Spatial and Temporal Patterns in Iowa Shore Fly Diversity 12

Indices to measure species diversity (H'), species richness (s), and species evenness (J') are calculated for 12 habitats containing 101 species of shore flies in Iowa. It is shown that there is a significant positive correlation between richness and diversity and evenness and diversity and a significant negative correlation between evenness and sample size. There is no correlation between richness and evenness or diversity and sample size. An attempt is made to explain, in terms of habitat characteristics, the correlations between these indices. A stepwise multiple regression analysis indicated that evenness is most important in determining Iowa shore fly diversity and that sample size has no significant effect on the diversity index. The temporal (seasonal) patterns of the three indices in selected habitats are described.