Dissolved organic matter dynamics in stream ecosystems

河流生态系统中溶解有机物的动态

• 批准号: RGPIN-2014-06526
• 负责人: Xenopoulos, Marguerite
• 金额: $ 1.97万
• 依托单位: Trent University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=631926
• 关键词: Dissolved; organic; matter; dynamics; stream

One of the most obvious environmental changes caused by humans is the alteration of the landscape. Usuallythis involves the reduction of forested cover at the expense of agricultural and urban areas. Almost inevitably,these changes in land use affect the quality and quantity of surface and subsurface waters because of alteredconnections between the land and water. For rivers in these landscapes, new landscape connections can modifyorganic matter (generally measured in carbon units as dissolved organic carbon, DOC) which now originatesprimarily from agricultural crops, manure and urban waste instead of natural vegetation, soils and wetlands.Novel linkages with modified landscape and rivers also change the chemistry of river carbon, which canchange the healthy functioning of our rivers. In this project, I will examine how the DOC changes in qualityand quantity in river watersheds of contrasting land use from the Great Lakes Basin in South-central Ontario.These data will be used to further examine how land use alterations of physical (e.g., streamflow), chemical(e.g., nutrients), and biological (e.g., stream foodwebs) alter the processing and export of DOC. In doing so, Iwill test how agriculturally and urban-derived DOC and nutrients affects microbial growth, food webcomposition, and ecosystem function such as the decay of materials (leaf-litter), nutrient uptake by algae andnitrogen recycling. Finally, I will test for river DOC responses to climate change because these might beaffected by periods of warm weather and drought. This research will help us understand how human-derivedmaterials (agricultural fertilizers and residential waste) will affect the health and integrity of aquatic systems.

人类引起的最明显的环境变化之一是景观的改变。通常这涉及以牺牲农业和城市地区为代价来减少森林覆盖率。由于土地与水之间联系的改变，土地利用的这些变化几乎不可避免地影响地表水和地下水的质量和数量。对于这些景观中的河流，新的景观连接可以改变有机物质（通常以碳单位作为溶解有机碳，DOC 来衡量），有机物质现在主要来自农作物、粪便和城市废物，而不是自然植被、土壤和湿地。与改良景观的新联系河流也会改变河流碳的化学成分，从而改变河流的健康运转。在这个项目中，我将研究安大略省中南部五大湖盆地对比土地利用的河流流域中 DOC 的质量和数量如何变化。这些数据将用于进一步研究物理（例如，水流）的土地利用变化如何）、化学（例如营养物质）和生物（例如水流食物网）改变了 DOC 的加工和出口。在此过程中，我将测试农业和城市产生的 DOC 和营养物质如何影响微生物生长、食物网组成和生态系统功能，例如材料（落叶层）的腐烂、藻类对营养物质的吸收和氮循环。最后，我将测试河流 DOC 对气候变化的反应，因为这些可能会受到温暖天气和干旱时期的影响。这项研究将帮助我们了解人类来源的材料（农业肥料和生活垃圾）将如何影响水生系统的健康和完整性。