Location: Range Management ResearchTitle: Do long-lived ants affect soil microbial communities? Author
Submitted to: Biology and Fertility of Soils
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/8/2011
Publication Date: 1/15/2012
Citation: Whitford, W., Ginzburg, O., Berg, N., Steinberger, Y. 2012. Do long-lived ants affect soil microbial communities? Biology and Fertility of Soils. 48:227-233. Interpretive Summary: About one-half of the world’s land surface is dry land regions that include deserts. Despite their inherent aridness, deserts are biological rich areas of the world. For example, 10 percent of all ant species in North America are found in the deserts of the southwestern US, an area that is only 5 percent of the US. This study looked at the long-term influence of ants, and their nests, on one aspect of biological richness – the number of different species of microbial organisms in the soil. Ant nests had a noticeable impact on organisms in the soil below the nests. Ant nests can remain in the same location for decades, and these nests change the organisms that exist in the soil below these nests.
Technical Abstract: This study was designed to test the hypothesis that desert ant species that build nests that remain viable at a particular point in space for more than a decade produce soil conditions that enhance microbial biomass and functional diversity. We studied the effects of a seed-harvester ant, Pogonomyrmex rugosus, and two generalist ant species, Aphaenogaster cockerelli and Myrmecocystus depilis, on soil microbial communities. Microbial biomass was higher in P. rugosus-modified soils than in reference soils when soil water content was higher than 3%. Microbial biomass was either higher in reference soils or exhibited no difference in reference soils and nest-modified soils of A. cockerelli and M. depilis. There were differences in microbial functional diversity and microbial community level physiological profiles (MicroResp method) between ant-nest-modified and reference soils of the three ant species on some sampling dates. Temporal patterns of soil microbial communities associated with the ant species resulted from differences in soil moisture, density, and species composition of the annual plant communities associated with the ant nests and in reference areas. Differences in annual plant communities associated with ant nests and surrounding areas resulted in different chemical inputs into the soil organic-matter pools. This study shows that generalizations about the effects of longlived ant nests on soil biota in arid regions must consider feeding behaviors of the ant species and temporal patterns of rainfall.