Sand Hills Biocomplexity: Integrating Biogeophysical Processes across Space and Time

这个项目解决了在过去的几千年里，58,000平方公里的内布拉斯加沙丘，西半球最大的沙丘地区，沙，草和水之间的相互作用。地质记录表明，沙山在全新世经历了几次荒漠化和恢复的循环，大多数沙丘被认为不到9000年。今天，沙丘几乎完全被天然草原所稳定。重大干旱不稳定的重要部分的沙丘，最近1000年前，本，但沙丘一直保持其草覆盖，并在随后的几次区域性drugs.The研究抵抗动员在这里提出的将启动一个大规模的操纵实验，以测试四个假设的影响植被破坏地下水补给。再加上微气象测量的地表能量通量，结果将提供输入（去）植被的陆地表面和区域气候之间的反馈的中尺度模拟方案。研究人员还将利用光激发光测年法绘制过去2500年沙丘活动的空间格局，湖泊沉积物分析提供了过去干旱的更高分辨率（年代际）记录。该系统将作为一个模型，用于研究地球物理过程如何相互作用，以产生景观抵抗力和生态恢复力。沙山的结构相对简单，面积大到足以影响边界层动力学。这将是第一个使用这样一个综合的、跨学科的项目来了解沙丘的项目。来自古生态学、地貌学、生态学、地理空间分析和气象学等学科的一系列科学家已经聚集在一起完成这项任务。 在更广泛的影响方面，该项目可以作为一个模型系统，在K-12以及大学水平的复杂的环境变化的跨学科教学。非线性和反馈是非常真实的任何人走过这一景观，特别是在最近的沙丘井喷。该项目将结合一个已经成功的K-12科学教师网络，包括科学教育工作者的暑期实习和研讨会，以及一个带有数据可视化工具的网站，将数据交给学生。该项目还将培训30多名研究生和本科生实习生，使他们了解当代环境科学的广度。

This project addresses the interactions among sand, grass, and water over 58,000 km2 Nebraska Sand Hills, the largest sand dune area in the Western Hemisphere, over the last few thousand years. The geologic record indicates that the Sand Hills have gone through cycles of desertification and restoration several times in the Holocene and most dunes are thought to be less than 9000 years old. Today the dunes are almost entirely stabilized by native grasslands. Major droughts destabilized significant portions of the Sand Hills as recently as 1000 years before the present, but the dunes have maintained their grass cover and resisted mobilization during several subsequent regional droughts.The research proposed here would initiate a large-scale manipulative experiment to test four hypotheses regarding the effect of devegetation on groundwater recharge. Coupled with micrometeorological measurements of surface energy fluxes, the results will provide inputs for mesoscale modeling scenarios of the feedbacks between the (de-)vegetated land surface and the regional climate. The investigators will also use optically stimulated luminescence dating to map the spatial pattern of dune field activity during the last 2500 years, with lake sediment analyses providing a more high resolution (decadal) record of past droughts.This system will serve as a model for how biogeophysical processes interact to yield landscape resistance and ecological resilience. The structure of the Sand Hills is relatively simple and the area large enough to influence boundary layer dynamics. This will be the first project to understand the Sand Hills using such an integrated, cross-disciplinary project. A range of scientists from such disciplines as paleoecology, geomorphology, ecology, geospatial analysis, and meteorological has been assembled for this task.. In terms of Broader Impacts, this project can serve as a model system for interdisciplinary teaching about complex environmental change both at the K-12 as well as university levels. Nonlinearities and feedbacks are very real to anyone walking through this landscape, especially after recent dune blowouts. The project will incorporates an already successful ongoing K-12 science teacher network, including summer internships and workshops for science educators, and a web site with data visualization tools that puts data in the hands of students. The project will also train over 30 graduate students and undergraduate interns, exposing them to the breadth of contemporary environmental science.