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的干旱。地下发现的水分储存是这些生态系统恢复能力的核心，然而，目前尚不清楚根区水分将如何应对气候变化，如积雪减少或干旱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，超出了常规传感和采样的深度。因此，根区储水量是水循环中约束最差、观测最少的变量之一。这项研究将产生新的根区蓄水措施，以支持对气候变化下森林植被和溪流供水的改进预测。该项目还将培养下一代水文学家和地球科学家，通过侧重于经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，应对气候变化中的水资源挑战。预计下个世纪气候的复杂和相互作用的变化将对高地森林产生不成比例的影响，因为高地森林在补给地下蓄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部的水分如何抑制或放大它们对水文气候变化的敏感性，还存在一些悬而未决的问题。该提案将集中记录德克萨斯州、加利福尼亚州和科罗拉多州的水文监测点网络中的根区水分储存情况，以评估根区水分对气候变异性的反应。重要的是，水分储存的测量将延伸到土壤下的风化基岩。然后，这些地面测量将被用来推进基于卫星的方法，以在更大的尺度上测量根区水分。由此产生的数据集将为生态水文模型提供信息，以评估根区水分存储模式如何应对干旱、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(森林服务局)、当地水机构的伙伴关系，以及NSF支持的研究，包括关键区域合作网络。教育活动将通过有针对性的暑期研究计划和德克萨斯大学奥斯汀分校GeoFORCE推广计划的导师网络，以及将当地案例研究整合到德克萨斯大学本科生地球科学课程中，增加体验式地球科学教育的机会和公平性。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。

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.