Rights statement: This is the peer reviewed version of the following article: Morris, P. J., Baird, A. J., Eades, P. A., & Surridge, B. W. J. ( 2019). Controls on near‐surface hydraulic conductivity in a raised bog. Water Resources Research, 55, 1531– 1543. https://doi.org/10.1029/2018WR024566 which has been published in final form at https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018WR024566 This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
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Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Controls on near-surface hydraulic conductivity in a raised bog
AU - Morris, Paul
AU - Baird, Andrew
AU - Eades, Phil A.
AU - Surridge, Benjamin William James
N1 - This is the peer reviewed version of the following article: Morris, P. J., Baird, A. J., Eades, P. A., & Surridge, B. W. J. ( 2019). Controls on near‐surface hydraulic conductivity in a raised bog. Water Resources Research, 55, 1531– 1543. https://doi.org/10.1029/2018WR024566 which has been published in final form at https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018WR024566 This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
PY - 2019/2/28
Y1 - 2019/2/28
N2 - Shallow water tables protect northern peatlands and their important carbon stocks from aerobic decomposition. Hydraulic conductivity, K, is a key control on water tables. The controls on K, particularly in degraded and restored peatlands, remain a subject of ongoing research. We took 29 shallow (~50 cm) peat cores from an estuarine raised bog in Wales, UK. Parts of the bog are in close-to-natural condition, while other areas have undergone shallow peat cutting for fuel and drainage, followed by restoration through ditch blocking. In the laboratory we measured horizontal (Kh) and vertical (Kv) hydraulic conductivity. We fitted linear multiple regression models to describe log10-transformed Kh and Kv on the basis of simple, easy-to-measure predictors. Dry bulk density and degree of decomposition were the strongest predictors of Kh and Kv. Perhaps surprisingly, the independent effect of hummocks was to produce higher-Kv peat than in lawns; while the independent effect of restored diggings was to produce higher-K peat than in uncut locations. Our models offer high explanatory power for Kh (adjusted r2 = 0.740) and K (adjusted r2 = 0.787). Our findings indicate that generalizable predictive models of peat K, similar to pedotransfer functions for mineral soils, may be attainable. Kh and Kv possess subtly different controls that are consistent with the contrasting roles of these two properties in peatland water budgets. Our near-surface samples show no evidence for the low-K marginal peat previously observed in deeper layers at the same site, indicating that such structures may be less important than previously believed.
AB - Shallow water tables protect northern peatlands and their important carbon stocks from aerobic decomposition. Hydraulic conductivity, K, is a key control on water tables. The controls on K, particularly in degraded and restored peatlands, remain a subject of ongoing research. We took 29 shallow (~50 cm) peat cores from an estuarine raised bog in Wales, UK. Parts of the bog are in close-to-natural condition, while other areas have undergone shallow peat cutting for fuel and drainage, followed by restoration through ditch blocking. In the laboratory we measured horizontal (Kh) and vertical (Kv) hydraulic conductivity. We fitted linear multiple regression models to describe log10-transformed Kh and Kv on the basis of simple, easy-to-measure predictors. Dry bulk density and degree of decomposition were the strongest predictors of Kh and Kv. Perhaps surprisingly, the independent effect of hummocks was to produce higher-Kv peat than in lawns; while the independent effect of restored diggings was to produce higher-K peat than in uncut locations. Our models offer high explanatory power for Kh (adjusted r2 = 0.740) and K (adjusted r2 = 0.787). Our findings indicate that generalizable predictive models of peat K, similar to pedotransfer functions for mineral soils, may be attainable. Kh and Kv possess subtly different controls that are consistent with the contrasting roles of these two properties in peatland water budgets. Our near-surface samples show no evidence for the low-K marginal peat previously observed in deeper layers at the same site, indicating that such structures may be less important than previously believed.
KW - peat
KW - peatland
KW - permeability
KW - von post
KW - multiple regression
KW - loglinear
U2 - 10.1029/2018WR024566
DO - 10.1029/2018WR024566
M3 - Journal article
VL - 55
SP - 1531
EP - 1543
JO - Water Resources Research
JF - Water Resources Research
SN - 1944-7973
IS - 2
ER -