Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Universitetsparken 15, DK -2100 Copenhagen E, Denmark; Center for Permafrost (CENPERM), Department of Geoscience and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, DK -1350 Copenhagen K, Denmark.
Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Universitetsparken 15, DK -2100 Copenhagen E, Denmark; Center for Permafrost (CENPERM), Department of Geoscience and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, DK -1350 Copenhagen K, Denmark.
Sci Total Environ. 2016 Dec 15;573:131-138. doi: 10.1016/j.scitotenv.2016.08.100. Epub 2016 Aug 21.
Emissions of biogenic volatile organic compounds (BVOCs) from terrestrial ecosystems are important for the atmospheric chemistry and the formation of secondary organic aerosols, and may therefore influence the climate. Global warming is predicted to change patterns in precipitation and plant species compositions, especially in arctic regions where the temperature increase will be most pronounced. These changes are potentially highly important for the BVOC emissions but studies investigating the effects are lacking. The aim of this study was to investigate the quality and quantity of BVOC emissions from a high arctic soil moisture gradient extending from dry tundra to a wet fen. Ecosystem BVOC emissions were sampled five times in the July-August period using a push-pull enclosure technique, and BVOCs trapped in absorbent cartridges were analyzed using gas chromatography-mass spectrometry. Plant species compositions were estimated using the point intercept method. In order to take into account important underlying ecosystem processes, gross ecosystem production, ecosystem respiration and net ecosystem production were measured in connection with chamber-based BVOC measurements. Highest emissions of BVOCs were found from vegetation communities dominated by Salix arctica and Cassiope tetragona, which had emission profiles dominated by isoprene and monoterpenes, respectively. These results show that emissions of BVOCs are highly dependent on the plant cover supported by the varying soil moisture, suggesting that high arctic BVOC emissions may affect the climate differently if soil water content and plant cover change.
陆地生态系统排放的生物源挥发性有机化合物（BVOC）对大气化学和二次有机气溶胶的形成很重要，因此可能会影响气候。预计全球变暖将改变降水和植物物种组成的模式，特别是在温度升高最明显的北极地区。这些变化对 BVOC 排放具有潜在的重要影响，但缺乏相关研究。本研究旨在调查从干燥苔原到湿地的高北极土壤水分梯度范围内的 BVOC 排放的质量和数量。使用推拉式围栏技术在 7 月至 8 月期间五次采样生态系统 BVOC 排放物，并使用气相色谱-质谱法分析吸附在吸收管中的 BVOC。使用点截距法估计植物物种组成。为了考虑到重要的基础生态系统过程，在与基于腔室的 BVOC 测量相关的测量中测量了总生态系统生产力、生态系统呼吸和净生态系统生产力。发现 BVOC 排放最高的植被群落由北极柳和北极紫菀主导，其排放特征分别以异戊二烯和单萜为主。这些结果表明，BVOC 的排放高度依赖于不同土壤水分所支持的植被覆盖，这表明如果土壤含水量和植被覆盖发生变化，高北极 BVOC 的排放可能会以不同的方式影响气候。
