skip to main content


Title: Quantifying soil carbon accumulation in Alaskan terrestrial ecosystems during the last 15 000 years

Northern high latitudes contain large amounts of soil organic carbon (SOC), of which Alaskan terrestrial ecosystems account for a substantial proportion. In this study, the SOC accumulation in Alaskan terrestrial ecosystems over the last 15 000 years was simulated using a process-based biogeochemistry model for both peatland and non-peatland ecosystems. Comparable with the previous estimates of 25–70 Pg C in peatland and 13–22 Pg C in non-peatland soils within 1 m depth in Alaska using peat-core data, our model estimated a total SOC of 36–63 Pg C at present, including 27–48 Pg C in peatland soils and 9–15 Pg C in non-peatland soils. Current vegetation stored 2.5–3.7 Pg C in Alaska, with 0.3–0.6 Pg C in peatlands and 2.2–3.1 Pg C in non-peatlands. The simulated average rate of peat C accumulation was 2.3 Tg C yr −1, with a peak value of 5.1 Tg C yr −1 during the Holocene Thermal Maximum (HTM) in the early Holocene, 4-fold higher than the average rate of 1.4 Tg C yr −1 over the rest of the Holocene. The SOC accumulation slowed down, or even ceased, during the neoglacial climate cooling after the mid-Holocene, but increased again in the 20th century. The model-estimated peat depths ranged from 1.1 to 2.7 m, similar to the field-based estimate of 2.29 m for the region. We found that the changes in vegetation and their distributions weremore » the main factors in determining the spatial variations of SOC accumulation during different time periods. Warmer summer temperature and stronger radiation seasonality, along with higher precipitation in the HTM and the 20th century, might have resulted in the extensive peatland expansion and carbon accumulation.« less
ORCiD logo [1] ;  [2] ;  [3]
  1. Purdue Univ., West Lafayette, IN (United States). Department of Earth, Atmospheric, and Planetary Sciences
  2. Purdue Univ., West Lafayette, IN (United States). Department of Earth, Atmospheric, and Planetary Sciences and Department of Agronomy
  3. Lehigh Univ., Bethlehem, PA (United States). Department of Earth and Environmental Sciences
Publication Date:
Grant/Contract Number:
SC0008092; FG02-08ER64599
Published Article
Journal Name:
Biogeosciences (Online)
Additional Journal Information:
Journal Name: Biogeosciences (Online); Journal Volume: 13; Journal Issue: 22; Journal ID: ISSN 1726-4189
European Geosciences Union
Research Org:
Univ. of Oregon, Eugene, OR (United States)
Sponsoring Org:
Country of Publication:
United States
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1426151