Warming-induced vegetation growth cancels out soil carbon-climate feedback in the northern Asian permafrost region in the 21st century

Abstract

Permafrost soils represent an enormous carbon (C) pool that is highly vulnerable to climate warming. We used the model output ensemble of the Coupled Model Intercomparison Project Phase 6 to estimate the C storage in soil, litter, and vegetation in the current extent of northern Asian permafrost during 1900–2100. The contemporary (1995–2014) C storage was estimated to be 368.1 ± 82.5 Pg C for the full column depth of the soil, 13.3 ± 4.6 Pg C in litter, and 22.2 ± 3.2 Pg C in vegetation biomass, while these C storage levels are projected to decline by 3.9 Pg C (1.1%) in soils, increase of 0.03 Pg C (0.2%) in litter, and increase by 21.1 Pg C (95.3%) in vegetation biomass by the end of the 21st century under SSP585. The total C storage was dominated by warming-induced vegetation growth. Partial correlation analysis showed that surface air temperature (TAS), soil liquid water, and soil mineral nitrogen (SMN) dominated the soil and vegetation C pools, while SMN controlled litter C during the historical period. Under future scenarios, TAS and SMN dominated the changes of soil and litter C, while TAS determined the vegetation C increase. The growing soil C loss with warming indicates positive C-climate feedback in soils; this warming-induced acceleration of soil C loss was canceled out by the enhanced vegetation C accumulation, leading to a strong C sink in the 21st century.

Metaproteomics reveals functional partitioning and vegetational variation among permafrost-affected Arctic soil bacterial communities

“…Long-term greenhouse warming experiments at Toolik Field Station, Arctic Alaska, USA, have documented progressive reduction in topsoil trophic complexity and increases in plant stature, rooting depth, leaf litter accumulation, the evenness of topsoil microbial diversity, and subsoil microbial respiration ( 25 , 26 ). Greening itself might substantially offset soil C losses ( 27 ), since woody plant biomass can store more carbon for a given amount of nitrogen, generally the limiting nutrient during the Arctic growing season ( 28 ). Interactions between microbes in the seasonally thawed active layer of the soil and the overlying, progressively greening vegetation are biogeochemically critical, since roughly one-third of Arctic soil carbon is within 1 m of the land surface ( 2 ).…”

Theory of the driving model of land use change on the evolution of carbon stock: A case study of Chongqing, China

“…al., 2021), and in North Asia, warming is accelerating the accumulation of vegetative carbon(Liu et al, 2022)3. Appropriate grazing management may be a critical control in dryland rangelands to maximize the provision and control of ecosystem carbon services(Onatibia et al, 2015); the level of household residential a uence is also an important driver of household carbon footprint(Feng et al, 2021); arti cial treatment of dryland straw is an effective channel for increasing soil organic carbon(Li et al, 2016); and soil organic carbon is negatively affected by land use change in semi-arid environments in northern Iran(Kooch et al, 2022); land occupation by solar power plants has also become one of the most popular ways to achieve global carbon neutrality targets in Korea(Kim et al, 2022); and in Bangladesh, the development of rice-vegetable land farming practices has led to an increase in soil carbon stocks with soil depth(Munny et al, 2021).…”