Collaborative Research: Understanding spatiotemporal dynamics of plant-soil feedbacks: Consequences for shrub-grass interactions in a dryland ecotone

合作研究：了解植物-土壤反馈的时空动态：旱地生态交错带灌木-草相互作用的后果

• 批准号: 2105402
• 负责人: Jennifer Rudgers
• 金额: $ 30.75万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2105402&HistoricalAwards=false
• 关键词: Collaborative; Research; Understanding; spatiotemporal; dynamics

Understanding factors that allow species to migrate into new suitable habitats has become increasingly urgent because of the rapid pace of human-caused environmental change. This project combines field and lab experiments to evaluate how plant-plant and plant-microbe interactions influence the migration of creosote, one of the most common and important shrubs of the warm deserts of North America (Sonoran, Chihuahuan and Mojave), into adjacent grasslands. The expansion of woody plants at the expense of grassland, a phenomenon called shrub encroachment, is global in scale and expected to accelerate under future warmer climates and elevated atmospheric CO2. The microbes that live in and near plant roots (the plant microbiome) likely play key roles in affecting the rate of shrub encroachment but their influence on shrub establishment and migration success has not yet been examined. To predict how plant-microbe and plant-plant (in this case shrub/grass) interactions will drive or slow plant population expansion in future climates requires evaluating the spatial and temporal scales at which these interactions occur. Using both field and lab experiments and mathematical models, this project will enable forecasts of how plant-plant and plant-microbe interactions reshape the abundance and distributions of shrub and grass species at the limits of their geographic distributions. Shrubland-grassland dynamics affect the amount of carbon stored by an ecosystem, drive rangeland management decisions, influence strategies to conserve biodiversity, and extend over 330 million hectares of North America alone. This project trains students at many levels, and builds partnerships with stakeholders and managers to ensure knowledge transfer to the benefit of society. A science-art collaboration is also embedded in the research activities, including the design and creation of 3D-printed plant models and artistic interpretations of plant morphologies. A museum exhibit of these models and microbe plant interactions will be created to expand public outreach and create an aesthetic expression of the inter-relationships of microbes and plants.The proposed research will elucidate how plant root and soil associated microbes influence plant species range movements under environmental change. Research activities include the acquisition of novel quantitative data on key parameters that determine range spread: the spatial extent and temporal speed at which plants influence their microbial environment and the relative strength of the microbe/plant feedbacks compared to plant/plant competitive interactions. Experiments on field observations will determine the underlying mechanisms of plant-microbe interactions by addressing the following questions: (1) What is the spatial extent of plant-soil feedback between foundation species at ecotones where range limits collide? This question will be addressed using spatially-explicit paired field and greenhouse experiments to quantify the spatial extent of plant/microbe feedbacks as they influence both grass and shrub performance. (2) How does elevated CO2 affect microbial feedbacks and coexistence between foundation species at these ecotones? This question will be addressed using a growth chamber experiment to contrast microbial feedbacks and competition between grass and shrubs under ambient versus elevated CO2. (3) By what mechanisms do plant species cultivate unique microbial communities through time? This will be addressed with a field experiment to evaluate mechanisms underlying soil and microbial modification by plants and the temporal scale of each mechanism. Finally, quantitative models will be developed using the data from these experiments and observations to address the question, (4) How do soil microbes contribute to range expansion, contraction, or stabilization at species range limits, and how will elevated CO2 change range limit dynamics? The project breaks new ground ni evaluating plant/soil feedbacks in a spatial and temporal context using a well-documented, ecologically important, and experimentally tractable range shift: the encroachment of C3 woody shrubs into C4 grasslands in the American Southwest. Shrub encroachment can dramatically alter biodiversity and ecosystem processes, including carbon storageThis award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

由于人类引起的环境变化速度很快，了解使物种迁移到新的合适栖息地的因素变得越来越紧迫。该项目结合了实地和实验室实验，以评估植物-植物和植物-微生物的相互作用如何影响杂酚油的迁移，杂酚油是北美温暖沙漠（索诺兰，奇瓦瓦和莫哈韦）最常见和最重要的灌木之一，进入邻近的草原。 木本植物以牺牲草地为代价的扩张，这种现象称为灌木入侵，是全球性的，预计在未来气候变暖和大气CO2升高的情况下会加速。生活在植物根部及其附近的微生物（植物微生物组）可能在影响灌木入侵率方面发挥关键作用，但它们对灌木建立和迁移成功的影响尚未得到研究。为了预测植物与微生物和植物与植物（在这种情况下是灌木/草）的相互作用将如何推动或减缓未来气候中植物种群的扩张，需要评估这些相互作用发生的空间和时间尺度。利用田间和实验室实验以及数学模型，该项目将能够预测植物-植物和植物-微生物的相互作用如何在其地理分布的极限下重塑灌木和草本物种的丰度和分布。灌木草原动态影响生态系统储存的碳量，推动牧场管理决策，影响保护生物多样性的战略，仅北美就有3.3亿公顷。该项目在多个层面培训学生，并与利益攸关方和管理人员建立伙伴关系，以确保知识转让造福社会。科学与艺术的合作也嵌入到研究活动中，包括3D打印植物模型的设计和创建以及植物形态的艺术诠释。这些模型和微生物植物相互作用的博物馆展览将被创建，以扩大公众宣传，并创造一个微生物和植物的相互关系的美学表达。拟议的研究将阐明植物根系和土壤相关微生物如何影响环境变化下的植物物种范围运动。研究活动包括获取确定范围扩展的关键参数的新的定量数据：植物影响其微生物环境的空间范围和时间速度，以及与植物/植物竞争相互作用相比微生物/植物反馈的相对强度。野外观测实验将通过解决以下问题来确定植物-微生物相互作用的潜在机制：（1）在生态交错带范围界限冲突的基础物种之间的植物-土壤反馈的空间范围是什么？这个问题将解决使用空间明确的配对领域和温室实验，以量化植物/微生物反馈的空间范围，因为它们影响草和灌木的性能。(2)二氧化碳浓度升高如何影响这些生态交错区基础物种之间的微生物反馈和共存？这个问题将使用生长室实验来解决，以对比环境与CO2浓度升高下草和灌木之间的微生物反馈和竞争。(3)植物物种通过什么机制培养独特的微生物群落？这将通过实地实验来解决，以评估植物对土壤和微生物的改造机制以及每个机制的时间尺度。 最后，定量模型将开发使用这些实验和观察的数据来解决这个问题，（4）土壤微生物如何有助于范围扩大，收缩，或稳定在物种的范围限制，以及如何将升高的CO2变化范围限制动态？该项目打破了新的地面NI评估植物/土壤反馈的空间和时间的背景下，使用一个有据可查的，生态上重要的，实验上易于处理的范围转移：C3木本灌木侵入C4草原在美国西南部。灌木入侵可以极大地改变生物多样性和生态系统过程，包括碳储存这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。