Dissertation Research: A Study of the Relationship of Climate and Vegetation to the Stable Isotope Chemistry of Soils in Grassland Ecosystems of the Great Plains

研究大平原气候、植被与草地土壤稳定同位素化学的关系。已经选择了六个不同温度、水分和植被状况的研究地点，并将监测生物量产生、粉尘积累和土壤二氧化碳产生。这一背景信息与气候资料相结合，将为解释这些土壤中的碳酸盐三角洲13C和180提供依据。本研究的主要目的是研究蛋白石植硅体的13C数据和闭塞碳的化学组成。将检测从土壤中提取的蛋白石叶状岩的三角洲13C，并将确定它是否代表C3与C4植被的比率以及土壤有机质的三角洲13C。这项工作将证明蛋白石植硅体以及土壤成因碳酸盐作为古环境重建研究的工具的适宜性。这项研究应具有基础性的生态学意义，并有可能为土壤科学提供一种重要的新方法。生态系统研究计划建议提供支持。

A study of the relationship of climate and vegetation to the stable isotope chemistry of grassland soils in the Great Plains will be conducted. Six study sites in differing temperature, moisture, and vegetation regimes have been selected and will be monitored for biomass production, dust accumulation, and soil CO2 production. This background information, in conjunction with climatic data, will provide a basis for interpreting the delta 13C and delta 180 of pedogenic carbonate in these soils. An investigation of the data 13C and chemical composition of occluded C in opal phytoliths is the major goal of this research. The delta 13C of opal phyoliths extracted from the soil will be examined and it will be determined whether it represents the ratio of C3 to C4 vegetation and the delta 13C of the soil organic matter. The work will demonstrate the suitability of opal phytoliths, as well as pedogenic carbonate, as tools in paleoenvironmental reconstruction studies. This research should be of fundamental ecological importance as well as potentially useful in providing a significant new method for soil science in general. The Ecosystem Studies Program recommends support.