CREST-PRF: Identifying Zones of Biological Activity Using a Spatially Distributed Metabolism Model in an Aridland River

科学与技术卓越研究中心博士后研究奖学金（CREST- prf）项目支持具有重大潜力的CREST中心研究人员，并为他们提供培训和研究经验，以拓宽视野，促进跨学科互动，并使他们在科学界处于领导地位。这个CREST- prf项目与新墨西哥大学CREST水与环境中心（CWE）的研究重点一致。本研究的目的是测量干旱区河流系统初级生产和生态系统呼吸的时空变化程度。干旱区河流在河边（即浴缸环）有典型的初级生产带，为消费生物提供了大量的食物来源。然而，当应用一般的全系统代谢方法时，这些系统的代谢可能被低估了。将空间变化纳入代谢模型将为量化初级生产总值（GPP）和生态系统呼吸（ER）的方法和理解代谢驱动因素提供新的见解。目标1：确定总初级生产和生态系统呼吸的时空变化；目的2是比较用于量化代谢的方法；目的3探讨流量变化对生物生产力带的影响。所获得的知识可转移到其他河流系统，并可作为一种工具，使管理人员了解在恢复水生生境、生态系统功能和濒危物种生存方面最有效的环境流动。包括旱地河流的旱地河流在新陈代谢领域的研究很少；然而，面对不断变化的气候条件，它们是最脆弱的系统。政府间气候变化专门委员会（ipcc）分析了干旱河网代谢率的时空信息，可将其纳入区域和全球碳预算的估算中。常用的全系统代谢方法假设GPP和ER的估计值代表整个范围。然而，干旱区河流的代谢并不均匀，且存在空间差异。本研究项目分析的时空复杂性水平将在多个尺度上推进碳过程控制的基础知识。该项目整合了多个实体收集的长期高分辨率环境数据的多个来源，并利用强大的计算资源来处理大数据。从整体的角度来看，本研究将有助于对干旱区河流生产力及其在区域碳收支中的作用的基本认识。此外，该研究地点与工程河流系统密切相关，这些系统正在经历流量的减少和改变，以及随后的水质退化和下游的营养污染。建模方法和结果将可转移到大型河流系统。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 Centers of Research Excellence in Science and Technology-Postdoctoral Research Fellowship (CREST-PRF) track within the CREST program supports beginning CREST Center investigators with significant potential and provides them with training and research experiences that will broaden perspectives, facilitate interdisciplinary interactions and establish them in positions of leadership within the scientific community. This CREST-PRF project is aligned with the research focus of the CREST Center for Water and the Environment (CWE) at the University of New Mexico. The goal of this research is to measure the extent of time and space variability in primary production and ecosystem respiration in an aridland river system. Aridland rivers have characteristic zones of primary production at the river edges (i.e., bathtub ring) that provides a substantial food source to consumer organisms. Yet, metabolism of these systems is likely underestimated when applying common methods for whole-system metabolism. Addressing space variation into metabolism models will offer new insight on methods for quantifying gross primary production (GPP) and ecosystem respiration (ER) and understanding of drivers of metabolism. The following objectives focus on a 9 km study reach in the middle Rio Grande, New Mexico: Objective 1 is to identify space and time variability of gross primary production and ecosystem respiration; Objective 2 is to compare methodology used to quantify metabolism; and Objective 3 is to explore the influence of changing discharge on the zone of biological productivity. The knowledge gained is transferrable to other river systems and can be used as a tool to inform managers on environmental flows that are most effective at restoring aquatic habitat, ecosystem function and survival of endangered species. Dryland rivers, which encompasses aridland rivers, are poorly studied systems in the field of metabolism; yet, are the most vulnerable systems regarding changing climate conditions. Spatiotemporal information learned about metabolic rates in an aridland river network can be integrated into estimates of regional and global carbon budgets analyzed by the Intergovernmental Panel on Climate Change. Common methods of whole-system metabolism assume estimates of GPP and ER are representative of the whole reach. However, stream metabolism is not homogeneous and varies spatially in aridland rivers. The level of spatial and temporal complexity analyzed in this research project will advance fundamental knowledge in controls on carbon processes at multiple scales. This project integrates multiple sources of longterm, high resolution environmental data collected by several entities and leverages robust computational resources to process big data. Taking a holistic approach, this research will contribute to the basic understanding of the productivity of aridland rivers and the role in regional carbon budgets. Moreover, this research site is germane to engineered river systems undergoing reductions and alterations of streamflow and subsequent degradation of water quality and nutrient pollution downstream. Modeling methods and results will be transferable to large river systems.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.