Habitat Characteristics and the Diversity Patterns of Shore Flies (Diptera: Ephydridae)

A generalized relationship between the basic characteristics of shore fly habitats and the spatial patterns of the habitats' species diversity (H'), richness and evenness was derived using linear step-wise multiple regression. We postulated that there are 13 basic characteristics of all ephydrid habitats and that these characteristics are important in regulating species diversity and abundance patterns. The variation in species diversity (H') was primarily accounted for by frequency of inundation (36.6%),] substrate moisture (17.3%), physical stability (14.5%), and the presence of sand (5.7%). The variation in species richness was primarily accounted for by the type of vegetation (30.0%), the abundance of vegetation (22.6%), the presence of running water (14.0%), substrate moisture (11.4%), and the frequency of inundation (7.1%). The variation in species evenness was primarily accounted for by the presence of sand (42.1%), presence of a shore (18.0%), presence of standing water (9.8%), presence of mud (8.1%), abundance of vegetation (7.2%), and frequency of inundation (6.7%). The results of this study indicate that not all evolutionary responses of shore flies to the environment need to be fine-tuned but can at times be rather generalized.