1、第 1 页 中文 4700 字， 2980 单词， 16700 英文字符 出处： Progress in Natural Science 19 (2009) 1445 1451 原 文 Mitigation of Lake Eutrophication: Loosen Nitrogen Control and Focus On Phosphorus Abatement Haijun Wang, Hongzhu Wang Abstract Traditionally, nitrogen control is generally considered an important component
2、of reducing lake eutrophication and cyanobacteria blooms. However, this viewpoint is refuted recently by researchers in China and North America. In the present paper, the traditional viewpoint of nitrogen control is pointed out to lack a scientific basis: the N/P hypothesis is just a subjective assu
3、mption; bottle bioassay experiments fail to simulate the natural process of nitrogen fixation. Our multi-year comparative research in more than 40 Yangtze lakes indicates that phosphorus is the key factor determining phytoplankton growth regardless of nitrogen concentrations and that total phytoplan
4、kton biomass is determined by total phosphorus and not by total nitrogen concentrations. These results imply that, in the field, nitrogen control will not decrease phytoplankton biomass. This finding is supported by a long-term whole-lake experiment from North America. These outcomes can be generali
5、zed in terms that a reduction in nitrogen loading may not decrease the biomass of total phytoplankton as it can stimulate blooms of nitrogen-fixing cyanobacteria. To mitigate eutrophication, it is not nitrogen but phosphorus that should be reduced, unless nitrogen concentrations are too high to indu
6、ce direct toxic impacts on human beings or other organisms. Finally, details are provided on how to reduce controls on nitrogen and how to mitigate eutrophication. Keywords Lake eutrophication; Cyanobacteria bloom 1. Introduction Eutrophication of waters is the phenomenon of an ecosystem becoming more productive by nutrient enrichment, stimulating primary producers. It is usually characterized by algal blooms, causing water quality deterioration and fish kills. It is becoming a global en
