植物群落特征对城市公园绿地碳汇效能的影响研究

Effects of Plant Community Characteristics on Carbon Sequestration Ef ciency in Urban Parks

城市公园绿地作为城市范围内具有固碳作用的主要生态资源,具有不可或缺的生态价值,在缓解和应对全球气候变化的过程中发挥着至关重要的作用。为了探究影响城市公园绿地植物群落碳汇效能的关键特征因子,有效提升城市生态系统的碳汇绩效,以杭州经济技术开发区的城市公园绿地为研究对象,共选取72个样地,对植物群落特征因子(落叶树种占比、平均径级、平均冠幅、平均固碳能力和样地密度)与碳汇效能之间的关系进行Pearson相关性分析。结果表明:(1)常绿树种与落叶树种对植物群落碳汇效能的贡献能力相当;(2)当径级范围在10~20 cm时,平均径级对植物群落碳汇效能具有显著正向影响;(3)平均冠幅对植物群落碳汇效能具有显著正向影响;(4)平均固碳能力对植物群落碳汇效能具有显著正向影响,植物群落中高碳汇树种的比例越高,碳汇效能越高;(5)群落密度虽然是实现高碳汇效能的基础条件,对碳汇效能有一定的促进作用,但具备高密度,并不一定具备高碳汇效能,低密度植物群落通过合理配置也能具备高碳汇效能。最后提出了城市公园绿地高碳汇植物群落优化设计策略,以期为后续城市公园绿地碳汇能力的研究和建设提供参考,提升城市绿地碳汇对中国2060年实现碳中和目标的贡献。

Urban park green space has indispensable ecological value as a signifi cant environmental resource with carbon sequestration within the city.In addition,it plays a crucial role in mitigating and responding to global climate change.To explore the critical characteristic factors affecting the carbon sequestration effi ciency of the urban park green space plant community and effec-tively improve the carbon sequestration performance of the urban ecosystem,a total of 72 plots were selected from urban park green space in Hangzhou Economic and Technological Development Zone.SPSS software was used to analyze the relationship between plant community distinguishing factors(proportion of deciduous species,mean diameter class,mean crown magni-tude,mean carbon sequestration capacity,and plot density)and carbon sequestration effi ciency.The results showed that:(1)Evergreen trees and deciduous trees had the same contribution to the carbon sink effi ciency of plant communities;(2)When the diameter class range is 10~20 cm,the average diameter class has a signifi cant positive impact on the carbon sink effi ciency of plant communities;(3)The average canopy width has a signifi cant positive impact on the carbon sink effi ciency of plant communities;(4)The average carbon sequestration capacity has a signifi cant positive impact on the carbon sequestration ef-fi ciency of plant communities.The higher the proportion of high carbon sequestration tree species in plant communities,the higher the carbon sequestration effi ciency;(5)Although community density is the essential condition for achieving high carbon sequestration effi ciency and has a specifi c role in promoting carbon sequestration effi ciency,high density does not necessarily have high carbon sequestration effi ciency.Low-density plant communities can also have high carbon sequestration effi ciency through reasonable collocation.At the end of the study,the optimization design strategy of plant communities with high carbon sinks in urban park green space was proposed to provide a reference for the subsequent research and construction of carbon sink capacity of urban park green space and improve the contribution of urban green space carbon sink to China’s carbon neu-tral goal in 2060.