水生态学杂志2024，Vol.45Issue(4)：155-164,10.DOI:10.15928/j.1674-3075.202205100159
珠江河网密刺苦草种群衰退的表观性状特征指示
Morphological Traits Indicating Decline of the Vallisneria denseserrulata Population in the Pearl River Network
摘要
Abstract
Submerged macrophyte beds(SMBs)play important roles in aquatic ecosystem,but the succession characteristics of SMBs in urban river systems are still poorly understood.In this study,Vallis-neria denseserrulata in the Pearl River network was selected for research,and we investigated the mor-phologic traits of V.denseserrulata at different sites in different months and explored the decline charac-teristics and main influencing factors.We also discussed strategies for maintaining V.denseserrulata beds in different river sections based on differentiation of morphologic traits.In February,August and Decem-ber of 2017,the spatial distribution investigation of submerged macrophyte beds in the lower Pearl River network was carried out at 13 sites(S1-S13)by field investigation and fishery survey.In the same months of 2018 and 2019,monitoring of the morphologic traits of the V.denseserrulata population was conducted at S3,S5 and S8.The relationship of V.denseserrulata morphologic traits and environmental factors were then analyzed using multivariate statistical methods including redundancy analysis(RDA)and principal component analysis(PCA).Results show that the morphologic traits of V.denseserrulata presented obvi-ous differences in temporal-spatial distribution in 2018.The plant height and weight of V.denseserrulata in beds at S3 and S8 increased from February to August,then decreased from August to December,while the plant height and weight of V.denseserrulata at S5 continued to increase.In December,growth charac-teristics of V.denseserrulata differed among sites,with the population at S5 entering the flowering and fruiting stage,while the populations at S3 and S8 were in recession.The RDA results show that plant height was primarily affected by water depth,medium particle size components and total phosphorus con-tent in sediments,while the plant weight was primarily affected by total phosphorus content in sediments.The PCA results show that the 9 morphological traits comprehensively characterized the clonal growth ability,sexual reproduction ability and multi-year growth ability,and determined population maintenance strategies.The V.denseserrulata population at S5 was characterized by sustained growth during the winter and allocation of resources for sexual reproduction,adapting to environmental changes,and this enabled the population to persist in the following year.Another case,represented by the V.denseserrulata popula-tions at S3 and S8,shows that the growth capacity of the populations declined during the winter,with no allocation of sexual reproduction resources.Having failed to meet adverse environmental conditions,the populations faced rapid population decline and even disappearance the following year.关键词
密刺苦草/表观性状/有性繁殖/种群恢复/珠江河网Key words
Vallisneria denseserrulata/morphological trait/sexual reproduction/population restoration/Pearl River network分类
生物科学引用本文复制引用
李毅,杨婉玲,王超,赖子尼,李海燕,刘乾甫,高原,麦永湛,曾艳艺..珠江河网密刺苦草种群衰退的表观性状特征指示[J].水生态学杂志,2024,45(4):155-164,10.基金项目
中国水产科学研究院中央级公益性科研院所基本科研业务费专项资金(2022SJ-XT3,2018-SJ-ZH06) （2022SJ-XT3,2018-SJ-ZH06）
国家自然科学基金(31500434). （31500434）
