Ant (Hymenoptera: Formicidae) responses to environmental stressors in the northern Chihuahuan Desert

TitleAnt (Hymenoptera: Formicidae) responses to environmental stressors in the northern Chihuahuan Desert
Publication TypeJournal Article
Year of Publication2000
AuthorsNash M.S., Whitford WG, Van Zee J, Havstad K
JournalCommunity and Ecosystem Ecology
Date PublishedApril 1, 2000
Accession NumberJRN00295
ARIS Log Number141872
Keywordsant, Chihuahuan Desert, environmental stressors, Hymenoptera: Formicidae, pulse grazing, shrub removal

We studied responses of ant communities to shrub removal and intense, pulse seasonal grazing by domestic livestock for four consecutive years. Weighted relative abundance and percent of traps in which an ant species occurred were analyzed using randomized, complete block design split in time analysis of variance to test for significant differences between means of ant groups. The ant community in the Chihuahuan Desert grassland is dominated by small, liquid-feeding ants, Conomyrma insana (Buckley), and large seed harvesting ants, Pogonomyrmex desertorum (Wheeler). The weighted relative abundance of C. insana was significantly reduced on the plots without shrubs. The relative abundance of P. desertorum was significantly lower on grazed plots without shrubs than on the ungrazed plots without shrubs. There were no detectable effects of shrub removal or intense, pulse grazing on the less abundant ant species. These results suggest the recent encroachment of shrubs into Chihuahuan Desert grasslands has increased the relative abundance of the dominant ant species in these communities. Intensive grazing by livestock has had an adverse effect on the most abundant seed-harvester, P. desertorum.