不同水文条件下光养生物膜藻类对氮、磷营养盐的响应  

Response of Phototrophic Biofilm Algae to Different Nitrogen/Phosphorus Levels and Hydrological Conditions

作　　者：杨宋琪 赵璐 欧阳添 纪璐璐 罗光宏[1] 吴忠兴[2] YANG Song-qi;ZHAO Lu;OUYANG Tian;JI Lu-lu;LUO Guang-hong;WU Zhong-xing(Gansu Microalgae Technology Innovation Center,Key laboratory of Hexi Corridor Resources Utilization of Gansu,Hexi University,Zhangye 734000,P.R.China;Key Laboratory of Eco-environments in Three Gorges Reservoir Region(Ministry of Education),Southwest University,Chongqing 400715,P.R.China)

机构地区：[1]河西学院甘肃省微藻技术创新中心甘肃省河西走廊特色资源利用重点实验室,甘肃张掖734000 [2]西南大学三峡库区生态环境教育部重点实验室,重庆400715

出　　处：《水生态学杂志》2024年第3期94-102,共9页Journal of Hydroecology

基　　金：甘肃省科技计划资助(22JR5RG565,20JR5RA192);国家自然科学基金项目(42177055,41877410)。

摘　　要：揭示生物膜藻类对河流水体流态与营养盐的响应,为河流生物膜藻类研究及生物多样性保护提供依据。在微型跑道池模拟流水(0.5 m/s)和静水(0 m/s)条件的基础上,通过设置不同浓度氮(1.51、2.51和5.51 mg/L)、磷(0.1、0.2和0.4 mg/L)及氮磷比(8、16和32)环境培养野外采集的原位生物膜并铺设人工基质,探究流速差异和营养浓度对河流光养生物膜藻类物种组成及密度的影响。非度量多维排序(NMDS)分析结果表明,无论流速还是非流速环境下,原位和建群生物膜藻类群落在不同氮、磷和氮磷比环境中均呈现明显分离(P<0.001),且建群生物膜中各分组藻类群落具有更明显的差异。双因素方差分析结果表明,磷与流速单一及交互效应显著影响藻类的生长及建群(P<0.001);而氮处理中,氮与流速的交互效应仅对建群生物膜藻类影响显著(P<0.001)。同时,还发现生物膜中硅藻、蓝藻和绿藻的生长对营养盐与流速变化的响应并不一致,其中非流速-高氮、磷营养盐更适宜于蓝藻和绿藻的生长。总之,差异流速和氮、磷浓度变化影响了光养生物膜藻类的响应模式,且建群初期的生物膜藻类对外界环境变化敏感。Phototrophic biofilms are an important producer in river ecosystems and play a vital role in river biogeochemical cycles.However,the impact of habitat heterogeneity,such as changing water velocity and nutrient levels,on phototrophic biofilm algae is unknown.In this study,we investigated the single and combined effects of water velocity and nutrient levels on species composition and algal density in phototrophic biofilms.Biofilms in situ and on artificial substrates were cultured in a micro-raceway pond under lotic and lentic conditions(0.5 m/s and 0 m/s)and with different nutrient levels(nitrogen:1.51,2.51 and 5.51 mg/L;phosphorus:0.1,0.2 and 0.4 mg/L;N/P ratios:8,16 and 32).Non-metric multidimensional scaling(NMDS)shows that the biofilm algae communities on both natural and artificial substrates were significantly separated into different nutrient groups(P<0.001).This was the case under both lotic and lentic flow conditions,but the difference was more significant(higher F values)with biofilms on the artificial substrate.Two-way analysis of variance(two-way ANOVA)indicates that algal growth and colony formation in the phosphorus treatment groups were significantly affected by the single variable and their interaction(P<0.001).However,among the nitrogen treatment groups,the interaction between nitrogen and velocity showed a significant effect only on the biofilms formed on artificial substrates(P<0.001).The growth of Bacillariophyta,Cyanobacteria and Chlorophyta in biofilms did not respond consistently to nutrient and hydrological variables,but the lentic condition and high nitrogen-phosphorus levels favored the growth of Cyanophyta and Chlorophyta.In conclusion,biofilms in the early stage of colony formation were affected by hydrological disturbance and the response of the biofilm algae community varied with N and P levels and hydrologic conditions.Our results provides new insights for river ecological protection.

关 键 词：流速差异 氮磷浓度 氮磷比 光养生物膜 藻类 

分 类 号：Q948[生物学—植物学]