Chemodiversity of Cyanobacterial Toxins Driven by Future Scenarios of Climate Warming and Eutrophication.
Chemodiversity of Cyanobacterial Toxins Driven by Future Scenarios of Climate Warming and Eutrophication.
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DOI：
10.1021/acs.est.3c02257
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发表时间：
2023-08
影响因子：
11.4
通讯作者：
Yalan Yang;Huan Wang;Shuwen Yan;Tao Wang;Peiyu Zhang;Huan Zhang;Hongxia Wang;L. Hansson
中科院分区：
文献类型：
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作者：
Yalan Yang;Huan Wang;Shuwen Yan;Tao Wang;Peiyu Zhang;Huan Zhang;Hongxia Wang;L. Hansson
气候变化和富营养化是两种可能改变淡水生态系统结构及其服务功能的环境威胁，但我们对未来气候变暖情景下生态系统结构和功能将如何演变知之甚少。因此，我们创建了不同的实验气候情景，包括目前的条件，平均气温上升3.0°C，以及“热浪”情景(即，温度变异性增加)，以评估气候变化对富营养化和除草剂同时压力下浮游植物群落的影响。我们发现，气候变暖的影响，特别是热浪，与蓝藻丰度和毒素产生的增加有关，这是由微囊藻从主要无毒转变为有毒的驱动因素。蓝藻毒素浓度较高的原因可能是数量增加，因为在气候变暖和富营养化的双重压力下，单个微囊藻的毒素产生能力下降。富营养化和较高的温度显著增加了微囊藻的生物量，导致蓝藻毒素浓度的增加。相比之下，单单变暖并没有产生更高的蓝藻丰度或蓝藻毒素浓度，这可能是由于可用的营养库耗尽所致。同样，除草剂草甘膦本身并不影响任何浮游植物类群的丰度。在营养丰富的情况下，由于潜在的蓝藻毒素生产者的生物量大幅增加，蓝藻毒素浓度比仅在变暖下高得多。从更广泛的角度来看，我们的研究表明，在未来气候变暖的情况下，如果要控制有毒蓝藻的优势，就必须减少营养负荷。
Climate change and eutrophication are two environmental threats that can alter the structure of freshwater ecosystems and their service functions, but we know little about how ecosystem structure and function will evolve in future scenarios of climate warming. Therefore, we created different experimental climate scenarios, including present-day conditions, a 3.0 °C increase in mean temperature, and a "heatwaves" scenario (i.e., an increase in temperature variability) to assess the effects of climate change on phytoplankton communities under simultaneous stress from eutrophication and herbicides. We show that the effects of climate warming, particularly heatwaves, are associated with elevated cyanobacterial abundances and toxin production, driven by a change from mainly nontoxic to toxic Microcystis spp. The reason for higher cyanobacterial toxin concentrations is likely an increase in abundances because under the dual pressures of climate warming and eutrophication individual Microcystis toxin-producing ability decreased. Eutrophication and higher temperatures significantly increased the biomass of Microcystis, leading to an increase in the cyanobacterial toxin concentrations. In contrast, warming alone did not produce higher cyanobacterial abundances or cyanobacterial toxin concentrations likely due to the depletion of the available nutrient pool. Similarly, the herbicide glyphosate alone did not affect abundances of any phytoplankton taxa. In the case of nutrient enrichment, cyanobacterial toxin concentrations were much higher than under warming alone due to a strong boost in biomass of potential cyanobacterial toxin producers. From a broader perspective our study shows that in a future warmer climate, nutrient loading has to be reduced if toxic cyanobacterial dominance is to be controlled.