POPULATION-DYNAMICS OF THE EARTHWORM AMYNTHAS-ALEXANDRI (MEGASCOLECIDAE, ANNELIDA) IN CULTIVATED SOILS OF THE KUMAUN HIMALAYAS

The population dynamics of the earthworm Amynthas alexandri was observ ed over 2 years in cultivated soils at Chanfi and Khurpatal near Naini tal. Both hand sorting and formalin extraction were used to sample ear thworms from the top 20 cm of soil. The density and biomass of earthwo rms fluctuated substantially during the year. Maximum density (58.4 m( -2)) and biomass ( 19.6 g m(-2)) were recorded in the rainy period and minimum during the dry period. Within the top 20 cm, 51-69% of the to tal numbers of earthworms were collected from the 0-10 cm soil layer a nd the proportion of biomass in the same layer was 51-83%. Most (80-90 %) of the worms collected were clitellate. The C:N ratio of the soil d ecreased with increasing depth in both localities.