Colony dynamics and Plant Community Associations of the Harvester Ant, Pogonomyrmex salinus (Hymenoptera: Formicidae) in Sagebrush-Steppe Habitat.

摘要: We present the results of a 5-yr field study on colony dynamics and plant community associations Owyhee harvester ants, Pogonomyrmex salinus (Olsen), in sagebrush-steppe habitat southwestern Idaho. Over period, total number ant colonies across 16 sites increased from 843 to 878 (4.15%) as result 315 deaths 350 initiations. Up 7.1% initiations may have been instances nest relocation. Colonies had higher rate failure their first year than subsequent years (12.4 vs 4.6-8.4% over next 3 yr). Of 11 analyzed for dispersion, one was significantly clumped others did not differ random. Population density final ranged 0.1 62.9 colonies/ha best described by an inverse relationship with sagebrush cover positive coverage non-Bromus (non-cheatgrass) understory vegetation. interpret these both terms 1) food resources-harvester ants avoid cheatgrass seeds diet, preferring instead small-seeded grasses forbs, 2) structure-harvester prefer nesting open areas where ground is exposed sun they can clear vegetation vicinity nests. Given we report, transition sagebrush-dominated grasslands that occurring rapidly throughout much western United States prove costly native species whose are readily consumed ants.