Peat definitions: A critical review

Abstract

Peatlands are carbon-rich ecosystems that comprise the largest terrestrial carbon store. Peatland preservation has been acknowledged on the global scale as a key nature-based component in addressing climate change. Despite their importance, there is no globally recognised definitions for peat or peatland, which influences efforts in quantifying global peat carbon stocks. We present a critical review on peatland definitions, including peat nomenclature and changing criteria for peatland classification through time. We focus on two important criteria: the minimum depth of the surface organic layer and the minimum percentage of organic carbon. We highlight the disparity between definitions, peatland nomenclature and peatland classifications. It is challenging to determine whether one definition should take precedence over another, even when considering the most common criteria. We propose that future peatland definitions focus on carbon storage and potential greenhouse gas emissions. This involves four physical and chemical characteristics of the peatland deposit: (1) Peatland extent, (2) peat thickness, (3) peat carbon content and (4) peat bulk density (volumetric carbon content). The growth dynamics and carbon flux of the peatland deposit should also become a routine part of inventories. In future, international technical agencies and experts can advise on the standardisation of concept definitions and methods, these must focus on the preservation of peatlands from the perspective of climate science.

Unravelling substrate availability and redox interactions on methane production in peat soils of China

“…Among three peat soils collected from different climatic environments in present study, the LWM peatland was from a relatively warm subtropical monsoon climate with an average annual temperature of 10.8°C, the lowest TC content (14.49 ± 0.02%) and C/N ratio (12.35 ± 0.03), contributed to a higher rate of OM decomposition (Table 1). The study suggests that the carbon content in LWM peat soil is usually much lower than that of the most typical peatlands (Lourenco et al, 2022). For TP peat soils, the combination of higher elevations, and cool and humid climates resulted in the poorly decomposed OM with the highest TC content (47.80 ± 2.32%) and C/N ratio (15.42 ± 0.28).…”

Seasonal Formation of Low-Sorbing Methylthiolated Arsenates Induces Arsenic Mobilization in a Minerotrophic Peatland

“…The Lehstenbach peatland is acidic (pH 4–5.5) (Figure S3), minerotrophic, Fe-rich, and has a peat thickness between 40 and 160 cm . The soil has an organic carbon content of about 33 wt % (at 30–40 cm depth) (Table S1) and can, therefore, be classified as organic soil, i.e., peat. , …”

“…Peatlands are peat-accumulating environments, such as bogs, fens, and mires, with peat depths >0.4 m and soil organic carbon contents >20 wt %. , Peatlands are important sinks for arsenic (As) − due to sorption, not only to mineral matter but also to natural organic matter (NOM). Under reducing conditions, inorganic oxylated As­(III) (arsenite) dominates.…”

Fire regime of peatlands in the Angolan Highlands

“…The study site is in the southeast of Angola, predominantly within Moxico province, spanning a latitudinal range of 11°54′–13°54′S and longitudinal range of 18°05′–20°34′E, and covering approximately 61,590 km 2 . The LULC classification map produced by Lourenco et al, ( 2022a , b ) includes six land cover classes: peatland, miombo woodland, valley grassland, upland grassland, water, and cleared/ cultivated land (Fig. 1 ).…”

“…The Angolan Highlands are hydrologically and ecologically important, supporting miombo woodlands (Mendelsohn, 2019 ), grasslands, subsistence agricultural land, and peatland deposits (Lourenco et al, 2022a ). Peatlands are terrestrial ecosystems that facilitate the growth of peat, an organic-rich soil that consists of partially decomposed organic matter derived from plant material (Dargie et al, 2017 ; IPS, 2021 ; Lourenco et al, 2022b ). Peatlands provide multiple ecosystem services that are significant to the United Nation’s Sustainable Development Goals, including water filtration, carbon storage, supporting biodiversity, and aid agricultural production and food security (Food and Agriculture Organisation: FAO, 2020 ).…”