掌握生态岸坡植被特征及碳密度,可为“双碳”目标下护岸工程型式的选择和植被应用方案提供参考。通过对天津市3条城市一级河道的7个典型生态护岸工程型式的岸坡植被进行现场调查,利用生物量和含碳系数计算不同护岸工程型式(自然原型、自然型、多自然型、人工型)及坡位(坡顶、坡面、坡脚)的植被碳密度。结果表明:1)坡顶生境条件不受工程型式影响,以人工林地为主,是岸坡最主要的碳储空间,其植被组成与结构因景观设计差异呈现多样化,植被种类、密度、群落结构及多样性均显著影响碳密度。2)坡面生境条件受护岸工程型式影响大,植被组成和结构对碳密度具有综合性影响。3)坡脚以自然生长的草本植物为主,植被碳密度在不同工程型式间没有显著差异。4)在实际工程中,岸坡坡顶在植物选择和群落结构设计上存在较大的优化空间,建议按照高碳密度植物群落模式营建;在坡面,应通过精细的生境分析,适当地引入灌木和木质藤本植物,提升坡面的碳储量;在坡脚,应以保证工程稳定性和加强水陆土壤的连接为主,整体提升岸坡的碳储量。

Understanding the vegetation characteristics and carbon density of ecological slopes is crucial for selecting appropriate revetment engineering types and vegetation schemes under China's carbon neutrality and peaking goals.This study was conducted to study the vegetation characteristics of the ecological bank protection projects of seven typical sites along three primary urban rivers in Tianjin.Through field surveys,we calculated the carbon storage of vegetation at different revetment forms and locations using biomass and carbon content coefficients,and analyzed the carbon contribution of the slope vegetation.The results indicate that:1) Slope crests,dominated by artificial woodlands with arbor-shrub-grass or arbor-grass communities,serve as the primary carbon storage zones,where carbon density is influenced by plant species,density,community structure,and diversity;2) Slope faces,affected by revetment types,are primarily covered by herbaceous plants,with vegetation type significantly impacting carbon density;3) Slope toes,characterized by naturally growing herbs,show no significant differences in vegetation carbon density across revetment types.There is significant potential for optimization in the selection of high-carbon storage plants and community structures.It is recommended to construct according to high-carbon storage plant community models.By conducting a detailed habitat analysis of the slope surface and appropriately introducing shrubs and vines,significant carbon storage functions can be achieved.The carbon density of the vegetation at the toe of the slope did not show significant differences between different forms.It is recommended to focus on stability and strengthening the connection between aquatic and terrestrial soils at the foot of bank revetment,thus enhancing the overall carbon storage contribution of the slope.