Southern Hemisphere bog persists as a strong carbon sink during droughts
Southern Hemisphere bog persists as a strong carbon sink during droughts
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南半球沼泽在干旱期间仍然是强大的碳汇
DOI：
10.5194/bg-14-4563-2017
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发表时间：
2017
期刊：
影响因子：
4.9
通讯作者：
L. Schipper
中科院分区：
文献类型：
--
作者：
J. Goodrich;D. Campbell;L. Schipper
抽象的。泥炭地生态系统是全新世以来全球重要的碳汇。大多数关于泥炭地碳收支和气候变化影响的研究都是在北方半球泥炭藓占主导地位的系统中进行的。鉴于泥炭地在其他地理和气候区域的重要性，需要更好地了解全球泥炭地类型的泥炭地碳动态。在新西兰，大部分历史上的泥炭地面积已被排干用于农业，但对未改变的泥炭地残余物中的碳交换和储存速率知之甚少，这些泥炭地残余物主要由联合的电线草（Empodisma robustum）控制。我们使用涡度协方差来测量生态系统尺度的CO2和CH 4通量和水平衡的方法来估计溶解有机碳的次表层通量从最大的剩余提出的泥炭沼泽在新西兰，Kopuatai沼泽。净生态系统碳平衡（NECB）估计了四年，其中包括两个干旱的夏天，一个相对潮湿的夏天，和一个气象平均的夏天。在所有测量年中，沼泽是一个巨大的碳汇，范围从134.7到216.9 gC m−2 yr−1，这是由于每年的生态系统净生产量很大（161.8到244.9 gCO 2-C m−2 yr−1）。相对于大多数北方半球泥炭地，年甲烷通量较大（14.2至21.9 gCH 4-C m−2 yr−1），尽管夏季和秋季排放对干燥条件高度敏感，导致根据地下水位位置非常可预测的季节性。溶解有机碳的年通量与甲烷排放量相似，但变化较小，范围为11.7至12.8 gC m−2 yr−1。夏末干旱期间经历的干燥条件导致年度碳储存量显著减少，这几乎同样是由于地下水位降低和温度升高导致生态系统呼吸增强，以及由于蒸汽压不足相关的植被压力导致总初级生产量减少。然而，在干旱年份的Kopuatai沼泽的净碳吸收是大的，即使是最大的NECB报告从北方半球沼泽。此外，全球变暖的潜在通量表明，沼泽是一个强大的汇温室气体在所有年份，尽管相对较大的年度甲烷排放量。我们的研究结果表明，E. robustum适应干旱条件下导致弹性泥炭地干旱响应的NECB。
Abstract. Peatland ecosystems have been important global carbon sinks throughout the Holocene. Most of the research on peatland carbon budgets and effects of variable weather conditions has been done in Northern Hemisphere Sphagnum-dominated systems. Given their importance in other geographic and climatic regions, a better understanding of peatland carbon dynamics is needed across the spectrum of global peatland types. In New Zealand, much of the historic peatland area has been drained for agriculture but little is known about rates of carbon exchange and storage in unaltered peatland remnants that are dominated by the jointed wire rush, Empodisma robustum. We used eddy covariance to measure ecosystem-scale CO2 and CH4 fluxes and a water balance approach to estimate the sub-surface flux of dissolved organic carbon from the largest remaining raised peat bog in New Zealand, Kopuatai bog. The net ecosystem carbon balance (NECB) was estimated over four years, which included two drought summers, a relatively wet summer, and a meteorologically average summer. In all measurement years, the bog was a substantial sink for carbon, ranging from 134.7 to 216.9 gC m−2 yr−1, owing to the large annual net ecosystem production (161.8 to 244.9 gCO2–C m−2 yr−1). Annual methane fluxes were large relative to most Northern Hemisphere peatlands (14.2 to 21.9 gCH4–C m−2 yr−1), although summer and autumn emissions were highly sensitive to dry conditions, leading to very predictable seasonality according to water table position. The annual flux of dissolved organic carbon was similar in magnitude to methane emissions but less variable, ranging from 11.7 to 12.8 gC m−2 yr−1. Dry conditions experienced during late summer droughts led to significant reductions in annual carbon storage, which resulted nearly equally from enhanced ecosystem respiration due to lowered water tables and increased temperatures, and from reduced gross primary production due to vapor pressure deficit-related stresses to the vegetation. However, the net C uptake of Kopuatai bog during drought years was large relative to even the maximum reported NECB from Northern Hemisphere bogs. Furthermore, global warming potential fluxes indicated the bog was a strong sink for greenhouse gases in all years despite the relatively large annual methane emissions. Our results suggest that adaptations of E. robustum to dry conditions lead to a resilient peatland drought response of the NECB.
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影响因子：
4.8
作者：
Kuiper, Jan J.;Mooij, Wolf M.;Robroek, Bjorn J. M.
通讯作者：
Robroek, Bjorn J. M.
影响因子：
6.2
作者：
Desai, Ankur R.;Richardson, Andrew D.;Stauch, Vanessa J.
通讯作者：
Stauch, Vanessa J.
水生二氧化碳逃逸是否应该纳入泥炭地生态系统的当代碳预算中？
影响因子：
3.7
作者：
Billett M
通讯作者：
Billett M
水文驱动的生态系统呼吸决定了北方泥炭地的碳平衡
DOI：
10.1016/j.scitotenv.2013.06.077
发表时间：
2013
期刊：
The Science of the total environment
影响因子：
--
作者：
Gazovic;Forbrich;Kutzbach;M. Wilmking
通讯作者：
M. Wilmking