The ICP forests Level I biodiversity data. A harmonized data source and baseline for plant species and structural diversity on european forest ecosystems

Structural and compositional biodiversity surveys on the ICP Forests extensive monitoring plots (Level I) have been incorporated into the ICP Forests database as LI-BioDiv dataset. Data were collected in the period 2005-2008 and delivered by 27 partners according to harmonized methods. During the integration process data was validated based on a complex system of checkroutines that had been defined before. Conflicts were solved in collaboration with the experts from National Focal Centres and the Expert Panels on Biodiversity and Ground Vegetation, and on Forest Growth. The LI-BioDiv dataset is structured in six forms: GPL (general plot location and information, 3340 plots), DBH (tree diameter, status, and composition, 3201 plots), THT (tree top and crown base height, 3083 plots), CAN (canopy closure, layers, number of trees, 3210 plots), DWD (deadwood, 2950 plots), and GVG (ground vegetation composition, 3124 plots). A transnational internal evaluation process was established and a set of items approved by the related Expert Panels and the ICP Forests Programme Co-ordinating Centre (PCC). Four working groups are producing the first results in terms of scientific papers; the other evaluation projects and the related groups of experts and scientists are described. Recommendations and lessons learned from this experience are shortly provided.