A Survey of Ant Species in Three Habitats at Mount St. Helens National Volcanic Monument

Jessamy J Rango

doi:10.1155/2012/415183

Abstract

Ants were surveyed in three habitats at Mount St. Helens in 2008. The area most impacted by the 1980 eruption is the Pumice Plain. Less impacted is the Blowdown Zone where trees were toppled due to the blast. Two habitats were surveyed in the Pumice Plain varying in vegetation density (Pumice Plain Low-Vegetation (PPLV) and Pumice Plain High-Vegetation (PPHV)), and one habitat was surveyed in the Blowdown Zone (BDZ). Ten ant species were collected with the most species collected from the BDZ habitat and the least from the PPLV habitat. Ant abundance was higher at the BDZ and PPHV habitats than at the PPLV habitat. Ant biodiversity was highest at the BDZ habitat than at the PPHV and PPLV habitats. Significant correlations between ant community parameters and plant community parameters were also found. Few plants in the PPLV habitat may contribute to the lack of ants. High ant species richness at the BDZ habitat may be due to complex plant architecture. Results from this study suggest that ants are important focal species in tracking biotic recovery following disturbances.

Highlights

IntroductionMount St. Helens erupted on May 18, 1980, strongly impacting a 600 km area as a result of a northern lateral blast of the volcano [1]
Five ant species were unique to the Blowdown Zone (BDZ) habitat type (Camponotus modoc, Tapinoma sessile, Formica argentea, L. alienus, and M. hunteri), whereas only one ant species was unique to the PPHV habitat type (Formica obscuripes)
The two most commonly collected ant species were found at the Pumice Plain-Low Vegetation (PPLV) habitat type

Summary

Introduction

Mount St. Helens erupted on May 18, 1980, strongly impacting a 600 km area as a result of a northern lateral blast of the volcano [1]. The volcanic eruption began with a magnitude 5.1 earthquake, which dislodged the northern slope of the mountain leading to the largest landslide in recorded history [1]. Material from the landslide covered a 60 km area referred to as the Debris Avalanche [1]. Pyroclastic flows emanating from the volcano covered 15 km of land immediately north of the volcano, which is referred to as the Pumice Plain [1]. Organisms in the Pumice Plain were vaporized as a result of the volcanic blast [1]

Methods

Results

Conclusion