As global climate change progresses, Artic permafrost melts. Deeper layers of permafrost contain organic matter which can migrate into deeper soil by a process called cryoturbation. While this organic matter does not decompose in frozen soils, it decomposes rapidly in melting permafrost. Warming soils may experience increased litter input and earthworm colonization. The effects of litter addition and earthworm colonization on the decomposition and condition of permafrost remain unclear. This study used laboratory experiments to compare effects of willow litter (Salix caprea) addition and earthworm activity (Aporectodea caliginosa) on cryogenic organic matterfrom permafrost soils mixed in mineral soil and mineral soil itself. Respiration and stability of organic matter was monitored over two years with new litter added three times once litter in the soil with earthworms had disappeared from the soil surface. After a two-year period, treatments with litter addition and with earthworms alone showed increased system respiration, but effects were non-cumulative. The soil samples receiving earthworms showed higher proportions of organic matter stabilized in the mineral fraction by the end of the experiment. These preliminary lab results suggest that litter supply and earthworm colonization may both stabilize and speed up mineralization of organic matter released from melting permafrost.

随着全球气候变化的进展，北极永久冻土融化。较深层的永久冻土含有有机物，这些有机物可以通过称为低温扰动的过程迁移到更深的土壤中。虽然这种有机物在冻土中不会分解，但在融化的永久冻土中会迅速分解。土壤变暖可能会导致凋落物输入和蚯蚓定植增加。凋落物的添加和蚯蚓的定植对永久冻土的分解和状况的影响仍不清楚。本研究使用实验室实验来比较添加柳树凋落物（ Salix caprea）和蚯蚓活动（Aporectodea caliginosa）对混合在矿质土壤和矿质土壤本身中的永久冻土中的低温有机物的影响。在两年内监测有机物的呼吸和稳定性，一旦土壤中含有蚯蚓的枯枝落叶从土壤表面消失，就添加新的枯枝落叶三次。两年后，添加垫料和单独使用蚯蚓的处理显示系统呼吸增加，但效果是非累积的。实验结束时，接受蚯蚓的土壤样品显示出较高比例的稳定在矿物质部分的有机物。这些初步实验室结果表明，凋落物供应和蚯蚓定植可能既稳定又加速了永久冻土融化释放的有机物的矿化。