Abiotic Controls on the Tropic Status of Oligotrophic Water

本研究将调查原来自土壤的元素铝（Al）和磷(P)如何在通过土壤孔隙流向下游湖泊的水中相互作用，从而阻止磷在地表水中被藻类生物利用。这会导致营养不良状况（即，水的营养浓度非常低）。如果酸性较低，固体氢氧化铝将吸附并永久捕获水中的磷。“酸雨”、气候变化或其他因素引起的地表水酸度的变化应引起Al和P相互作用的变化，从而引起地表水生物生产力的变化。这些水质反应将通过实验室和实地实验、在四个长期流域地点（缅因州、西弗吉尼亚州和捷克共和国）进行的研究以及面向动态过程的数学模型进行调查。磷通常是溪流和湖泊中生物的限制性营养物质。从自然来源或人类活动中向地表水过量供应磷会导致富营养化（高生产力水），这种情况可能会产生不良影响。许多地表水的磷供应是高的，但大部分磷不能为生物群所利用，造成贫营养状况。这项研究将解释生态系统中磷通量高，但相关地表水营养状况的难题。

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.