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

LTREB 更新：橡子豆类以及橡树林中啮齿动物、蜱虫和莱姆病风险的动态

• 批准号: 1456527
• 负责人: Richard Ostfeld
• 金额: $ 45万
• 依托单位: Cary Institute of Ecosystem Studies, Inc.
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1456527&HistoricalAwards=false
• 关键词: LTREB; Renewal; Acorn; pulses; dynamics

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.

莱姆病每年困扰着数十万美国人。 目前还没有疫苗，诊断方法和治疗方法都存在问题；避免接触携带疾病的蜱是保护公众的主要手段。该项目将确定是什么调节了蜱虫的数量以及携带病原体的蜱虫的比例，从而提供有关人们何时何地最容易接触莱姆病的详细信息。 研究人员将继续长期收集有关美国受影响最严重地区之一的橡子、蜱虫、老鼠、其他宿主和气候的数据。 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十六年研究过程中建立的强有力的合作，为 K-12 课堂教学、本科教育和广泛的公共教育做出贡献。公共健康效益确保公共媒体广泛报道该研究。该项目将通过参与研究来培训本科生、研究生以及博士后研究人员。莱姆病风险可以根据过去的橡子生产来预测，但新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 个橡树林地块进行研究，以收集橡子生产的长期数据；小鼠、花栗鼠、松鼠以及幼虫、若虫和成年黑腿蜱的种群动态；蜱虫莱姆病细菌感染率；并勾选对特定气候变量的反应。另外五年的数据涵盖更广泛的宿主丰度、蜱负担、资源和气候条件，将为构建所有蜱生命阶段、探索和附着的稳健模型提供经验基础，以解决蜱种群的生物和非生物驱动因素动力学。模型还将扩展，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-小鼠-蜱虫相互作用中意外事件的重要性。尽管大多数年份的高小鼠丰度之后都会出现高若虫丰度，但最近的小鼠高峰之后并没有出现若虫高峰。桅杆-小鼠-蜱虫系统的更稳健和预测模型需要探索特定的突发事件，这些突发事件可能是偶发的。将分析橡子产量的长期趋势，以将各个物种的肥大事件的幅度和时间的时间变化分解为由于种子产量的个体差异与总体丰度和种群规模结构的变化而导致的模式。对幼虫和若虫寻找宿主的季节性时间的分析将与宿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。