Collaborative Research: NSFGEO-NERC: Aeolian dust responses to regional ecosystem change

概述：拟议的研究将建立粉尘排放对北美区域生态系统变化的响应，这是由于三种干扰制度：1)与能源（石油和天然气）开发相关的众多离散的、小规模的（<10公顷）、突然的生态系统变化；2)离散的、大规模的（1000公顷）、与火和生态反馈相关的突发性生态系统变化，促进了入侵草和改变了火-风侵蚀制度；3)与荒漠草原持续灌木入侵相关的弥漫性、大尺度（1000公顷）、广泛性生态系统变化。基于遥感和大尺度标准化生态数据集驱动的新型沙尘排放模型将用于解决土壤和植被-风沙相互作用的机制。这些模型将使用来自国家风蚀研究网络观测站的数据进行校准，然后应用于探索研究区域的粉尘排放模式。国家生态数据集将用于分析驱动因素和解释沙尘排放对区域生态系统变化的响应。知识价值：本提案探讨了地貌机制和区域生态系统变化（土地利用和土地覆盖变化）对北美沙尘排放量的影响。源自北美沙漠的沙尘对人类健康、交通系统、水资源、农业生产及其对生物地球化学循环和气候的反馈产生深远影响，具有重要的区域性意义。由于干旱、土地利用和管理压力以及气候变化，沙源地区正在经历生态系统结构和功能的变化。样地尺度的研究探索了旱地植被变化与风成过程之间的相互作用。然而，生态系统变化对当前和未来区域粉尘排放的意义尚未在大范围内确定。这项研究将改变我们对人类土地利用压力和自然干扰如何影响区域粉尘排放的不同类型生态系统变化的理解。研究结果将显著提高我们对沙尘循环与生态系统变化的人为驱动因素之间耦合关系的理解。

Overview: The proposed research will establish dust emission responses to regional ecosystem change across North America due to three disturbance regimes: 1) numerous discrete, small scale (<10 ha), abrupt ecosystem changes associated with energy (oil and gas) development; 2) discrete, large scale (>1000 ha), abrupt ecosystem change associated with fire and ecological feedbacks that promote invasive grasses and altered fire-wind erosion regimes; and 3) diffuse, large scale (>1000 ha), pervasive ecosystem changes associated with sustained shrub invasion of desert grasslands. New dust emission models driven by remote-sensing and broad-scale standardized ecological datasets will be used to resolve the mechanics of soil and vegetation-aeolian transport interactions. The models will be calibrated using data from National Wind Erosion Research Network observatory sites, then applied to explore patterns of dust emission across the study regions. National ecological datasets will be used to analyze the drivers and interpret dust emission responses to regional ecosystem changes across the disturbance regimes. Intellectual Merit: This proposal examines the geomorphic mechanisms and impacts of regional ecosystem change (land use and land cover change) on the magnitude of North American dust emission. Dust originating from North American deserts is regionally important for its profound impacts on human health and transportation systems, water resources, agricultural production, and its feedbacks to biogeochemical cycling and climate. Dust source regions are experiencing changes in ecosystem structure and function due to drought, land use and management pressures, and climate change. Plot-scale research has explored the interactions between vegetation change and aeolian processes in drylands. However, the significance of ecosystem changes for current and future regional dust emissions has not been established over large areas. This research will transform our understanding of how different types of ecosystem change due to human land-use pressures and natural disturbances impact regional dust emissions. Findings will significantly improve our understanding of the coupling between the dust cycle and anthropogenic drivers of ecosystem change.