SG: Quantifying the contribution of plant-soil feedbacks to coexistence in a sagebrush steppe

SG：量化植物-土壤反馈对山艾树草原共存的贡献

• 批准号: 1655522
• 负责人: Peter Adler
• 金额: $ 15万
• 依托单位: Utah State University
• 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: 2017-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1655522&HistoricalAwards=false
• 关键词: SG; Quantifying; contribution; plant; soil

In many natural ecosystems, dozens of plant species can be found growing together in very small areas. However for over 100 years researchers have struggled to explain why no single species can exclude all the others. It is thought that species can coexist only when the ability of each to outcompete the others is limited by something different. For example, they may each need different resources for growth, be infected by or eaten by different things, or need different environmental conditions. However, showing that this idea holds in nature has proven difficult. This project will build on existing research on plant coexistence in sagebrush steppes. This research shows that the plant species that are most common coexist because of differences in what limits how successful seedlings are at getting established. These differences in establishment are suspected to be caused by differences in the fungal pathogens living in the soil and infecting roots of the different species. In this study, the researchers will use a field experiment, greenhouse experiment, and computer models based on historical and experimental data to find out how big the role of fungal pathogens is in maintaining the coexistence of plant species. The sagebrush steppe that this work will study is an at-risk ecosystem that has economic and conservation importance. This research will be useful to land managers working in these systems, because it will increase understanding of how important native plant species can be helped in their regeneration. Therefore it will lead to improved ways to manage and restore this ecosystem. The results will be used to create fact sheets for use by land managers, and will be made available to them and to others through existing networks of state, federal, university and NGO personnel interested in sagebrush steppe conservation.Progress in empirical coexistence research requires integration of modern, quantitative approaches such as population modeling, with classical mechanistic approaches such as experiments targeting specific coexistence mechanisms. This proposal combines these approaches by focusing on one potential mechanism that has recently generated tremendous interest and is likely important in perennial vegetation: plant-soil feedbacks (PSF). First, a field experiment will quantify intra- and interspecific effects of fungal PSFs on germination-emergence and establishment. A companion greenhouse experiment will address questions about differences between field and lab-based PSF studies, and place this case study in the context of the current literature. Second, results from the field experiment will be incorporated in an existing, phenomenological multispecies population model, enabling comparisons of the overall stability of coexistence under a scenario in which only PSFs drive interactions at the recruitment stage, and a scenario including all possible sources of intra- and interspecific effects on recruitment. By combining field experiments, greenhouse studies, long-term demographic data, and models, this work will quantify the contribution of PSFs to the overall stability of coexistence in a sagebrush steppe community. This novel experimental and modeling framework can be extended to other communities and coexistence mechanisms in the future.

在许多天然生态系统中，可以在很小的地区发现数十种植物物种。但是，在100多年来，研究人员一直在努力解释为什么没有单一物种可以排除其他物种。人们认为，只有当每个物种胜过其他物种的能力受到不同的限制时，物种才能共存。例如，他们可能每个人都需要不同的资源才能增长，被不同事物感染或食用，或者需要不同的环境条件。但是，证明这一想法在本质上已被证明很困难。 该项目将基于有关Sagebrush草原中植物共存的现有研究。这项研究表明，由于限制了幼苗建立的成功程度，最常见的共存植物物种。这些建立差异怀疑是由于生活在土壤中的真菌病原体的差异和感染不同物种的根部的差异引起的。在这项研究中，研究人员将根据历史和实验数据使用现场实验，温室实验和计算机模型，以了解真菌病原体在维持植物物种共存方面的作用。这项工作将研究的鼠尾草草原是具有经济和保护重要性的高风险生态系统。这项研究对在这些系统中工作的土地管理人员将很有用，因为它将增加对本地植物物种如何在其再生中的重要性的理解。因此，它将带来改进的管理和恢复生态系统的方法。结果将用于创建事实表，以供土地管理者使用，并通过现有的州，联邦，大学和非政府组织对Sagebrush Steppe Conservation的现有网络提供给他们以及其他人的使用。现代定量方法（例如人口建模），采用经典的机械方法，例如针对特定共存机制的实验。该提案通过关注最近引起极大兴趣的一种潜在机制来结合这些方法，并且在多年生植被中可能很重要：植物土壤反馈（PSF）。首先，现场实验将量化真菌PSF对发芽出现和建立的种内和间种间影响。伴侣温室实验将解决有关现场和基于实验室的PSF研究之间差异的问题，并将此案例研究放在当前文献的背景下。其次，实验实验的结果将纳入现有的现象学多种种群模型中，从而可以比较在只有PSF在招聘阶段驱动相互作用的情况下共存的整体稳定性，以及包括所有可能的场景，包括所有可能的来源 - 对招聘的种间影响。通过结合现场实验，温室研究，长期人口统计数据和模型，这项工作将量化PSF对Sagebrush Steppe社区共存的整体稳定性的贡献。将来，这个新颖的实验和建模框架可以扩展到其他社区和共存机制。