DISSERTATION RESEARCH: Dissolved Organic Matter Controls on Terrestrial Carbon Sequestration and Export

摘要土壤碳循环通常以植物光合作用输入的碳和土壤腐殖物质积累的异养呼吸平衡为特征。 淋溶在土壤有机质的分解、迁移、稳定和损失中的作用很少在地下碳循环的概念或数值模型中得到体现。 尽管已知淋溶是潮湿森林土壤中大量矿物质和营养元素迁移和损失的主要机制，但情况仍然如此。 本研究旨在量化（a）溶解有机碳（DOC）在土壤中的通量和储存（B）的季节变化的碳输出到流从两个对比鲜明的沿海加州生态系统。 将监测进入、穿过土壤、在渠首和水系中流出的水通量，同时将分析溶液样品的碳浓度、成分和年龄。 我们将耦合DOC通量的信息，以详细分析土壤碳的空间分布，其相对丰度，年龄和营业额。

AbstractThe soil carbon cycle is commonly characterized by photosynthetic inputs of carbon by plants balanced by heterotrophic respiration of accumulated soil humic substances. The role of leaching in decomposition, transport, stabilization and loss of soil organic matter is rarely represented in conceptual or numerical models of belowground carbon cycling. This is despite the fact that leaching is known to be a dominant mechanism of transport and loss of numerous mineral and nutritive elements in humid forest soils. This study seeks to quantify (a) the fluxes and storage of dissolved organic carbon (DOC) in the soil and (b) the seasonal changes in the rate of carbon export to streams from two contrasting coastal California ecosystems. Water fluxes entering, moving through the soil, exiting at the channel head and in the stream networks will be monitored, while solution samples will be analyzed for carbon concentration, composition and age. We will couple this information on DOC fluxes to detailed analyses of the spatial distribution of soil carbon, its relative recalcitrance, age and turnover.