Collaborative Research: Distance- and Phylogeny-based Pathogen Transmission in Forest Communities

一些植物病原体在自然植物群落中引起破坏性流行病，但许多其他病原体的影响有限，甚至可以作为维持物种丰富的植物群落结构和多样性的重要因素。预测特定植物病原体的传播和影响取决于了解其可感染的植物物种范围以及景观中寄主物种的空间分布和丰度。在这里，我们将在巴拿马低地的潮湿热带森林和加利福尼亚中部海岸的温带混合森林中工作，以研究森林中植物物种的组成和空间格局如何影响高多样性和低多样性植物群落中疾病传播的可能性。通过一系列交叉接种，我们将直接测量病原体在进化上接近或更远的宿主之间共享的潜力。利用空间明确的流行病学模拟模型，我们将这些寄主范围的经验估计与森林中已绘制的样地中已知的树种空间格局相结合，以检验具有不同生活史和不同寄主宽度的病原体在森林群落中传播的可能性。该研究结果将为森林管理、植物病虫害检疫等问题提供信息，并对自然群落中植物-病原体相互作用中寄主范围的重要性有基本的了解。

Some plant pathogens cause destructive epidemics in natural plant communities, but many others have limited impacts, or can even act as important agents in maintaining structure and diversity in species-rich plant communities. Predicting the spread and impacts of a particular plant pathogen depends on understanding the range of plant species it can infect as well as the spatial arrangement and abundance of host species in the landscape. Here we will work in both the moist tropical forest of lowland Panama and the mixed temperate forest on the central coast of California to examine how the composition and spatial patterns of plant species in the forest affects the potential for disease spread in high- and low-diversity plant communities. Through a series of cross inoculations we will measure directly the potential for pathogens to be shared among hosts that are evolutionarily closely or more distantly related. Using a spatially-explicit epidemiological simulation model, we will couple these empirical estimates of host range with the known spatial pattern of tree species in mapped plots in the forests, to examine the likelihood of spread through forest communities of pathogens with different life histories and different host breadths. The results of this research will inform issues of forest management, plant pest quarantine, and a basic understanding of the importance of host range in plant-pathogen interactions in natural communities.