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Effects of Detrital Inputs and Roots on Carbon Saturation Deficit of a Temperate Forest Soil
Author(s) -
Mayzelle M.M.,
Krusor M.L.,
Lajtha K.,
Bowden R.D.,
Six J.
Publication year - 2014
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2013.09.0415nafsc
Subject(s) - silt , litter , saturation (graph theory) , chemistry , plant litter , soil water , soil carbon , temperate climate , temperate forest , soil organic matter , agronomy , environmental science , soil science , environmental chemistry , botany , nutrient , biology , mathematics , paleontology , organic chemistry , combinatorics
Soil C sequestration has been proposed as a tool for addressing climate change. However, models used to predict soil C sequestration do not account for C saturation and functional differences among soil C pools. In this study, we examined differences in soil C pool content of a forest soil in Pennsylvania following 20 yr of detrital manipulation (i.e., control, no roots, no leaf litter, no inputs, double leaf litter). Detrital input treatments had a highly significant (ANOVA, F = 10.6, p < 0.0001) effect on soil C in the 0‐ to 5‐cm soil depth. However, soil C pools responded differently to the different treatments: the intra‐microaggregate silt + clay, intra‐microaggregate particulate organic matter (POM), and silt + clay within large macroaggregates in plots receiving no detrital inputs had significantly lower C concentrations (1.1, 2.5, and 0.4 g C kg −1 soil, respectively) than the control, double‐leaf‐litter, and no‐roots plots. Carbon in coarse POM within small macroaggregates was significantly lower in double‐leaf‐litter (4.5 g C kg −1 soil) and no‐leaf‐litter plots (6.6 g C kg −1 soil) than all other treatments (15.3–28 g C kg −1 soil). The intra‐microaggregate fractions in double‐leaf‐litter plots had greater C concentrations than in the control plots; along with moderate C concentrations in all bulk soil samples, this suggests that the soil is not yet approaching C saturation. This study reinforces the use of microaggregates within large macroaggregates as a diagnostic fraction for changes in soil C content and demonstrates that altering the organic matter source and quantity significantly affects soil C sequestration dynamics. Consideration of these factors will enable improved assessment of soil C sequestration capacity and management.