Peatland pools are tightly coupled to the contemporary carbon cycle.
Peatland pools are tightly coupled to the contemporary carbon cycle.
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DOI：
10.1111/gcb.16999
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发表时间：
2023-11
影响因子：
11.6
通讯作者：
J. Dean;M. Billett;T. E. Turner;M. Garnett;Roxane Andersen;Rebecca M McKenzie;K. Dinsmore;A. J. Baird;P. Chapman;Joseph Holden
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文献类型：
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作者：
J. Dean;M. Billett;T. E. Turner;M. Garnett;Roxane Andersen;Rebecca M McKenzie;K. Dinsmore;A. J. Baird;P. Chapman;Joseph Holden
泥炭地是全球重要的土壤碳(C)储存库，形成于千禧年的时间尺度上，但面临着人类和气候干扰造成的不稳定风险。池塘是许多泥炭地普遍存在的特征，可以包含非常高浓度的以溶解和颗粒状有机形式动员的碳，以及作为温室气体二氧化碳(CO2)和甲烷(CH4)的碳。这些水生碳形态的放射性碳含量(14C)告诉我们，C池是由当代初级生产产生的，还是来自以前储存了数千年的深层泥炭层释放的不稳定的C。我们提供了新的14C和稳定的C(δ13C)同位素数据，这些数据来自英国六个泥炭地池塘的97个水样，重点是溶解和颗粒有机碳以及溶解的二氧化碳。我们的观察涵盖了两种不同的水池类型：天然泥炭地水池和通过堵沟努力重新湿润泥炭地形成的水池(修复水池)。碳库以现代碳为主，各种形态的碳大多数(约50%-75%)年龄在300年以下。这两种类型的水池都很容易转化和分解水柱中的有机碳，并向大气排放二氧化碳，尽管与大气混合和随后的二氧化碳排放在自然水池中更为明显。我们的结果显示，尽管在周围的泥炭中存在大量千禧年的碳，但几乎没有证据表明天然或修复池中深层的老碳不稳定。一个可能的例外是CH4沸腾(冒泡)，我们的观察表明，千禧年的C可以通过这一途径从泥炭地池塘中排放出来。我们的结果表明，沟渠堵塞形成的修复池可以有效地防止深层老碳通过水生出口从湿地泥炭中释放出来。
Peatlands are globally important stores of soil carbon (C) formed over millennial timescales but are at risk of destabilization by human and climate disturbance. Pools are ubiquitous features of many peatlands and can contain very high concentrations of C mobilized in dissolved and particulate organic form and as the greenhouses gases carbon dioxide (CO2) and methane (CH4). The radiocarbon content (14C) of these aquatic C forms tells us whether pool C is generated by contemporary primary production or from destabilized C released from deep peat layers where it was previously stored for millennia. We present novel 14C and stable C (δ13C) isotope data from 97 aquatic samples across six peatland pool locations in the United Kingdom with a focus on dissolved and particulate organic C and dissolved CO2. Our observations cover two distinct pool types: natural peatland pools and those formed by ditch blocking efforts to rewet peatlands (restoration pools). The pools were dominated by contemporary C, with the majority of C (~50%–75%) in all forms being younger than 300 years old. Both pool types readily transform and decompose organic C in the water column and emit CO2 to the atmosphere, though mixing with the atmosphere and subsequent CO2 emissions was more evident in natural pools. Our results show little evidence of destabilization of deep, old C in natural or restoration pools, despite the presence of substantial millennial‐aged C in the surrounding peat. One possible exception is CH4 ebullition (bubbling), with our observations showing that millennial‐aged C can be emitted from peatland pools via this pathway. Our results suggest that restoration pools formed by ditch blocking are effective at preventing the release of deep, old C from rewetted peatlands via aquatic export.