MSA: Evaluating the continuity of NEON and AmeriFlux data streams recorded at collocated sites from tundra to subtropics

了解气候、土地利用和物种分布的变化对我们的自然界的影响是大系统生物学面临的一个巨大挑战。需要长期的观察来发现生态变化，并自信地对未来做出预测。国家生态观测网(NEON)建设是一项为期30年的工程，于2019年完成。大多数数据集目前的长度不到五年。该项目将评估在美国各地最近测量的霓虹灯站点进行的新测量与在先前存在的、附近的ameriFlux站点已经进行的长期测量之间的连续性。这项分析利用了从阿拉斯加到佛罗里达的8个霓虹灯区域的11个站点的数据。一个关键的重点是描述这些生态系统有节奏的“呼吸”的数据(即它们如何与大气交换二氧化碳和水蒸气)。该分析是对霓虹灯数据质量的独立和基本的交叉检查，从而增加了霓虹灯数据对用户社区的有用性和价值。将通过宣传活动产生更广泛的影响，这些活动强调正式和非正式的科学教育，并为下一代科学领袖提供实践培训。该项目利用北亚利桑那大学的地理位置，为在STEM领域传统上代表性不足的美洲原住民社区提供学习机会。长期生态数据集的一致性和连续性至关重要，以便能够可靠地检测到全球变化的指纹。尽管霓虹灯将持续30年，但全球变化带来的环境挑战足够紧迫，科学家和社会都不能等待那么长时间。如果来自霓虹灯的新数据集能够与来自其他观测网络的先前存在的长期数据集相结合，就可以更快地更好地了解生态系统变化的轨迹。这个项目提出的问题是“现有的ameriFlux数据能否被用来将直到2017年才开始的霓虹灯数据集扩展到过去？”这项研究将确定这些重叠数据集中的一致性是否取决于所考虑的时间尺度和发生地点异质性的空间尺度。该项目采用多尺度方法，结合了跨越广泛气候梯度的地点的频域和地理空间分析。对于每个站点，“连续性记分卡”将提供必要的诊断信息，以确保可以从综合时间序列中得出有效的推论。证明稳健的连续性将使科学家能够利用更长时间的观测记录的力量。外展工作将包括研讨会、嘉宾讲座、课堂访问和社区示范，突出“大数据”在了解全球变化在区域和大陆范围内的生态影响方面的作用。来自少数族裔群体的两名社区大学生将被招募为该项目的研究助理，在他们过渡到北亚利桑那大学的理科学士课程时提供宝贵的培训。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Understanding the impact of changes in climate, land use, and species distribution on our natural world is a grand challenge for Macrosystems Biology. Long-term observations are needed to detect ecological changes, and to confidently make predictions about the future. Construction of the National Ecological Observatory Network (NEON), a 30-year project, was completed in 2019. Most data sets are currently less than five years in length. This project will evaluate the continuity between new measurements conducted at recently-instrumented NEON sites across the United States, and longer-term measurements already conducted at pre-existing, nearby, AmeriFlux sites. The analysis leverages data from 11 sites across 8 NEON domains from Alaska to Florida. A key emphasis is on data characterizing the rhythmic ‘breathing’ of these ecosystems (i.e. how they exchange carbon dioxide and water vapor with the atmosphere) over days, seasons, and years. The analysis serves as an independent and fundamental cross-check of NEON data quality, thereby increasing the usefulness and value of NEON data to user communities. Broader impacts will accrue through outreach activities emphasizing formal and informal science education, and offering hands-on training for the next generation of scientific leaders. The project leverages Northern Arizona University’s geographic location to provide learning opportunities for Native American communities traditionally underrepresented in STEM fields.Consistency and continuity in long-term ecological data sets are essential so that the fingerprints of global change can be reliably detected. While NEON will run for 30 y, the environmental challenges posed by global change are pressing enough that neither scientists nor society can wait that long. Better understanding of the trajectory of ecosystem change will be attainable sooner if new data sets from NEON can be integrated with pre-existing long-term data sets from other observation networks. This project asks “can existing AmeriFlux data be used to extend, back in time, NEON datasets that did not begin until 2017?” The study will determine whether agreement in these overlapping data sets is dependent on both the temporal scale being considered and the spatial scales on which site heterogeneity occurs. The project adopts a multi-scale approach that incorporates frequency-domain and geospatial analyses across sites spanning a broad climatic gradient. For each site, a “continuity scorecard” will provide diagnostic information needed to ensure valid inferences can be derived from integrated time series. Demonstration of robust continuity will enable scientists to leverage the power of longer observational records. Outreach efforts will include workshops, guest lectures, classroom visits, and community demonstrations highlighting the role of “big data” in understanding the ecological impacts, at regional to continental scale, of global change. Two community college students from underrepresented minority groups will be recruited as research assistants on this project, providing valuable training as they transition to Bachelor of Science programs at Northern Arizona University.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.