Terrestrial Ecology Section, Department of Biology, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark;
Center for Permafrost (CENPERM), University of Copenhagen, DK-1350 Copenhagen K, Denmark.
Proc Natl Acad Sci U S A. 2020 Dec 22;117(51):32476-32483. doi: 10.1073/pnas.2008901117. Epub 2020 Nov 30.
Volatile organic compounds (VOCs) are released from biogenic sources in a temperature-dependent manner. Consequently, Arctic ecosystems are expected to greatly increase their VOC emissions with ongoing climate warming, which is proceeding at twice the rate of global temperature rise. Here, we show that ongoing warming has strong, increasing effects on Arctic VOC emissions. Using a combination of statistical modeling on data from several warming experiments in the Arctic tundra and dynamic ecosystem modeling, we separate the impacts of temperature and soil moisture into direct effects and indirect effects through vegetation composition and biomass alterations. The indirect effects of warming on VOC emissions were significant but smaller than the direct effects, during the 14-y model simulation period. Furthermore, vegetation changes also cause shifts in the chemical speciation of emissions. Both direct and indirect effects result in large geographic differences in VOC emission responses in the warming Arctic, depending on the local vegetation cover and the climate dynamics. Our results outline complex links between local climate, vegetation, and ecosystem-atmosphere interactions, with likely local-to-regional impacts on the atmospheric composition.
挥发性有机化合物（VOCs）会随温度变化从生物源中释放出来。因此，随着气候持续变暖，北极生态系统预计将大幅增加其 VOC 排放量，而目前的变暖速度是全球气温上升速度的两倍。在这里，我们表明，持续的变暖对北极 VOC 排放有强烈的、不断增加的影响。我们结合了来自北极苔原的几项变暖实验的数据的统计建模和动态生态系统建模，将温度和土壤湿度的影响通过植被组成和生物量变化分解为直接影响和间接影响。在 14 年的模型模拟期间，变暖对 VOC 排放的间接影响虽然显著，但小于直接影响。此外，植被变化还会导致排放的化学形态发生变化。直接和间接的影响导致变暖的北极地区的 VOC 排放响应存在巨大的地域差异，这取决于当地的植被覆盖和气候动态。我们的研究结果概述了局部气候、植被和生态系统-大气相互作用之间的复杂联系，这可能会对大气成分产生局部到区域的影响。
