PARENT SESSION
Poster Session 3: Aquatic Ecology
Monday, August 8, 5:00 PM - 6:30 PM, Exhibit Hall 210 D, Level 2, Palais des congrès de Montréal
Potential impacts of deposition and decomposition of 17-year periodical cicadas; on woodland ponds and streams.
Pray, Corey*,1, Nowlin, Weston1, Vanni, Michael1, Stevens, Henry1, Gonzalez, Maria, Fields, Matthew1, 1 Miami University, Oxford, Ohio, U.S
ABSTRACT- The emergence of the 17-year periodical cicadas (Homoptera: Cicadidae: Magicicada) is an infrequent, highly synchronized event, with local cicada densities varying between 60-300 individuals per m2. Cicadas constitute a large aboveground movement of nutrients and their carcasses may fall into small woodland ponds and low-order streams. It is currently unknown if nutrient inputs from cicada carcasses represent a significant but infrequent resource pulse to these ecosystems. In this study, we determined the deposition and decomposition rates of periodical cicadas in woodland aquatic habitats. During the summer of 2004, we measured cicada litter inputs into ten temporary ponds and six reaches of 1st and 2 nd order streams, and contrasted these inputs to leaf litter inputs in the fall. In addition, we determined the decomposition rates of cicadas (mass loss and nutrient release rates) in the laboratory. Nutrient inputs to ponds and streams through cicada deposition were significantly correlated with local cicada emergence densities. Compared to autumnal leaf litter inputs, cicada N and P inputs were, on average 13% and 10% of leaf litter inputs, respectively. In the decomposition experiment, male and female cicadas exhibited similar mass loss rates. However, female cicadas exhibited significantly greater increase in C:N and C:P ratios than males over the duration of the experiment. These results indicate that when compared to males, females lost N and P at faster rates relative to C. Our results support the hypothesis that periodical cicadas can represent a relatively large and potentially important nutrient subsidy to woodland aquatic habitats and that the nutrient release rates by decomposing cicadas can be relatively large.
Key words: Periodical Cicadas, Nutrients, Deposition, Decomposition