Experimental evidence for sustained carbon sequestration in fire-managed, peat moorlands
Experimental evidence for sustained carbon sequestration in fire-managed, peat moorlands
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DOI：
10.1038/s41561-018-0266-6
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发表时间：
2019-02-01
影响因子：
18.3
通讯作者：
Chiverrell, R. C.
中科院分区：
文献类型：
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作者：
Marrs, R. H.;Marsland, E-L;Chiverrell, R. C.
泥炭沼泽地是北方地区重要的生境，储存了全球约30%的土壤碳(C)。在泥炭上规定燃烧是一种非常有争议的管理策略，广泛地与碳损失联系在一起。在这里，我们量化了轻度管理的北部沼泽地规定燃烧的影响，并表明对泥炭和碳积累速率的影响并不像人们普遍认为的那么糟糕。我们在一个独特的重复生态实验中使用了地层学技术，利用已知的燃烧频率来量化泥炭和碳的累积率(自1923年左右开始管理的0，1，3和6次燃烧)。堆积率在其他地方的沼泽地是典型的，只有在6次烧伤处理中才显著降低。但随着焚烧频率的增加，影响逐渐增强，每增加一次焚烧，累积速率分别降低4.9g m(-2)a r(-1)和1.9g C cm(-2)yr(-1)，但不能阻止累积。物种多样性和形成泥炭的物种丰度也随着焚烧频率的增加而增加。我们的数据挑战了人们的普遍看法，即转向烧氧对泥炭生长至关重要，并表明适当的规定燃烧既可以减轻气候变暖时的野火风险，又可以产生相对较快的泥炭生长和持续的碳固存。
Peat moorlands are important habitats in the boreal region, where they store approximately 30% of the global soil carbon (C). Prescribed burning on peat is a very contentious management strategy, widely linked with loss of carbon. Here, we quantify the effects of prescribed burning for lightly managed boreal moorlands and show that the impacts on peat and C accumulation rates are not as bad as is widely thought. We used stratigraphical techniques within a unique replicated ecological experiment with known burn frequencies to quantify peat and C accumulation rates (0, 1, 3 and 6 managed burns since around 1923). Accumulation rates were typical of moorlands elsewhere, and were reduced significantly only in the 6-burn treatment. However, impacts intensified gradually with burn frequency; each additional burn reduced the accumulation rates by 4.9 g m(-2) yr(-1) (peat) and 1.9 g C cm(-2) yr(-1), but did not prevent accumulation. Species diversity and the abundance of peat-forming species also increased with burn frequency. Our data challenge widely held perceptions that a move to O burning is essential for peat growth, and show that appropriate prescribed burning can both mitigate wildfire risk in a warmer world and produce relatively fast peat growth and sustained C sequestration.