Effect of Soil Moisture on Demographic Dispersion, Species Association and Diversity of Primary Producers in a Sub-tropical Swamp Forest

The present study was conducted in five communities of a sub-tropical swamp forest of Doon Valley, India. The aim of the present paper is to study the various changes in the community structure as a result of change in seasons and soil moisture regime. In moist communities local species were dominant and as the soil moisture (%) lessened their dominance decreased. Importance Value Index (IVI) of all dominant species of the swamp varied significantly during the study period, indicating that they are noticeably affected by the changes in the moisture regime of the swamp. Various indices of association were calculated to find out species association and the results of these indices shows that all the local species were closely associated. Species richness, Shannon- Wiener diversity index (H'), concentration of dominance (Cd) and beta diversity (β) of the five communities were also calculated. Pearson's correlation was used to find out relationship between soil moisture (%) and diversity indices. The results of the correlation analysis reveal that soil moisture (%) was negatively correlated with species richness and H' and positively related with Cd and β diversity.