Seasonally frozen ground (SFG) significantly contributes to global carbon sinks. Global warming and anthropogenic-induced disturbances threaten the carbon storage capacity of SFG. Challenges in evaluating the SFG carbon storage potential include the lack of understanding of the control mechanisms of soil organic carbon (SOC) variations and timely spatial estimates of SOC. In this study, we investigated SOC stocks in SFG in the Tibet Autonomous Region, China, in 2020 and 2021. We employed partial least squares structural equation modeling (PLS-SEM) to explore the effect of complex processes (interacting roles of climate, plant physiology and phenology, freeze-thaw cycle, soil environment, and C inputs) on SOC and mapped SOC stocks in the topmost 30 cm. We identified four causal pathways: (1) an indirect pathway representing the effect of climate on plant physiology and phenology through changes in freeze-thaw cycles and soil environment, (2) an indirect pathway representing the effect of climate on C inputs through changes in freeze-thaw cycles, soil environment and plant physiology and phenology, (3) an indirect pathway representing the effect of climate on freeze-thaw cycles, and (4) an indirect pathway representing the effect of climate on the soil environment through changes in freeze--thaw cycles. C inputs exerted the greatest control on SOC. The effect of these factors decreased with increasing soil depth. We used PLS-SEM to generate maps of SOC stocks in SFG at a 500 m resolution with a moderate accuracy. The estimated mean SOC stocks in the 0-30 cm layer reached 6.87 kg m(-2), with a 95% confidence interval ranging from 6.2 to 7.5 kg m(-2). Our results indicated that it is critical to consider the depth dependence of the direct and indirect effects of environmental factors when assessing the control mechanisms of SOC vari-ations. In this work, we also demonstrated that spatially explicit SOC estimates based on timely investigations are important for assessing C stocks against the background of considerable environmental changes across the Ti-betan Plateau.
机构:
Wageningen Univ, Soil Geog & Landscape Grp, POB 47, NL-6700 AA Wageningen, Netherlands
ISRIC World Soil Informat, POB 353, NL-6700 AJ Wageningen, NetherlandsWageningen Univ, Soil Geog & Landscape Grp, POB 47, NL-6700 AA Wageningen, Netherlands
Heuvelink, Gerard B. M.
Kempen, Bas
论文数: 0引用数: 0
h-index: 0
机构:
ISRIC World Soil Informat, POB 353, NL-6700 AJ Wageningen, NetherlandsWageningen Univ, Soil Geog & Landscape Grp, POB 47, NL-6700 AA Wageningen, Netherlands
Kempen, Bas
Morras, Hector J. M.
论文数: 0引用数: 0
h-index: 0
机构:
Inst Suelos, INTA CIRN, N Repetto & Los Reseros S-N, RA-1686 Hurlingham, Buenos Aires, ArgentinaWageningen Univ, Soil Geog & Landscape Grp, POB 47, NL-6700 AA Wageningen, Netherlands
机构:
Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Alpine Ecol, Beijing 100101, Peoples R ChinaChinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Alpine Ecol, Beijing 100101, Peoples R China
Ding, Jinzhi
Wang, Tao
论文数: 0引用数: 0
h-index: 0
机构:
Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Alpine Ecol, Beijing 100101, Peoples R China
Chinese Acad Sci, CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China
Lanzhou Univ, Sch Life Sci, Lanzhou 730000, Gansu, Peoples R ChinaChinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Alpine Ecol, Beijing 100101, Peoples R China
Wang, Tao
Piao, Shilong
论文数: 0引用数: 0
h-index: 0
机构:
Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Alpine Ecol, Beijing 100101, Peoples R China
Chinese Acad Sci, CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China
Peking Univ, Coll Urban & Environm Sci, Sino French Inst Earth Syst Sci, Beijing 100871, Peoples R China
Univ Chinese Acad Sci, Beijing 100049, Peoples R ChinaChinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Alpine Ecol, Beijing 100101, Peoples R China
机构:
Wageningen Univ, Soil Geog & Landscape Grp, POB 47, NL-6700 AA Wageningen, Netherlands
ISRIC World Soil Informat, POB 353, NL-6700 AJ Wageningen, NetherlandsWageningen Univ, Soil Geog & Landscape Grp, POB 47, NL-6700 AA Wageningen, Netherlands
Heuvelink, Gerard B. M.
Kempen, Bas
论文数: 0引用数: 0
h-index: 0
机构:
ISRIC World Soil Informat, POB 353, NL-6700 AJ Wageningen, NetherlandsWageningen Univ, Soil Geog & Landscape Grp, POB 47, NL-6700 AA Wageningen, Netherlands
Kempen, Bas
Morras, Hector J. M.
论文数: 0引用数: 0
h-index: 0
机构:
Inst Suelos, INTA CIRN, N Repetto & Los Reseros S-N, RA-1686 Hurlingham, Buenos Aires, ArgentinaWageningen Univ, Soil Geog & Landscape Grp, POB 47, NL-6700 AA Wageningen, Netherlands
机构:
Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Alpine Ecol, Beijing 100101, Peoples R ChinaChinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Alpine Ecol, Beijing 100101, Peoples R China
Ding, Jinzhi
Wang, Tao
论文数: 0引用数: 0
h-index: 0
机构:
Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Alpine Ecol, Beijing 100101, Peoples R China
Chinese Acad Sci, CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China
Lanzhou Univ, Sch Life Sci, Lanzhou 730000, Gansu, Peoples R ChinaChinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Alpine Ecol, Beijing 100101, Peoples R China
Wang, Tao
Piao, Shilong
论文数: 0引用数: 0
h-index: 0
机构:
Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Alpine Ecol, Beijing 100101, Peoples R China
Chinese Acad Sci, CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China
Peking Univ, Coll Urban & Environm Sci, Sino French Inst Earth Syst Sci, Beijing 100871, Peoples R China
Univ Chinese Acad Sci, Beijing 100049, Peoples R ChinaChinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Alpine Ecol, Beijing 100101, Peoples R China