Water and oxygen regimes of four soil types at Newcastleton Forest, south Scotland

Summary The water and oxygen status of four upland soils under Sitka spruce plantations was studied for 2 years. In a brown earth, waterlogging only occurred ephemerally in the subsoil and oxgen concentrations were generally high. In contrast, waterlogged and near-anaerobic conditions persisted for much of the year in stagnogley and stagnohumic gley soils. In a peaty stagnopodzol moist conditions occurred above and below the thin ironpan, but while high oxygen concentrations generally persisted in the subsoil, low concentrations were common in the soil above. In the brown earth, healthy roots of Sitka spruce were present at a depth of 85 cm, but in the gley soils rooting was mainly limited to 25 cm and many roots were dead. In the peaty stagnopodzol, roots penetrated the ironpan and grew in the subsoil to 75 cm depth.