DISSERTATION RESEARCH: Understanding the influence of eolian dust on soils in the San Juan Mountains, CO

在过去的200年里，科罗拉多西南部的圣胡安山脉的灰尘沉积增加了500%。在高山湖泊沉积物的化学成分中，这种灰尘的增加是显而易见的，但是，目前还不清楚这些灰尘的增加是否影响了该地区的土壤化学。本研究的目的是量化的作用，粉尘沉积到土壤必需元素库相对于当地基岩风化的圣胡安山。这项研究将利用灰尘和当地基岩之间的锶同位素化学差异，以量化这些元素来源对土壤的贡献。此外，在这项研究中使用的同位素方法允许评估植物和微生物吸收的粉尘衍生元素的可用性。这项研究不仅将量化土壤中灰尘的积累，还将评估灰尘对这些土壤中植物和微生物生产力的贡献。此外，这项工作将提供深入了解灰尘的重要性，土壤形成和风化通量在很长的时间尺度。这也将有助于透视土地利用和气候变化在该地区灰尘沉积中的作用。 该项目还将为调查人员提供机会，为科罗拉多西南部传统上在此类活动中服务不足的人群提供教育和外展计划。

Dust deposition has increased by as much as 500% over the past 200 years in the San Juan Mountains for southwestern Colorado. This increase in dust is evident in alpine lake sediment chemical composition, however it is unclear if these increases in dust have influenced soil chemistry in this region. The purpose of this research is to quantify the role of dust deposition to soil essential element pools relative to the weathering of local bedrock in the San Juan Mountains. This study will exploit the difference in strontium isotope chemistry between dust and local bedrock in order to quantify the contribution of these sources of elements to soils. Furthermore, the isotopic methods used in this study allow for an assessment of the availability of the dust-derived elements for plant and microbial uptake. This research will not only quantify the accumulation of dust in soils, it will also serve to assess the contribution of dust to productivity of plants and microbes in these soils. In addition, this work will provide insight into the importance of dust for soil formation and weathering fluxes over long time-scales. This will also lend perspective to the role of changing land-use and climate in dust deposition in this region. This project will also provide the opportunity for the investigators to serve in education and outreach programs based in southwestern Colorado for populations that are traditionally underserved in such activities.