| Abstract: |
Earthworms are key soil ecosystem engineers that influence decomposition, nutrient cycling, soil aggregation, aeration and organic matter transformation. Their distribution is strongly affected by land use, soil properties and vegetation structure. Northeast India, part of the Indo-Burma biodiversity hotspot, contains highly diverse landscapes including natural forests, plantations, grasslands, agricultural fields and disturbed habitats. This paper synthesizes available evidence on the spatial ecology of earthworm communities across these land-use gradients. Regional studies report around 125 earthworm species belonging to 28 genera and 10 families, with approximately 68.8% native and 31.2% exotic species. In Assam, earthworm density ranged from 56 to 238 individuals m⁻² and biomass from 1.0 to 5.4 g m⁻² across different habitats. In Manipur, natural mixed forest supported 12 species compared with only four in an oak plantation. Mixed forests have also shown higher Shannon diversity values than highly disturbed habitats. Soil moisture, pH, organic carbon, litter quality, vegetation heterogeneity and land-use intensity emerge as major determinants of community structure. The findings indicate that earthworm abundance alone cannot represent soil biodiversity; species richness, functional composition and native–exotic turnover must also be considered. |
