涡河水生植被特征及分布成因

Characteristics and distribution causation of aquatic macrophytes in Guohe River of East China

通过野外调查及室内测定,运用TWINSPAN聚类和CCA排序等方法对淮河流域涡河水生植物的组成、群落类型进行了研究,并探讨了影响水生植物分布的关键环境要素。结果表明:涡河共有水生植物27种,隶属于20科23属,其中以沉水植物和挺水植物居多(占总数的74%)。涡河水生植物可划分为8个群落类型,即针蔺+藨草群落(Form.Eleo-charis congesta+Scirpus trigueter)、藨草+喜旱莲子草群落(Form.S.trigueter+Alternanthera philoxeroides)、藨草群落(Form.S.trigueter)、金鱼藻群落(Form.Ceratophyllum demersum)、喜旱莲子草群落(Form.A.philoxeroides)、芦苇+喜旱莲子草群落(Form.Phragmites australis+A.philoxeroides)、荇菜群落(Form.Nymphoides peltatum)、菱+萍蓬草群落(Form.Trapa bispinosa+Nuphar pumilum)。各群落间水体铵态氮、水体硝态氮、水体总磷、水深等环境因子变异较大。CCA排序结果表明,水体理化性质如硝态氮含量、磷酸根离子及总磷是影响该区水生植物分布的关键因素。

On the basis of field survey and laboratory measurement,and by using Two-Way Indicator Species Analysis（TWINSPAN） and CCA ordination,this paper studied the species composition and community type of aquatic macrophytes in the Guohe River of Huaihe River Basin,and approached the key environmental elements affecting the distribution of the macrophytes.A total of 27 aquatic macrophyte species belonging to 20 families and 23 genera were recorded,of which,submerged and emergent species were the dominant species,accounting for 74% of the total.The macrophytes could be classified into 8 community types,i.e.,Form.Eleocharis congesta ＋ Scirpus trigueter,Form.S.trigueter ＋ Alternanthera philoxeroides,Form.S.trigueter,Form.Ceratophyllum demersum,Form.A.philoxeroides,Form.Phragmites australis ＋ A.philoxeroides,Form.Nymphoides peltatum,and Form.Trapa bispinosa ＋ Nuphar pumilum.There existed greater variations in the environmental factors,especially the concentrations of NH4＋-N,NO3--N,and total P in water body and the water depth,among the 8 community types.The CCA ordination showed that the physical and chemical characteristics of water body,such as the NO3--N,PO4-and total P concentrations,were the key factors determining the distribution of aquatic macrophytes in the Guohe River.