Particulate organic carbon formation and phosphorus/iron supply ratios along pH and trophic gradients in lakes

湖泊中沿 pH 值和营养梯度变化的颗粒有机碳形成和磷/铁供应比

• 批准号: 238800-2007
• 负责人: Molot, Lewis
• 金额: $ 1.12万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2009
• 资助国家: 加拿大
• 起止时间: 2009-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=425675
• 关键词: Particulate; organic; carbon; formation; phosphorus

Globally, lake sediments store a very large amount of carbon. The presence of algal remains in sediments such as pigments, cell walls, etc indicates that sediment carbon is partially derived from algae. However, evidence shows that algal carbon is readily mineralized by the microbial community so it appears that there must be a major non-biological source of sediment carbon. During the last grant cycle, work in my laboratory demonstrated that irradiation of acidic stream waters with artificial sunlight resulted in formation of particulate organic carbon (POC) from dissolved organic carbon (DOC) and that formation of particulate iron played a major role, probably because DOC adheres to the surface of newly formed particulate iron. We hypothesize that this mechanism plays a major role in transferring DOC to sediments. The first part of this proposal seeks to extend this work by examining the extent of POC formation in acidic and non-acidic waters in the absence of UVB.

在全球范围内，湖泊沉积物储存了大量的碳。沉积物中存在藻类残留物，如色素、细胞壁等，表明沉积物中的碳部分来源于藻类。然而，有证据表明，藻类碳很容易被微生物群落矿化，因此，沉积物碳似乎有一个主要的非生物来源。在上一个资助周期中，我的实验室的工作证明，用人造阳光照射酸性水流导致溶解有机碳（DOC）形成颗粒有机碳（POC），颗粒铁的形成起了主要作用，可能是因为DOC附着在新形成的颗粒铁的表面。我们假设这一机制在DOC向沉积物转移中起主要作用。本提案的第一部分旨在通过检查在没有UVB的酸性和非酸性水域中POC形成的程度来扩展这项工作。