In the high-Arctic, increased temperature results in permafrost thawing and increased primary production. This fresh plant-derived material is predicted to prime microbial consortia for degradation of the organic matter stored in tundra soils. However, the effects of warming and plant input on the microbial community structure is hardly known. We assessed the use of glycine, a readily available C and N source, and cellulose, a long C-biopolymer, by prokaryotic and fungal communities using DNA-SIP in tundra soils incubated at 8 °C or 16 °C. Glycine addition contributed mainly to instantaneous microbial carbon use and priming of soil organic matter decomposition, particularly under elevated temperature. By contrast, cellulose was linked to the dominant and active microbial communities, with potential carbon stabilization in soils. Our findings stress the importance of the type of plant-derived material in relation to microbial metabolism in high-Arctic soils and their consequences for the carbon cycle in response to global warming.

在高北极地区，温度升高会导致永久冻土融化并增加初级生产力。预计这种新鲜的植物衍生材料会引发微生物群落，以降解储存在苔原土壤中的有机物质。然而，气候变暖和植物输入对微生物群落结构的影响鲜为人知。我们评估了原核和真菌群落使用 DNA-SIP 在 8°C 或 16°C 温育的苔原土壤中对甘氨酸（一种容易获得的 C 和 N 源）和纤维素（一种长 C-生物聚合物）的使用。添加甘氨酸主要有助于瞬时微生物碳的使用和土壤有机质分解的引发，特别是在高温下。相比之下，纤维素与主要和活跃的微生物群落有关，在土壤中具有潜在的碳稳定作用。