CAREER: How hydroclimate variability is transmitted through the critical zone

地球上一些最具生产力和生物多样性的森林经历了长期干旱。在地下发现的水分储存是这些生态系统恢复力的核心，然而，尚不清楚根区水分将如何响应气候变化，例如积雪减少或干旱的严重程度和频率增加。这在很大程度上是因为森林根区通常延伸到岩石中，超出了传统传感和采样的深度。因此，根区水分储存是水循环中最缺乏约束和很少观察到的变量之一。这项研究将产生根区储水量的新测量方法，以支持在气候变化下改善对森林植被和河流供水的预测。该项目还将通过侧重于体验式本科生培训以及本科生和研究生研究培训的教育计划，为下一代水文学家和地球科学家应对气候变化中的水资源挑战做好准备。预计下个世纪气候变化的复合和相互作用将对山地森林产生不成比例的影响，山地森林在补充地下水含水层和向河网供水方面发挥着重要作用。关于储存在这些森林根区的水分如何抑制或增强它们对水文气候变化的敏感性，还有一些悬而未决的问题。该提案将在德克萨斯州、加利福尼亚州和科罗拉多州的水文监测点网络上集中记录根区水分储存，以评估根区水分如何响应气候变化。重要的是，水分储存的测量将从土壤下延伸到风化的基岩。然后，这些地面测量将用于推进基于卫星的方法，以便在更大的尺度上测量根区区域水分。由此产生的数据集将为生态水文模型提供信息，以评估根区水分储存模式如何响应干旱、积雪变化和土地利用干扰。实地工作和学生培训将利用与美国农业部（林业局）、当地水务机构和美国国家科学基金会支持的研究（包括关键区域协作网络）的伙伴关系。教育活动将增加体验式地球科学教育的机会和公平性，通过有针对性的夏季研究项目和德克萨斯大学奥斯汀分校GeoFORCE外展项目的毕业生指导网络，并将当地案例研究整合到德克萨斯大学地球科学本科课程中。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。

Some of Earth’s most productive and biodiverse forests experience prolonged drought. Moisture stores found below ground are central to the resilience of these ecosystems, however, it remains unclear how root-zone moisture will respond to changes in climate, such as decreased snowpack or increased severity and frequency of drought. This is largely because forest root-zones commonly extend into rock beyond depths of conventional sensing and sampling. Consequently, root-zone moisture storage is one of the most poorly constrained and sparsely observed variables in the water cycle. This research will generate new measurements of root-zone water storage to support improved forecasting of water supply to forest vegetation and streams under climate change. This project will also prepare the next generation of hydrologists and geoscientists to tackle water resource challenges in a changing climate through an educational plan focused on experiential undergraduate training as well as undergraduate and graduate student research training. The compounding and interacting changes to climate projected for the next century are expected to disproportionately impact upland forests, which play an important role in recharging groundwater aquifers and supplying water to river networks. There are open questions about how moisture stored in the root-zone of these forests may dampen or amplify their sensitivity to hydroclimate variability. This proposal will intensively document root-zone moisture storage across a network of hydrologic monitoring sites in Texas, California and Colorado to evaluate how root-zone moisture responds to climate variability. Importantly, measurements of moisture storage will extend beneath soils into the weathered bedrock. These on-the-ground measurements will then be used to advance satellite-based methods for measuring root-zone zone moisture at larger scales. The resulting datasets will inform an ecohydrologic model to evaluate how patterns of root-zone moisture storage respond to drought, changes in snowpack, and land use disturbance. Field work and student training will leverage partnerships with the USDA (Forest Service), local water agencies, and NSF-supported research, including the Critical Zone Collaborative Network. Educational activities will increase access and equity in experiential geoscience education through a targeted summer research program and mentorship network for graduates of the University of Texas at Austin’s GeoFORCE outreach program and the integration of a local case-study into the University of Texas undergraduate geoscience curriculum.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.