基于功能特征的城市植物群落生态功能评价

Evaluation of ecological function for urban plant communities based on functional traits

功能特征是植物实现生态功能的重要基础,基于功能特征的功能多样性是评价生物多样性和植物功能的重要指标。本文基于深圳市建成区587个乔灌植物样地和1779个草本植物样地的调查数据,分析主要植物群落类型及其功能特征,比较不同绿地类型乔灌草植物在滞尘、降噪、降温增湿、生物多样性保护等四个生态功能方面的功能多样性。TWINSPAN分类结果表明,41个乔灌群落类型和54个草本群落类型中,涉及乔灌样地数量≥10个的群落类型有9个,涉及草本样方数量≥30个的群落类型共15个。对群落标志植物及优势植物功能特征的分析显示,乔灌植物常见为阔叶(100%)、常绿(79.47%)、小树冠(93.04%)、不固氮(90.54%)、叶片无毛或近无毛(76.95%),草本植物则多为小型果(97.07%)、干果(91.33%)、不固氮(93.9%)。各绿地类型功能多样性的排序在乔灌植物与草本植物之间大致相反。乔木植物的滞尘、降噪、降温及生物多样性功能的多样性均以公园绿地最高,灌木植物则分别以居住区、公园、道路及公园绿地最高,草本植物以上前3种功能以荒地最高,最后一种以居住区绿地最高。荒地与其他绿地群落结构差异较大。建议深圳市建成区绿地建设进一步重视居住区及单位绿地各项功能的多样性。本研究可为城市植物功能评价及城市植物规划与物种配置、生物多样性保护和提高生态系统服务提供借鉴。

Functional traits are important foundation for the ecological functions of plants.Functional diversity based on functional traits is an important indicator for assessing biodiversity and plant functions.With the investigation data of 587 tree-shrub plots and 1779 herb plots in the built-up area of Shenzhen,we analyzed plant community types and their functional traits,compared functional diversity of plants from the perspective of four ecological functions,including dust retention,noise attenuation,temperature reduction and humidity increase,and biodiversity conservation.The results of TWINSPAN classification showed that among the 41 tree-shrub community types and 54 herb community types,there were nine tree-shrub community types with≥10 plots and 15 herb community types with≥30 plots.The analyses on indicator species and dominant species in communities by plots showed that functional traits of trees and shrubs were commonly broadleaf(100%),evergreen(79.47%),small crowns(93.04%),non-N-fixing plants(90.54%),leaf glabrous or hairless(76.95%),and herb plants were mostly small fruit(97.07%),dried fruit(91.33%),and non-N-fixing plants(93.9%).The orders of functional diversities for different types of green space were roughly opposite for tree-shrub and herb.The highest functional diversities of dust retention,noise attenuation,temperature reduction and humidity increase and biodiversity conservation for trees all presented in park green space.For shrubs,the highest values were found in residential zone,park,road and park green space.For herbs,the highest values of the first three functions were found in wasteland,and that of the last one was in residential green space.Community structures of wasteland were different with other green space.Our results suggest that the construction of green space in the built-up area of Shenzhen should pay more attention to functional diversity of residential and institutional green space.This study provides reference for the evaluation of urban vegetation function,planning and design of green space,selection of plant species,urban biodiversity conservation,and ecosystem service improvement.