Collaborative Research: LiT: ETBC: Plant-microbe feedback mechanisms affecting decomposition and nutrient availability and interactions with climate change

草原生态系统占地球陆地面积的30%以上，为牧场等广泛的农业活动提供了资源基础。草原对气候变化很敏感，因为它们存在于炎热干燥天气常见、降雨量不可预测的地方，也因为它们的植物群落可能会随着气候和大气中二氧化碳浓度的上升而迅速变化。草原土壤储存了大量的长寿碳，这些碳可以缓冲气候变化，如果这些碳释放到大气中，也可以加速气候变化。土壤微生物群落是土壤碳吸收或流失的最终驱动力。该项目调查了在怀俄明州夏延市附近草原正在进行的最先进的操纵性气候变化实验-草原加热和二氧化碳浓缩(PHACE)实验中，植物-微生物相互作用如何调节土壤碳循环。30个地块暴露在气候条件的组合中，包括预计在21世纪末之前发生的变暖和二氧化碳条件，以及变化的降水。这项实验的一个重要组成部分是比较具有不同植物群落(包括入侵物种)的本地草原和受干扰草原之间的碳和养分循环。应用分子和同位素方法的实验室和生长室实验将检验从现场观察和测量中产生的具体假设。该项目预计将减少土壤养分、生物群落和气候变化之间相互作用的不确定性，从而改进对未来大气二氧化碳浓度和相关变暖影响的预测。该项目将通过在Phace现场开展一年一度的野外日活动并在大众媒体上发表文章，联系农业资源管理机构、牧场主和土地所有者，他们关注气候变化、干扰和杂草入侵对牧场生产力的影响。通过将土壤数据纳入一个全面的数据库，将促进跨地点协作和数据合成。该项目将为来自代表性不足群体的两名研究生、几名本科生和两名博士后科学家提供强有力的跨学科培训。参加怀俄明大学自然科学硕士学位项目的在职中学科学教师将被邀请到现场进行实践课程开发，并将对少数民族高中生进行指导。科罗拉多州立大学新的夏季土壤研究所(http://soilinstitute.nrel.colostate.edu))将把学生带到Pace现场进行采样和分析。

Grassland ecosystems comprise over 30% of the Earth's terrestrial surface, and provide a resource base for extensive agricultural activities such as ranching. Grasslands are sensitive to climate change because they exist where hot, dry weather is common and rainfall is unpredictable, and because their plant communities may rapidly shift in response to rising climate and atmospheric CO2 concentrations. Grassland soils contain large stores of long-lived carbon, which could either buffer climate change, or accelerate it if this carbon is released to the atmosphere. Soil microbial communities are the ultimate drivers of soil carbon uptake or loss. This project investigates how plant-microbe interactions regulate soil carbon cycling within an ongoing, state-of-the-art, manipulative climate change experiment in grasslands near Cheyenne, Wyoming, the Prairie Heating and CO2 Enrichment (PHACE) experiment. Thirty plots are exposed to combinations of climate conditions, including warming and CO2 conditions expected to occur before the end of the 21st century, and altered precipitation. An important component of the experiment is the comparison of carbon and nutrient cycling between native and disturbed grasslands with distinct plant communities, including invasive species. Laboratory and growth chamber experiments applying molecular and isotopic methods will test specific hypotheses generated from observations and measurements in the field. This project is expected to reduce uncertainties related to interactions between soil nutrients, biological communities and climate change, leading to improved predictions of future atmospheric CO2 concentrations and associated warming effects.This project will reach out to agricultural resource management agencies, ranchers and landowners who are concerned about impacts of climate change, disturbance and weed invasion on rangeland productivity, by conducting annual Field Days at the PHACE site and publishing articles in the popular press. Cross-site collaboration and data synthesis will be promoted by incorporating soil data into a comprehensive database. The project will provide strong interdisciplinary training to two graduate students, several undergraduates, and two postdoctoral scientists from under-represented groups. In-service middle school science teachers participating in the University of Wyoming Master's of Science in Natural Science degree program will be invited to the field site for hands-on lesson development, and minority high school students will be mentored. The new Summer Soil Institute at Colorado State University (http://soilinstitute.nrel.colostate.edu) will bring students to the PHACE field site for sampling and analyses.