Collaborative Research: Periodical Cicadas and Forest Community Dynamics

火灾、干旱和生物入侵等大范围的干扰可能会产生重大的生态后果。然而，当它们在空间和时间上不可预测时，很难研究它们的影响。这项研究将确定周期蝉对森林系统动态的影响。根据物种的不同，周期蝉每17或13年出现一次，它们以树根为食，在地下长时间觅食。2004年的爆发很可能是地球上最大的昆虫暴发之一，这为我们提供了一个难得的机会来批判性地检查一次重大生物干扰的影响。初步研究表明，蝉对树种有强烈的喜好，偏爱幼龄演替林地，对树木生长有慢性影响。我们将比较高密度和无蝉类地点的森林组成，并将通过网状早期演替森林块来操纵蝉的定居。蝉对不同寄主物种的长期影响将通过对树轮的分析来检验。这项研究将提高我们对干扰事件和森林动态的理解，并可能为其他较难预测的生物干扰提供有用的模型。此外，这项研究提供了一个独特的机会来教育当地社区有关森林系统的知识，并积极地让学生参与到一个结合了“科学即过程”学习活动的激动人心的活动中。

Broad-scale disturbances such as fire, drought and biological invasions can have major ecological consequences. However, it is difficult to study their effects when they are unpredictable in space and time. This research will determine the effect of periodical cicadas on the dynamics of forest systems. Periodical cicadas emerge every 17 or 13 years, depending upon species, after extended below-ground feeding on tree roots. The 2004 emergence is likely to be one of the largest insect outbreaks on Earth, providing the rare opportunity to critically examine the impact of a major biological disturbance. Preliminary work suggests that cicadas have strong preferences among tree species, favor young successional forest sites, and have chronic effects on tree growth. We will contrast forest composition in high density vs. cicada-free sites, and will manipulate cicada colonization by netting blocks of early successional forest. Long-term effects of cicadas on different host species will be examined through the analysis of tree rings. This research will improve our understanding of disturbance events and forest dynamics, and may serve as a useful model for other, less predicable biotic disturbances. Further, this research provides a unique opportunity to educate the local community about forest systems, and to actively involve students in an exciting event that incorporates "science as process" learning activities.