高速公路岩石路堑边坡不同恢复年限植被固碳量变化特征

Analysis on variation characteristics of vegetation carbon sequestration in highway rock cutting slope with different restoration years

摘要:

【目的】不同生长年限高速公路边坡植被的固碳量会随着植物生长、群落发育不断发生变化，本研究旨在分析小尺度、断续、独立的高速公路边坡生态恢复工程下植被固碳量变化特征。【方法】 以国家京沪高速公路山东境内植被恢复 2、12 和 22 年的 3 处岩石路堑边坡生态恢复工程为研究区，采用样方调查及生物量法对植被固碳量进行测算。【结果】区内共发现 35 种植物，8 种典型群落；2 年期坡面覆盖度达到 85%，平均高度 32 cm，分化出现了以禾本科 、菊科 、豆科为主的草本群落（VCS： 241. 75~286. 09 g/m² ）和以刺槐、紫穗槐、马棘、胡枝子为主的灌草群落（VCS：301. 72~323. 22 g/m² ）； 恢复 12、22 年坡面覆盖度超过 95%，平均高度 330 cm，物种明显增加，全部形成以刺槐、紫穗槐为主的优势群落（VCS：778. 86~808. 63 g/m² ）；禾本科杂草、爬藤植物的固碳效率较豆科草本植物低，以刺槐、紫穗槐、胡枝子、马棘为主的灌草群落单位面积的固碳能力远强于草本群落。【结论】该结果可为高速公路边坡的植物群落设计、公路养护管理、植被碳汇效益评估等提供参考。

Abstract:

【Objective】 The carbon sequestration of vegetation in highway slopes with different restoration years varies continuously with plant growth and community development. In the past，few studies have analyzed the change characteristics of vegetation carbon sequestration in small-scale，intermittent and independent highway slope ecologi- cal restoration projects.【Method】 Three rocky cutting slope ecological restoration projects in the years of vegetation resoration 2，12 and 22 of Beijing-Shanghai Expressway （G2） were studied，and vegetation carbon sequestration was calculated by quadrat survey and biomass method.【Result】 The results showed that 35 plant species and 8 typical communities were found in the area. The 2-year slope vegetation coverage reached 85%，and the average plant height reached 32 cm. These slopes had evolved herb communities and shrub - herb communities. The herb communities were dominated by Gramineae，Asteraceae and Leguminosae（VCS：241. 75~286. 09 g/m² ），and the shrub - herb communities were dominated by R. pseudoacacia，A. fruticosa，H. rhamnoides and L. bicolor （VCS：301. 72~ 323. 22 g/m² ）. The slope vegetation coverage of 12 and 22 years was more than 95%，and the average plant height reached 330 cm. The species increased significantly，all the dominant communities were dominated by Robinia pseudoacacia and Amorpha fruticosa （VCS：778. 86~808. 63 g/m² ）. Carbon sequestration efficiency of gramineous weeds and climbing plants was lower than that of leguminous herbs，carbon sequestration capacity per unit area of shrub-herb communities dominated by Robinia pseudoacacia，Amorpha fruticosa，Lespedeza bicolor and Hippophaerhamnoides was far greater than that of herb communities. This was consistent with the existing research results that shrubs contributed the most to the stability of slope vegetation.【Conclusion】 The conclusion could provide reference for plant community design，highway maintenance management and vegetation carbon sink benefit evaluation of high- way slopes.