Species composition and abundance of ants and other invertebrates in stands of crested wheatgrass (Agropyron cristatum) and native grasslands in the northern Great Plains

Canadian Journal of Zoology, Volume 0, Issue 0, Page 49-55, e-First articles.

Habitat alteration by exotic plant species can have profound effects on vertebrates, but its effects on invertebrates are less well-known. Crested wheatgrass (Agropyron cristatum (L.) Gaertn.) is a perennial grass that has been planted on >106 ha of the Great Plains. We tested the hypothesis that invertebrate communities (especially ants) differed between native grasslands and A. cristatum stands, using pitfall traps in Saskatchewan and Montana. Ant species composition differed significantly between native grasslands and A. cristatum stands, but there were no differences in total ant abundance, the abundance of functional groups, or species richness. Ant species richness was significantly greater in Montana than Saskatchewan. In Saskatchewan, bare ground was positively related to total ant abundance and the abundance of “cold-climate specialist” and “opportunist” functional groups of ants. In Montana, the cover of forbs was positively related to total ant abundance. The abundances of individual ant species were not predicted by any vegetation characteristics, except for Formica obscuripes Forel, 1886, which increased significantly with litter. The total abundance of other invertebrates was greater in native grasslands than in A. cristatum stands, although not significantly so. Within each vegetation type, variation in ant communities may depend either directly on the effects of vegetat...

Source: Canadian Journal of Zoology - November 25, 2013 Category: Zoology Tags: article Source Type: research