Global Peat lands CO2 under climate change

This review provide a global insight to peatlands CO2 exchange under climate changes and anthropogenic catastrophes. Peatlands are playing a significant role in balancing the global carbon cycle. However, climate change has substantially affected the peatlands CO2 exchange, including gross primary productivity (GPP), ecosystem respiration (ER) and net ecosystem CO2 exchange (NEE). How do global peatlands CO2 exchangevary under climate change,still need further exploration. Through synthesized data, this review aims to comprehensively understand the CO2 exchange patterns of boreal, temperate and tropical peatlands, as well as in fens and bogs under climate change. Our results showed a negative NEE (-1.39gCO2m-2d-1) of global peatlands, indicates that global peatlands are still acting ascarbon sinks. The CO2exchange patterns differed among different climatic zones. The GPP in tropical peatlands (23.81gCO2m-2d-1) is significantly higher than boreal (6.25 gCO2m-2d-1) and temperate(3.63 gCO2m-2d-1; p< 0.05). The ER was highest in tropical (24.46 gCO2m-2d-1), while lowest in temperate peatlands (5.25 gCO2m-2d-1; p< 0.05). Such GPP and ER patterns resulted in both negative NEE in boreal (-5.22gCO2m-2d-1) and temperate zones (-0.04 gCO2m-2d-1), implying their carbon sink function. However, positive NEE (3.17gCO2m-2d-1) in tropical peatlands indicates that they have been shifted to carbon sources. In terms of peatland types,NEE was higher in fens (-5.83 gCO2m-2d-1) than in bogs (-0.33gCO2m-2d-1), reflecting the higher efficiency of fens in sequestrating atmosphere CO2 than bogs. Our findings highlight the urgent need to make effective management strategies to promote sustainable land use to reduce carbon loss, particularly in tropical peatlands.本综述全面剖析了气候变化与人为灾害影响下，全球泥炭地的二氧化碳（CO₂）交换过程。泥炭地在维持全球碳循环平衡中发挥着关键作用。然而，气候变化已对泥炭地的CO₂交换过程产生显著影响，涉及总初级生产力（gross primary productivity, GPP）、生态系统呼吸（ecosystem respiration, ER）以及生态系统净CO₂交换（net ecosystem CO₂ exchange, NEE）。气候变化背景下全球泥炭地的CO₂交换过程将呈现何种变化规律，仍有待进一步探究。 通过整合数据集，本综述旨在全面解析气候变化下北方、温带与热带泥炭地，以及富营养泥炭沼泽（fen）和贫营养泥炭沼泽（bog）的CO₂交换格局。 本研究结果显示，全球泥炭地的NEE为负值（-1.39 gCO₂·m⁻²·d⁻¹），表明全球泥炭地仍发挥着碳汇功能。 不同气候区的CO₂交换格局存在显著差异：热带泥炭地的GPP为23.81 gCO₂·m⁻²·d⁻¹，显著高于北方泥炭地（6.25 gCO₂·m⁻²·d⁻¹）与温带泥炭地（3.63 gCO₂·m⁻²·d⁻¹；p<0.05）。 生态系统呼吸速率（ER）以热带泥炭地最高（24.46 gCO₂·m⁻²·d⁻¹），温带泥炭地最低（5.25 gCO₂·m⁻²·d⁻¹；p<0.05）。 上述GPP与ER的分布格局使得北方与温带泥炭地的NEE均为负值（分别为-5.22 gCO₂·m⁻²·d⁻¹与-0.04 gCO₂·m⁻²·d⁻¹），印证了二者的碳汇功能；而热带泥炭地的NEE为正值（3.17 gCO₂·m⁻²·d⁻¹），表明其已转变为碳源。 就泥炭地类型而言，富营养泥炭沼泽（fen）的NEE为-5.83 gCO₂·m⁻²·d⁻¹，高于贫营养泥炭沼泽（bog）的-0.33 gCO₂·m⁻²·d⁻¹，反映出富营养泥炭沼泽固持大气CO₂的效率优于贫营养泥炭沼泽。 本研究结果凸显了制定有效管理策略、推动可持续土地利用以减少碳流失的紧迫性，针对热带泥炭地的相关工作尤为关键。