On variation of diversity of soil oribatids (Acari, Oribatida) in three differently used soil habitats- a waste disposal site, a natural forest and a tea garden in the northern plains of Bengal, India

Soil samples were collected from three different habitats at monthly intervals. Order Oribatida was the highest numerically abundant group of acrarines followed by order Mesostigmata. ANOVA indicated significant difference (p<0.05) in population density of oribatid mites among the sites. Five, eight and ten species of oribatid mites were recorded from the waste disposal site at Panga, Denguajhar tea estate and Bodaganj forest respectively. Tectocepheus velatus, Lamellobates palustris and the species of genus Scheloribates were dominant in all the sites. Species abundance distribution at waste disposal site fitted well to geometric series while log normal model appeared applicable at tea estate and forest site. Population density as well as Shannon’s index of diversity (H’) was highest at forest site. Right tailed sum diversity ordering showed following orderforest floor > tea estate > waste disposal site. Richness and evenness indices were also highest at Bodaganj forest for the higher number of species and population density. Dominance index was highest at the waste disposal site. Greater similarity was recorded between tea estate and waste disposal site. Beta diversity was a moderately high in the sampling region.