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Spatial Variability in Properties Affecting Organic Horizon Carbon Storage in Upland Soils
Author(s) -
Stutter M.I.,
Lumsdon D.G.,
Billett M.F.,
Low D.,
Deeks L.K.
Publication year - 2009
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/sssaj2008.0413
Subject(s) - podzol , moorland , soil carbon , environmental science , soil water , soil science , spatial variability , histosol , soil survey , hydrology (agriculture) , soil horizon , horizon , soil organic matter , geology , geography , mathematics , soil biodiversity , statistics , geotechnical engineering , geometry , archaeology
Quantifying the amount and distribution of soil organic carbon (SOC) within natural soils is important for sample design, C budgeting/pool estimation, and understanding SOC turnover at a process level. We examined the distribution of SOC across a typical UK upland, moorland catchment to establish the amount and spatial structure of variability in key soil properties affecting SOC stocks, namely O horizon C content, bulk density (D B ) and horizon depth. Organic horizons of Histosols and Gleysols had greater SOC contents but smaller bulk densities than Podzols and Leptosols. Consequently, SOC density differences between soils were minimized and horizon depth variation became crucial to the measurement of SOC stocks. However, individual Podzol profiles stored appreciable amounts of SOC in O horizons (up to 50 kg m −2 ). Geostatistical analyses showed spatially structured variance in many properties relating to SOC storage at both plot (variograms reaching sills at ranges 3–8 m) and catchment scales (ranges 437–529 m). The increase in variance from plot to catchment scales was large for O horizon depth. However, D B showed complex scale and soil type inter‐relationships, with similar variance at different scales. We show that detailed soil investigations spanning multiple spatial scales are necessary to quantify soil C storage properties for purposes of hydro‐ecological modeling and C budgeting at small catchment scales. This has implications for upscaling to regional or national soil C databases.