RAPID: Forest dynamics driven by canopy defoliation during insect outbreaks

本项目将研究林木毛虫（Malacosoma disstria）爆发对温带森林的树苗建立、生产力和群落结构的影响。 使整个森林树冠落叶的昆虫的爆发是零星发生的，可能只持续一两年。 因此，对它们的研究有限。 然而，考虑到树木的寿命长，落叶事件可能是决定森林内长期动态和演替的重要因素。 以前的研究主要集中在落叶对树木生长和存活的负面影响;很少关注与增加林下光照和土壤养分相关的对树苗建立的积极影响。 该项目利用了密歇根州南部一个地区正在发生的大规模森林毛虫爆发，该地区包括以前建立的长期研究地点。 从长期研究中获得的树木动态数据提供了一个罕见的基线，可以与昆虫爆发的影响进行比较。 这项研究必须立即开始，以便在落叶事件高峰期间收集数据。 因此，这一项目是作为快速反应研究赠款供资的，气候变暖导致温带森林的生长季节延长，冬季温暖，这将导致食叶昆虫更频繁地爆发。 这个项目将提供关于这种变化对森林动态的影响的重要资料。 这项研究将在Manistee国家森林进行，对该森林和温带类似森林的管理具有重要意义。 该项目将为一名博士后学者以及研究生和本科生提供研究培训。 当地K-12学校的教师和学生也将参与实地研究。

This project will study the impact of an outbreak of the forest tree caterpillar (Malacosoma disstria) on tree seedling establishment, productivity and community structure of temperate forests. Outbreaks of insects that defoliate whole forest canopies occur sporadically and may last only a year or two. For this reason, they have received limited study. However, considering the long lifespan of trees, defoliation events may be an important factor determining the long term dynamics and succession within forests. Prior research has focused on the negative impacts of defoliation on tree growth and survival; far less attention has been given to the positive impacts on tree seedling establishment associated with increased understory light and soil nutrients. This project takes advantage of an ongoing, massive outbreak of forest tree caterpillars in a section of lower Michigan that encompasses previously established long term research sites. The data on tree dynamics from the long term study provide a rare baseline against which the impact of the insect outbreak can be compared. It is critical that this research start immediately in order to collect data during the peak of the defoliation event. Consequently, this project is being funded as a grant for rapid response research (RAPID).Climate warming has resulted in longer growing seasons and milder winters in temperate forests, which should lead to more frequent outbreaks of insect defoliators. This project will provide important information on the consequences of such change to forest dynamics. This research will be conducted in the Manistee National Forest and has important implications to the management of this forest and similar forests in the temperate zone. The project will provide research training for a postdoctoral scholar and for graduate and undergraduate students. Local K-12 school teachers and students will also be engaged in the field research.