城市绿地群落结构完善度评价及生态管理对策:以深圳经济特区为例

在样地调查数据分析基础上,利用样地面积、乔木株数、乔木平均胸径、乔木平均高度、乔木平均冠幅、群落结构类型、群落总盖度构造了群落总体结构完善度指标(GSCI)和单位面积群落结构完善度指标(USCI),对深圳特区城市绿地植物群落结构完善度进行了评价,并利用Shannon-W iener指数、S impson指数、Hurlbert均匀度指数和P ielou均匀度指数对群落物种多样性进行了评价.结果表明现有绿地群落结构的完善程度还不是太理想,稀树草坪式结构的绿地占了相当比例;GSCI与USCI之间存在着极显著的相关性(df=74,r=0.863 6,p<0.01),但USCI更适宜于测度群落完善程度;对人为干扰频繁的城市绿地而言,样地面积的大小并未能影响群落物种多样性程度的高低(df=74,r=0.1621,p=0.1590).最后提出了城市绿地的生态管理对策.

Assessment of Structural Complexity and Ecological Management Policy for Urban Green Space: A Case Study of Shenzhen Special Economic Zone

Field data were collected and analyzed to better understand urban forest ecosystems of Shenzhen Special Economic Zone.Based on factor analysis,seven items including area of plots,number of trees,mean diameter at breast height (DBH) of trees,mean height of trees,mean canopy width of trees,community's structural layers,and community's overall coverage were used to form two indices: General Structural Complexity Index(GSCI) and Unitary Structural Complexity Index(USCI).The two indices were developed to assess the overall structural complexity of plant communities.In addition,species diversity was assessed by using Shannon-Wiener,Simpson,Hurlbert,and Pielou indices.Results showed that the overall structural complexity of plant communities were still at low level,which was characterized with widespread combination of sparse trees and lawns;there existed the significant correlation between GSCI and USCI(df =74,r=0.8636,p<0.01),and USCI was more suitable to measure the overall structural complexity;under the frequent human disturbance,there did not exist the significant correlation between area of plot and overall species diversity(df=74,r=0.1621,p=0.1590).Finally,aiming at enhancement of urban forest ecosystems of Shenzhen Special Economic Zone,corresponding management policies and suggestion were put forward.