Diversity and Pattern in Plants and Insects

Abstract

The plants and Homoptera on three old fields in southeast Michigan were sampled. Within fields, correlations between plant and insect diversity were generally weak. But using all samples from three fields, evenness (J) and diversity (H) of the insects were highly correlated with plant evenness and plant diversity, respectively. For example, 72% of the variance in insect H could be accounted for by variation in plant H. Number of species (S) showed a positive but weaker correlation. When correlations were based on the pooled samples from each field, all three statistics for insects were highly correlated with those for the plants. Insect H was also highly correlated with plant structure (foilage height diversity FHD) over all three fields. These two measures of plant diversity (H and FHD) were highly correlated and were equally good correlates of insect H. Together they accounted fir 79% of the variance in insect H. This extends to insects a correlation between plant and animal diversity, already well established for birds and possibly true for lizards and rodents. It leaves open the unresolved question as to whether plant structure or plant species diversity is more important.