BIOSPHERE 2 REEXAMINED: ANT SPECIES COMPOSITION WITHIN A HUMAN-CONSTRUCTED ECOSYSTEM

—The ant communities within Biosphere 2, a massive, enclosed set of human-constructed habitats in southern Arizona, had not been examined in .20 yr. Throughout 2018, we conducted five ant surveys within and around Biosphere 2 to determine the current species composition and to determine whether species within the facility are establishing in the surrounding native habitat. As in previous surveys, we found exceedingly high numbers of Paratrechina longicornis, an invasive ant species, within every Biosphere 2 “biome” that we examined. We also found it to be present in the habitat surrounding the structure. How species that thrive in disturbed ecosystems infiltrate and affect native ecosystems is critical to understand, especially for systems intended to be sealed, such as Biosphere 2.