悬浮泥沙对藻类生长、光合作用及固碳能力的影响  

Effects of suspended sediment on growth,photosynthesis and carbon sequestration of algae in the lower reaches of the Three Gorges Reservoir

作　　者：白芳 贡丹丹 郭伟杰[1,2] 李鲁丹 杨宋琪 赵伟华 杨文俊[3] BAI Fang;GONG Dandan;GUO Weijie;LI Ludan;YANG Songqi;ZHAO Weihua;YANG Wenjun(Basin Water Environmental Research Department,Yangtze River Scientific Research Institute,Wuhan 430010;Hubei Provincial Key Lab of Basin Water Resource and Eco-Environmental Science,Changjiang River Scientific Research Institute,Wuhan 430010;Administration Office,Changjiang River Scientific Research Institute,Wuhan 430010;Gansu Microalage Technology Innovation Center,Key Laboratory of Hexi Corridor Resource Utilization of Gansu,Hexi University,Zhangye 734000)

机构地区：[1]长江科学院,流域水环境研究所,武汉430010 [2]流域水资源与生态环境科学湖北省重点实验室,武汉430010 [3]长江科学院院长办公室,武汉430010 [4]河西学院,甘肃省微藻技术创新中心,河西走廊特色资源利用重点实验室,张掖734000

出　　处：《环境科学学报》2025年第3期462-470,共9页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金重点项目(No.52130903);国家自然科学基金青年项目(No.42307100)。

摘　　要：三峡工程的长期运行导致下游河道水沙情势发生极大变化,进而影响下游水生态环境质量.水沙调控是维护和恢复水生态系统健康的有效措施.目前,关于水生生物对水沙调控的研究多围绕鱼类开展,而针对初级生产力贡献者和鱼类主要饵料的浮游植物则相对较少.本研究选取三峡库区下游河道3种常见藻类为对象,探究不同悬浮泥沙含量下藻类的生长、光合及固碳能力.结果发现,相较于蓝藻和绿藻,硅藻更耐受高浓度泥沙环境.在0.5 g·L^(-1)泥沙处理下,虽然在前10 d时出现轻微抑制,但之后Chl a含量迅速升高至(1637.80±60.10)μg·L^(-1).光合电子传递效率结果显示,当泥沙浓度分别为0.3 g·L^(-1)和0.5 g·L^(-1)时,硅藻的最大电子传递效率(ETRmax)分别为36.60±0.01和30.40±0.02,均显著高于对照组,同时光合放氧速率分别达到(100.32±0.56)和(110.64±0.62)μmol·mg-1·h^(-1).此外,所有泥沙处理组固定的总有机碳含量均高于对照组,其中,0.15 g·L^(-1)泥沙组中所固定的有机碳含量最高.综上,适宜三峡库区下游优势硅藻的合理调控泥沙范围应在0.15~0.3 g·L^(-1)之间.研究结果可为三峡库区水沙调控工程取得最佳生态效益提供依据和指导,对库区下游河道生态恢复具重要意义.The long-term operation of the Three Gorges Project has significantly altered the water and suspended sediment conditions in the receiving downstream-river,which in turn affects the health of the downstream aquatic ecosystems.Water-sediment regulation is an effective strategy to maintain and restore the health of these ecosystems.However,current research on water-sediment regulation largely focused on fish,while phytoplankton,which forms the base of the food web and serves as a primary food source for fish,is relatively understudied.In this study,we selected three common algal species in the lower reaches of the Three Gorges Reservoir to investigate their growth,photosynthesis and carbon sequestration capacity under varying suspended sediment concentrations.The results showed that diatoms were more adaptable to the high sediment concentration than cyanobacteria and green algae.Under the 0.5 g·L^(-1)sediment treatment,although a slight inhibition was observed during the first 10 d,chlorophyll-a(Chl a)rapidly increased to(1637.80±60.10)μg·L^(-1).The photosynthetic electron transfer efficiency showed that the ETRmax of diatoms was 36.60±0.01 and 30.40±0.02 under sediment concentrations of 0.3 and 0.5 g·L^(-1),respectively,both significantly higher than the control group.Meanwhile,the photosynthetic oxygen evolution rates were(100.32±0.56)and(110.64±0.62)μmol·mg-1·h^(-1).In addition,the total organic carbon(TOC)levels were higher in all sediment-treated groups compared to the control,with the highest organic carbon accumulation observed in the 0.15 g·L^(-1)sediment group.These findings suggested that the optimal sediment concentration range for dominant diatom species in the lower reaches of the Three Gorges Reservoir area should be between 0.15 and 0.3 g·L^(-1).This study provides important insights and guidance for optimizing sediment regulation in the Three Gorges Reservoir to achieve the best ecological outcomes,which is of important implications to the ecological restoration of the downstream river

关 键 词：悬浮泥沙 藻类 光合作用 固碳能力 三峡库区 

分 类 号：X171[环境科学与工程—环境科学]