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林业科学 ›› 2025, Vol. 61 ›› Issue (6): 85-98.doi: 10.11707/j.1001-7488.LYKX20240612

• 研究论文 • 上一篇    下一篇

林火烟气沉降背景下土壤理化性质对杉木挥发性有机物排放特征的影响

陈佳宇,李哲瀚,赵平欣,詹笑宇,马远帆,郭福涛*()   

  1. 福建农林大学林学院 海峡两岸红壤区水土保持协同创新中心 福州 350002
  • 收稿日期:2024-10-19 出版日期:2025-06-10 发布日期:2025-06-26
  • 通讯作者: 郭福涛 E-mail:guofutao@126.com
  • 基金资助:
    国家自然科学基金(32171807)。

Effects of Soil Physicochemical Properties on Emission Characteristics of Biogenic Volatile Organic Compounds from Cunninghamia lanceolata under Forest Fire Smoke Deposition

Jiayu Chen,Zhehan Li,Pingxin Zhao,Xiaoyu Zhan,Yuanfan Ma,Futao Guo*()   

  1. College of Forestry, Fujian Agricultural and Forestry University Collaborative Innovation Center of Soil and Water Conservation inRed Soil Region of the Cross-Strait Fuzhou 350002
  • Received:2024-10-19 Online:2025-06-10 Published:2025-06-26
  • Contact: Futao Guo E-mail:guofutao@126.com

摘要:

目的: 揭示林火烟气沉降背景下土壤理化性质对杉木挥发性有机物释放特征的影响,探讨火后土壤-植物-大气之间的相互作用,为火后生态修复与大气环境评估提供科学依据。方法: 选择福建省三明市尤溪县国有林场的杉木幼苗作为研究对象,设置烟气空白组、低浓度组和高浓度组,分别燃烧0、50和150 g可燃物进行烟气处理。在密闭烟气处理后的第7、30和90天,利用预浓缩系统和气相色谱-质谱联用仪测定植物挥发物的化学组成及释放速率,连续监测土壤理化性质变化,并运用结构方程模型(SEM)分析林火烟气浓度、杉木挥发性有机物释放速率、土壤理化性质间的潜在关联。结果: 1)林火烟气处理后的第7天烟气浓度对10~20 cm土层氮含量和10~20 cm土层pH值有显著正效应,第30天时对10~20 cm土层氮含量有显著负效应,而对10~20 cm土层pH值有显著正效应。第90天时对10~20 cm土层pH有显著负效应。随烟气处理后时间的推移,除0~20 cm土层中磷含量和0~10 cm土层的低浓度组中碳含量在第30天下降并于90天回升外,0~20 cm土层中氮含量、pH值、电导率和10~20 cm土层碳含量均呈下降趋势。2)杉木释放出8种重要的烯烃,包括1-丁烯、1-己烯、反式-2-丁烯、顺式-2-丁烯、1-戊烯、异戊二烯、反式-2-戊烯和顺式-2-戊烯,其中异戊二烯、1-己烯、1-戊烯和1-丁烯的释放速率最高,处理后30天时各杉木挥发性有机物释放速率显现差异,90天时趋于一致。烟气处理后30天时烟气浓度与异戊二烯的释放速率有显著负相关(P<0.01)。处理后90天时反式-2-丁烯的释放速率相较空白组显著下降(P<0.01)。在低浓度处理组中,处理后第7天时显著提高了1-丁烯的释放速率(P<0.01)。3)林火烟气改变了土壤的理化性质,土壤氮、磷元素含量、pH值与杉木挥发性有机物的释放存在一定联系,10~20 cm土层氮含量对异戊二烯的释放有直接的显著正效应(P<0.001),0~10 cm土层磷含量对异戊二烯的释放速率有直接的显著负效应(P<0.01),10~20 cm土层pH值对异戊二烯的释放速率有直接的极显著负效应(P<0.001)。结论: 在林火烟气沉降背景下,土壤理化性质(尤其是土壤氮含量、磷含量、pH值)的动态变化对杉木的异戊二烯等挥发性有机物的排放具有显著调控作用。这些发现丰富了林火发生后土壤-植物-大气环境的理论,也可为火后生态管理提供建议,如适量补充氮肥可以增强植物的抗氧化能力,合理地施磷和调节土壤pH值有助于控制植物挥发性有机物的排放,降低对区域空气质量的影响。

关键词: 林火烟气, 杉木, 挥发性有机物, 土壤理化性质, 结构方程模型

Abstract:

Objective: The study aim to reveal the effects of soil physicochemical properties on the emission characteristics of biogenic volatile organic compounds from Cunninghamia lanceolata under forest fire smoke deposition. It further explores the post fire interactions among soil, vegetation, and the atmosphere, providing a scientific basis for ecological restoration and atmospheric environmental assessment after forest fires. Method: C. lanceolata seedlings from the state-owned forest farm of Youxi County, Sanming City, Fujian Province were selected as the research objects. A blank group, a low-concentration group, and a high-concentration group were set up to burn 0, 50, and 150 g of combustibles for flue gas treatment. At 7, 30, and 90 days after enclosed smoke exposure, the chemical composition and emission rates of plant volatiles were determined using a preconcentration system coupled with gas chromatography-mass spectrometry (GC-MS). Concurrently, changes in soil physicochemical properties were continuously monitored, and structural equation modeling (SEM) was employed to analyze the potential relationships among smoke concentration, the emission rates of biogenic volatile organic compounds from C. lanceolata, and soil physicochemical parameters. Result: 1) On day 7 after smoke treatment, smoke concentration had a significant positive effect on both nitrogen content and pH in the 10–20 cm soil layer. By the 30th day, it exhibited a significant negative effect on nitrogen content in that layer while maintaining a significant positive effect on pH. On the day 90, smoke concentration showed a significant negative effect on pH in the 10–20 cm layer. Over time following smoke treatment, with the exception of phosphorus in the 0–20 cm layer and carbon in the low concentration group of the 0–10 cm layer, which declined on day 30 and rebounded by day 90. The nitrogen content, pH, and electrical conductivity in the 0–20 cm layer, as well as carbon content in the 10–20 cm layer, all displayed a continuous downward trend. 2) Eight important olefins were released from C. lanceolata, including 1-butene, 1-hexene, trans-2-butene, cis-2-butene, 1-pentene, isoprene, trans-2-pentene and cis-2-pentene, among them, isoprene, 1-hexene, 1-pentene and 1-butene exhibited the highest emission rates. At 30 days post-treatment, the emission rates of biogenic volatile organic compounds from C. lanceolata showed differences among, which tended to converge by day 90. At 30 days post-treatment, smoke concentration exerted a significant negative effect on isoprene emission rate (P<0.01). By 90 days post-treatment, the emission rate of trans-2-butene was significantly lower than that of the control(P<0.01). In the low concentration treatment group, 1-butene emission rate was significantly elevated at 7 days post-treatment(P<0.01). 3) Forest fire smoke altered the physicochemical properties of the soil, among which nitrogen and phosphorus content, as well as soil pH, were closely associated with the emission of biogenic volatile organic compounds from C. lanceolata. Structural equation modeling showed that soil nitrogen content had a direct, significant positive effect on isoprene emission (P?<?0.001), while soil phosphorus content had a direct, significant negative effect (P?<?0.01). Additionally, soil pH exhibited a highly direct, significant negative effect on isoprene emission (P?<?0.001).【Conclusion】Under the context of forest fire smoke deposition, dynamic changes in soil physicochemical properties, especially soil nitrogen and phosphorus contents and pH, significantly regulate the emissions of biogenic volatile organic compounds such as isoprene from C. lanceolata. These findings enrich our understanding of the soil-plant-atmosphere interactions following forest fire and offer guidance for post fire ecological management: for example, moderate nitrogen supplementation can enhance plant antioxidant capacity, while judicious phosphorus application and pH adjustment help control biogenic volatile organic compounds emissions and mitigate regional air quality impacts.

Key words: forest fire smoke, Cunninghamia lanceolata, biogenic volatile organic compounds, soil physicochemical properties, structural equation model(SEM)

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