Effect of Different Habitats on Richness of Land Snail Fauna in Knuckles Forest Range in Sri Lanka

Abstract

Richness of land snail fauna is not uniform over the all regions in the country and severalfactors are believed to be affected on richness of land snail fauna. This study aimed toinvestigate the effects of different habitats on the richness of land snail fauna in Knucklesforest range.

A sample of 115 plots of size 100 x 2 m2 was considered. These plots were selected coveringseven different types of habitats in Knuckles forest: montane forest, submontane forest,montane zone cardamom forest, submontane zone cardamom forest, submontane zonegrasslands, intermediate zone forest, and intermediate zone homegardens. Plots from eachhabitat were selected based on the convenience for sampling. Inside each plot, number ofindividuals belonging to each species was recorded as the responses.

Multivariate analysis of variance (MANOVA) technique was used to test the dependence ofnumber of individuals and number of species on habitats. Results of MANOVA were testedby applying univariate analysis of variation (ANOVA) technique for each response separatelyto confirm the results of MANOVA. For the above analysis, log transformed data of numberof individuals and species were used as the responses. Finally, Chi-Square test was used toconfirm the dependence of land snail fauna on habitats.

Results of statistical analysis confirmed that the richness of land snail fauna in the all habitatsconsidered is not significantly different. Habitat-wise variation of richness of land snail faunacan not be observed in this region. This implies that richness of land snail fauna in Knucklesforest range does not vary with different habitats considered.