Arthropods as Pioneers in the Regeneration of Life on the Pyroclastic-Flow Deposits of Mount St. Helens

The eruption of Mount St. Helens, on May 18, 1980, affected an area of 600 km² within which communities of animals and plants sustained a wide range of impacts, depending on proximity to the volcano and local topography. The most extreme destruction occurred in the area immediately north of the crater, now known as the Pumice Plain (see map, Figure 9.1), where the eruption apparently destroyed the entire biota over tens of square kilometers. Our interest concerned the response of arthropods to the eruption and changed landscape, particularly in the most intensively disturbed area and one remote site. Early questions to address included the following: