MCA: Incorporating Carbon Use Efficiency into Strategies for Ecosystem Restoration

美国中部曾经拥有地球上最大的高草草原生态系统。由于农业和城市发展，这一生态系统及其对土壤健康、碳储存和生物多样性所带来的好处大部分已经丧失。今天，生态系统恢复是土地管理者和科学家共同努力将高草草原等生态系统恢复到北美景观的一种重要方式，同时也带来了它们所带来的好处。典型的恢复策略侧重于播种本地植物。这种方法忽略了数以百万计的土壤微生物，它们也因耕作和施肥而受到破坏。研究表明，在恢复后的系统中，许多过程没有发挥其潜力，因为土壤中微生物的数量和类型仍然永久改变。至关重要的是，这影响了恢复土壤中可以保留多少碳。重新制定恢复目标，以便将重点放在管理作为最佳碳汇的生态系统上，这是平衡温室气体排放和扭转环境变化影响的重要一步。实现这一目标的第一步需要更深入地了解基本管理选择如何影响土壤微生物的碳利用。该项目利用现有的nsf资助的研究，包括两个指标（土地面积和植物种类数量），并将检查土壤微生物在这些不同处理中利用碳的效率。这个职业中期进步奖（MCA）将为处于职业生涯关键时刻的科学家提供支持，通过学习测量微生物重要特征的新技术来推进他们的研究。这项工作的结果将与密歇根州西南部的六个区域土地管理组织广泛交流。本研究的主要目的是了解植物丰富度和恢复面积对恢复草原碳利用效率（CUE）、土壤细菌和真菌群落组成、功能和异质性的影响。这些目标将通过保护土地实验（CLE）来解决，这是凯洛格生物站长期生态研究（LTER）站点正在进行的研究项目。CLE维护着12个地点，面积从0.3 - 3.2公顷不等，这些地点在2015年种植了低丰度和高丰度的植物种子混合物。这是一个理想的实验，其中测试应用的问题，如何恢复策略影响微生物多样性和异质性使用空间明确的抽样设计。下一代DNA测序和分析，假定的功能途径预测和其他常见的土壤指标是PI的标准程序，但当与基于速率的碳通量测量相结合时，这些变量的价值将得到增强。该项目通过提供时间和资源，与新罕布什尔大学的一位专家同事一起学习基于18o -同位素的CUE测定，扩大了PI的研究专长。网络和协作的机会有望导致具有实际应用的跨学科项目，并涉及非营利性土地管理组织。最终的结果将包括新的恢复策略，最大限度地恢复地下碳储存，同时保持可处理和成本效益。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The central United States once contained the largest tallgrass prairie ecosystem on Earth. Through agricultural and urban development, most of this ecosystem - and the benefits it provided to soil health, carbon storage and biodiversity - were lost. Today, ecosystem restoration is an important way that land managers and scientists can work together to return ecosystems such as tallgrass prairies to the North American landscape, along with the benefits they provide. Typical restoration strategies focus on seeding native plants. That approach overlooks the millions of soil microorganisms that were also disrupted through tilling and fertilization. Research shows that many processes fall short of their potential in restored systems because the amounts and types of microorganisms in the soil remain permanently altered. Critically, this affects how much carbon can be retained in the restored soil. Reframing restoration goals so that they focus on managing ecosystems that act as optimal carbon sinks is an important step toward balancing greenhouse gas emissions and reversing the effects of environmental change. The first step to accomplishing this goal requires greater understanding of how basic management choices affect soil microbial carbon use. This project leverages an existing NSF-funded study that includes two metrics (land area and number of plant species) and will examine the efficiency with which soil microorganisms use carbon in these different treatments. This mid-career advancement award (MCA) will provide support for a scientist at a critical career juncture to advance their research by learning new techniques for measuring an important trait of microorganisms. Results of this work will be communicated broadly with six regional land management organizations in southwest Michigan.The main goal of this research is to understand how plant richness and restoration area influence carbon use efficiency (CUE), soil bacterial and fungal community composition, function and heterogeneity in restored prairies. These goals will be addressed using the Conservation Lands Experiment (CLE), an ongoing research project at Kellogg Biological Station Long-Term Ecological Research (LTER) site. The CLE maintains 12 sites ranging from 0.3 – 3.2 hectares, which were planted with low- and high-richness plant seed mixes in 2015. It is an ideal experiment in which to test applied questions about how restoration strategies influence microbial diversity and heterogeneity using a spatially-explicit sampling design. Next-generation DNA sequencing and analyses, putative functional pathway prediction and other common soil metrics are standard procedures for the PI, but the value of these variables will be enhanced when coupled with rate-based measurements of carbon fluxes. This project expands the PI’s research expertise by providing time and resources to learn 18O-isotope-based CUE assays with an expert colleague at the University of New Hampshire. Opportunities for networking and collaboration are expected to lead to interdisciplinary projects that have real-world applications and involve non-profit land management organizations. Ultimately, outcomes will include new restoration strategies that maximize belowground restoration for carbon storage, while remaining tractable and cost-effective.This 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.