Rapid Recovery from Eutrophication of a Stratified Lake by Disruption of Internal Nutrient Load
Rapid Recovery from Eutrophication of a Stratified Lake by Disruption of Internal Nutrient Load
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DOI：
10.1007/s10021-008-9185-5
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发表时间：
2008-11-01
期刊：
影响因子：
3.7
通讯作者：
Wauer, Gerlinde
中科院分区：
文献类型：
--
作者：
Mehner, Thomas;Diekmann, Markus;Wauer, Gerlinde
生态系统的恢复是困难的，由于反馈机制，稳定的营养退化状态。在这里，我们显示了快速恢复的富营养化分层湖泊响应多个恢复，针对高的外部和内部营养负荷的反馈机制，缺乏营养级联，缺乏结构化的沿岸的栖息地。蒂夫瓦伦湖（德国）暴露于铝和钙处理和渔业管理超过5年。在此期间，在湖泊磷浓度下降了80%以上，透明度，浮游动物生物量和鱼类组合结构和生物量立即响应，几乎线性磷浓度的减少。浮游植物生物量和叶绿素a（chl a）浓度同样因恢复而下降，但下降趋势被浮游植物生物量异常高的恢复年打断。浮游动物：浮游植物的生物量比和叶绿素a：磷的比例接近其他分层湖泊在自然恢复过程中观察到的值。Tiefwarensee对外部负荷减少的缓慢响应和对化学处理的快速响应表明，内部P循环和负荷的中断是Tiefwarensee的决定性恢复措施。至少在短期内，减少外部负荷是必要的，但不是充分的措施，而低努力量渔业管理则不太重要。与其他案例研究的比较证实，措施，旨在补充磷是最有效的方法，以恢复分层湖泊在短期内，但转移到一个永久的近原始状态是可能的，只有通过额外的P输入控制。
Restoration of anthropogenically eutrophied lake ecosystems is difficult due to feedback mechanisms that stabilize the trophically degraded state. Here, we show rapid recovery of a eutrophic stratified lake in response to multiple restoration that targeted the feedback mechanisms of high external and internal nutrient loads, lack of a trophic cascade, and lack of structured littoral habitats. Lake Tiefwarensee (Germany) was exposed to aluminium and calcium treatment and fisheries management over 5 years. Within this period, in-lake phosphorus concentrations declined by more than 80%, and transparency, zooplankton biomass and fish assemblage structure and biomass responded immediately and almost linearly to the reduction in phosphorus concentrations. Phytoplankton biomass and chlorophyll a (chl a) concentrations likewise decreased in response to restoration, but the declining trend was interrupted by one recovery year with unusually high phytoplankton biomasses. The zooplankton:phytoplankton biomass ratio and the chl a:phosphorus ratio approached values observed in other stratified lakes during natural recovery from eutrophication. The slow response of Tiefwarensee to the reduction of external load, and the quick response to the chemical treatment suggest that the disruption of internal P recycling and loading was the decisive restoration measure in Tiefwarensee. The external load reduction was a necessary but not sufficient measure, at least in the short-term, whereas the low-effort fisheries management was of minor importance. A comparison with other case studies confirms that measures aiming to inactivate phosphorus are the most efficient approaches to restore stratified lakes in the short-term, but a shift to a permanent near-pristine state is possible only by additional P input control.