INTRODUCTION Sustainable forest management (SFM) is a key concept that underpins modern forestry practice by recognizing the need to balance the social, ecological, and economic outputs from forests, as outlined in Europe in the principles agreed upon through the Ministerial Conference on the Protection of Forests in Europe (MCPFE 2003a). However, assessing the overall sustainability of different types of forestry practice is complicated because of variation both in the nature of the forest resource and in the impacts of different management measures in space and over time (Kimmins 1992).