Soil Fauna of Ranibari Community Forest, Kathmandu, Nepal

Abstract

Ranibari Community Forest (RCF) is the important forest patch present within the highly urbanized Kathmandu valley with information gaps on soil invertebrate fauna. This study aimed to explore soil meso and macro fauna of the forest. Fourteen random quadrats (1m × 1m) were laid, within the seven blocks. Leaf litter samples and soil cores were collected, screened, sieved on a white sheet to extract fauna. Sampling was done once a fortnight from May to November, 2019. The result showed that the diversity, abundance and species richness of soil fauna were seen highest in summer season (Hˈ = 2.897, Abundance = 1973, S = 84) dominated by Collembola. In addition to that, the QBS-ar value was seen highest in summer as well (QBS-ar = 417) which successively decreased in succeeding seasons. In case of the habitat type, soil fauna was seen to be more diverse and evenly distributed in soil layers throughout the seasons but the abundance was greater in leaf litters, particularly in summer. Fauna like Chilopoda, Diplopoda, Haplotaxida and Isopoda were seen to be affected negatively by soil temperature in case of summer and autumn seasons. Soil moisture content was found to be positively correlated with immature insects, earthworms and millipedes in rainy and autumn seasons. Besides, the pH of soil was seen to affect Diplura only in autumn season. The relation of fauna with the physico-chemical parameters (temperature, moisture and pH) and also with other taxa shows their ecological roles and adaptation to specific microclimate.