| 摘要: |
| 在社会经济发展和流域开发持续的背景下,砷污染已成为我国部分水体面临的重要环境问题,目前对砷污染防控的生态效应与修复效果评价仍缺乏系统识别。湖泊生态系统中浮游植物是重要的生产者,砷等重金属污染可以直接影响浮游植物生长、物种演替和初级生产力水平,浮游植物已成为指示砷污染水平及其生态效应的敏感指标。本研究以长期受到砷污染胁迫并经历多次污染治理的阳宗海为研究对象,设置南、中、北三个调查位点,于2015年4月-2019年12月对浮游植物和水质因子开展季节调查和空间分析,通过识别浮游植物生物量的时空分布模式与驱动因子,评价了砷污染与治理下浮游植物生物量的变化机制和生态修复效果。调查结果显示,采样期间阳宗海浮游植物以蓝藻门为主,浮游植物的生物量的范围为0.7-30.4mg/L,平均生物量在2016年(3.0±1.8mg/L)最低、在2017年(10.5±8.9mg/L)最高。与2017年相比,2019年浮游植物平均生物量(8.8±5.1mg/L)下降,与第一次砷污染治理(2009-2011年)后浮游植物丰度上升的趋势不同,可能与第二次砷污染治理(2017-2019年)后浮游动物丰度的上升有关。ANOVA分析结果显示,浮游植物生物量存在显著的季节差异(p<0.05)而空间差异不明显(p>0.05)。相关分析结果显示,阳宗海浮游植物生物量与砷浓度和透明度显著负相关,而与水体温度和pH显著正相关。多元线性回归分析进一步显示,砷和水温是驱动阳宗海浮游植物生物量变化的显著环境因子(F=19.28, R2=0.48)。由此可见,在重金属污染湖泊经过多次修复后,水体砷遗留物的毒性效应仍然对浮游植物生长产生了明显的抑制作用,表明了水体重金属污染物具有长期的沉积物释放作用与持久的生态毒理效应。 |
| 关键词: 阳宗海 浮游植物 生物量 砷污染 污染治理 |
| DOI： |
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| 基金项目:(32060276,31960250,41461096)、云南省重点研发计划(202203AC100002-02)、云南省John P.Smol院士工作站(202005AF150005)和异龙湖高原浅水湖泊云南省野外科学观测研究站联合资助. 2022-XX-XX收稿；2022-XX-XX收修改稿. 郑昕(1998~),女,硕士研究生；E-mail：909257754@qq.com. |
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| Spatio-temporal distribution and driving factors of phytoplankton biomass in Yangzong Lake under the background of arsenic pollution treatment |
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郑昕, Chen Li, Qiu Fei, Zhang Tao, Zhang Zhaoyang, Shang Li, Bai NingJing, Chen Xiaolin, Zhao ShuaiYing, Kong Lingyang, Chen Guangjie
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Yunnan Normal Univerity
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| Abstract: |
| Arsenic contamination has become an important environmental issue of some water bodies in China in the background of economic development and basin exploitation. To date, little is known about the effects of arsenic pollution prevention and ecological restoration. Phytoplankton is the key primary producer in lake ecosystems. Arsenic can affect the phytoplankton growth, species succession and primary productivity directly, and has become a sensitive indicator of arsenic pollution and its ecological effects. Yangzong lake has a long history of arsenic pollution and experiences multiple remediation. We conducted a seasonal survey on phytoplankton and environmental factors of Yangzong lake covering the south,central and north parts of the lake basin from April in 2015 to December in 2019, in order to identify the spatio-temporal pattern and driving factors of phytoplankton biomass, and further evaluated the mechanism of phytoplankton biomass changes and effect of eco-restoration under arsenic pollution and treatment. The results showed that the phytoplankton was mainly composed of cyanophyta. The phytoplankton biomass was in range of 0.7-30.4mg/L, with lowest in 2016 (3.0±1.8mg/L) and highest in 2017 (10.5±8.9mg/L). The biomass in 2019 (8.8±5.1mg/L) decreased as compared with 2017, contrary to the upward trend of phytoplankton biomass reported after the first arsenic treatment from 2009 to 2011, which may related to the decrease of the zooplankton abundance after the second arsenic treatment from 2017 to 2019. The phytoplankton biomass showed significant seasonal variations (p<0.05), while no obvious spatial fluctuation was observed (p>0.05). The correlation analysis showed that the phytoplankton biomass had a significantly negative correlation with arsenic concentration and transparency, but a significantly positive correlation with water temperature and pH. The multivariable linear regression model further showed that temperature and arsenic were the significant environmental factors in driving the change of biomass (F=19.28, R2=0.48). Thus the arsenic residues in water body still inhibit the phytoplankton growth after multiple remediation in heavy metal polluted lakes, indicating that heavy metal pollutants have long-term sediment release and lasting ecotoxicological effect. |
| Key words: Yangzong Lake Phytoplankton Biomass Arsenic pollution Pollution treatment |
