The importance of where to dump the refuse: seed banks and fine roots in nest of Atta cephalotes and Atta colombica

FARJI-BRENER, ALEJANDRO GUSTAVO; MEDINA, C

San José, Costa Rica

Congreso; Asociation for Tropical Biology, San José, Costa Rica. “Tropical Diversity Origins, Maintenance, con Conservation”; 1997

Asociation for Tropical Biology (ATB)

The location of the nutrient-rich organic refuse produced by a leaf-cutting ant colony varies among ant species. Atta cephalotes locate their organic refuse in subterranean chambers, whereas Atta colombica place their organic refuse on the soil surface near the nest. We studied the effect of the absence or presence of an external organic refuse on the abundance of fine roots and seed bank composition in the superficial horizons in ant nests. We sampled soils from ant nests or dumps and adjacent areas of 15 adult nests of Atta cephalotes at La Selva (LS), Costa Rica, and of 15 of Atta colombica nests on Barro Colorado Island (BCI), Panama. Soils from Atta cephalotes nests did not differ from adjacent soils in abundance of fine root and seed diversity. In contrast, organic refuses from Atta colombica nests were less diverse in seed composition (due to the great abundance of Miconia argentea), and had a greater abundance of fine roots than adjacent areas. Thus the external location of the ant nest organic refuse is potentially important determining the different types of plant recolonization in abandoned or dead ant nests. The relative abundance of these Atta species may influence the structure and/or the composition of the tropical forests.