Bog breathing: the extent of peat shrinkage and expansion on blanket bogs in relation to water table, heather management and dominant vegetation and its implications for carbon stock assessments
Bog breathing: the extent of peat shrinkage and expansion on blanket bogs in relation to water table, heather management and dominant vegetation and its implications for carbon stock assessments
复制标题
沼泽呼吸：与地下水位、石南花管理和优势植被相关的沼泽泥炭收缩和扩张程度及其对碳储量评估的影响
DOI：
10.1007/s11273-019-09672-5
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发表时间：
2019
影响因子：
1.8
通讯作者：
A. Heinemeyer
中科院分区：
文献类型：
--
作者：
Phoebe A. Morton;A. Heinemeyer
泥炭地是全球重要的碳储量。泥炭土碳储量评估依赖于碳浓度、体积密度和土壤深度的测量。然而，泥炭地表水平——以及因此产生的土壤深度——的变化（“沼泽呼吸”）在很大程度上是对与地下水位变化有关的泥炭收缩和膨胀的一种反应。本研究评估了该机制在野外和实验室条件下影响碳储量计算的程度和潜力。在英国，大多数泥炭地都是高地覆盖沼泽，其中很大一部分被管理为“松鸡沼泽”。目前这包括旋转燃烧，尽管越来越多地考虑替代管理。对英格兰北部地层状沼泽上的三个松鸡沼泽进行了泥炭深度和地下水位调查，比较了不同石南管理干预（燃烧、割草和未割）下泥炭深度和地下水位的变化。其中一个地点还允许调查与坡度和三种主要沼泽植被类型（石南、棉草和泥炭藓）有关的变化，并将其与在模拟干旱和再湿润时期的受控实验室条件下观察到的泥炭岩心变化进行比较。记录了深度和体积密度的变化，并计算了对碳储量估算的潜在影响。结果强调了特定地点的关系作为潜在的栖息地条件指标，并表明先前报道的地表泥炭碳损失可能也可以用泥炭收缩和膨胀引起的明显变化来解释。建议准确记录体积密度和泥炭总深度测量，作为泥炭碳储量评估的一部分。
Peatlands represent a globally important carbon stock. Peat soil carbon stock assessments rely on measurements of carbon concentration, bulk density and soil depth. However, peat surface levels - and thus soil depths - change (“bog breathing”) largely as a response to peat shrinkage and expansion in relation to water table changes. This study assessed the magnitude of and potential for this mechanism to influence carbon stock calculations under field and laboratory conditions. In the UK, most peatlands are upland blanket bogs, of which a large proportion are managed as ‘grouse moors’. This currently involves rotational burning, although alternative management is increasingly considered. Peat depth and water tables were investigated on three grouse moors on blanket bog in northern England, comparing changes under different heather management interventions (burning, mowing and uncut). One site also allowed investigation of changes in relation to slope and under the three major bog vegetation types (ling heather, cottongrass and Sphagnum moss), which were compared to observed changes in peat cores under controlled laboratory conditions simulating periods of drought and rewetting. Changes in depth and bulk density were recorded and the potential implications for carbon stock estimates were calculated. Results highlight site specific relationships as potential habitat condition indicators and demonstrate that previously reported surface peat carbon losses resulting from enhanced decomposition under rising temperatures might also be explained by apparent changes due to peat shrinkage and expansion. It is recommended to accurately record bulk density and total peat depth measurements as part of peat carbon stock assessments.