Title: Observational needs for estimating Alaskan soil carbon stocks under current and future climate

Abstract

Abstract Representing land surface spatial heterogeneity when designing observation networks is a critical scientific challenge. Here we present a geospatial approach that utilizes the multivariate spatial heterogeneity of soil‐forming factors—namely, climate, topography, land cover types, and surficial geology—to identify observation sites to improve soil organic carbon (SOC) stock estimates across the State of Alaska, USA. Standard deviations in existing SOC samples indicated that 657, 870, and 906 randomly distributed pedons would be required to quantify the average SOC stocks for 0–1 m, 0–2 m, and whole‐profile depths, respectively, at a confidence interval of 5 kg C m ⁻² . Using the spatial correlation range of existing SOC samples, we identified that 309, 446, and 484 new observation sites are needed to estimate current SOC stocks to 1 m, 2 m, and whole‐profile depths, respectively. We also investigated whether the identified sites might change under future climate by using eight decadal (2020–2099) projections of precipitation, temperature, and length of growing season for three representative concentration pathway (RCP 4.5, 6.0, and 8.5) scenarios of the Intergovernmental Panel on Climate Change. These analyses determined that 12 to 41 additional sites (906 + 12 to 41; depending upon the emission scenarios) would be needed to capture the impact of future climate on Alaskanmore » whole‐profile SOC stocks by 2100. The identified observation sites represent spatially distributed locations across Alaska that captures the multivariate heterogeneity of soil‐forming factors under current and future climatic conditions. This information is needed for designing monitoring networks and benchmarking of Earth system model results.« less

Authors:

Vitharana, U. W. A.  ^[1];

• Search DOE PAGES for author "Vitharana, U. W. A."
• Search DOE PAGES for ORCID "0000-0002-9427-7902"

Mishra, U.  ^[2];

• Search DOE PAGES for author "Mishra, U."
• Search DOE PAGES for ORCID "0000-0001-5123-2803"

Jastrow, J. D.  ^[2];

• Search DOE PAGES for author "Jastrow, J. D."
• Search DOE PAGES for ORCID "0000-0001-7069-4560"

Matamala, R. ^[2]; Fan, Z. ^[3]

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+ Show Author Affiliations

1. Department of Soil Science University of Peradeniya Peradeniya Sri Lanka
2. Environmental Science Division Argonne National Laboratory Argonne Illinois USA
3. Environmental Science Division Argonne National Laboratory Argonne Illinois USA, USDA‐ARS Jornada Experimental Range Las Cruces New Mexico

Publication Date:

Tue Feb 21 00:00:00 EST 2017

Research Org.:

Argonne National Laboratory (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER)

OSTI Identifier:

1344316

Alternate Identifier(s):

OSTI ID: 1344317; OSTI ID: 1392295

Grant/Contract Number:  

DE‐AC02‐06CH11357; AC02-06CH11357

Resource Type:

Published Article

Journal Name:

Journal of Geophysical Research. Biogeosciences

Additional Journal Information:

Journal Name: Journal of Geophysical Research. Biogeosciences Journal Volume: 122 Journal Issue: 2; Journal ID: ISSN 2169-8953

Publisher:

American Geophysical Union (AGU)

Country of Publication:

United States

Language:

English

Subject:

58 GEOSCIENCES; 54 ENVIRONMENTAL SCIENCES; Permafrost; Sampling; Soil organic carbon; Spatial heterogeneity