Identifying mechanisms driving spatiotemporal disease dynamics in converted landscapes

在全球范围内，景观正在从自然栖息地转变为农业和其他人类主导的景观的马赛克。土地利用的这些变化影响了动植物物种，与未受干扰的景观相比，通常会导致生物多样性的下降。伴随着生物多样性的下降，感染现存动植物的病原体的丰度和多样性也发生了变化。病原体的传播可由于合适宿主的可获得性的变化、非生物环境的变化、宿主运动的改变或景观变化的某些其他影响而减少或增加。由于全球景观转换的频率和规模正在不断增加，量化病原体负担的变化是及时和关键的。我们目前缺乏准确预测正在转换的景观中特定病原体的反应的能力。在这个项目中，我将使用多种方法来找出在变化的地貌中影响病原体的因素：1)我将对1至15年前从天然林转变为小农农田的地点的小型哺乳动物进行纵向调查。然后，我将研究小型哺乳动物的丰富度和多样性如何随时间变化，并确定这如何影响寄生线虫的流行。2)我将调查环境类型和不同生境在区域景观中的分布如何影响宿主和病原体在种群之间的移动。3)我将开发模型并分析一个全球数据库，以调查哪些潜在的宿主、寄生虫和环境特征对于预测土地转换的短期反应是重要的。这种方法有望提高对病原体传播如何在动态景观中改变的理解，并提供更好的能力来预测未来传播可能如何改变，特别是在不同人为引起的土地利用变化的情况下。

Around the globe, landscapes are being converted from natural habitats into a mosaic of agriculture and other human-dominated landscapes. These shifts in land use impact plant and animal species and usually lead to declines in biodiversity compared to undisturbed landscapes. Concomitant to this decline in biodiversity is a change in abundance and diversity of the pathogens that infect the animals and plants present. Transmission of a pathogen can decline or increase due to changes in availability of suitable hosts, changes in the abiotic environment, altered movement of hosts or some other impact of changing landscapes. It is timely and critical to quantify changes in pathogen burden, as there is an ongoing increase in frequency and scale of landscape conversion globally. We currently lack the ability to accurately predict the response of a particular pathogen in a landscape undergoing conversion. In this project I will use a combination of approaches to disentangle factors affecting pathogens in changing landscapes: 1) I will establish a longitudinal survey of small mammals at sites that have been converted from natural forests to smallholder agricultural fields from 1 to 15 years prior. I will then examine how the small mammal abundance and diversity changes across time and determine how that impacts prevalence of a parasitic nematode. 2) I will investigate how the types of environments and distribution of different habitats across the regional landscape affect movement of hosts and pathogens between populations. 3) I will develop models and analyze a global database to investigate which underlying host, parasite, and environmental traits are important for predicting short-term responses to land conversion. This approach is expected to lead to an improved understanding of how pathogen transmission is altered in dynamic landscapes and provide a better ability to predict how transmission may change in the future, particularly with different anthropogenic induced land use change.