了解叶绿素(Chla)对营养素的响应的敏感性(例如,氮和磷)浓度对于预测蓝藻水华风险很重要。然而,湖中的营养物质影响蓝藻生长和爆发的过程是非线性的,渐进的、空间和时间上的异质性,目前研究中提出的营养素和Chla之间浓度的单一响应阈值可能很难反映这些特征。由于三十年来区域社会经济的快速发展,中国太湖富营养化严重,每年都有蓝藻水华。在这项研究中,我们量化了不同形式的氮和磷对湖水和沉积物孔隙水中Chla浓度的相互作用影响。并提出了具有连续变化的精细响应阈值范围来表征Chla浓度与NH4-N之间的关系,总氮(TN)和总磷(TP)浓度。结果表明,TP是影响太湖大部分地区蓝藻水华空间变异的主导因子,其次是TN。因此,TP应该是太湖未来减少污染负荷的重中之重。污染因素之间的相互作用的影响大于它们单独的总和。NH4-N和溶解的无机磷(DIP)可能被藻类优先消耗以促进生长,应成为太湖养分控制工作的重点。对于蓝藻风险预测,预防和控制,NH4-N,TN和TP浓度为0.06mg/L,2.89mg/L和0.06mg/L,分别,可以用来指示太湖蓝藻水华的开始,浓度为0.34mg/L,4.67mg/L和0.11mg/L,分别,可用作参考阈值,以指示严重的蓝藻水华。
Understanding the sensitivity of the response of chlorophyll (Chla) to nutrients (e.g., nitrogen and phosphorus) concentrations is important for predicting cyanobacterial bloom risk. However, the processes by which nutrients in lake that affect cyanobacterial growth and outbreaks are nonlinear, gradual and spatially and temporally heterogeneous, and the single response thresholds of concentrations between nutrients and the Chla proposed in current studies maybe hardly reflect these characteristics. Due to three decades of rapid regional socio-economic development, the eutrophication in Taihu Lake of China is serious and there are cyanobacterial blooms every year. In this study, we quantified the interaction effects of different forms of nitrogen and phosphorus on Chla concentrations in lake water and sediment pore water. And a refined response threshold range with continuous variation was proposed to characterize the relationship between the Chla concentration and the NH4-N, total nitrogen (TN) and total phosphorus (TP) concentrations. The results showed that TP was the dominant factor influencing the spatial variation of cyanobacteria blooms in most areas of Taihu Lake, followed by TN. TP should therefore be the highest priority for future pollution load reduction in Taihu Lake. The effects of the interactions between the pollution factors were greater than the sum of them individually. NH4-N and dissolved inorganic phosphorus (DIP) are likely to be preferentially consumed by algae for growth and should be the focus of nutrient control efforts in Taihu Lake. For cyanobacterial risk prediction, prevention and control, NH4-N, TN and TP concentrations of 0.06 mg/L, 2.89 mg/L and 0.06 mg/L, respectively, can be used to indicate the beginning of cyanobacterial blooms in Taihu Lake, and concentrations of 0.34 mg/L, 4.67 mg/L and 0.11 mg/L, respectively, can be used as reference thresholds to indicate serious cyanobacterial blooms.