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Soil Organic Carbon Storage and Stability in the Aspen-Conifer Ecotone in Montane Forests in Utah, USA
AbstractTo assess the potential impact of conifer encroachment on soil organic carbon (SOC) dynamics and storage in montane aspen-conifer forests from the interior western US, we sampled mineral soils (0–15 cm) across the aspen-conifer ecotones in southern and northern Utah and quantified total SOC stocks, stable SOC (i.e., mineral-associated SOC (MoM)), labile SOC (i.e., light fraction (LF), decomposable (CO2 release during long-term aerobic incubations) and soluble SOC (hot water extractable organic carbon (HWEOC)). Total SOC storage (47.0 ± 16.5 Mg C ha−1) and labile SOC as LF (14.0 ± 7.10 Mg C ha−1), SOC decomposability (cumulative released CO2-C of 5.6 ± 3.8 g C g−1 soil) or HWEOC (0.6 ± 0.6 mg C g−1 soil) did not differ substantially with vegetation type, although a slight increase in HWEOC was observed with increasing conifer in the overstory. There were statistically significant differences (p = 0.035) in stable MoM storage, which was higher under aspen (31.2 ± 15.1 Mg C ha−1) than under conifer (22.8 ± 9.0 Mg C ha−1), with intermediate values under mixed (25.7 ± 8.8 Mg C ha−1). Texture had the greatest impact on SOC distribution among labile and stable fractions, with increasing stabilization in MoM and decreasing bio-availability of SOC with increasing silt + clay content. Only at lower silt + clay contents (40%–70%) could we discern the influence of vegetation on MoM content. This highlights the importance of chemical protection mechanisms for long-term C sequestration.
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Dobarco, M.R.; Van Miegroet, H. Soil Organic Carbon Storage and Stability in the Aspen-Conifer Ecotone in Montane Forests in Utah, USA. Forests 2014, 5, 666-688.View more citation formats
Dobarco MR, Van Miegroet H. Soil Organic Carbon Storage and Stability in the Aspen-Conifer Ecotone in Montane Forests in Utah, USA. Forests. 2014; 5(4):666-688.Chicago/Turabian Style
Dobarco, Mercedes R.; Van Miegroet, Helga. 2014. "Soil Organic Carbon Storage and Stability in the Aspen-Conifer Ecotone in Montane Forests in Utah, USA." Forests 5, no. 4: 666-688.