Clear-cut monitoring on French region of Limousin

[Departement_IRSTEA]DS [TR1_IRSTEA]METHODO / SYNERGIESince 2006, IFN (French National Forest Inventory) has been conducting an annual survey of clear-cuts on the French administrative region of Limousin (17060 km2). This work has been initiated as a part of the GSE (Global monitoring for environment and security Service Element) Forest monitoring European project, a common initiative of the European Commission and ESA. The goal of this project is to bridge the gap between producers of information derived from satellite data and users of this information, to develop a network of operational services in the environmental monitoring and security domains, at the 2008 horizon. As part of the project, a regional map of the clear-cuts has been produced for the two periods 2004-2005 and 2005-2006, for 3 core-end users: 2 forest cooperatives (CAFSA, CFBL) and the forest wood and pulp technical center (FCBA). Clear-cutting mapping is based on a pixel-to-pixel change detection method between two normalised images followed by a series of morphological filters to improve the map's quality. This method has been used by IFN since 1999 for an annual survey of clear-cutting of maritime pine on the Aquitaine massif with satisfactory results. Clear-cuts maps allow forest cooperatives to prospect new members and to propose reforestation services after clear cuts to members and other forest owners. In 2007, CAFSA realized a survey of all clear cuts larger than 4 ha, detected on the satellite derived map for the period 2004-2005. It shows that after a coniferous high forest clear-cut, about half of the stands are reforested. From the remaining half becomes agricultural lands. Thus, one of the benefits of this clear cut map delivered to forest cooperatives is to permit the monitoring of land cover and land cover changes as a support to the development of forest related services