Abiotic Controls on the Tropic Status of Oligotrophic Water

对贫营养水热带状态的非生物控制

• 批准号: 0415348
• 负责人: Stephen Norton
• 金额: --
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0415348&HistoricalAwards=false
• 关键词: Abiotic; Controls; Tropic; Status; Oligotrophic

This research will investigate how the elements aluminum (Al) and phosphorus (P), both originally from soil, interact in water moving through soil pores to downstream lakes in ways that prevent P from being biologically available to algae in surface waters. This causes oligotrophic conditions (i.e., water with very low nutrient concentrations). Solid aluminum hydroxide will adsorb and can permanently capture P from the water if the acidity is low. Changes in the acidity of surface waters from "acid rain", climate change, or other factors should induce changes in the interaction between Al and P, and thus changes in the biological productivity of surface waters. These water quality responses will be investigated with laboratory and field experiments, studies at four long-term watershed sites (in Maine, West Virginia, and the Czech Republic), and dynamic process-oriented mathematical models.Phosphorus is commonly the limiting nutrient for organisms in streams and lakes. An excessive supply of P to surface water from natural sources or human activities can cause eutrophication (highly productive water), a condition that can have undesirable effects. The supply of P to many surface waters is high, but the majority of the P is not available for biota, causing oligotrophic conditions. This research will explain the conundrum of high fluxes of P in ecosystems, yet oligotrophic conditions in associated surface waters.

这项研究将调查元素铝（Al）和磷（P），都来自土壤，如何在水通过土壤孔隙移动到下游湖泊的方式，防止P被生物可利用的藻类在表面沃茨相互作用。这导致贫营养状况（即，营养物质浓度极低的水）。如果酸度低，固体氢氧化铝将吸附并可以永久捕获水中的P。“酸雨”、气候变化或其他因素引起的地表沃茨酸度的变化应引起Al和P之间相互作用的变化，从而引起地表沃茨生物生产力的变化。这些水质响应将通过实验室和现场实验、在四个长期集水区（缅因州、西弗吉尼亚州和捷克共和国）的研究和面向动态过程的数学模型进行调查。从自然来源或人类活动向地表水过量供应磷可导致富营养化（高产水），这是一种可能产生不良影响的状况。许多表层沃茨的磷供应量很高，但大部分磷不能为生物群所利用，造成贫营养状况。这项研究将解释的难题，高通量的磷在生态系统中，但贫营养的条件下，在相关的表面沃茨。