Meeting Abstract
Mass mortality events (MMEs), in which large numbers of animals die in a relatively short period of time, are increasing in frequency and are linked to climate change. How MMEs impact ecosystems and how quickly—or if—ecosystems recover from these disturbances are unanswered questions. MMEs are unpredictable, occurring throughout the world without warning. Consequently, studies have been reactive, and initiated too late for baseline data to address questions about ecosystem resistance and resilience. In contrast, we gathered baseline data and then simulated MMEs in a controlled experimental design. To acquire sufficient biomass, we used feral swine (Sus scrofa) carcasses that resulted from state-wide trapping efforts. At each of five sites, we established four 18m2 circular plots, which were randomly assigned to one of four treatments in a factorial design that crossed carcass addition and vertebrate scavenger exclosures (wire fencing and netting roof). Sites were randomly assigned to one of five biomass treatments (25, 60, 180, 360, 725 kg per plot), with more than 2700 kg of carcasses used in the whole experiment. The experiment is ongoing, but initial results have shown effects on plant, invertebrate, and vertebrate communities, as well as soil properties. We found a significant and interactive effect of biomass treatment and exclosures, indicating the importance of vertebrate scavengers increased with carrion biomass. Excluding vertebrate scavengers reduced decomposition rate and significantly increased carrion fly production, probably by reducing competition for carrion and consumption of fly larvae. Although preliminary, our results are consistent with the hypothesis that vertebrate scavenger communities can mitigate or mask some of the effects associated with MMEs.
