Vegetation diversity assessment in Southern Belgium's permanent forest inventory.

Southern Belgium’s permanent forest inventory (IPRFW) has been running since February 1994. Its main objective is to identify and control the state and evolution of Wallonia’s forests. Because of the growing awareness of the importance of biodiversity and the potential ability of a national forest inventory to assess and monitor it (Köhl, 1996; Tomppo, 1996), since 1997 the inventory has been compiling exhaustive listings (relevés) of the vegetation present in each woodland-based field plot. The inventory was designed to use this floristic information to determine the forest type of each sample unit, characterizing its vegetation diversity and monitoring its evolution across the repeated measures of the inventory, normally taken every 10 years. The inventory’s current methodology for vegetation description is based on the well-known phytosociological relevé method of Braun-Blanquet. This chapter presents only a few examples of data processing results. Furthermore, several problems related to field operations and data processing are also analysed in order to enhance the next inventory cycle scheduled for 2008. The proposed methodological adjustments are designed in such a way that the data and results obtained are useful not only from the point of view of biodiversity, but also for everyday forest management practice. This chapter summarizes the current status of the regional forest inventory in Wallonia with respect to vegetation diversity issues and highlights the need for further methodological progress.