Structure and seasonality in an arthropod community

This study explores the relationship between species composition and the structure of an arthropod community in an open field, and attempts to determine the factors which account for changes in species composition and abundance. The numerical response of the arthropods to seasonal change is examined by factor analysis and compared with compositional changes reflected in the heterogeneity of the community. Seasonality in the insect community is exhibited by complex patterns of temporal niche diversification involving all trophic levels. Primary seasonal components revolve around distinctions between summer and winter species based on resource availability and utilization patterns. Summer and winter species are characterized by their responses to qualitatively different properties of the environment: winter species respond to temperature variability while summer species respond to average temperatures. The evidence suggests that the heterogeneity of the community is closely associated with events occuring in the vegetation. In general, more complex vegetation structure is reflected in an increase in the heterogeneity of the insects.