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营养和沉积物负荷的增加影响沿海生态系统的生物多样性和功能。由于缺乏长期监测数据,本研究通过古湖泊学研究方法对栖息地和硅藻多样性的时间变化进行了评估。本文研究了过去大约200年内芬兰湾水体富营养化对硅藻群落结构和物种丰度的影响。浮游硅藻丰度随水体富营养化和浊度的升高而显著增加。在总溶解氮浓度低于400～600g/L的阈值后,底部生境减少,硅藻物种丰度显著下降;数据分析表明多样性和生产力之间并不呈单峰型关系。城市样点物种丰度随19世纪末城市化进程而显著下降,由于20世纪80年代中期点源负荷的停止而使其中两个城市样点的丰度得以恢复,然而由于大集水区负荷扩散效应的影响,第三个样点的物种丰度没有恢复的迹象。农村样点的变化较小,且20世纪40年代后才开始发生变化。
Increases in nutrient and sediment load affect the biological diversity and function of coastal ecosystems. Due to the lack of long-term monitoring data, this study assessed the temporal changes in habitat and diversity of diatoms through paleoclimatic research. This paper studies the effect of eutrophication on the diatoms community structure and species abundance in the Gulf of Finland over the past 200 years or so. The abundance of diatom planktonic increases with the increase of eutrophication and turbidity. After the total dissolved nitrogen concentration was below the threshold of 400-600 g / L, the bottom habitat decreased and the species abundance of diatoms decreased significantly. The data analysis showed that there was no single peak relationship between diversity and productivity. The species richness of urban samples decreased significantly with the urbanization process at the end of the 19th century. As a result of the discontinuation of point source load in the mid-1980s, the abundance of samples in two of the cities was restored. However, due to the effect of load spreading in large catchments The third sample showed no sign of recovery of species abundance. Changes in rural areas were small and did not begin to change until after the 1940s.