摘要
环境异质性在一定程度上不仅可以增加物种多样性,而且影响了陆生生物群落的稳定性.然而,环境异质性如何影响水生态系统附石硅藻群落的物种多样性却较少报道.因此,以三峡库区支流香溪河的附石硅藻为研究对象,通过量化和比较香溪河在时间尺度上的环境异质性,探究其在驱动物种多样性变化的作用.结果表明,环境异质性、分类β-多样性和功能β-多样性均表现为非蓄水期显著高于蓄水期,且周转组分均对不同水文期β-多样性贡献较大,而分类α-多样性则是蓄水期显著高于非蓄水期.此外,功能α-多样性中除功能丰富度非蓄水期显著高于蓄水期外,功能均匀度和功能分散度均无显著差异.基于相似或相异度矩阵的多元回归(MRM)分析表明,NH_(4)^(+)-N和SiO_(3)^(2-)-Si是影响非蓄水期香溪河附石硅藻群落的关键环境异质因子,而影响蓄水期香溪河附石硅藻群落的关键环境异质因子为NH_(4)^(+)-N、 SiO_(3)^(2-)-Si和TP.这表明三峡库区不同水文期的环境异质性显著影响附石硅藻的群落结构,导致群落内物种发生分化,影响了水生生态系统稳定性.
Environmental heterogeneity can not only increase species diversity to some extent but also affect the stability of terrestrial communities.However,how environmental heterogeneity affects species diversity of epilithic diatom communities in aquatic ecosystems is rarely reported.In this study,therefore,epilithic diatoms and their roles in driving species diversity were explored by quantifying and comparing the environmental heterogeneity in Xiangxi River,a tributary of the Three Gorges Reservoir Area(TGR),on a time scale.The results showed that environmental heterogeneity,taxonomicβ-diversity,and functionalβ-diversity in non-impoundment periods were significantly higher than those in impoundment periods.Moreover,the turnover components in the two hydrological periods showed the highest contribution toβ-diversity.However,the taxonomicα-diversity in impoundment periods was significantly higher than that in non-impoundment periods.In addition,functional richness in functionalα-diversity was significantly higher in non-impoundment periods than that in impoundment periods,whereas there was no significant difference in other functionalα-diversity,i.e.,functional dispersion and functional evenness,found between the two periods.Multiple regression on(dis)similarity matrices(MRM)analysis indicated that ammonium nitrogen(NH_(4)^(+)-N)and silicate(SiO_(3)^(2-)-Si)were the key environmental heterogeneous factors affecting the epilithic diatom community in Xiangxi River during the non-impoundment periods,whereas the key heterogeneous factors were ammonium nitrogen(NH_(4)^(+)-N),silicate(SiO_(3)^(2-)-Si),and total phosphorus(TP)during the impoundment periods.These results suggested that the environmental heterogeneity during different hydrological periods in TGR can significantly affect the community structure of epilithic diatoms,resulting in the differentiation of species within the community and even affecting the stability of aquatic ecosystems.
作者
纪璐璐
赵璐
欧阳添
杨宋琪
郑保海
杜雨欣
李玉鑫
李佳欣
施军琼
吴忠兴
JI Lu-lu;ZHAO Lu;OUYANG Tian;YANG Song-qi;ZHENG Bao-hai;DU Yu-xin;LI Yu-xin;LI Jia-xin;SHI Jun-qiong;WU Zhong-xing(Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region,Key Laboratory of Eco-environments in Three Gorges Reservoir Region,Ministry of Education,Southwest University,Chongqing 400715,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2023年第4期2083-2092,共10页
Environmental Science
基金
国家自然科学基金项目(42177055,41877410)。
关键词
环境异质性
附石硅藻
功能多样性
分类多样性
功能性状
environmental heterogeneity
epilithic diatom
functional diversity
taxonomic diversity
functional trait
