Effects of different harvesting intensities on the macro nutrient pools in aged oak coppice forests

Abstract

Improved knowledge concerning nutrient removals through harvesting in former coppice forests is crucial for the sustainable management of these forests. This is especially true if the resumption of coppicing is being considered to serve increasing fuel wood demands. In this study the nutrient contents of various tree compartments of sessile oak (Quercus petraea (Mattuschka) Liebl.) and hornbeam (Carpinus betulus L.) from two sites differing in soil fertility were determined using allometric equations to calculate nutrient removal associated with different harvesting intensities.Stand level nutrient contents in tree compartments were comparable between both study sites. The results for exchangeable base cations, plant available P, and total N indicate that coppicing is not a priori an unsustainable forest management system. On sites with large soil nutrient pools, even whole trees may be harvested without substantial reductions in ecosystem nutrient pools. However, on sites with a low nutrient capital, current harvesting practices would result in relatively high rates of nutrient export. In these stands, harvesting intensity should be based on careful selection of the tree compartments removed, e.g. stem only, to conserve nutrients on site.This study describes the impact of simulated tree harvesting on soil nutrient pools in aged coppice forest for the first time. Based on our findings, general assumptions related to soil sustainability of coppicing are replaced by clear recommendations regarding silvicultural nutrient management. Considering the large areas of aged coppice forests in Europe this study provides a methodological template which is needed to enhance their sustainable management.