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.

Pros and Cons of Strategies to Reduce Greenhouse Gas Emissions from Peatlands: Review of Possibilities

“…Peat plays a vital role in peatland ecosystems for vegetation growth and habitats, ensuring biological diversity [1][2][3]. Peatlands are critical in climate regulation as carbon sinks [1,[4][5][6][7][8][9]. Peatlands are the most significant natural terrestrial carbon sink, which can continuously attract carbon from the atmosphere over long periods [8,10,11].…”

“…Peatlands are the most significant natural terrestrial carbon sink, which can continuously attract carbon from the atmosphere over long periods [8,10,11]. While peatlands cover only 3% [12][13][14] of the area, they store 30% of the world's carbon [8,9]. The resource's quality has decreased [15][16][17][18], and peat is currently viewed more as an emission source [5,15,19,20].…”

Editorial: Peatlands for climate change mitigation in agriculture

“…Given the importance of peatlands to the Earth's climate system, and the extent to which human activities have changed these systems from net sinks to net sources of GHGs, it remains remarkable that key observational evidence remains inadequate. The paper by Zhao et al (2023) provides an important analysis of current observational gaps and specifically calls for additional GHG observations in Africa, Latin America and the Caribbean, as overall assessments of the GHG balance of natural and managed peatland systems are scarce. However, targeting future measurements and restoration activities requires detailed mapping of peatlands, peatland types and conditions, and anthropogenic management activities around the world, which remains a challenge.…”

Detecting spatial patterns of peatland greenhouse gas sinks and sources with geospatial environmental and remote sensing data

“…Factors such as temperature, precipitation, soil pH, vegetation composition, and water table depth play a signi cant role (Abdalla et al, 2016;Oertel et al, 2016). The spatial heterogeneity of these factors leads to considerable uncertainty in peatland net emissions and their spatial distribution (Zhao et al, 2023). Typically, the soils of drained peatlands serve as a source of CO 2 , whereas undrained peatlands act as sinks for CO 2 and as sources for CH 4 ( Field-based GHG measurement methods such as chamber measurements (Holland et al, 1999;Lundegårdh, 1927;Smith & Connen, 2004;Zhao et al, 2023) and eddy covariance towers (Dou & Yang, 2018;Foken et al, 2012) are conventional ways of estimating GHG uxes between ecosystems and the atmosphere.…”

“…The spatial heterogeneity of these factors leads to considerable uncertainty in peatland net emissions and their spatial distribution (Zhao et al, 2023). Typically, the soils of drained peatlands serve as a source of CO 2 , whereas undrained peatlands act as sinks for CO 2 and as sources for CH 4 ( Field-based GHG measurement methods such as chamber measurements (Holland et al, 1999;Lundegårdh, 1927;Smith & Connen, 2004;Zhao et al, 2023) and eddy covariance towers (Dou & Yang, 2018;Foken et al, 2012) are conventional ways of estimating GHG uxes between ecosystems and the atmosphere. However, these methods are limited in their spatial coverage, presenting signi cant challenges for comprehensive landscape-level evaluations (Lees et al, 2018;Shono & Jonsson, 2022;Wurtzebach et al, 2019).…”