摘要
蓝藻和绿藻是贵阳红枫湖的主要浮游植物类群。水体中色素含量与比例是水体中藻类的种群丰度、种群结构及生理特征的综合表现。为了探究红枫湖蓝藻和绿藻的6种光合色素含量的时空变化规律并分析其与环境因子的相关性,于2023年在贵阳红枫湖进行不同季节和地点的采样分析。研究结果表明,夏季较高的水温(WT)、氨氮(NH_(3)-N)、硝氮(NO_(3)^(-)-N)、总氮(TN)、总铁(TFe)导致红枫湖水体中蓝藻和绿藻生物量的升高,因此叶绿素a(Chla)、叶绿素b(Chlb)、藻蓝蛋白(PC)、别藻蓝蛋白(APC)、藻红蛋白(PE)等5种光合色素含量均为夏季最高(Tukey’s HSD,P<0.05)。夏季绿藻竞争优势升高,因此夏季Chlb及Chlb/Chla最高。秋季Chla、Chlb含量高于春季,但PC、APC、PE含量接近,因此秋季Chla含量的升高主要是由绿藻等不含PC、APC、PE的真核藻类生物量升高引起的。秋季较高的温度、光照以及营养盐含量降低,且藻细胞处于衰亡期,导致藻细胞内类胡萝卜素(Car)含量及Car/Chla升高。春季PC/Chla和PE/Chla最高,表明蓝藻中的湖泊假鱼腥藻(Pseudanabaena limnetica)在春季的竞争优势较大。冬季APC/Chla、APC/PC、APC/PE高于其他季节,可能与冬季湖丝藻(Limnothrix redekei)、拟柱孢藻(Cylindrospermopsis raciborskii)等不含PE的蓝藻优势度升高以及冬季的低温、低光及营养盐缺乏等环境因子对蓝藻细胞的胁迫有关。本研究PC/Chla、PE/Chla、PE/PC分别为2.11~2.96、1.39~2.38、0.67~0.81,表明红枫湖水体的浮游植物种群结构以湖泊假鱼腥藻为绝对优势种。RDA分析结果显示,环境因子分别解释了色素含量和比例变化的89.17%、70.87%,但PC/Chla、PE/Chla与各环境因子均无显著相关性。表明红枫湖水体以湖泊假鱼腥为主要优势种的藻类种群结构受环境因子变化的影响较小。pH值(pH)、溶解氧(DO)、盐度(Sal)、电导率(EC)、总固体悬浮物(TDS)、透明度(SD)、浊度(Turb)等理化因子是浮游藻类生长的被动影响因子。pH值夏季略高于春秋季,冬季最低。夏、秋季浮游藻类光合放氧量高于春季,但夏、秋季DO低于春季。夏、秋季较高的WT导致水体中氧气的溶解度降低、浮游生物呼吸耗氧量升高、有机物的分解耗氧量增加。夏、秋季较高的浮游藻类生物量对水体中无机盐的吸收量较高,因此Sal、EC、TDS相对较低。夏秋季红枫湖水体Turb升高、SD降低主要由浮游藻类生物量升高引起的。将军湾NH_(3)-N、NO_(3)^(-)-N、TFe含量最高,后午TP含量最高、TN/TP最低。因此将军湾Chla含量最高,后午Chlb、PC、APC、PE含量最高。大坝Chla含量最低,但非生物颗粒物增多会引起Turb升高、SD降低。研究结果将为蓝藻水华的监测预警及防控治理提供参考。
Cyanobacteria and green algae are the main phytoplankton groups in Hongfeng Lake located in Guiyang.The pigment content and proportion in water reflect the integrated effects of the population abundance,population structure,and physiological characteristics of algae.To investigate the spatiotemporal variations of six photosynthetic pigments in blue-green algae and green algae in Hongfeng Lake and analyze their correlation with environmental factors,we conducted sampling at different seasons and locations in Hongfeng Lake,Guiyang in 2023.The results indicate that the higher water temperature(WT),ammonia nitrogen(NH3-N),nitrate nitrogen(NO-3-N),total nitrogen(TN),and total iron(TFe)in summer promoted the biomass accumulation of cyanobacteria and green algae in Hongfeng Lake.Therefore,the content of five photosynthetic pigments,including chlorophyll a(Chl a),chlorophyll b(Chl b),phycocyanin(PC),allophycocyanin(APC),and phycoerythrin(PE),reached the highest levels in summer(Tukey’s HSD,P<0.05).Due to the competitive advantage of green algae in summer,both the content of Chl band the ratio of Chl b/Chl apeaked in summer.While the content of Chl aand Chl bin autumn exceeded that in spring,the content of PC,APC and PE remained similar.This suggests that the increase of Chl acontent in autumn was mainly caused by the increase of biomass of eukaryotic algae such as green algae,which lack PC,APC and PE.Under higher temperatures and light intensity,coupled with reduced nutrient availability and the algal cells were in a period of decay,the content of carotenoids(Car)and Car/Chl a in algal cells increased.The highest PC/Chl a and PE/Chl a occurred in spring,indicating the significant competitive advantage of the cyanobacterium Pseudoanabaenalimneticaduring this season.In winter,the ratios of APC/Chl a,APC/PC,and APC/PE were higher than other seasons,potentially due to the dominance of PE-free blue-green algae such as Limnothrixredekei and Cylindrospermopsisraciborskii under stress environmental factors,such as low temperature,low light,and nutrients deficiency.The ranges of PC/Chl a,PE/Chl a,and PE/PC values in this study were 2.11-2.96,1.39-2.38,and 0.67-0.81,respectively,indicating that Pseudanabaenalimneticadominated the phytoplankton population structure in Hongfeng Lake.The RDA analysis revealed that environmental factors explained 89.17%and 70.87%of the variation in pigment content and proportion,respectively.However,there was no significant correlation between PC/Chl a,PE/Chl a and various environmental factors,indicating that Pseudanabaena limnetica-dominated population structure of Hongfeng Lake was relatively stable against environmental factors.The pH value(pH),dissolved oxygen(DO),salinity(Sal),electrical conductivity(EC),total dissolved solids(TDS),transparency(SD),turbidity(Turb)and other physico-chemical factors are the secondary regulators of phytoplankton growth.The pH value was slightly higher in summer than in spring and autumn,and lowest in winter.Despite higher photosynthetic oxygen production in summer and autumn,DO levels were lower than that in spring,attributed to reduced oxygen solubility at higher WT,increased respiration demand,and enhanced organic matter decomposition.The high phytoplankton biomass in summer and autumn led to greater uptake of inorganic salts,resulting in lower Sal,EC and TDS.Similarly,increased Turb and the decreased SD were mainly caused by elevated phytoplankton biomass.Spatially,General Bay exhibited higher NH3-N,NO-3-N,and TFe concentration compared to other locations,while Houwu had the highest TP content but the lowest TN/TP ratio.Therefore,Chl acontent was the highest in General Bay,whereas the content of Chl b,PC,APC,and PE peaked in Houwu.The dam site had the lowest Chl acontent but the highest Turb and lowest SD,which reflected the influence of non-biological particulate matter.These finding provide a scientific basis for monitoring,early warning,prevention and control of cyanobacterial blooms in Hongfeng Lake.
作者
刘树文
LIU Shuwen(School of Biological Sciences,Guizhou Education University,Guiyang 550018,China)
出处
《生态毒理学报》
北大核心
2025年第5期52-65,共14页
Asian Journal of Ecotoxicology
基金
国家自然科学基金地区项目(31660115)。
关键词
红枫湖
色素含量
色素比例
环境因子
时空分布
Hongfeng Lake
contents of photosynthetic pigments
proportions of photosynthetic pigments
environmental factors
spatiotemporal distribution
