EFFECT OF SOIL EDAPHIC AND CHEMICAL FACTORS ON THE POPULATION DENSITY OF A TERRESTRIAL DETRITIVORE COLLEMBOLAN- Cyphoderus javanus IN DIFFERENT PLACES OF THIRUVANANTHAPURAM DISTRICT

Soil is one of the most precious resources of earth which provide home for different kinds of microarthropods. Collembolans are potential biomarkers of soil fertility and ecosystem health. Attempts were made to evaluate the influence of soil physio-chemical properties on the population density and distribution of Cyphoderus javanus in three selected sites of Thiruvanathapuram district- Neyyar, Vithura and Agasthyavanam Biological Park. Extraction of soil microarthropods were carried out by modified Berlese Tullgren funnel and soil physico-chemical factors were analysed by standard laboratory procedures. The results of present investigation revealed that soil physico-chemical factors showed site and season wises variations. At three sites, mean population density was observed very high in top soil layer during post -monsoon season (Neyyar 27±1.58; Vithura 23.2±1.5 and Agastyavanam 16 ±2.2) and very low during pre-monsoon season (Neyyar 16.6±1.4; Vithura 11.4±2.3 and Agastyavanam 6.8 ±1.3). A clear pattern of vertical migration of Cyphoderus javanus were observed with changing edaphic factors like soil temperature and moisture. PCA results inferred that temperature, moisture, exchangeable acid, organic carbon, gravel, clay, nitrogen, phosphorus, calcium and magnesium are the most influential parameters affecting the density and vertical distribution of Cyphoderus javanus in selected sites of Thiruvananthapuram district.