安全与环境学报

为了评估公路路域植被对施工碳排放的固碳潜力及抵消能力，研究基于路域植被数据构建固碳计算模型，选取树高、胸径、冠幅为主导特征因子，土壤有机碳与根系生物量为次要因子，结合Pearson相关性分析及样方调查与异速生长方程，估算公路两侧20 m范围内圆柏固碳量。结果显示：植被固碳能力受群落结构与多因子共同影响，其中特定规格树种（平均胸径＞0.18 m、平均树高＞6 m、平均冠幅＞11 m）的固碳潜力更强。研究路段2 a建设期的累计固碳量为50.60 t/km，施工期第1年与第2年碳中和率分别为8%、5%，计算结果显示，需要32 a才能抵消工程碳排放，表明仅依靠路域绿化难以短期实现碳中和。研究可为公路路域植被固碳能力评估与低碳公路建设提供科学依据，并缩短碳补偿周期。

A carbon sequestration calculation model was developed based on roadside vegetation data， using tree height， Diameter at Breast Height (DBH)， and crown spread as primary characteristic factors， while soil organic carbon and root biomass served as secondary factors. Pearson's correlation analysis was conducted to examine the relationships between these characteristic factors and carbon stocks. By combining this analysis with field plot survey data and allometric growth equations， the carbon sequestration capacity of Juniperus chinensis within a 20-meter radius on either side of the road was estimated. The results indicate that the carbon sequestration capacity of vegetation is influenced by multiple factors， including community composition， tree species diversity， tree height， DBH， and crown spread. Specifically， trees with certain dimensions (DBH > 0.18 m， tree height > 6 m， crown spread > 11 m) demonstrated significantly greater carbon sequestration potential. Based on growth stages， the study sample was categorized into three groups: young， middle-aged， and mature stands. During the young stand stage， crown spread exhibited the strongest influence on carbon density; the middle-aged stage proved crucial for increasing carbon density， while the mature stage saw the highest levels of carbon stored per tree and total carbon storage. The optimal planting density was determined to be 0.25–0.33 trees/m². Over the two-year construction period of the study section， the vegetation sequestered a cumulative total of 50.60 t/km， resulting in carbon neutrality rates of 8% and 5% in the first and second years， respectively. It is estimated that approximately 32 years will be needed to fully offset construction-related carbon emissions. By establishing a tiered planting system based on the varying carbon sequestration capabilities of different tree species and clearly quantifying engineering parameters， it has been demonstrated that prioritizing tree species with high carbon sequestration potential can enhance the overall carbon sequestration efficiency of the community. This approach not only improves the carbon sequestration efficiency of roadside vegetation but also mitigates the delayed carbon sequestration effect observed in young forests.