Dissertation Research: Contributions of Charophycean Algae & Sphagnum Moss to Long-term Carbon Storage in Boreal Peatlands. Dissolved Organic Carbon Uptake & Carbon

格雷厄姆北方泥炭地是公认的碳积累场所。 最近的数据表明存在两种以前未定量评估的潜在碳保留机制，即溶解有机碳（以糖的形式）的吸收和利用，以及轮藻和泥炭藓产生抗降解细胞壁多酚。 第一个过程从环境中去除固定碳的可靠形式，而第二个过程则产生相对长期储存形式的碳。 这两个过程都会干扰细菌将固定碳转化回二氧化碳的能力，从而促进泥炭地碳积累。 培养的轮藻和泥炭藓将用于糖转运基因的克隆和测序以及基因表达研究。 轮藻多样性和生物量的现场数据将与 pH、DOC、DIC 和细菌生物量的现场测量值以及使用实验室培养物测量的加载糖和产生多酚壁化合物的物种特异性能力相关联。 还将对泥炭藓抗性壁材料的生产和原丝阶段 DOC 的利用进行评估。 该项目的目标是改进对泥炭地固碳量的估计。

Graham Boreal peatlands are a recognized site of carbon accumulation. Recent data suggests the occurrence of two potential mechanisms for carbon retention that have not previously been quantitatively assessed, namely, the uptake and utilization of dissolved organic carbon (in the form of sugars), and production of degradation-resistant cell wall polyphenolics by charophytes and Sphagnum moss. The first of these processes removes liable forms of fixed carbon from the environment, while the second generates relatively long-term storage forms of carbon. Both processes interfere with the ability of bacteria to convert fixed carbon back to CO2, and thus contribute to peatland carbon accumulation. Cultured charophytes and Sphagnum will be used for cloning and sequencing of sugar transport genes, and for gene expression studies. Field data for charophyte diversity and biomass will be correlated with field measurements of pH, DOC, DIC, and bacterial biovolumes, and with species-specific abilities to load sugars and generate polyphenolic wall compounds measured with the use of laboratory cultures. Assessments of Sphagnum production of resistant wall materials and utilization of DOC by protonematal stages will also be made. The goal of the project is to improve estimates for the amount of carbon sequestered in peatlands.