广州河涌区乡村聚落植物多样性特征及其影响因素

Characteristics and influencing factors of plant diversity in riverside rural settlement in Guangzhou

【目的】分析广州南沙河涌区典型乡村聚落带植物多样性在水平及垂直方向上的分布特征。【方法】采用实地调查、卫星影像解译及相关统计方法探索随着河段区位及居住建设活动变化的植物多样性特征差异。【结果】①研究区共记录植物44科70属77种,其中乔木42种,灌木19种,草本13种,藤本3种,以蔷薇科Rosaceae和棕榈科Palmae植物种类最多,桑科Moraceae和芸香科Rutaceae次之。②不同河段优势植物种类无显著差异,乔木以龙眼Dimocarpus longan、小叶榕Ficus concinna和黄皮Clausena lansium为主,灌木以桂花Osmanthus fragrans、九里香Murraya exotica和米仔兰Aglaia odorata为主,草本以香蕉Musa nana和青皮竹Bambusa textilis为主。③研究区域西闸至东闸不同河段内,乔木多样性整体呈下降趋势,灌木和草本无明显趋势,整体均匀度无明显变化趋势,但居住段乔灌草的多样性和均匀度指数显著高于其他河段,而农业段各项指数都低于其他河段;河道宽度与草本植物多样性显著相关,建筑盖度与灌木均匀度显著相关。④研究区植被呈垂直分布,以4 m和8 m为界限分为上中下3层,下层以香蕉、青皮竹和龙眼为主,中层以龙眼、黄皮、落羽杉Taxodium distichum和白颜树Gironniera subaequalis为主,上层以龙眼、小叶榕和大王椰子Roystonea regia为主;不同高度层优势树种不同。【结论】人为活动对大型乔木影响较小,但对盆栽类灌木和草本类等小型可灵活栽植的植物影响较为显著。

[Objective]This study aims to analyze the horizontal and vertical distribution characteristics of plants diversity in typical riverside rural settlement zones along the Nansha river of Guangzhou,and explore the variation law of plant diversity with the change of the river sections and residential activities.[Method]The basic data were obtained by field survey,satellite image interpretation and mathematical statistics.[Result]A total of 77 species of 70 genera and 44 families were recorded,including 42 species of trees,19 species of shrubs,13 species of herbs and 3 species of vines,among which Rosaceae and Palmae had the most species,followed by Moraceae and Rutaceae.There were no significant differences in dominant plant species in different river sections.The dominant trees were Dimocarpus longan,Ficus microphylla and Clausena lansium,while the main shrubs were Osmanthus fragrans,Murraya exotica and Aglaia odorata,and the main herbs were Musa nana and Bambusa textilis.In different reaches from the west gate to the east gate in the study area,tree diversity showed a downward trend as a whole,while no obvious trend was found in shrubs,herbs and overall evenness.However,the diversity and evenness index of trees,shrubs and herbs in the residential section were significantly higher than those in other sections,while the indices in the agricultural section were lower than those in other sections.The river width was significantly correlated with herb diversity,and building coverage was significantly correlated with shrub evenness.Vegetation in the study area was vertically distributed and divided into upper,middle and lower layers with 4 m and 8 m as boundaries.The dominant tree species in different height layers were different.M.nana,B.textilis and D.longan were dominant in the lower layer.D.longan,C.lansium,Taxodium distichum and Gironniera subaequalis were dominant in the middle layer.D.longan,F.concinna and Clausena lansium were dominant in the upper layer.[Conclusion]Human activities have little impact on large trees,but significant impact on small flexible plants such as potted shrubs and herbs.