Sean T. Sturges
Department of Geology, Carleton College, Northfield, MN, 55057
Abstract. This study attempted to investigate the relationship between Atta cephalotes and soil genesis and composition in a tropical lowland rainforest in Costa Rica. Studies have shown that A. cephalotes has an extraordinary impact on the rainforest as an herbivore. However, extensive study has not taken place with respect to the influence of A. cephalotes on the rainforest flora through its underground activities; nest building and fungus raising, even though A. cephalotes is thought to turnover the soil of the entire rainforest floor every 200 to 300 years. A. cephalotes construct extensive underground nests that serve to significantly alter both the physical and chemical characteristics of soil horizons. By measuring soil compaction and porosity on and off A. cephalotes nests, I endeavored to further quantify the effect of A. cephalotes activity on the soil profile. Due to excessive rainfall I could unfortunately gather few data. However, it seems as though it is the experimental procedure that is the shortcoming of the investigation, not a flaw in the focus of inquiry.