Periodical cicada emergences affect masting behavior of oaks

Oaks (Quercus spp.) are well-known “masting” species exhibiting highly
variable and synchronized acorn production. We investigated the hypothesis
that periodical cicadas (Magicada spp.), well-known to have
strong effects on the ecosystems in which they occur, affect acorn
production of oaks through their xylem feeding habits as nymphs, the
oviposition damage they inflect as adults during emergences, or the
nutrient pulse resulting from the decomposition of their bodies following
breeding. We found negative effects on acorn production during emergence
years and the year following emergences, and enhanced acorn production two
years post-emergence. We also found evidence suggesting a significant
effect of cicada emergences on spatial synchrony of acorn production by
trees growing within the range of the same cicada brood compared to
different broods. These results demonstrate that periodical cicadas act as
a trophic environmental “veto” depressing acorn production during and
immediately following emergences, after which the nutrient pulse
associated with the cicada’s demise enhances oak reproduction.