青岛不同城市公园木本植物对群落β多样性的贡献

Contribution of Woody Plants toβDiversity in Different Urban Parks of Qingdao

为衡量城市公园中木本植物的分布及物种构成对城市绿地生态系统植物多样性的影响和重要性,以青岛太平山公园及其周边小型公园的木本植物群落为研究对象,运用植物群落二元丰富度的方差分解法探讨物种对研究区域β多样性的贡献(SCBD)和样地对研究区域β多样性的贡献(LCBD),进一步分析了单一物种、不同科类、不同植物类型及不同园区对β多样性的相对重要性。主要结果:单一物种对群落β多样性的影响与其在不同园区出现的机会相关,出现频数过高的优势树种和出现频数过低的弱势树种对群落β多样性的贡献均较低,而出现频数居中的树种如朴树(Celtis sinensis)、榉树(Zelkova serrata)、黄连木(Pistacia chinensis)等木本植物对群落β多样性的贡献最高;木本植物群落中的优势科如蔷薇科(Rosaceae)、柏科(Cupressaceae)、松科(Pinaceae)、无患子科(Sapindaceae)对群落β多样性有重要贡献,其科类下的物种组成数量较高,同时物种独特性程度也较高;青岛城市公园的木本植物类群以落叶阔叶树种为主,从整体上看,落叶植物的SCDB值高于常绿植物,阔叶植物的SCDB值高于针叶植物,但从个体水平上看,落叶树种的SCBD平均值低于常绿树种,阔叶树种的SCBD平均值低于针叶树种,虽然常绿植物或针叶植物的物种丰富度较低,但物种独特性较高,具有较高的保护价值;中中山公园对群落β多样性的贡献度最大,LCBD值与园区的物种丰富度呈正相关关系。应加强保护物种丰富度较高的公园,同时利用不同园区的环境异质性增加木本植物的独特性这对保护城市绿地植物多样性具有重要价值。

To evaluate the influence and importance of woody plants’distribution and species composition in urban parks on the plant diversity of urban green space ecosystems,the woody plant communities in Taiping Mountain Park and its surrounding small parks in Qingdao City were studied.The variance decomposition method of the bivariate richness of plant communities investigated the contribution of species toβDiversity(SCBD)and plots toβdiversity(LCBD).The relative importance of single species,families,plant types,and parks toβdiversity was further analyzed.The main results:The influence of single species onβdiversity was related to its occurrence in different parks.The dominant tree species with a high frequency of occurrence and the weak tree species with a low frequency of occurrence had lower contributions toβdiversity.The most frequent tree species,such as Celtis sinensis,Zelkova serrata,and Pistacia chinensis,contributed most toβdiversity.The dominant families in the woody plant community,such as Rosaceae,Cupressaceae,Pinaceae,and Sapindaceous,made essential contributions toβdiversity,and their species composition and specialism were higher than other families.Deciduous broad-leaved tree species dominated the woody plant groups in Qingdao urban park.Overall,the SCDB values of deciduous plants were higher than those of evergreen plants,and those of broad-leaved plants were higher than those of coniferous plants.However,at the individual level,the average SCBD value of deciduous trees was lower than that of evergreen trees,and that of broad-leaved trees was lower than that of coniferous trees.Although the species richness of evergreen or conifer plants was lower,the species uniqueness of evergreen or conifer plants was higher,and they had higher conservation value.The contribution of Zhongshan Park toβdiversity was the largest,and the LCBD values were positively correlated with the species richness of the park.This study suggests that parks with high species richness should be protected,and using environmental heterogeneity in different parks to increase the uniqueness of woody plants is of great value in preserving the plant diversity of urban green space.