Invertabrate Abundance and Biomass Distribution Patterns in Western and Central Montana

Abstract

We measured terrestrial invertebrate abundance and biomass at six different locations in western and central Montana from 2000 to 2002. Habitats at these sites included grass, shrub, or forest. Each of the three habitats occurred at two separate locations. At each site, 10 pitfall traps were  constructed and sampled on a monthly basis from June through October. We searched for 15 taxonomic orders or classes and found all but two. Grass habitats had the highest invertebrate abundance and biomass followed by shrub and forest habitats respectively. Terrestrial invertebrate abundance and biomass were highest in mid-to-late summer (July and August) in western and central Montana. Average peak invertebrate abundance occurred in August and average peak invertebrate biomass occurred in July.