海南省3座城市的植物多样性水平对比研究

目的通过对海南省3座城市的植物组成进行分析，探讨了各城市植物多样性形成差异的驱动因素，为今后城市植物多样性保护和布局等研究工作提供参考。方法以海南省的海口、文昌和三亚为研究对象，在城市规划区域内进行随机抽样的调查方法，调查内容包括样方内的物种、胸径、冠幅、株高、数量、植被覆盖面积等信息，应用β相异性指数研究群落和物种的组成差异，对各城市植物多样性在物种、功能和谱系层面进行显著性差异分析，通过对比探讨影响城市植物多样性差异的因素。结果（1）海口市规划区共统计了227种植物，归属于71科184属；三亚市规划区共统计了244种植物，归属于76科204属；文昌市规划区共统计了230种植物，归属于72科181属。（2）3座城市的乡土物种β相异性均高于外来物种，乔木层的物种β相异性比灌木层和草本层低。（3）3座城市的乔木层物种多样性指数无显著差异；文昌的灌木层物种多样性指数显著低于海口和三亚2个城市（P < 0.05）；三亚和文昌草本层的Simpson指数和Shannon-Wiener指数均呈现显著差异（P < 0.05），且文昌的各多样性指数值较高。（4）文昌和另外2座城市之间灌木层的功能均匀度指数（FEve）和功能离散度指数（FDis）均呈现了显著差异，文昌的灌木层功能多样性指数显著低于海口和三亚（分别为P < 0.01和P < 0.001），与灌木层的物种多样性结果一致。（5）文昌乔木层的谱系多样性指数（PD）值显著高于海口，三亚灌木层的PD指数值显著高于文昌，文昌草本层的PD指数值显著高于海口和三亚（P < 0.01）。灌木层和草本层的谱系均匀度指数（PSE）结果与PD指数一致（分别为P < 0.001和P < 0.01），但在乔木层没有呈现显著差异（P = 0.690）。结论海南省3座城市的乡土物种组成差异性比外来物种更为明显，但整体植被种类未呈现出明显的同质性的特征。3座城市物种多样性、功能多样性和谱系多样性水平的高低趋势基本保持一致。未来研究中，分析城市中多个层面的植物多样性差异，可以更全面地对多样性格局的保护和控制提供决策依据。 

Comparison in plant diversity in Haikou,Sanya and Wenchang cities of Hainan Province,southern China

ObjectiveThe driving factors of plant diversity differences among three cities in Hainan Province, southern China were discussed through the analysis of plant compositions. It provided a reference for future research on the protection and layout of urban plant diversity.MethodIn this research, Haikou City, Wenchang City and Sanya City were taken as research objects. A sample survey was conducted using random sampling in urban planning areas. We carried out surveys on the species list within the plot, the DBH, crown width, height and quantity of trees, as well as the vegetation coverage area in the plot, etc. The β-dissimilarity index was used to study the compositional differences of communities and species in different cities. We analyzed the differences in plant species diversity at the species, function, and phylogenetic levels, and factors which may influence urban plant diversity differences.Result(1) In the planning area of Haikou City, there were 227 plant species of 184 genera in 71 families. In the planning area of Sanya City, there were 244 plant species of 204 genera in 76 families. In the planning area of Wenchang City, there were 230 plant species of 181 genera in 72 families. (2) In the three cities, the β-dissimilarity index of the native species was higher than that of the exotic species, and the species β-dissimilarity of the arbor layer was lower than that of the shrub layer and the herb layer. (3) There was no significant difference in species diversity index values of the arbor layer. Diversity index value of shrub species in Wenchang City was significantly lower than those in Haikou and Sanya cities (P < 0.05). The herb layer diversity index values of Sanya and Wenchang showed significant differences (P < 0.05), and Wenchang’s diversity index value was higher. (4) The functional evenness index (FEve) and the functional dispersion index (FDis) of the shrub layer were significantly different, which were reflected between Wenchang City and the other two cities (P < 0.01 and P < 0.001, respectively). The diversity index value of Wenchang City was lower than that of Haikou and Sanya cities, which was consistent with the species diversity of the shrub layer. (5) The pedigree phylogenetic index (PD) of Wenchang City arbor layer was significantly higher than that of Haikou City (P < 0.01). The PD index of Sanya City shrub layer was significantly higher than that of Wenchang City. The PD index of Wenchang City herb layer was significantly higher than that of Haikou and Sanya cities (P < 0.01). The phylogenetic species evenness (PSE) results for the shrub and herb layers were consistent with the PD index (P < 0.001 and P < 0.01, respectively), but did not show significant differences in the arbor layer (P = 0.690).ConclusionThe vegetation types of the three cities in Hainan Province did not exhibit obvious homogeneity, while the differences in native species composition were more pronounced than those of exotic species. Species diversity, functional diversity and phylogenetic diversity levels in the three cities basically showed the same trend. In future studies, the analysis of plant diversity from multiple layers in cities could provide a more comprehensive decision-making basis for both the protection and the control of diversity patterns.