|
Read Full Article (file size: 866434 bytes) Cited by
GLOBAL BIOGEOCHEMICAL CYCLES,
VOL. 19,
GB3011,
doi:10.1029/2005GB002536,
2005
Soil organic carbon dynamics as related to land use history in the northwestern Great Plains
Zhengxi Tan
South Dakota Center for Biocomplexity Studies, Brookings, South Dakota, USA
Shuguang Liu
SAIC, Sioux Falls, South Dakota, USA
Carol A. Johnston
South Dakota Center for Biocomplexity Studies, Brookings, South Dakota, USA
Thomas R. Loveland
U.S. Geological Survey, Sioux Falls, South Dakota, USA
Larry L. Tieszen
U.S. Geological Survey, Sioux Falls, South Dakota, USA
Jinxun Liu
Research Associateship Program at the USGS National Center for EROS, National Research Council, Sioux Falls, South Dakota,
USA
Rachel Kurtz
U.S. Geological Survey, Sioux Falls, South Dakota, USA
Abstract
Strategies for mitigating the global greenhouse effect must account for soil organic carbon (SOC) dynamics at both spatial
and temporal scales, which is usually challenging owing to limitations in data and approach. This study was conducted to characterize
the SOC dynamics associated with land use change history in the northwestern Great Plains ecoregion. A sampling framework
(40 sample blocks of 10 × 10 km2 randomly located in the ecoregion) and the General Ensemble Biogeochemical Modeling System (GEMS) were used to quantify the
spatial and temporal variability in the SOC stock from 1972 to 2001. Results indicate that C source and sink areas coexisted
within the ecoregion, and the SOC stock in the upper 20-cm depth increased by 3.93 Mg ha−1 over the 29 years. About 17.5% of the area was evaluated as a C source at 122 kg C ha−1 yr−1. The spatial variability of SOC stock was attributed to the dynamics of both slow and passive fractions, while the temporal
variation depended on the slow fraction only. The SOC change at the block scale was positively related to either grassland
proportion or negatively related to cropland proportion. We concluded that the slow C pool determined whether soils behaved
as sources or sinks of atmospheric CO2, but the strength depended on antecedent SOC contents, land cover type, and land use change history in the ecoregion.
Received 14
April
2005;
accepted 15
June
2005;
published 17
August
2005.
Keywords: General Ensemble Biogeochemical Modeling System (GEMS);
land use history;
soil organic carbon.
Index Terms: 0428 Biogeosciences: Carbon cycling (4806); 0414 Biogeosciences: Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912); 0402 Biogeosciences: Agricultural systems; 1632 Global Change: Land cover change.
Read Full Article (file size: 866434 bytes) Cited by
Citation: Tan, Z., S. Liu, C. A. Johnston, T. R. Loveland, L. L. Tieszen, J. Liu, and R. Kurtz
(2005),
Soil organic carbon dynamics as related to land use history in the northwestern Great Plains,
Global Biogeochem. Cycles,
19,
GB3011,
doi:10.1029/2005GB002536.
Copyright 2005 by the American Geophysical Union.
|