Fine roots of pedunculate oak (Quercus robur L.) in the Netherlands seven years after liming

Abstract

Liming of poor and acidic forest stands has often proved to improve soil chemical status, to alleviate nutritional imbalances and as a result, to improve health and growth of the forest stand. In this study an equivalent dosis of 1.6 t ha-1 CaO was applied to a young and an old Quercus robur L. stand on acidic sandy soils in the southeast of the Netherlands. Seven years after the lime application the effects on soil and roots were intensively studied. Prior to liming, the youngest stand suffered from a deficiency in five nutrients, whereas in the older stand only two elements were inadequate. Results indicate a consistent improvement in cation availability and soil pH seven years after lime application. Regarding the roots, the two stands show a different reaction in response to liming. In the young stand, liming increased specific root length and number of apices with mycorrhizae per cm of fine root length in most of the profile, whereas in the old stand, liming stimulated fine root biomass and length, but only in the top soil. The leaf nutrient status was most improved in the youngest and poorest stand, where lime had greatest impact on the soil exploration system (roots, mycorrhizae).