The potential consequences of global warming for ecosystem carbon stocks are a major concern, particularly in high-latitude regions where soil carbon pools are especially large. Research on soil and plant carbon responses to warming are often based on short-term (< 10 year) warming experiments. Furthermore, carbon budgets from boreal forests, which contain at least 10–20% of the global soil carbon pool, have shown mixed responses to warming. In this study, we measured carbon and nitrogen budgets (i.e., soil and understory vegetation carbon and nitrogen stocks) from a 13-year greenhouse warming experiment in an Alaskan boreal forest. Although there were no differences in total aboveground + belowground pools, the carbon in the moss biomass and in the soil organic layer significantly decreased with the warming treatment (− 88.3% and − 19.1%, respectively). Declines in moss biomass carbon may be a consequence of warming-associated drying, while shifts in the soil microbial community could be responsible for the decrease in carbon in the soil organic layer. Moreover, in response to warming, aboveground plant biomass carbon tended to increase while root biomass carbon tended to decrease, so carbon allocation may shift aboveground with warming. Overall these results suggest that permafrost-free boreal forests are susceptible to soil carbon loss with warming.

中文翻译：

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土壤和植物的碳预算对阿拉斯加北方森林长期变暖的反应

全球变暖对生态系统碳储量的潜在后果是一个主要问题，特别是在土壤碳库特别大的高纬度地区。土壤和植物碳对变暖的反应研究通常基于短期（<10 年）变暖实验。此外，至少占全球土壤碳库 10-20% 的北方森林的碳收支对变暖的反应不一。在这项研究中，我们测量了阿拉斯加北方森林 13 年温室变暖实验中的碳和氮收支（即土壤和林下植被碳和氮库）。尽管地上+地下池的总量没有差异，但苔藓生物量和土壤有机层中的碳随着升温处理显着降低（- 88.3% 和- 19.1%，分别）。苔藓生物量碳的减少可能是与变暖相关的干燥的结果，而土壤微生物群落的变化可能是土壤有机层中碳减少的原因。此外，响应于变暖，地上植物生物量碳趋于增加，而根系生物量碳趋于减少，因此碳分配可能随着变暖而转移到地上。总体而言，这些结果表明，无永久冻土的北方森林随着变暖容易受到土壤碳损失的影响。地上植物生物量碳呈增加趋势，而根系生物量碳呈下降趋势，因此碳分配可能随着气候变暖而转移到地上。总体而言，这些结果表明，无永久冻土的北方森林随着变暖容易受到土壤碳损失的影响。地上植物生物量碳呈增加趋势，而根系生物量碳呈下降趋势，因此碳分配可能随着气候变暖而转移到地上。总体而言，这些结果表明，无永久冻土的北方森林随着变暖容易受到土壤碳损失的影响。