Evidence for older carbon loss with lowered water tables and changing plant functional groups in peatlands
Evidence for older carbon loss with lowered water tables and changing plant functional groups in peatlands
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泥炭地中因地下水位降低和植物功能群变化而导致碳损失的证据
DOI：
10.1111/gcb.16508
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发表时间：
2022
影响因子：
11.6
通讯作者：
Kane, Evan S.
中科院分区：
文献类型：
--
作者：
Stuart, Julia E. M.;Tucker, Colin L.;Lilleskov, Erik A.;Kolka, Randall K.;Chimner, Rodney A.;Heckman, Katherine A.;Kane, Evan S.
泥炭地的碳(C)积累能力与植物生产力和分解的不平衡有关。随着气候变化，泥炭地净碳储量的连续性依赖于初级生产的增加来抵消生态系统呼吸（ER）的增加，以及浸水泥炭中较老的碳的持续存在。泥炭地地下水位的降低通常会增加分解速率，但同时发生的植物群落转移可以相互作用地改变ER和植物生产力响应。地下水位变化和植物群落对老泥炭碳损失的综合影响尚不清楚。我们采用全因子1‐m3中尺度阵列，采用维管植物功能组处理（未处理对照、莎草和ericacaceae）和地下水位处理（自然和降低）来测试植物和水深对co2通量、分解和老碳损失的影响。我们使用生态系统co2呼吸、散装泥炭、植物和孔隙水溶解无机C的Δ14C和δ13C构建混合模型，将ER划分为潜在来源。我们发现，降低地下水位的处理是在炸弹峰值（1955年）之前由深层浸水泥炭修复的。莎草处理的溶解无机碳特征最古老，泥炭对ER的贡献比例最高。分解分析证实，随着地下水位降低至泥炭地表以下40厘米处，分解率持续较高。在低水位处理中，异养呼吸在生长季节高峰超过了植物呼吸。总初级生产速率仅受植被的影响，而生态效率则受植被和地下水位处理的影响。呼吸作用和初级生产与地下水位降低以及较早的碳损失的解耦表明，气候和土地利用引起的泥炭地水文变化会增加泥炭地碳储量的脆弱性。
A small imbalance in plant productivity and decomposition accounts for the carbon (C) accumulation capacity of peatlands. As climate changes, the continuity of peatland net C storage relies on rising primary production to offset increasing ecosystem respiration (ER) along with the persistence of older C in waterlogged peat. A lowering in the water table position in peatlands often increases decomposition rates, but concurrent plant community shifts can interactively alter ER and plant productivity responses. The combined effects of water table variation and plant communities on older peat C loss are unknown. We used a full‐factorial 1‐m3mesocosm array with vascular plant functional group manipulations (Unmanipulated Control, Sedge only, and Ericaceous only) and water table depth (natural and lowered) treatments to test the effects of plants and water depth on CO2fluxes, decomposition, and older C loss. We used Δ14C and δ13C of ecosystem CO2respiration, bulk peat, plants, and porewater dissolved inorganic C to construct mixing models partitioning ER among potential sources. We found that the lowered water table treatments were respiring C fixed before the bomb spike (1955) from deep waterlogged peat. Lowered water table Sedge treatments had the oldest dissolved inorganic14C signature and the highest proportional peat contribution to ER. Decomposition assays corroborated sustained high rates of decomposition with lowered water tables down to 40 cm below the peat surface. Heterotrophic respiration exceeded plant respiration at the height of the growing season in lowered water table treatments. Rates of gross primary production were only impacted by vegetation, whereas ER was affected by vegetation and water table depth treatments. The decoupling of respiration and primary production with lowered water tables combined with older C losses suggests that climate and land‐use‐induced changes in peatland hydrology can increase the vulnerability of peatland C stores.
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影响因子：
2.6
作者：
Bengtsson F;Granath G;Rydin H
通讯作者：
Rydin H
影响因子：
9.7
作者：
Agethen, Svenja;Sander, Michael;Knorr, Klaus-Holger
通讯作者：
Knorr, Klaus-Holger
DOI：
10.1098/rsta.2005.1671
发表时间：
2005-12-15
影响因子：
5
作者：
Holden, J
通讯作者：
Holden, J
放射性碳分析量化了整个生态系统变暖实验中随着温度升高而造成的泥炭碳损失
DOI：
10.1029/2021jg006511
发表时间：
2021
期刊：
Journal of Geophysical Research: Biogeosciences
影响因子：
--
作者：
Wilson, Rachel M.;Griffiths, Natalie A.;Visser, Ate;McFarlane, Karis J.;Sebestyen, Stephen D.;Oleheiser, Keith C.;Bosman, Samantha;Hopple, Anya M.;Tfaily, Malak M.;Kolka, Randall K.
通讯作者：
Kolka, Randall K.
影响因子：
5.2
作者：
Chanton, J. P.;Glaser, P. H.;Cooper, W. T.
通讯作者：
Cooper, W. T.