Collaborative Research: RUI: how landscape fragmentation interferes with plant-pathogen interactions that maintain local plant diversity

合作研究：RUI：景观破碎化如何干扰维持当地植物多样性的植物-病原体相互作用

基本信息

批准号：
1655972
负责人：
Cathy Collins
金额：
$ 37.17万
依托单位：
Bard College
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-04-01 至 2023-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1655972&HistoricalAwards=false
关键词：
Collaborative Research RUI how landscape

项目摘要

Many natural areas are being broken up into smaller fragments due to land-use changes such as suburban sprawl. Compared with larger fragments, small fragments are often extreme environments because they can experience stresses like higher temperatures, more light, and lower soil moisture. This research looks at how plants living in different sized fragments are affected by their pathogens. Interactions between plants and their pathogens are important because although pathogens are best known for the damage they cause they can also help preserve biological diversity. This is because each plant species has its own unique group of pathogens that specialize on it, and slows growth or kills just the plants they infect. This can keep any single plant species from dominating in an area. However, not all pathogens can thrive in the extreme environments found in small patches. It may be that in small patches, different types of pathogens that slow growth or kill multiple plant species indiscriminately are more common. If this is the case, they could decrease plant diversity compared with large patches. By uncovering how plants and pathogens interact in different patch sizes this work will be relevant for understanding the biodiversity consequences of breaking up natural areas, and may affect management of natural landscapes. Both lead researchers for this project are early-career faculty at undergraduate colleges, and will incorporate undergraduate students into all aspects of this work, including community outreach.Three parallel studies will be conducted to assess how plant-pathogen interactions are altered by landscape fragmentation, focusing on fungal pathogens in particular. First, researchers will bury seeds of twelve plant species in patches of different sizes at the Kansas Fragmentation Site, allowing the seeds to be colonized by potential pathogens and testing to see if the seeds remain viable after a year of burial. This will determine if seed mortality due to fungal pathogens is most influenced by ecological factors that vary with patch size, such as plant host density, plant species richness, and microclimatic conditions (such as temperature and soil moisture). Second, the fungal community from these buried seeds will be characterized using both culture-based methods and culture-independent molecular tools. This will determine whether fungal community structure varies predictably with patch size, host identity, and host density. Finally, a combination of greenhouse and field experiments will test the hypothesis that negative feedbacks (when plants "culture" host-specific pathogens in the soil surrounding their roots) are strongest in the interiors of large patches, rather than on the edges of large patches or in small patches. It is predicted that thermally stressful environments on edges and small patches will favor generalist fungi, reducing the influence of diversity-maintaining feedbacks on smaller fragments. Collectively, these studies link individual plant-fungal interactions to observed landscape patterns in plant diversity.

由于郊区扩张等土地利用变化，许多自然区域正在被分解成更小的碎片。与较大的碎片相比，小碎片通常处于极端环境中，因为它们会经历更高的温度、更多的光照和更低的土壤湿度等压力。这项研究着眼于生活在不同大小碎片中的植物如何受到病原体的影响。植物与其病原体之间的相互作用很重要，因为尽管病原体以其造成的损害而闻名，但它们也有助于保护生物多样性。这是因为每种植物都有自己独特的一组病原体，专门针对它，并减缓生长或仅杀死它们感染的植物。这可以防止任何单一植物物种在一个地区占据主导地位。然而，并非所有病原体都能在小斑块的极端环境中茁壮成长。在小斑块中，减缓生长或不加区别地杀死多种植物的不同类型的病原体可能更为常见。如果是这种情况，与大斑块相比，它们可能会降低植物多样性。通过揭示植物和病原体在不同斑块大小中如何相互作用，这项工作将有助于理解破坏自然区域的生物多样性后果，并可能影响自然景观的管理。该项目的两位首席研究人员都是本科院校的早期职业教师，并将让本科生参与这项工作的各个方面，包括社区外展。将进行三项平行研究，以评估景观破碎化如何改变植物与病原体的相互作用，特别关注真菌病原体。首先，研究人员将在堪萨斯碎片化地点将十二种植物的种子埋藏在不同大小的斑块中，让潜在的病原体在这些种子中定植，并测试这些种子在埋藏一年后是否仍能存活。这将确定真菌病原体引起的种子死亡率是否最受随斑块大小变化的生态因素的影响，例如植物寄主密度、植物物种丰富度和小气候条件（例如温度和土壤湿度）。其次，将使用基于培养的方法和独立于培养的分子工具来表征这些埋藏种子的真菌群落。这将确定真菌群落结构是否随斑块大小、宿主身份和宿主密度的变化而发生可预测的变化。最后，温室和田间实验的结合将检验这样的假设：负反馈（当植物在其根部周围的土壤中“培养”宿主特异性病原体时）在大斑块的内部最强，而不是在大斑块的边缘或小块。据预测，边缘和小斑块上的热应激环境将有利于多面性真菌，从而减少维持多样性的反馈对较小碎片的影响。总的来说，这些研究将个体植物-真菌相互作用与观察到的植物多样性景观格局联系起来。