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.

在许多自然生态系统中，可以发现几十种植物在非常小的区域内生长在一起。然而，100多年来，研究人员一直在努力解释为什么没有一个物种可以排除所有其他物种。人们认为，只有当每个物种的竞争能力受到某种不同的限制时，物种才能共存。例如，它们可能需要不同的生长资源，被不同的东西感染或吃掉，或者需要不同的环境条件。然而，证明这种想法在自然界中成立已被证明是困难的。 该项目将建立在现有的研究植物共存的山艾树草原。这项研究表明，最常见的植物物种共存，因为在什么限制如何成功的幼苗是在得到建立的差异。这些建立上的差异被怀疑是由生活在土壤中并感染不同物种根部的真菌病原体的差异引起的。在这项研究中，研究人员将利用田间实验、温室实验以及基于历史和实验数据的计算机模型，来了解真菌病原体在维持植物物种共存方面的作用有多大。这项工作将研究的山艾树草原是一个危险的生态系统，具有经济和保护的重要性。这项研究将有助于在这些系统中工作的土地管理人员，因为它将增加对本地植物物种在再生中的重要性的理解。因此，它将导致更好的方法来管理和恢复这一生态系统。结果将被用来创建由土地管理人员使用的情况说明书，并将提供给他们和其他人通过现有的网络的国家，联邦，大学和非政府组织人员感兴趣的山艾树草原conservation.Progress经验共存研究需要整合现代，定量的方法，如人口建模，与经典的机械方法，如针对特定的共存机制的实验。该提案将这些方法结合起来，专注于一个潜在的机制，最近产生了巨大的兴趣，可能是重要的多年生植被：植物-土壤反馈（PSF）。首先，田间试验将量化真菌PSF对发芽出苗和建立的种内和种间影响。一个同伴温室实验将解决现场和实验室的PSF研究之间的差异的问题，并把这个案例研究的背景下，目前的文献。第二，从现场实验的结果将纳入现有的，现象学的多物种种群模型，使共存的整体稳定性的比较下的情况下，只有PSF驱动器在招聘阶段的相互作用，和一个方案，包括所有可能的来源内和种间的招聘效果。通过结合田间实验，温室研究，长期的人口数据和模型，这项工作将量化的贡献，在山艾属草原社区共存的整体稳定性的PSF。这种新颖的实验和建模框架未来可以扩展到其他社区和共存机制。