Coevolution of Aeolian Landscapes and Soils

风沙景观与土壤的共同演化

• 批准号: 1920625
• 负责人: Joseph Mason
• 金额: $ 33.19万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1920625&HistoricalAwards=false
• 关键词: Coevolution; Aeolian; Landscapes; Soils

This project will focus on grass-stabilized sand dunes and loess landscapes (areas of thick wind-blown dust deposits) in the Great Plains, to determine how processes that shaped these landscapes in the past will influence their response to future climate change, especially more frequent severe drought or heavy rainfall. The research will test whether soil formation over hundreds to thousands of years, including accumulation of organic matter and fine dust, can significantly reduce the susceptibility of certain parts of these landscapes to wind and water erosion. The results will be important for predicting patterns of future accelerated erosion and dune activation, with major practical implications, since the level tablelands of the loess landscapes are prime agricultural land and the dunes are important rangeland and key recharge areas for the Ogallala Aquifer. Increased erosion could also affect sediment input to streams and release carbon stored in buried and surface soils in these landscapes. The project will provide research training to a diverse group of students and will include development of effective ways to communicate the results to local communities and other stakeholders.The project will test hypotheses on the interactions between geomorphic processes and soil formation in the evolution of loess tablelands and adjacent dune fields. The hypotheses propose that aeolian processes (deflation, slow loess accumulation, and dune activity) influence spatial patterns of soil formation and organic carbon accumulation, which in turn influence thresholds for wind and water erosion through effects on vegetation resilience and mechanical strength. Study sites will be selected to allow comparison of soil and sediment properties related to nutrient and water availability and shear strength on tableland summits and adjacent slopes with varying soil development and recent loess accumulation, and on dunes with varying soil development. Field and lab measurements will be combined with modeling of soil hydrology, geospatial analyses, and luminescence dating.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.

该项目将侧重于大平原的草稳定沙丘和黄土地貌（厚的风吹尘沉积区），以确定过去塑造这些地貌的过程将如何影响它们对未来气候变化的反应，特别是更频繁的严重干旱或暴雨。该研究将测试数百至数千年的土壤形成，包括有机物和细尘的积累，是否可以显着降低这些景观某些部分对风蚀和水蚀的敏感性。结果将是重要的预测模式，未来加速侵蚀和沙丘活化，具有重大的实际意义，因为黄土景观的水平台地是主要的农业用地和沙丘是重要的牧场和奥加拉拉含水层的关键补给区。侵蚀加剧也可能影响河流的沉积物输入，并释放储存在这些景观中的埋藏和表层土壤中的碳。该项目将向不同的学生群体提供研究培训，并将包括制定向当地社区和其他利益攸关方通报研究结果的有效方法，该项目将检验关于黄土高原和邻近沙丘演变过程中地貌过程与土壤形成之间相互作用的假设。这些假说提出，风沙过程（通货紧缩，缓慢的黄土堆积，沙丘活动）影响土壤形成和有机碳积累的空间格局，这反过来又影响阈值的风和水的侵蚀，通过影响植被恢复力和机械强度。将选择研究地点，以便比较与土壤发育不同和最近黄土堆积的台地山顶和邻近山坡以及土壤发育不同的沙丘上的养分和水的可用性以及抗剪强度有关的土壤和沉积物特性。该奖项反映了NSF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。

项目成果

Hydrology of a Semiarid Loess‐Paleosol Sequence, and Implications for Buried Soil Connection to the Modern Climate, Plant‐Available Moisture, and Loess Tableland Persistence

• DOI: 10.1029/2022jf006800
• 发表时间: 2022-12
• 期刊: Journal of Geophysical Research: Earth Surface
• 作者: T. McDowell;J. Mason;T. Vo;E. Marín-Spiotta