摘要
为了明确水体腐殖酸富集引起的水体褐化对沉水植物的潜在影响,通过室内模拟的方法,研究了不同程度褐化对狐尾藻生长、光合荧光特性与抗氧化系统的影响.结果表明,腐殖酸添加(10~40mg/L)导致水体可利用营养元素(碳、氮)的显著增加,同时水体出现明显褐化的现象.水体褐化与狐尾藻生长呈单峰关系.轻度褐化(溶解性有机碳≤8.35mg/L)促进狐尾藻生长,狐尾藻生物量峰值平均增加26.2%~28.9%.植物通过其形态和生理特征的适应性调整,能够克服水体褐化对光照的削弱作用.但高度褐化(溶解性有机碳≥13.74mg/L)导致狐尾藻生长受到显著抑制,其生物量峰值平均下降9.5%,此外,狐尾藻光合作用受抑制以及抗氧化系统严重损伤,表明植物无法适应高度褐化下的弱光胁迫.因此,亟需重视水体腐殖酸类溶解性有机质迅速增加可能引起的生态效应.
In order to clarify the potential effects of brownification,caused by humic acid enrichment,on submerged macrophytes in freshwaters,this study investigated the effects of brownification at different degrees on the growth,photosynthetic fluorescence and antioxidant system of Myriophyllum spicatum L.through indoor experiments.The results showed that the addition of humic acid(10~40mg/L)led to a significant increase in the available nutrients in the water column,as well as water brownification.Brownification and macrophyte growth have a unimodal relationship.Low degrees of brownification,with dissolved organic carbon(DOC)less than 8.35mg/L,promoted the growth of M.spicatum L,and the average peak biomass of plants increased by 26.2%~28.9%.Macrophytes could overcome the low light availability resulted from brownification owing to the plasticity in morphological and physiological traits.However,a high degree of brownification(DOC≥13.74mg/L)significantly inhibited the growth,and the peak biomass of plants decreased by 9.5%.Additionally,the photosynthesis inhibition and collapse of antioxidant systems of macrophytes indicated that they could not adapt to low light stress under a high degree of brownification.Consequently,this study highlighted that more attention should be paid to the ecological effects of humic acids enrichment in freshwater.
作者
万翔
巴翠翠
刘帅磊
王国祥
杨飞
WAN Xiang;BA Cui-cui;LIU Shuai-lei;WANG Guo-xiang;YANG Fei(Nanjing Institute of Environmental Sciences,Ministry of Ecology and Environment,Nanjing 210042,China;School of Environment,Nanjing Normal University,Nanjing 210023,China;Cewud Group Company Ltd.,Wuhan 430200,China)
出处
《中国环境科学》
CSCD
北大核心
2023年第S1期251-257,共7页
China Environmental Science
基金
国家自然科学基金资助项目(41971043)
关键词
沉水植物
腐殖酸
褐化
溶解性有机质
光合作用
submerged macrophyte
humic acid
brownification
dissolved organic matter
photosynthesis
