Long-term Effects of Canopy Opening and Liming on Soil Nutrient Dynamics in a European Beech (Fagus sylvatica L.) Forest

Abstract

Forest management has a considerable influence on the soil nutrient dynamics of forest ecosystems. This study was designed to examine the long-term effects of lime application and canopy removal on soil nutrient budgets in a mature European beech (Fagus sylvatica L.) forest. In 1989, trees were felled to create four 30-m wide circular gaps in this beech forest, and two of these gaps and the surrounding area were limed with 3 t ha−1 of fine dolomite, whereas the remaining two gaps and most parts of the stand were not limed. Main nutrient concentrations in the forest floor and in the mineral soil were determined in 1989, 1997, and 2011. In addition, we examined the influence of liming and gaps on the forest floor organic matter. The significant effects of liming and gap creation on the forest floor dry mass in 1997 were no longer obvious in 2011, unlike their influence on the C and N pools, which was still significant in 2011. In the long-term, the forest floor C and N pools increased less in the limed and opened plots compared with the untreated stand, and the N pool only decreased in the mineral soil of the limed gaps. Soil acidity was reduced significantly 8 years after liming at any depth in the limed plots (limed stand, limed gaps) and in the deeper layers (5–40 cm) of the unlimed plots, indicating a general soil recovery from acid depositions in earlier decades. After 22 years, the pH values were still higher at 5 to 10 cm mineral soil depth in the limed plots, which partly reflected the higher base saturation in the mineral soil of the limed gaps. However, the pH values were surprisingly dropping from 1997 to 2011 in the upper soil layers of all plots. Overall, some effects of canopy opening and liming on soil nutrients lasted for more than two decades in this European beech forest.