Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA.
Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH 03824, USA.
Science. 2017 Oct 6;358(6359):101-105. doi: 10.1126/science.aan2874.
In a 26-year soil warming experiment in a mid-latitude hardwood forest, we documented changes in soil carbon cycling to investigate the potential consequences for the climate system. We found that soil warming results in a four-phase pattern of soil organic matter decay and carbon dioxide fluxes to the atmosphere, with phases of substantial soil carbon loss alternating with phases of no detectable loss. Several factors combine to affect the timing, magnitude, and thermal acclimation of soil carbon loss. These include depletion of microbially accessible carbon pools, reductions in microbial biomass, a shift in microbial carbon use efficiency, and changes in microbial community composition. Our results support projections of a long-term, self-reinforcing carbon feedback from mid-latitude forests to the climate system as the world warms.
在一项为期 26 年的中纬度硬木林土壤增温实验中，我们记录了土壤碳循环的变化，以研究其对气候系统的潜在影响。我们发现，土壤增温导致土壤有机质分解和二氧化碳向大气释放出现四阶段模式，其中包括大量土壤碳损失阶段和无明显损失阶段交替出现。有几个因素共同影响土壤碳损失的时间、幅度和热驯化。这些因素包括微生物可利用碳库的枯竭、微生物生物量的减少、微生物碳利用效率的转变以及微生物群落组成的变化。我们的研究结果支持了从中纬度森林向气候系统释放长期、自我强化的碳反馈的预测，因为世界正在变暖。
