南宁市几个功能区的植被群落结构特征分析

Vegetation Community Structure in Different Functional Areas of Nanning City, Guangxi Province

摘要:

借助数量分析技术分析了广西南宁市植被结构特征。结果表明：（1）主要的绿化乔木有45种，灌木24种。这些植物基本上代表了南宁市绿化植物的主体，但在生物量比重等方面，还是少数种类占主要优势，亟待调整。（2）绿地植被群落的平均胸径与密度成极显著负相关，显示城市植被与自然植被的相似性，而总冠幅盖度与总密度和综合重要值之间成极显著正相关，则显示了城市人工植被的特殊性；（3）绿地面积与胸径成显著正相关，而与密度、冠幅盖度成极显著与近显著的负相关，与重要值成负相关，则显示空间资源对群落特征的影响与自然植被是相似的；（4）聚类分析与主分量分析反映了人工绿地的群体特征，分类结果与功能区划分基本一致，个别样地则不一致；无论格局多样化，还是格调较为均一的绿色景观，均反映了人文美学价值取向对绿地建设的影响；（5）整体上看，南宁市植被结构还存在较大的优化空间。

Abstract:

Based on a forest survey in Nanning city, this paper discusses the characteristics of the urban forest. Seventeen patches of the forest were selected for this survey, representing 4 functional areas of the city, i.e. education, living, transportation and commercial areas. There were 45 tree species and 24 shrub species as major components of the urban greening. Minority species were dominant in biomass. The pattern of the species distribution needs a rapid improvement. The average DBH of the community was significantly correlated with density, indicating the similarity between urban forest and natural forest. However, negative correlation between canopy coverage and density or modified importance value （mlV） suggested that the urban forest was special. Forest area had a significantly positive corelation with DBH, while importance index, indicating that spatial resources had negative with density, canopy coverage and synthetic same impact on community structure in urban forest as those in natural forest. The result of the classification of the urban forests by cluster and PCA analysis coincided with that based on the functional area, except a few patches of the forests. The patterns of the forest distribution in functional areas reflected that human cultural value had an impact on greening events. The vegetation community in the city still had large space to be improved and optimized.