Identification and Role of Low Molecular Weight Organic Acids in a Subalpine Ecosystem

亚高山生态系统中低分子量有机酸的鉴定和作用

• 批准号: 8718149
• 负责人: Fiorenzo Ugolini
• 金额: $ 32.36万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-05-01 至 1993-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8718149&HistoricalAwards=false
• 关键词: Identification; Role; Low; Molecular; Weight

The origin and identity of low molecular weight organic acids in soils will be studied in coniferous ecosystems in the Pacific Northwest. These acids along with fulvic acids may drive the soil formation process, podsolization, in these ecosystems. Some of these acids may control the availability of Ca and Al to plants from soil solution. The work could go a long way toward explaining the tolerance of conifers to high Al soils and to the maintenance of available Ca in the rhizosphere under these conditions. The work is also significant to understanding what controls the concentrations of dissolved organic carbon and Al that move from the soil to streams in the forested landscape. Three potential sources of organic acids will be examined; root exudates, decaying organic matter, and mycorrhizal fungi. Both field and laboratory studies of organic acid sources will be undertaken. Field research will include comparison of organic acids in soils of root-free and control plots. Soil solutions will be sampled by lysimetry and extractions. A variety of state-of-the-art techniques will be used to identify low molecular weight acids. These techniques include gas chromatography, high pressure liquid chromatography and GC/MS. The forms in which Al exist in the soil-root matrix will be determined using a special application of electron microscopy. Dr. Ugolini has an outstanding research record in this area. The institutional support available to him at the University of Washington is first-rate.

中低分子量有机酸的来源和鉴别 将研究太平洋针叶林生态系统中的土壤 西北 这些酸沿着富里酸， 在这些生态系统中，土壤形成过程，即灰化。 一些 这些酸可以控制钙和铝的可用性， 植物从土壤溶液。 这项工作可以大大有助于 解释针叶树对高铝土壤和土壤的耐受性 根际有效钙的维持 条件 这项工作对于理解 控制溶解有机碳和铝的浓度 从土壤中迁移到森林景观中的溪流中。 三个潜在的有机酸来源将被检查;根 分泌物、腐烂的有机物和菌根真菌。 两 有机酸源的现场和实验室研究将 进行。 实地研究将包括比较有机 无根和对照地块土壤中的酸。 土壤溶液 将通过溶渗法和浸提进行采样。 将使用各种最先进的技术来识别 低分子量酸。 这些技术包括气体 色谱法、高压液相色谱法和GC/MS。 铝在土壤-根系基质中的存在形式为 使用电子显微镜的特殊应用确定。 Ugolini博士在这一领域有着出色的研究记录。 的 他在牛津大学获得的机构支助 华盛顿是一流的。