thumbnail

Distribution and landscape controls of organic layer thickness and carbon within the Alaskan Yukon River Basin

Geoderma

By:
, , , , , , and
DOI: 10.1016/j.geoderma.2014.04.008

Links

Abstract

Understanding of the organic layer thickness (OLT) and organic layer carbon (OLC) stocks in subarctic ecosystems is critical due to their importance in the global carbon cycle. Moreover, post-fire OLT provides an indicator of long-term successional trajectories and permafrost susceptibility to thaw. To these ends, we 1) mapped OLT and associated uncertainty at 30 m resolution in the Yukon River Basin (YRB), Alaska, employing decision tree models linking remotely sensed imagery with field and ancillary data, 2) converted OLT to OLC using a non-linear regression, 3) evaluate landscape controls on OLT and OLC, and 4) quantified the post-fire recovery of OLT and OLC. Areas of shallow (< 10 cm), moderate (≥ 10 cm and < 20 cm), moderately thick (≥ 20 cm and < 30 cm), and thick (≥ 30 cm) OLT, composed 34, 20, 14, and 18% of the YRB, respectively; the average OLT was 19.4 cm. Total OLC was estimated to be 3.38 Pg. A regional chronosequence analysis over 30 years revealed that OLT and OLC increased with stand age (OLT: R2 = 0.68; OLC: R2 = 0.66), where an average of 16 cm OLT and 5.3 kg/m2 OLC were consumed by fires. Strong predictors of OLT included climate, topography, near-surface permafrost distributions, soil wetness, and spectral information. Our modeling approach enabled us to produce regional maps of OLT and OLC, which will be useful in understanding risks and feedbacks associated with fires and climate feedbacks.

Study Area

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Distribution and landscape controls of organic layer thickness and carbon within the Alaskan Yukon River Basin
Series title:
Geoderma
DOI:
10.1016/j.geoderma.2014.04.008
Volume
230-231
Year Published:
2014
Language:
English
Publisher:
Elsevier
Contributing office(s):
Earth Resources Observation and Science (EROS) Center
Description:
16 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geoderma
First page:
79
Last page:
94
Country:
United States
State:
Alaska
Other Geospatial:
Yukon River Basin