LERFOB Network

The LerFob network is a network of permanent silvicultural plots in regular high forests, the oldest of which were installed in 1883. This network includes comparison tests of thinning intensities. This network is unique in France in terms of the very long duration of its monitoring and measurement campaigns (all the trees are numbered and have been individually surveyed since measurements became practicable in the stands). The oldest individual circumference records date back to 1904. There are still active sites in 21 forests in the northern half of France, for a total of 434 plots and a surface area of nearly 110 hectares. For the most part (more than 3/4 of the active experimental areas), these plots concern sessile oak and beech. The oldest part of these Beech and Oak networks was created in 2 periods. For beech, in 1883, a set of plots was installed in the forest of The Hague (Meurthe-et-Moselle) in pure beech or mixed beech-oak stands about 30 years in age. Then, from 1922 to 1924, 3 other sets of plots were installed in the forests of Retz (Aisne), Darney (Vosges) and Eawy (Seine-Maritime) in pole or young stands from 35 to 60 years in age; at the same time, single plots in older forest stands of various ages (100 to 160 years) were also installed. The oak network was installed between 1925 and 1934 in the forests of Bellême (Orne), Blois (Loir-et-Cher), Champenoux (Meurthe-et-Moselle) and Tronçais (Allier). Today, the entire network, including the active plots and those that have come to an end or disappeared (due to climatic events such as storms), comprises 1070 plots for a total area of nearly 410 hectares in 75 forests. In the past, the network covered a much wider range of species than today. In particular, softwoods (spruce, fir, Douglas fir) accounted for half of the area. The network provides active experimental sites and is a source of experimental data. Nearly all of the experimental sites are located in public forests. For hardwoods, the origin of the stands is mainly natural regeneration.