Permafrost regions store a large amount of soil organic carbon (SOC). Although permafrost degradation with climate warming can stimulate soil organic matter (SOM) decomposition, it remains unknown that whether the permafrost existence benefits SOM preservation. Here, a boundary area of permafrost and non-permafrost zone was selected to test the hypothesis that SOM underlain by permafrost has been better preserved than the area without permafrost under similar climatic conditions. The interactions among topography, vegetation cover, permafrost, soil variables and SOC distribution were examined. The results showed the sites beneath wet meadow land covers, which are usually underlain by permafrost, have higher SOC stocks than those of alpine meadows without permafrost. Based on mixed effects models, both soil water content and bulk density explained higher SOC content variances in the sites without permafrost than the sites underlain by permafrost. The north-facing non-permafrost sites have significantly higher SOC contents than those in south-facing non-permafrost sites. Vegetation cover, aspect, and permafrost have mixing effects on SOC contents both in permafrost and non-permafrost sites. Soil particle size and the rock fragment content are good predictors for prediction of SOC contents, while the best predictor was depending on the presence of permafrost. These results suggested that under similar climatic conditions, permafrost existence favors the preservation of SOM, this should be taken into consideration in the future carbon emission from permafrost regions since permafrost degradation can lag behind climate warming in many areas.

多年冻土地区储存了大量的土壤有机碳（SOC）。尽管随着气候变暖而造成的多年冻土退化可以刺激土壤有机物（SOM）分解，但是仍然存在未知的永久冻土是否有利于SOM保存的问题。在此，选择了多年冻土和非多年冻土的边界区域，以检验以下假设：在相似的气候条件下，由多年冻土形成的SOM比没有多年冻土的区域得到了更好的保存。研究了地形，植被覆盖，多年冻土，土壤变量和SOC分布之间的相互作用。结果表明，通常被永久冻土覆盖的湿润草地土地覆盖下的位置具有比没有永久冻土的高山草甸更高的SOC储量。基于混合效应模型，土壤含水量和堆积密度都说明无多年冻土的土壤中SOC含量的变化要高于多年冻土所覆盖的土壤。朝北的非多年冻土站点的SOC含量明显高于朝南的非多年冻土站点。植被覆盖，坡向和多年冻土对多年冻土和非多年冻土地区的SOC含量都有混合作用。土壤颗粒大小和碎石含量是预测SOC含量的良好预测指标，而最佳预测指标取决于多年冻土的存在。这些结果表明，在相似的气候条件下，多年冻土的存在有利于SOM的保存，这在未来的多年冻土地区碳排放中应予以考虑，因为多年冻土的退化可能会落后于许多地区的气候变暖。