mean densities of only 15 ind. m-2. Our results showed the great adaptability of Glossoscolicidae to various levels of disturbances and suggested the possibility of a large occurrence of this worm species in sub-tropical forest ecosystem of Imphal, Manipur.