西安市三环内居住用地附属绿地的整体及区域植被特征研究

Study on the Overall and Regional Vegetation Characteristics of the Resident-affiliated Green Space within the Third Ring Road of Xi’an City

[目的]通过调查西安三环路内居民区植被分布特征,为同类城市绿地空间合理布局提供参考。[方法]采用地理网格法对西安市三环路内的78个居民点进行了调查。在总体和区域尺度上,对植物种类、优势科属、应用频度、树种配置及树种丰富度等进行调查评估。[结果]树种丰富度8.78、多样性5.11、均匀度0.71、单调度0.06。树种聚集性明显,整体林龄较小,乔-灌-草群落占明显优势。乡土/外地、常绿/落叶、观赏/非观赏配置分别为1∶0.38、1∶3.84和1∶0.49。一至三环区从中心往外树种丰富度和数量逐渐增加,以乡土树种为主,外来树种所占比例逐渐增加,树木胸径呈降低趋势。[结论]建议应考虑树种的多样性及协调性,加强整个城市的树种配置,重视对一二环居民区配套绿化的更新,加大对三环区小树的管理和养护,发挥其改善环境的潜力。

[Objective]To reveal the vegetation distribution characteristics of the resident-affiliated green space within Third Ring Road of Xi’an,and provide reference for the greenspace planning and management of similar cities.[Method]The geographical grid method was conducted to select 78 residential sites within the Third Ring Road in Xi’an City.Based on the overall and the regional scale,the plant species,dominant families and genera,application frequency,tree species allocation and tree species richness of resident-affiliated green space was surveyed and evaluated.[Result]For the whole city,the richness of tree species was 8.78,the diversity was 5.11,the evenness was 0.71,and the single regulation was 0.06.The aggregation of tree species was obvious and the overall age of trees was young.For the vertical structure,the arbor-shrub-grass community accounted most.And the ratios of native/exotic,evergreen/deciduous,and ornamental/non-viewing were 1∶0.38,1∶3.84,and 1∶0.49,respectively.From the city center to outside,that is from first to third region,the tree species richness and trees amount increased gradually.Although all three regions were dominated by native trees,the proportion of exotic trees gradually increased.While the diameter at breast height(DBH)of trees showed an opposite trend.[Conclusion]For the whole city,we suggested that the diversity and coordination of tree species should be fully considered,and the allocation and maintenance of trees should be strengthened.For the first and second ring region,more attention should be payed to update the greenspace of the residential areas.For the third ring region,the management of greenspace should be strengthened to promote the growth of small trees and play their potential to improve the environment.