Amphibian Disease Dynamics in a Fragmented Landscape

描述（由申请人提供）：新鉴定的真菌病原体， Batrachochytrium最近被认为是导致 世界各地的两栖动物我们的目的是确定壶菌病的起源（ 疾病引起的Batrachochytrium），并了解如何人为 环境变化影响其流行和传播。我们的研究将 特别关注Batrachochytrium和 黄腿山蛙（学名：Rana muscosa），一种曾经在澳大利亚很常见的两栖动物。 加州的塞拉内华达州山脉。R. muscosa是一个理想的学习主机，因为它 尽管种群数量下降，但仍然很常见，可以用于实验， 并且群体受到壶菌感染的强烈影响。如同 动物种群在世界各地，两栖动物在塞拉利昂内华达州是 受到越来越多的人为压力，包括 外来物种引进、生境破碎化和化学污染物 这些可能会改变疾病的流行和传播。使用团队， 病原真菌、流行病学、两栖动物生态学、种群 遗传学，统计和机械建模，我们的具体目标 1）描述Batrachochytrium的起源，以确定其是否 与内华达州的两栖动物的联系代表了一种古老的联系 或最近真菌扩展到以前未感染的青蛙; 2） 描述感染和传播对青蛙种群动态的影响， 对现有4 500个数据库中确定的地点进行时间重新调查 水体中的Sierra内华达州; 3）开发统计模型来描述 外来鱼类的影响，栖息地的破碎化， 农业污染物对蛙和壶菌的分布; 4）建立详细的机制模型，以预测 各种生物机制（自然和人为）对 壶菌病的发病率、空间分布和持续性， 预测该疾病对R. muscosa。由于缺乏对非洲动物种群疾病的研究， 野生的，我们的研究结果将提供重要的见解疾病 在其他系统中的动态，并帮助努力保护生物多样性， 面对新出现的传染病

DESCRIPTION (provided by applicant): The newly identified fungal pathogen, Batrachochytrium, has recently been implicated as causing the decline of amphibians worldwide. We aim to determine the origin of chytridiomycosis (the disease caused by Batrachochytrium), and understand how anthropogenic environmental changes influence its prevalence and spread. Our research will focus specifically on the relationship between Batrachochytrium and the mountain yellow-legged frog (Rana muscosa), a once-common amphibian in California's Sierra Nevada mountains. R. muscosa is an ideal study host as it is still common enough despite population declines to be used in experiments, and populations are strongly influenced by chytridiomycosis infection. As with animal populations throughout the world, amphibians in the Sierra Nevada are being subjected to an increasing array of anthropogenic stressors including exotic species introductions, habitat fragmentation, and chemical contaminants and these may change the prevalence and spread of disease. Using a team with expertise in pathogenic fungi, epidemiology, amphibian ecology, population genetics, and statistical and mechanistic modeling, our specific objectives are to: 1) describe the origin of Batrachochytrium to determine whether its association with amphibians in the Sierra Nevada represents an old association or a recent expansion of the fungus into previously uninfected frogs; 2) describe the effect of infection and spread on frog population dynamics using temporal resurveys of sites identified from an existing database of 4,500 water bodies in the Sierra Nevada; 3) develop statistical models to describe the effect of nonnative fish, habitat fragmentation, and windborne agricultural contaminants on the distribution of frogs and chytridiomycosis; and 4) develop detailed mechanistic models to predict the likely effects of various biological mechanisms (both natural and anthropogenic) on the incidence, spatial distribution, and persistence of chytridiomycosis, and to predict the impact of this disease on the abundance and dynamics of R. muscosa. Given the paucity of studies of disease in animal populations in the wild, the results of our study will provide important insights into disease dynamics in other systems, and aid in efforts to protect biodiversity in the face of emerging infectious diseases.