A Late Holocene Stable Isotope and Carbon Accumulation Record from Teringi Bog in Southern Estonia
A Late Holocene Stable Isotope and Carbon Accumulation Record from Teringi Bog in Southern Estonia
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DOI：
10.3390/quat5010008
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发表时间：
2022-02
期刊：
影响因子：
2.3
通讯作者：
N. Stansell;E. Klein;Kristyn Hill;J. Terasmaa;Justin D. Dodd;M. Boes;Mariliis Eensalu;Carolyn S. F
中科院分区：
文献类型：
--
作者：
N. Stansell;E. Klein;Kristyn Hill;J. Terasmaa;Justin D. Dodd;M. Boes;Mariliis Eensalu;Carolyn S. F
从爱沙尼亚南部的一个富营养沼泽采集的放射性碳定年泥炭芯记录了全新世晚期北方欧洲不断变化的环境条件和碳积累速率。现代观测表明，泥炭地的水平衡受到相对湿度变化的高度影响，其次是温度和降水。地表水的现代δ 18 O和δ 2 H值表明地下水是几个月降水的综合。表面蒸发对沼泽内的水几乎没有直接影响，这表明水的损失优先通过蒸腾和次表面流。整体泥炭δ 13 C值在全新世晚期表现出较高值的趋势，表明整体表面湿度增加的模式。δ 15 N值在~4130至3645 cal yr BP之间较低，表明环境较干燥，随后为中间值，直到~2995 cal yr BP。δ 15 N值从~2995 cal/yr BP再次下降到2470 cal/yr BP，表明恢复到较干燥的条件，然后是中间值，直到~955 cal/yr BP。δ 15 N值较高，表明从约955至250 cal yr BP的湿润条件，然后是现代的中间值。从~4200到2470 cal yr BP，碳积累率低到中等，然后是中等到高的值，直到~1645 cal yr BP。碳积累率低，直到~585 cal yr BP，其次是通过现代的中间值。地球化学数据，结合观测到的泥炭成分变化和全新世晚期的温度和地下水位波动的区域代理，表明在干燥和温暖的条件下，碳积累率相对较低，而当气候更潮湿和/或更冷时，碳积累率通常较高（高达~80 g C m−2 yr−1）。这些发现进一步表明，未来影响区域水平衡和温度的环境变化将影响北方泥炭地捕获和储存碳的潜力。
Radiocarbon-dated peat cores collected from an ombrotrophic bog in southern Estonia record shifting environmental conditions and carbon accumulation rates in northern Europe during the late Holocene. Modern observations indicate that the water balance of the peatland is highly influenced by changes in relative humidity, followed by temperature and precipitation. The modern δ18O and δ2H values of surface water suggest that the groundwater is an integration of several months of precipitation. There also appears to be little or no direct influence of surface evaporation on the water within the bog, suggesting that water loss is preferentially through transpiration and sub-surface flow. Bulk peat δ13C values exhibit a trend of higher values through the late Holocene, suggesting a pattern of overall increased surface wetness. The δ15N values were low from ~4130 to 3645 cal yr BP, suggesting drier conditions, followed by intermediate values until ~2995 cal yr BP. The δ15N values decrease again from ~2995 to 2470 cal yr BP, suggesting a return to drier conditions, followed by intermediate values until ~955 cal yr BP. The δ15N values were high, suggesting wetter conditions from ~955 to 250 cal yr BP, followed by intermediate values through the modern. Carbon accumulation rates were low to intermediate from ~4200 to 2470 cal yr BP, followed by intermediate-to-high values until ~1645 cal yr BP. Carbon accumulation rates were then low until ~585 cal yr BP, followed by intermediate values through the modern. The geochemical data, combined with observed changes in peat composition and regional proxies of temperature and water table fluctuations through the late Holocene, suggest that carbon accumulation rates were relatively low under dry and warm conditions, whereas accumulation was generally higher (up to ~80 g C m−2 yr−1) when the climate was wetter and/or colder. These findings further suggest that future environmental changes affecting the regional water balance and temperature will impact the potential for northern peatlands to capture and store carbon.