天津市临港城市湿地植物群落特征及多样性

[目的]探究城市湿地植被恢复的群落特征及物种多样性格局,为城市湿地保护和恢复策略的制订提供科学依据。[方法]采用样方法对天津临港恢复湿地的植物群落进行调查,计算群落植物种重要值,并利用组平均法聚类,分析物种多样性格局。[结果](1)乔灌草各层主要优势物种分别为国槐(Sophora japonica)、刺槐(Robinia pseudocaacia);柽柳(Tamarix chinensis)和芦苇(Phragmites australis),灌木层中的柽柳重要值最大。(2)植被划分为4组、17个群丛类型,过渡区广布种斑块频度最大(32.7%),以国槐+银杏群落(Sophora japonica+Ginkgo biloba)为主;滨水湿地斑块群落频度最小(17.3%),以柽柳—芦苇群落(Tamarix chinensis-Phragmites australis)为主。(3)Shannon-Wiener指数与Simpson指数总体变化趋势较一致,最高值均出现在金叶榆—紫穗槐(Ulmus pumila-Amorpha fruticosa)群落;Pielou均匀度指数≥0.8的样方占样方总数的53.8%;近水绿地斑块丰富度指数强度较大,物种复杂度高。(4)调查中发现有刺槐、旱柳(Salix matsudana)、火炬树(Rhust yphina)等乔木更新苗出现,出现明显的群落演替和自然更新现象。[结论]研究区植物种类丰富,近水绿地斑块物种多样性较高,但湿生植物群落总体优势不明显。

Plant Community Characteristics and Diversity of Urban Wetland at Lingany District of Tianjin City

[Objective] The plant community characteristics and species diversity patterns in restored urban wetland were researched to provide scientific basis for urban wetland protection and restoration strategies of vegetation.[Methods] Plant community of restored urban wetland at Lingany District of Tianjin City was in vestigated using quadrat sampling method.Species diversity-patterns was analyzed through group average clustering with data of important values.[Results] (1) The community's dominant species of tree layer,shrub layer layer and herb layer were Sophora japonica and Robinia pseudoacacia,Tamarix chinensis,and Phragmites communis.In shrub layer,Tamarix chinensis had the maximum important value.(2) Vegeta tion was divided into 4 groups,17 cluster types.Widespread species in the transitional area owned the biggest frequency(32.7％);Sophora japonica+ginkgo community accounted for the largest proportion;Tam aria chinensis-Phragmitesaustralis community accounted for the largest proportion in waterfront wetland patch which had the smallest frequency(17.3％).(3) The overall change trend of Shannon-Wiener diversity and Simpon diversity was consistent.The highest value appeared in Ulmus pumila-Amorpha fruticosa community.The ratio of ≥0.8 Pielu evenness accounted for 53.8％ of the total sample plots,and species richness of water-around green patches showed greater intensity.(4) Robinia pseudoacacia,Salix matsudana and Rhus typhina seedlings were found,which meaning community succession and natural regeneration emerged.[Conclusion] Plant species is very abundant in overall research area,water around green patches own high species diversity and the dominance of hygrophyte community is not obvious.