Quantifying the population-level cost of amphibian chytridiomycosis in a changing montane ecosystem

背景两栖动物壶菌病的新出现对世界许多地区的群落和生态系统产生了深刻的有害影响。我们的研究表明，树突壶菌（Batrachochytrium dendroatidis, Bd）正被广泛引入欧洲。然而，我们还没有数据来确定这些引进对naïve和本地两栖动物物种和群落的多样性和动态的影响，这些物种和群落在短期和中期的时间尺度上。本研究将利用我们自2003年以来一直收集的伊比利亚数据集。我们对126个地点的助产士蟾蜍（Alytes产科医生）进行了调查，并确定了31个发生感染的地点。最值得注意的是，这项调查表明，bda已被引入到比利牛斯山脉西部的一个小地区。自2007年以来，我们通过收集流行率、病原体基因型和死亡率数据，对该地区的感染情况进行了详细跟踪。学生将能够使用该数据集来评估关于生物和非生物驱动因素在调节无症状和有症状感染之间宿主-病原体动态中的相对作用的假设。在我们之前工作的基础上，学生将有机会匹配跨越广泛海拔范围的受感染和未受感染的湖泊。与此同时，他们将获得精细的气象变量以及受感染湖泊的死亡率数据。这将允许学生测量的死亡率，可归因于跨空间和时间尺度的结核菌感染。对协变量（生物和非生物）的分析将用于模拟受感染人群与未受感染人群的相对生存能力，我们对气候变化将如何影响这些山脉的理解将用于开发未来的预测。项目合作伙伴（ZSL）有研究壶菌病的历史，可以追溯到最初发现这种病原体，并有一个减轻壶菌病影响的全球推广计划。合作伙伴（CNRS）在比利牛斯山脉研究壶菌病的出现方面发挥了关键作用，也是RACE（壶菌病对欧洲两栖动物生物多样性的风险评估）的关键合作伙伴。该项目建立在TWJG和MCF之间牢固的工作关系的基础上，已经发表了15篇论文，并获得了NERC的共同资助。他们还共同指导NERC的一名学生研究Bd的遗传学和毒力，他的研究结果将被纳入这个博士项目。

Background The emerging panzootic of amphibian chytridiomycosis has had profound deleterious effects on communities and ecosystems in many areas of the world. Our research has shown that Batrachochytrium dendrobatidis (Bd) is being widely introduced across Europe. However, we do not yet have the data to ascertain the effects of these introductions on the diversity and dynamics of naïve, and native, amphibian species and communities across short, and medium-length, timescales. Study System This study will make use of an Iberian dataset that we have been collecting since 2003. We have surveyed midwive toads (Alytes obstetricans) in 126 sites, and have identified 31 where infection occurs. Most notably, this survey has shown that Bd has been introduced into a small region of the western Pyrenees. Within this region, we have been tracking infection in detail since 2007 by collecting prevalence, pathogen genotypes, and mortality data. The student will be able to use this dataset to evaluate hypotheses about the relative roles of biotic and abiotic drivers in modulating the host-pathogen dynamic between asymptomatic and symptomatic infection. By building upon our previous work, the student will have the opportunity to match infected and uninfected lakes that span a wide range of altitude. At the same time, they will have access to fine-grain meteorological variables as well as mortality data for infected lakes. This will allow the student to measure the amount of mortality that is attributable to Bd-infection across spatial and temporal scales. Analysis of the covariates (biotic and abiotic) will be used to model the relative viability of infected versus uninfected populations, and our understanding of how climate-change will effect these mountains will be used to develop future predictions. The project partner (ZSL) has a history of working on Bd that goes back to the original discovery of the pathogen, and whom have a global-outreach program in mitigating the effects of chytridiomycosis. The collaborators (CNRS) have a key role in studying the emergence of Bd in the Pyrenees and are key partners in RACE (Risk Assessment of Chytridiomycosis to European amphibian biodiversity). This project builds upon a strong working relationship between TWJG and MCF that has yielded 15 publications and a current co-held NERC grant. They also co-supervise a NERC student on the genetics and virulence of Bd, whose findings will be integrated into this PhD project.