摘要
植物向大气中排放了大量的挥发性有机化合物(Biogenic volatile organic compounds,BVOCs),其中,异戊二烯(Isoprene,ISO)、单萜和倍半萜等作为主要组成物质,对地球的大气化学和生态系统有重要影响.毛竹(Phyllostachys edulis)是我国分布最广、面积最大的大型散生竹种,由于其快速的生长和繁殖能力,在碳封存和减缓气候变化方面具有巨大的潜力,但目前对于不同秆龄毛竹林VOCs排放组成和ISO排放影响的研究存在空白.本研究利用动态顶空法采集并研究了不同年龄毛竹(幼年竹、成熟竹和老龄竹)排放的VOCs组成和相对含量的日变化,并结合“G93”模型计算了ISO的标准化排放速率和日间排放动态.结果表明:(1)毛竹林日间共排放26~89种VOCs物质,不同年龄毛竹VOCs排放种类和数量差异较大,幼龄竹VOCs排放数量约为成熟竹和老龄竹的1.57和2.11倍,不同年龄毛竹共同排放的VOCs包括醇类、醛类、酮类、醚类、酸类和烃类18种物质;(2)从相对含量来看,不同年龄毛竹VOCs排放日变化中烃类物质排放相对含量最高,其中,老龄竹在14:00排放的烃类物质占比最高(97.72%);(3)不同年龄毛竹ISO排放速率存在显著差异,幼龄竹日间ISO排放速率约为成熟竹和老龄竹的1.27和2.65倍;(4)不同年龄毛竹ISO排放的环境敏感性不同,幼龄竹和成熟竹ISO排放速率具有明显的日变化规律,峰值分别出现在14:00((10.82±1.1)μg·g^(-1)·h^(-1))和12:00((7.38±1.3)μg·g^(-1)·h^(-1)),而老龄竹则没有发现明显的排放峰值.综上,毛竹VOCs排放组成和ISO排放速率受到年龄和日动态的双重影响,这可能与不同年龄毛竹ISO排放速率的光照和温度敏感性不同有关.因此,考虑到不同年龄毛竹排放ISO的差异和日间排放变化规律,建议估算毛竹林VOCs排放潜力及大气环境影响时应全面考虑竹林年龄组成和环境影响响应.同时,竹林培育实践中应该重视竹林年龄结构的管理,这也将降低毛竹林大气环境污染风险.
Plants emit significant amounts of biogenic volatile organic compounds (BVOCs) into the atmosphere,including isoprene (ISO),monoterpenes,and sesquiterpenes.These compounds have a significant impact on the Earth's atmospheric chemistry and ecosystems.Phyllostachys edulis,commonly known as Moso bamboo,is a widely distributed and large monopodial bamboo species in China.It has great potential for carbon sequestration and climate change mitigation due to its rapid growth and reproduction.However,research on the composition of VOCs and the effect of ISO emissions from different culm ages of Moso bamboo forests is lacking.The dynamic headspace method was used in this study to collect and analyse the composition and relative content of VOCs released by Moso bamboo of different ages (young,mature,and old) throughout the day.The'G93'model was integrated to calculate the standardized emission rate and diurnal emission dynamics of ISO.The results indicate that Moso bamboo forests emit 26 to 89 diverse VOCs,with significant variations in both types and quantities across varying ages of bamboo.Juvenile bamboo emits approximately 1.57 and 2.11 times more VOCs than mature and old bamboo,respectively.The VOCs commonly released by Moso bamboos of varying culm ages consist of a group of 18 substances,including alcohols,aldehydes,ketones,ethers,acids,and hydrocarbons.Among the daily VOCs emissions from bamboos of different ages,hydrocarbon emissions,with isoprene (ISO) as the predominant compound,accounted for the highest proportion.Significant differences were observed in the ISO emission rates from Moso bamboos of different culm ages.Additionally,it is worth noting that the proportion of hydrocarbon emissions peaked at 14:00 for old bamboo,reaching 97.72%.It is important to maintain a clear and concise structure when presenting technical information.The daytime ISO emission rate from juvenile bamboo was found to be 1.27 and 2.65 times greater than that from mature and old bamboos,respectively.Notably,ISO emissions from Moso bamboo exhibited distinct sensitivities to environmental conditions based on age,with significant diurnal patterns in emission rates for both juvenile and old bamboos.The peak emission rates occurred at 14:00 ((10.82±1.1)μg·g^(-1)·h^(-1)) for juvenile bamboo and 12:00 ((7.38±1.3)μg·g^(-1)·h^(-1)) for old bamboo.No significant emission peak was observed for old bamboo.In summary,the emission profile of VOCs and ISO emission rates from Moso bamboo are affected by both the age of the bamboo and diurnal dynamics.This is mainly due to the differences in light and temperature sensitivities of ISO emission rates across different bamboo ages.Therefore,when estimating the potential VOCs emissions from Moso bamboo forests and their impact on the atmospheric environment,it is suggested to comprehensively consider the age composition of bamboo forests and the corresponding environmental impact,due to the differences in ISO emissions from Moso bamboo of different ages and the pattern of diurnal emission changes.Furthermore,it is important to focus on managing the age structure of Moso bamboo forests in cultivation practices.This will not only help to reduce the risk of atmospheric pollution in these forests but also ensure their sustainable growth.
作者
杨滨锴
姜萌微
王超
李丽
王福升
王效科
董丽娜
YANG Binkai;JIANG Mengwei;WANG Chao;LI Li;WANG Fusheng;WANG Xiaoke;DONG Lina(Bamboo Research Institute,Nanjing Forestry University,Nanjing 210037;School of Ecology and Environment,Nanjing Forestry University,Nanjing 210037;Co-Innovation Center for the Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037;Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085;Zhongshan Cemetery Administration,Nanjing 210014)
出处
《环境科学学报》
CAS
CSCD
北大核心
2024年第7期377-387,共11页
Acta Scientiae Circumstantiae
基金
国家自然科学基金面上项目(No.32171586,31971509)
江苏省“青蓝工程”优秀青年教师骨干计划(2022)。
