Nitrogen and phosphorus limitation and the management of small productive lakes
Nitrogen and phosphorus limitation and the management of small productive lakes
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DOI：
10.1080/20442041.2020.1714384
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发表时间：
2020-03-24
期刊：
影响因子：
3.1
通讯作者：
Carvalho, Laurence
中科院分区：
文献类型：
--
作者：
Maberly, Stephen C.;Pitt, Jo-Anne;Carvalho, Laurence
许多内陆沃茨富含营养物质，对生态造成有害影响，并为社会带来好处，但对其进行有效管理首先需要确定限制藻类生产的营养物质。营养物质和叶绿素a（Chl-a）的浓度被用来评估两个时间段内17海里的营养限制：历史（2005-2009; 1995-1998年在一个地点）和当代（2014-2018）。采用了不同的方法来评估养分限制，因为它们反映了养分供应及其转化为生物量的不同方面。在历史时期，3个海区为磷限制海区，3个海区为氮限制海区，5个海区为共限制海区，6个海区为非营养限制海区。在此期间，使用浮游植物叶绿素a的生态状况评估仅在2个站点处于良好或较高的生态状况（从水框架指令的角度来看）。当代略有改善，有4个站点处于良好状态。在网站，未能满足良好的生态状况，所需的减少磷浓度是最少的磷有限的网站，相反，减少氮是最少的氮有限的网站，这表明，修复营养减少将是最有效的，如果它是有针对性的使用特定网站的信息。即使在主要是P有限的网站，一旦输入的P已经减少，进一步的生态效益减少N在目标网站应探讨。
Many inland waters are enriched with nutrients, causing deleterious effects to their ecology and the benefits they provide for society, but their effective management first requires identification of the nutrient(s) that limit algal production. Concentrations of nutrients and chlorophyll a (Chl-a) were used to assess nutrient limitation seasonally at 17 meres over 2 time periods: historic (2005-2009; 1995-1998 at one site) and contemporary (2014-2018). Different approaches were used to assess nutrient limitation because they reflect different aspects of nutrient availability and their conversion into biomass. In the historic period, 3 meres were phosphorus (P) limited, 3 nitrogen (N) limited, 5 co-limited; the remaining 6 meres were not nutrient limited. For this period, ecological status assessed using phytoplankton Chl-a was only at good or high ecological status (sensu the Water Framework Directive) at 2 sites. The contemporary period was slightly improved, with 4 sites at good status. At the sites that failed to meet good ecological status, the required reduction in P concentration was least in P-limited sites and, conversely, the reduction in N was least in N-limited sites, suggesting that remediation by nutrient reduction would be most efficient if it was targeted using site-specific information. Even in primarily P-limited sites, once input of P has been reduced, further ecological benefit of reducing N at targeted sites should be explored.