Collaborative Research: A Pilot Study of the Spatiotemporal Scales of Diversification in the Pandora Moth/Ponderosa Pine System Using Dendrochronology and Evolutionary Biogeography

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。火灾和害虫等自然干扰是影响地球广大地区景观格局和过程的主要因素。在北美西部的山地森林中，昆虫爆发和火灾构成了主要的干扰因素，而气候变化可能是一个日益重要的复杂因素。扰动受到发生在各种空间和时间尺度上的过程的影响。因此，它们可以产生可以嵌套分层方式研究的时空模式。物种之间的相互作用，例如植物和它们的昆虫病原体之间的相互作用，也可能具有这样的特征。研究人员将使用黄松-潘多拉蛾模型系统研究非生物和生物干扰如何相互作用。特别是，他们对干扰生态学如何在多个空间和时间尺度上驱动两种生物的多样化感兴趣。之所以选择黄松生态系统，是因为它们构成了美国西部最重要的商业砍伐森林之一。潘朵拉蛾是黄松分布最广的落叶昆虫，是森林管理者关注的重要问题。潘多拉蛾的爆发产生了特有的树木年轮模式，可以通过树木年轮技术来检测，树木年轮技术也用于检测火灾事件和气候条件并确定日期。在黄松-潘多拉蛾系统范围内的10个战略定位地块上，对潘多拉蛾、气候、火灾和林分结构进行树木年轮重建。我们将用小波分析来检验这十个年表的循环模式，以帮助区分偶发性虫害爆发、干旱和火灾的相对影响。调查人员还将对所有这些环境变量进行重建，以记录其工作的空间和时间尺度，为每个地点的森林管理者提供具体的重建。利用基于dna的遗传标记确定潘多拉蛾遗传多样性的空间格局和种群间的关系，并与其他分析相结合进行分析。这些发现有可能产生一个大型昆虫爆发历史网络，最终将跨越整个松蛾系统的空间范围。该网络将能够分析以前从未探索过的空间尺度上的昆虫爆发动态，并将提供一个重要的框架，可用于生成和测试关于多种干扰相互作用的假设，以及驱动黄松和潘多拉蛾多样化的过程。本研究结果将为今后植物-草食系统扰动生态学和进化生物地理学的研究提供一个框架。这项研究将形成一个广泛的树木年轮年表网络，填补国际树木年轮数据库的空白。该项目还为本科生和研究生团队以及K-12教师提供了参与实地研究和实验室分析的资源。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Natural disturbances such as fires and pests are the primary factors influencing landscape patterns and processes over broad parts of the Earth. In the montane forests of the North American west, insect outbreaks and fire constitute the dominant disturbance agents, while climate change may be an increasingly important complicating factor. Disturbances are influenced by processes occurring across a variety of spatial and temporal scales. They therefore can produce spatio-temporal patterns that can be studied in a nested hierarchical fashion. Interactions between species, such as among plants and their insect pathogens, may also be so characterized. The investigators will examine how abiotic and biotic disturbances interact using the ponderosa pine-pandora moth model system. In particular, they are interested in how disturbance ecology drives diversification in both organisms across multiple spatial and temporal scales. Ponderosa pine ecosystems are chosen as they constitute one of the most important commercially logged forests in the western United States. The native pandora moth is the most widespread insect defoliator of ponderosa pine trees, and is an important concern of forest managers. Pandora moth outbreaks produce characteristic tree-ring patterns that can be detected through the dendrochronological techniques also used to detect and date fire events and climatic conditions. Tree-ring reconstructions will be developed for pandora moth, climate, fire, and stand-age structure from ten strategically located plots within the range of the ponderosa pine-pandora moth system. The ten resulting chronologies will be examined for cyclic patterns with wavelet analysis to help distinguish the relative influences of episodic insect outbreaks, drought, and fire. The investigators will also conduct reconstructions of all of these environmental variables to document the spatial and temporal scales over which they operate, providing specific reconstructions for forest managers at each site. Spatial patterns of genetic diversity and relationships among populations of the pandora moth will be determined from DNA-based genetic markers and analyzed in conjunction with the other analyses. The findings have the potential to result in a large network of insect outbreak histories, one that eventually will span the entire spatial extent of the pine-moth system. This network will enable analysis of insect outbreak dynamics on spatial scales that have not previously been explored, and will provide an important framework that can be used to generate and test hypotheses regarding the interaction of multiple disturbances, and the processes driving diversification in ponderosa pine and pandora moth. The results produced by this study will provide a framework for future investigations into the disturbance ecology and evolutionary biogeography of plant-herbivore systems. The research will result in a broad network of tree-ring chronologies that will fill gaps in the International Tree Ring Data Bank holdings. This project also provides resources for the involvement of a team of undergraduate and graduate students as well as K-12 teachers in the field research and laboratory analyses.