Canopy-associated arthropods in Acacia koa and Metrosideros tree communities along the Mauna loa Transect

Abstract

The spatial distribution and zonation of canopy-associated arthropods of Acacia koa and Metrosideros tree communities along an altitudinal transect on the east flank of Mauna Loa was determined by insecticidal fogging of the canopy with pyrethrum. Eight sites were on the Mauna Loa Transect, which has been intensively sampled by IBP participants in the Island Ecosystems IRP. Two sets of transect zones were determined on the basis of arthropod distribution. The influence of environmental and biotic factors, plant community structure and climate are interpreted according to distribution patterns. The distribution of arthropod groups coincided quite closely with vascular plant communities of the transect as defined by other studies. The composition, spatial distribution, and environmental relationships of arthropod canopy communities along the Mauna Loa Transect are compared with the situation pertaining along other lower elevational transects to sea level in Hawaii Volcanoes National Park as well as with other ecosystems in order to further characterize the arthropod canopy community. Host specificity, vegetation structure, competition between ecological homologs, and climate appeared to have the most important influence on population density and spatial distribution patterns of the arthropod taxa studied.