Peatlands, especially fens, are known to emit methane. Reindeer (Rangifer tarandus) use mires mainly as spring and summer pastures. In this work we observed that adding reindeer droppings to fen peat increased the potential methane production by 40%. This became apparent when droppings originating from reindeer kept in pen or pasture in winter were added to methanogenic fen peat samples. The droppings introduced Methanobacteriaceae (Methanobrevibacter; > 90% of the mcrA MiSeq reads) to the peat, which was originally populated by Methanosarcinaceae, Methanosaetaceae, Methanoregulaceae, Methanobacteriaceae, Methanomassiliicoccaceae, Methanocellaceae and Methanomicrobiaceae. The original community structure did not explain the induced methane production and neither did the origin of the droppings. Instead, the increment in methane production was explained by the increased methanogenic abundance, measured by mcrA qPCR, due to the addition of droppings. The result confirms that methanogens from the reindeer rumen participate in peat methane production. This finding suggests that reindeer grazing may increase methane emissions in northern fens.

众所周知，泥炭地，尤其是沼泽地，会排放甲烷。驯鹿（Rangifer tarandus）主要使用沼泽作为春季和夏季牧场。在这项工作中，我们观察到将驯鹿粪便添加到泥炭中可使潜在的甲烷产量增加 40%。当冬季饲养在围栏或牧场的驯鹿粪便被添加到产甲烷泥炭样品中时，这一点变得明显。粪便将甲烷杆菌科（甲烷短杆菌； > 90% 的mcrA MiSeq 读数）引入泥炭，泥炭最初由甲烷八叠球菌科、甲烷菌科、甲烷调节菌科、甲烷杆菌科、甲烷菌科、甲烷微菌科和甲烷菌科组成。原始群落结构不能解释诱导产生的甲烷，也不能解释粪便的起源。相反，由于粪便的增加，甲烷产量的增加可以通过mcrA qPCR测量的产甲烷丰度的增加来解释。结果证实，来自驯鹿瘤胃的产甲烷菌参与了泥炭甲烷的生产。这一发现表明，驯鹿放牧可能会增加北部沼泽地的甲烷排放。