Community structure and functional diversity of soil nematodes from Udupi district, Karnataka, India

Abstract

Nematodes constitute the most significant, most numerous, and diversified set of multicellular organisms on the earth. They live in various environments and exhibit a wide range of behavioural patterns. In the soil food web, they can be found at various trophic levels as herbivores (plant parasitic nematodes), bacterivores, fungivores, omnivores, and predators. As there were fewer studies on nematode ecology in the Udupi region, the present study aims to study the community structure and functional diversity of soil nematodes. Soil samples were collected following opportunistic random sampling employing a soil auger and were stored at 40C until transported to the laboratory. Nematodes were isolated from soil, killed, fixed, dehydrated, and displayed on a glass slide after isolation. The standard keys were used to identify the individual to genera level. 62 genera of soil nematodes belonging to 26 families and 7 orders were identified. Predator were the most prevalent communities. Various statistical indices for assessing nematode population ecology and nematodes specific indices were also calculated and it indicated a significant abundance of large plant parasitic nematodes. The region exhibits low levels of labile organic carbon and nutrient enrichment (Enrichment Index (EI):14.06 to 21.22). Despite this, the soil food web in the region is well-structured, indicated by Structure Index (SI) (85.51 to 89.74). Prevalence of fungal decomposition dominance and the soil appears to be minimally disturbed, as indicated by high channel index values and low Basal Index (BI) values, respectively