PARENT SESSION
Oral Session # 89: Insect Ecology II.
Presiding: R Sears
Friday, August 8. 8:30 AM to 12:00 PM, SITCC Meeting Room 101.
How Ant Nests Increase Soil Biota Species Richness: A Mechanistic Field Experiment.
Boulton, April*,1, Amberman, Keith2, 1 Biology Dept., Villanova, PA, USA2 Veterinary Hospital, Philadelphia, PA, USA
ABSTRACT- A few studies have shown that ants increase soil biota diversity and soil nutrient concentrations, but none have examined the mechanism behind this "ant effect." In this study, we employed a 2 X 2 complete factorial design (water X food) in the field to mimic the effects of harvester ant nests (Messor andrei). We hypothesized that, in the absence of ants, moisture and food additions would interact to produce conditions found in ant nests. Our results indicated that the addition of food to the soil (regardless of water addition) best mimicked the conditions found inside M. andrei nests. Our food-treated and ant-nest soils resembled each other with higher numbers of bacteria, nematodes, miscellaneous eukaryotes, and microarthropods compared to the other soil treatments with relatively depauperate soil biota. Microbial species richness was also highest in ant and food-treated samples. Moreover, the effect that ants can have on the soil occurs quickly-in a period of just two months based on our results. Because ants are widespread and are the most abundant eusocial insect with many long-lived species, they could substantially influence soil and belowground foodwebs in a number of ecosystems and may have important restoration/conservation implications for soil communities.
Key words: Messor andrei , ant-soil interactions, field experiment, soil foodwebs