Cicada Outbreak
Summer 2004
Many ecosystems receive large inputs of energy and
nutrients from outside the ecosystem boundaries, and ecological
theory suggests that these subsidies can have large impacts on
recipient ecosystems. The emergence of periodical cicadas constitutes
an important but infrequent energy and nutrient subsidy into small
ponds and streams. Large numbers of cicada carcasses fall into
aquatic systems, representing a potentially large and high quality
food source for many consumer species. The effects of these subsidies,
however, have not been explored. This cluster explored the consequences
of cicada carcasses for pond ecosystems during the emergence of
17-year cicadas in summer 2004. Students conducted a field experiment
in experimental tanks; the number of cicada carcasses will be
varied and the response of the food web (algae, invertebrates,
microbes, nutrients) will be quantified. In addition, students
conducted surveys of local pond and stream food webs and assess
the number of cicadas falling into these ecosystems. Students
also developed small-scale experiments and mathematical models
in conjunction with the large tank experiment, to assess some
of the mechanisms accounting for ecosystem response to cicadas.
