MSA: Self-organizing principles for upscaling ecosystem water and heterotrophic carbon fluxes

气候变化和土地管理正在全球范围内影响土壤，对土壤健康和生物多样性、植物生产力和气候调节产生不利影响。然而，土壤有机碳的损失及其作为二氧化碳的排放，这是由土壤微生物调节的碳向大气的主要输入（称为异养呼吸），仍然是最不确定的陆地碳通量之一。这项研究旨在了解异养呼吸如何根据宏观环境变量（例如，降雨和植被生产力）以及从生态系统到大陆尺度的生物群落和气候变化，通过结合来自多个观测网络的实验数据和微生物生长和代谢的数学模型。这项分析有助于绘制区域到大陆尺度的异养呼吸图，并通过更准确地估计土壤有机碳损失来评估气候变化对土壤和生态系统的潜在影响。这一努力使从事生态系统管理和可持续性工作的环境决策者能够规划有效的保护战略，特别是对气候变化最敏感的地区。该项目将培养多样化的学生，并将支持在微生物学、水文学、本研究的指导假设是，在生态系统尺度上，年异养呼吸与植物生产力的比值（与土壤碳收支有关的无因次测量）主要与干旱指数（湿度/干燥的无因次测量）相关。该项目将基于过程的微生物生长建模与通量塔数据集以及来自氖和其他区域和全球网络的土壤和生态系统碳通量的实地测量相结合，在量纲分析的π定理的指导下，探索解释生物群落中水和碳通量变化的基本定律的存在。一个简约的过程为基础的微生物模型正在被用来分析观察和统计微生物参数的宏观环境驱动因素，并确定关键的无量纲组管理的大规模动态。异养呼吸和环境驱动因素之间的宏观关系，然后用于重建大规模的碳通量的基础上的空间结构的主要环境drivers.This奖项反映了NSF的法定使命，并已被认为是值得支持的评估使用基金会的智力价值和更广泛的影响审查标准。

Climate change and land management are affecting soils globally, with detrimental consequences for soil health and biodiversity, plant productivity, and climate regulation. However, the loss of soil organic carbon and its emission as carbon dioxide, which is a major input of carbon to the atmosphere regulated by soil microorganisms (known as heterotrophic respiration), remains one of the most uncertain terrestrial carbon fluxes. This research aims to understand how heterotrophic respiration varies across biomes and climates depending on macroscopic environmental variables (for example, rainfall and vegetation productivity) and from the ecosystem to continental scale, by combining experimental data from multiple observational networks and mathematical models of microbial growth and metabolism. This analysis is helping to map heterotrophic respiration at regional to continental scales and assess the potential impact of climate change on soils and ecosystems by enabling more accurate estimates of soil organic carbon losses. The effort allows environmental policymakers working on ecosystem management and sustainability to plan effective conservation strategies, especially for those regions that are most sensitive to climate change. The project will train diverse students and will support the development of new interdisciplinary curricular material at the intersection of microbiology, hydrology, and environmental science and engineering.This research is guided by the hypothesis that at the ecosystem scale the ratio of annual heterotrophic respiration to plant productivity (a dimensionless measure related to the soil carbon budget) is primarily correlated with the aridity index (a dimensionless measure of wetness/dryness). The project combines process-based microbial growth modeling with flux tower datasets and field-based measurements of soil and ecosystem carbon fluxes from NEON and other regional and global networks to explore, guided by the π theorem of dimensional analysis, the existence of fundamental laws explaining the variability in water and carbon fluxes across biomes. A parsimonious process-based microbial model is being used to analyze observations and statistically link microbial parameters to macroscopic environmental drivers and identify key dimensionless groups governing the large-scale dynamics. The macroscopic relations between heterotrophic respiration and environmental drivers are then used to reconstruct large-scale carbon fluxes based on the spatial structure of primary environmental drivers.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.