游荡型黄河滩涂植物群落多样性及种间联结性

Plant diversity and interspecific associations of different floodplains in the wandering Yellow River

黄河干流流量季节性变化和小浪底“调水调沙”形成了黄河河南段特殊的游荡型滩涂生态系统,为揭示游荡型黄河滩涂(嫩滩、二滩、高滩和大堤)群落组成和种间关系及群落稳定性规律,于2015年9月至2018年11月,采用典型样方法在郑州黄河湿地自然保护区游荡型黄河滩涂开展群落学调查,利用149个草本层样方分析群落物种组成、多样性、种间联结性和群落稳定性。结果表明:(1)研究区植物共有90科289属445种,其中被子植物87科286属440种,裸子植物2科2属3种;蕨类植物仅见1属2种。(2)不同滩涂生境优势种具有显著差异,且总体狗牙根(Cynodon dactylon)、芦苇(Phragmites australis)和小蓬草(Erigeron canadensis)为优势种,国家二级保护植物野大豆(Glycine soja)呈斑块聚集分布,且为嫩滩和二滩亚优势种。(3)大堤物种多样性各指标取值最大,嫩滩次之,二滩和高滩较小。(4)χ^(2)检验、Jaccard指数、Pearson相关检验和Spearman秩相关检验表明,优势种种对种间联结性不强,各物种间相对独立。(5)二滩总体联结性呈现不显著负关联,其他3种类型均为显著负关联,M. Godron稳定性分析说明群落总体均处于不稳定演替阶段。因此,游荡型黄河滩涂生态系统总体不稳定,河道的游荡多变导致滩涂植物更新频繁,这可为黄河流域生态保护和高质量发展国家战略提供重要基础数据和科学指导。

The seasonal flow variation of the Yellow River mainstream and water-sediment regulation by the Xiaolangdi project have formed a special wandering floodplain ecosystem.In order to reveal the community composition,interspecific relationship and community stability of the wandering Yellow River floodplains(Newly-formed floodplain,Second floodplain,Highly-formed floodplain,Levee),we utilized the typical quadrat method to investigate plants in Zhengzhou Yellow River Wetland Provincial Nature Reserve of the typical wandering Yellow River floodplains from September 2015 to November 2018.We delved into the community species composition,species diversity,interspecific association and community stability based on 149 herb layer quadrats.The results showed that:(1)445 species were occurred in our four floodplains,belonging to 289 genera and 90 families.Among them,there were 440 species,286 genera and 87 families of angiosperms,and three species,two genera and two families of gymnosperms,and only one genus and two species of pteridophytes.(2)There were significant differences in dominant species among four floodplains.In general,Cynodon dactylon,Phragmites australis,and Erigeron canadensis were the dominant species.In Newly-formed floodplain and Second floodplain,Glycine soja(Class II protected plant,in China)was subdominant species,which distributed sporadically in patches.(3)The species diversity indices of the Levee were the largest,followed by the Newly-formed floodplain,and those of the Second floodplain and Highly-formed floodplain were smaller.(4)χ^(2)test,Jaccard index,Pearson correlation test and Spearman rank correlation test showed that the dominant species pairs were not strongly interspecific linked,and each species was relatively independent.(5)The overall association of Second floodplain showed non-significantly negative association,while that of the rest were significantly negatively associated.Combined with the M.Godron's stability analysis,the community was in an unstable successional stage.These results indicated that the wandering Yellow River floodplain ecosystem was generally unstable,and the wandering and variable river channel led to the frequent regeneration of floodplain community.This provides important basic data and scientific guidance for national strategies of ecological protection and high-quality development in the Yellow River Basin.