Physical properties of peat soils under different land use options. (25th July 2016)

• Record Type: Journal Article
• Authors: Mustamo, P.; Hyvärinen, M.; Ronkanen, A.‐K.; Kløve, B.
• Editors: Moffat, Andy J
• Is Part Of: Soil use and management. Volume 32:Number 3(2016:Sep.)
• Page Start: 400
• Page End: 410
• Publication Date: 2016-07-25
• Subjects: Peat -- land use -- soil physical properties -- soil hydrology -- drainage -- modelling; Soil management -- Periodicals; 631.4
• DOI: 10.1111/sum.12272
• Languages: English
• ISSNs: 0266-0032

Abstract

Abstract: Pristine peat soils are characterized by large porosity, low density and large water and organic matter contents. Drainage and management practices change peat properties by oxidation, compaction and mineral matter additions. This study examined differences in physical properties (hydraulic conductivity, water retention curve, bulk density, porosity, von Post degree of decomposition) in soil profiles of two peatland forests, a cultivated peatland, a peat extraction area and two pristine mires originally within the same peatland area. Soil hydraulic conductivity of the drained sites (median hydraulic conductivities: 3.3 × 10 −5 m/s, 2.9 × 10 −8 m/s and 8.5 × 10 −8 m/s for the forests, the cultivated site and the peat extraction area, respectively) was predicted better by land use option than by soil physical parameters. Detailed physical measurements were accompanied by monitoring of the water levels between drains. The model 'DRAINMOD' was used to assess the hydrology and the rapid fluctuations seen in groundwater depths. Hydraulic conductivity values needed to match the simulation of observed depth to groundwater data were an order of magnitude greater than those determined in field measurements, suggesting that macropore flow was an important pathway at the study sites. The rapid response of depth to groundwater during rainfall events indicated a small effective porosity and this was supported by the small measured values of drainable porosity. This study highlighted the potential role of land use and macropore flow in controlling water table fluctuation and related processes in peat soils.