Chemical Fogging and Sampling Using Climbers Provide Complimentary Information on Species Composition and Biodiversity of Mite Assemblages in Forest Canopies

Abstract

Arthropods are the most species-rich group in arboreal communities where mites are often both abundant and diverse. Manual sampling by climbers is generally used in studies of arboreal mites but chemical fogging is sometimes used as an alternative sampling method. In this study, mites (Acari: Oribatida, Acari: Mesostigmata) from the canopies of oak, ash, Scots pine and Sitka spruce forests in Ireland were sampled using chemical fogging and climbers. Results show that the inter-tree species comparisons of relative abundances, richness and species composition are very dependent on the method used. The number of taxa collected varied significantly between forest types but the differences varied depending on the method used. The highest species richness was recovered from oak by both techniques but the fogging samples suggested that Scots pine forests were the least diverse while manual collection suggested Sitka spruce were the least diverse. Each technique preferentially recovered different components of the assemblages. Fogging was the more efficient method for collecting large active species while climbers were the most effective way to sample small species inhabiting epiphytes. Neither method is more effective than the other, and both should instead be viewed as complementary. The use of both methods would provide a more comprehensive view of the canopy mite fauna.