Collaborative Research: Linking thermal tolerance to invasion dynamics: Environment and physiological capacity as regulators of geographical spread

入侵物种对当地生态系统、农业和林业构成越来越大的威胁。这项研究解决了环境、栖息地、当地生活史和当地生理特征如何相互作用来确定吉普赛蛾的地理范围的基本问题。吉普赛蛾于1869年从欧洲传入马萨诸塞州，现在从明尼苏达州延伸到北卡罗来纳州，分布在北美东部近100万平方公里的土地上。它是阔叶林的一种极具破坏性的害虫，对公共和私人财产造成广泛的经济和生态破坏，并对林产工业造成负面影响。在其活动范围的一些地方，吉普赛飞蛾正在迅速蔓延，而在其他地区，入侵前线是静止的或撤退的。到目前为止，美国只有三分之一的易受影响的森林类型遭到入侵，使美国大部分地区仍处于危险之中。这个项目解决了物种的入侵潜力如何沿着其前沿发生变化，以及不断变化的环境如何决定范围是扩大还是缩小。这项研究还包括培训和推广部分，将接触到广泛的学生学习者、教育工作者和社区利益相关者。这个项目的目标是利用吉普赛飞蛾活动范围限制下的扩张、停滞和收缩模式来研究吉普赛飞蛾特征的局部变化如何影响未来传播的可能性。具体地说，该项目测试了对高、低温极端温度的耐受性在整个范围内的差异，这些生理极限的局部适应性变化，以及在预测的区域环境变化下，这些特征如何与温度相互作用来影响入侵传播。为了确定极端温度如何影响入侵前线种群的生存和增长，将进行实验，以量化依赖温度的增长率、临界温度极限和特定温度的代谢率。此外，当前和未来环境条件的影响将使用具有特定区域当前和未来温度制度的生长室进行测试。目前极端越冬条件对孵化成功率的影响将通过在北部和南部山脉边缘部署一系列种群的卵块来测试。公开的气候数据，以及州和联邦机构每年测量整个2000公里范围边缘吉普赛蛾丰度的详尽采样工作，将被用来检查未来的传播潜力。这些实验方法，结合当前分布和传播率的信息，将有助于更好地理解入侵物种成功的潜在特征，并有助于识别未来可能变得或多或少容易受到入侵的地区。

Invasive species are an increasing threat to native ecosystems, agriculture, and forestry. This research addresses fundamental questions about how the environment, habitat, local life history, and local physiological traits interact to determine the geographic range of gypsy moths. Introduced from Europe to Massachusetts in 1869, gypsy moth now occurs over nearly a million square kilometers of eastern North America, extending from Minnesota to North Carolina. It is a highly damaging pest of hardwood forests, causing extensive economic and ecological damage to public and private property, as well as negatively impacting the forest products industry. In some parts of its range, gypsy moth is spreading rapidly across the landscape, while in other areas, the invasion front is static or retracting. So far, only one-third of susceptible forest types in the United States have been invaded, leaving large portions of the country still at risk. This project addresses how the invasive potential of a species can change along its leading edge and how a changing environment can determine whether ranges expand or contract. This research also includes training and outreach components that will reach a wide range of student learners, educators, and community stakeholders. The objective of this project is to use patterns of expansion, stasis, and contraction at gypsy moth range limits to examine how local changes in gypsy moth traits influence the potential for future spread. Specifically, the project tests for range-wide variation in tolerance to high and low temperature extremes, local adaptive changes in those physiological limits, and how these traits interact with temperature to influence invasive spread under predicted changes in regional environments. To determine how temperature extremes impact the survival and growth of populations from across the invasion front, experiments will be performed to quantify temperature-dependent growth rates, critical thermal limits, and temperature-specific metabolic rates. Additionally, the effects of current and future environmental conditions will be tested using growth chambers programed with region-specific current and future temperature regimes. The effects of current overwintering conditions at the range extremes on hatching success will be tested by deploying egg masses from a range of populations at both the northern and southern range edge. Publically available climate data, as well as the exhaustive sampling effort by state and federal agencies that annually measures the abundance of gypsy moth along the entire 2000 km range edge, will be used to examine future spread potential. These experimental approaches, combined with information on the current distribution and spread rate will lead to a greater understanding of traits underlying the success of invasive species and help to identify areas that may become more or less susceptible to invasions in the future.