Patterns of Species Diversity in the Temperate and Tropical Litter Mites

Species richness and diversity of litter mites were measured in 3 vegetative stands in Wyoming and in Costa Rica (a pine forest, a broad—leaved forest and a field) by sampling the natural litter and by experimentally manipulating the type (pine, broad—leaved and field litter) and amount (100 g dry weight/600 cm 2 plot) of litter present within each stand. Within sample species richness of the experimental plots was the same in all 4 forests (12—14 species/100 g litter) but the 2 fields supported significantly fewer species (5/100 g). In the natural forest litter, within sample richness ranged from 13 species (Costa Rica forest) to 27/600 cm 2 sample (Costa Rica pine); but again both fields were significantly less rich (4 and 6 species). Mite diversity (H') in the fields also was < the forests in both natural and experimental litter. Total within stand diversity and beta diversity were highest in the tropical forests. Also, a higher percentage of temperate species were classified as colonizers as opposed to the tropical species where the majority were noncolonizers; but tendency to colonize appears to be inversely related to the amount of litter present in a habitat.