Collaborative Research - Digging deeper: Do deeper roots enhance deeper water and carbon fluxes and alter the trajectory of chemical weathering in woody-encroached grasslands?

在草原上，木本植物的覆盖面积和数量都在增加。用木本植物代替草地可以改变水、养分和金属在土壤中的储存和移动方式。这个项目研究了堪萨斯州草原的这些变化。该项目将水科学、岩石化学和土壤化学领域联系起来。该项目将水在地下的流动和储存方式与土壤和岩石的化学分解方式联系起来。研究木本植物的根是如何改变地下水流的，这对于了解地球将如何应对未来的气候变化非常重要。这项研究提供了跨科学领域的培训，包括地质学、生物学和化学。将为包括K-12和大学在内的所有年级开发教材。本研究的目的是了解根系如何响应气候和土地利用的变化，以及根系如何通过景观控制水和养分的运动。具体而言，本研究研究了与木本植物侵蚀相关的深层根系如何促进水和碳向更深层的运输，增加水在地下的停留时间，并增强深层风化的潜力。为了实现这一目标，将在流域尺度上进行综合野外和建模方法。数据将在康扎草原（KS， USA）收集，那里长期的燃烧实验导致木本植被被侵占。本研究依赖于：1)植被覆盖、水流流量、水同位素和水溶质化学的长期测量；2)地下的新测量，包括根系密度和分布、土壤结构、土壤水势、土壤气体浓度和溶质化学。总的来说，这项研究将水停留时间与营养物质的通量联系起来。该项目与康扎环境教育计划合作，提供有关木本植物侵占草原的教育材料和培训。为本科生和研究生开发了一个在线水质和水量模块化工具箱。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。

Within grasslands, woody plants are increasing in cover and abundance. The replacement of grasslands by woody plants can change the way water, nutrients, and metals are stored and move through soil. This project studies these changes in grasslands in Kansas. The project links the fields of water science, rock chemistry and soil chemistry. The project connects the way water moves and is stored in the ground to how soil and rock chemically breaks down. Investigating how roots of woody plants altered water flow in the ground is important to understanding how Earth will respond to future changes in climate. This research provides training across different fields of science including geology, biology, and chemistry. Educational materials will be developed for all grade levels including K-12 and college. The goal of this research is to understand how roots respond to changes in climate and land use, and how roots control the movement of water and nutrients through landscapes. Specifically, this research studies how deeper roots associated with woody plant encroachment enhances transport of water and carbon to greater depths, increases the water residence time in the subsurface, and enhances the potential for weathering at depth. To accomplish this goal, integrated field and modeling approaches will be conducted at the watershed scale. Data will be collected at the Konza Prairie (KS, USA), where long-term burning experiments have resulted in the encroachment of woody vegetation. This research relies on: 1) long-term measures of vegetation cover, stream discharge, water isotopes, and water solute chemistry, and 2) new measurements of the subsurface including root density and distribution, soil structure, soil water potential, soil gas concentrations, and solute chemistry. Collectively, this research links water residence time to fluxes of nutrients. The project partners with the Konza Environmental Education Program to provide educational materials and training on woody plant encroachment into prairies. An online modular toolbox for water quality and quantity is developed for undergraduate and graduate students.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.