Work

Peat Hydraulic Structure Maintains the Stability of Permafrost Slope Peatlands in the Central Qinghai‐Tibet Plateau

Year: 2025

Type: article

Abstract: Permafrost‐affected peatlands on the central Qinghai‐Tibet Plateau (QTP) store globally significant amounts of carbon but face climate‐induced hydrological changes. The mechanisms enabling slope peatlands to sustain waterlogging under low net precipitation (precipitation minus evapotranspiration) remain uncertain. We combined field measurements (drone‐based topography, peat cores and porewater δ 18 O) with a modified DigiBog_Boreal model to elucidate water balance in Chadam peatland, a representative permafrost slope peatland on the central QTP. Laboratory analyses reveal that Chadam peatland is characterized by exceptionally high dry bulk density (0.48 ± 0.21 g cm −3 ( n = 8), compared to 0.12 ± 0.09 g cm −3 in northern peatlands ( n = 1,318)) and low horizontal hydraulic conductivity ( K h ), indicating distinct hydraulic properties. Model simulations parameterized with local steep slopes (5°), low net precipitation (mean 165 mm yr −1 ), and site‐specific peat properties demonstrated that only the low K h (initial 0.01 cm s −1 ; as measured in this study) simulation scenario can sustain millennial‐scale waterlogging. These conditions facilitate continued peat accumulation, matching observed peat thickness. In contrast, high‐conductivity scenarios (initial K h = 0.15 cm s −1 and 3 cm s −1 ), due to their low water retention capacity, fail to maintain elevated water tables both during peat initiation and over subsequent centuries (300–600 years) under identical climatic and terrain conditions. Aligning with model results, stable isotope (δ 2 H and δ 18 O) profiles corroborate strong evaporation and prolonged subsurface water residence times. These findings indicate that peatland hydrological stability depends on either low K h , sufficient net precipitation, or gentle topography to counteract destabilizing influences. This study identifies peat hydraulic conductivity as the primary control on hydrological stability in semi‐arid, high‐elevation permafrost peatlands, providing new insights into QTP peatland resilience under warming conditions.

Source: Water Resources Research

DOI: 10.1029/2025wr041170

Authors: Yuefeng Li, Zhengyu Xia, Jingjing Sun, Tingwan Yang, Zicheng Yu

Institutions: Northeast Normal University, Chinese Academy of Sciences, Northeast Institute of Geography and Agroecology

Language: English

Topic: Peatlands and Wetlands Ecology

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

SDGs: Climate action, Life on land

Open Access status: gold

Estimated APC paid: $3,000