Global observation gaps of peatland greenhouse gas balances: needs and obstacles

Abstract

Greenhouse gas (GHGs) emissions from peatlands contribute significantly to ongoing climate change because of human land use. To develop reliable and comprehensive estimates and predictions of GHG emissions from peatlands, it is necessary to have GHG observations, including carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O), that cover different peatland types globally. We synthesize published peatland studies with field GHG flux measurements to identify gaps in observations and suggest directions for future research. Although GHG flux measurements have been conducted at numerous sites globally, substantial gaps remain in current observations, encompassing various peatland types, regions and GHGs. Generally, there is a pressing need for additional GHG observations in Africa, Latin America and the Caribbean regions. Despite widespread measurements of CO₂ and CH₄, studies quantifying N₂O emissions from peatlands are scarce, particularly in natural ecosystems. To expand the global coverage of peatland data, it is crucial to conduct more eddy covariance observations for long-term monitoring. Automated chambers are preferable for plot-scale observations to produce high temporal resolution data; however, traditional field campaigns with manual chamber measurements remain necessary, particularly in remote areas. To ensure that the data can be further used for modeling purposes, we suggest that chamber campaigns should be conducted at least monthly for a minimum duration of one year with no fewer than three replicates and measure key environmental variables. In addition, further studies are needed in restored peatlands, focusing on identifying the most effective restoration approaches for different ecosystem types, conditions, climates, and land use histories.

Keywords: CH4; CO2; Chamber; Eddy covariance; Land use; N2O.

Fig. 1

Number of studies that conducted CO₂, CH₄ and N₂O flux measurements from peatlands (a) and their yearly distribution between 2000 and 2022 (b). Colors indicate the methods used for the measurements in (a) and different gas types in (b). Lines in (b) indicate the linear trends

Fig. 2

Number of studies that measured CO₂ (a), CH₄ (b) and N₂O fluxes (c) in different countries. Areas with peatland distribution are marked in black

Fig. 3

The gap index for peatland GHG flux observations in different countries. A higher index suggests a larger gap (i.e., a greater need) for observations

Fig. 4

Number of peatland GHG flux studies according to land use type. Colors indicate different gas types

Fig. 5

Number of peatland GHG flux studies according to country/region. Colors indicate different land use types

Fig. 6

Chamber GHG flux measurements for studies published in 2022 presented by: season coverage (a), duration (b), replicates (c), frequency (d), chamber type (e), gas analysis (f) and other measured environmental variables (g). NA indicates that information is not reported in the paper. Air_T, air temperature. Soil_T, soil temperature. C content, carbon content. N content, nitrogen content