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.