Posteruption Arthropod Succession on the Mount St. Helens Volcano: The Ground-Dwelling Beetle Fauna (Coleoptera)

Arthropods are important components of ecosystems because of the roles they play in pollination, herbivory, granivory, predator—prey interactions, decomposition and nutrient cycling, and soil disturbances. Many species are critical to the structure and functioning of their ecosystem, although some (particularly insects) are considered pests in farmlands and forests because of their detrimental effects from feeding on foliage and transferring pathogens to trees and crops. Arthropods also constitute a high-protein prey resource for vertebrate wildlife (especially small mammals, birds, reptiles, and amphibians), thus contributing to the existence and stability of these wildlife species. As such, studies of arthropod population dynamics and changes in species assemblages following natural disturbances are important for understanding ecosystem responses. In the case of the Mount St. Helens volcanic eruption, studies of arthropods not only can provide information on natural history and ecology of many different species but also are relevant for evaluating theories of disturbance ecology and postdisturbance successional processes.