LTREB Renewal: Acorn pulses and the dynamics of rodents, ticks, and Lyme-disease risk in oak forests

莱姆病每年折磨着成千上万的美国人。没有疫苗，诊断方法和治疗方法仍然存在问题；避免接触携带疾病的蜱虫是保护公众的主要手段。该项目将确定是什么控制了蜱虫的数量以及携带疾病病原体的蜱虫的比例，从而提供有关人们在何时何地最容易接触莱姆病的详细信息。研究人员将继续在美国受影响最严重的地区之一收集橡子、蜱虫、老鼠、其他宿主和气候的长期数据。结果将有助于通过避免和管理高风险地点和时间来减轻疾病负担。该项目将通过研究人员在这16年的研究过程中建立的强大合作，为K-12课堂教学、本科教育和广泛的公共教育做出贡献。公共卫生利益确保了公共媒体对研究的广泛报道。该项目将培养本科生和研究生，以及博士后研究人员，通过他们的参与研究。莱姆病的风险可以从过去的橡果产量来预测，然而新的模式和机制的发现使这些预测变得复杂。研究人员将继续对6个栎林地块进行研究，以收集橡子产量的长期数据；鼠、花栗鼠、松鼠和黑脚蜱幼虫、蛹和成虫的种群动态；蜱感染莱姆病菌流行情况；以及蜱虫对特定气候变量的反应。另外五年的数据涵盖了更广泛的宿主丰度、蜱虫负担、资源和气候条件，将为构建所有蜱虫生命阶段、探索和附着的健全模型提供经验基础，以解决蜱虫种群动态的生物和非生物驱动因素。还将扩展模型，以区分气候变量与宿主丰度和宿主资源对莱姆病风险的影响。将探讨橡子-鼠-蜱相互作用中偶然性的重要性。虽然大多数年份的高鼠丰度之后是高若虫丰度，但最近的小鼠高峰之后并没有出现若虫高峰。杆子-鼠标-滴答系统的更稳健和可预测的模型需要探索特定的偶然性，这些偶然性很可能是偶然性的。对橡子产量的长期趋势进行分析，将单个物种在数量和时间上的时间变化分解为种子产量的个体变化与总体丰度和种群大小结构变化的模式。对幼虫和若虫寻找寄主的季节时间的分析将与对寄主种群规模的估计相结合，以解释若虫感染流行率的变化，并改进对这一关键变量的预测。

Lyme disease afflicts hundreds of thousands of Americans each year. There is no vaccine and both diagnostic methods and treatments remain problematic; avoidance of exposure to disease-bearing ticks is the primary means of protecting the public. This project will identify what regulates the abundance of ticks and the proportion of ticks that carry the disease agent, providing detailed knowledge about when and where people are most at risk of exposure to Lyme disease. Researchers will continue long-term collection of data on acorns, ticks, mice, other hosts, and climate in one of the most heavily affected portions of the United States. Results will facilitate reduced burden of disease though avoidance and management of high risk places and times. The project will contribute to K-12 classroom teaching, undergraduate education, and extensive public education through strong collaborations the researchers have developed over the course of this sixteen-year study. Public health benefits ensure widespread coverage of the research by public media. The project will train undergraduate and graduate students, as well as postdoctoral researchers, through their participation in the research. Lyme-disease risk can be predicted from past acorn production, yet the discovery of new patterns and mechanisms complicates these predictions. The investigators will continue research on 6 oak-forest plots to collect long-term data on acorn production; the population dynamics of mice, chipmunks, squirrels, and larval, nymphal, and adult blacklegged ticks; infection prevalence of ticks with Lyme disease bacteria; and tick responses to specific climatic variables. Five additional years of data encompassing a more extensive range of host abundances, tick burdens, resources, and climatic conditions will generate the empirical base for constructing robust models of all tick life stages, questing and attached, to address biotic and abiotic drivers of tick population dynamics. Models will also be extended to distinguish the effects of climatic variables from those of host abundances and host resources on Lyme disease risk. The importance of contingencies in acorn-mouse-tick interactions will be explored. Although most years of high mouse abundance are followed by high nymph abundance, a recent mouse peak was not followed by a nymph peak. More robust and predictive models of the mast-mouse-tick system require the exploration of specific contingencies, which are likely to be episodic. Long-term trends in acorn production will be analyzed to decompose temporal variation in the magnitude and timing of masting events by individual species into patterns due to individual variation in seed production versus changes in overall abundance and population size structure. Analyses of the seasonal timing of host-seeking by larvae and nymphs will be integrated with estimates of host population size to explain variation in nymphal infection prevalence and to improve predictions for this critical variable.