author(s)
Sudhansu Bhagawati, Badal Bhattacharyya, Snigdha Bhattachajee, Himangshu Mishra and Binoy Kumar Medhi

abstract
The present study was undertaken to know the density and diversity of collembolans in Majuli river island during 2015-16. Altogether 1354.55 individuals of Collembola were extracted, which revealed the presence of 5 species viz., Cyphoderus sp., Entomobrya sp., Isotoma sp., Folsomia sp. and Hypogastrura sp. belonging to 4 families viz., Cyphoderidae, Entomobryidae, Isotomidae and Hypogastruridae. Cyphoderus sp. was recorded to be the most abundant species contributing 37.74 percent of population. During the study period, the diversity was recorded to be higher during summer indicating the presence of relatively stable habitats as compared to other seasons. The highest density (196.36 nos./sq.m.) of Collembola was registered during the summer season and the lowest during the winter season (39.09 nos./sq.m.). Monthly variation of collembolan density revealed the maximum population of Collembola during the month of August (206.82 nos./sq.m.) whereas minimum was registered during February (27.27 nos./sq.m). Correlation studies revealed a significant positive correlation of collembolan density and diversity with soil moisture (Density, r= 0.929, 0.923, 0.824 and 0.945); (Diversity, r= 0.702, 0.867, 0.622 and 0.904) and organic carbon (Density, r= 0.873, 0.973, 0.787 and 0.915); (Diversity, r= 0.732, 0.667, 0.735 and 0.843) during all the seasons, respectively. Other soil physicochemical properties viz., sand, silt, clay, soil microbial biomass carbon, pH and bulk density did not exhibited any distinct relationship with both the density and diversity of the collembolans.