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24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

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LERFOB Network: LerFob Experimental Silvicultural Network

Network and its devices names
LERFOB Network: LerFob Experimental Silvicultural Network
Coordination : Champenoux, 54280, France

Réseau LerFob

Distribution maps of "LerFob" network devices (active and completed) distributed by group: hardwoods (left) and softwoods (right) and grouped by forest.

Network description

The LerFob network has a network of permanent silvicultural plots (including comparative tests of thinning intensity) in regular high forest, the oldest of which were installed in 1883.
This network is unique in France in terms of the long duration of the trials monitoring and the long duration of the longitudinal series of measurements (all the trees were numbered and individually monitored as soon as the density of the stand made the operation practicable). The oldest individual circumference monitoring dates back to 1904.
The sites that are still active are present in 21 forest massifs in the northern half of France, representing 434 unit plots for a total 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 the Beech in 1883, a set of plots was installed in pure beech or beech and oak woods, about 30 years old, in the forest of The Hague (Meurthe-et-Moselle). Then from 1922 to 1924, three sets of plots were installed in the forests of Retz (Aisne), Darney (Vosges) and Eawy (Seine-Maritime) in perch or young forest stands aged 35 to 60 years, as well as single plots in forest stands of various ages (100 to 160 years).

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).
The entire network created since 1883, including the active schemes and all those that have come to an end or disappeared following climatic accidents - usually storms - comprises 1070 unit plots for a total area of nearly 410 hectares spread over 75 forest massifs and covers a much wider range of species than today. In particular, softwoods (spruce, fir, Douglas fir) accounted for half of the area.

The network is as much a source of active devices as it is a source of experimental data.

Nearly all of the devices have been installed in public forests, and for hardwoods, the origin of the stands is mainly natural regeneration.

Services offer

  • Compilation of experimental data
The data inventoried in the permanent plots of the network correspond mainly to measurements of circumference and health status on all trees in the plots and to measurements of total height on one sample.

The inventories are carried out regularly (usually every 3 to 5 years). In the most recent systems the time steps can even be annual.

Depending on the subject of the studies, other measures are added to these periodic inventories - for example on the crown (branching, crown projection) - or other technologies are used such as terrestrial Lidar.

The Experimental Growth Facility team is in charge of capturing and harmonizing the data files of active and non-active devices.
  • Support for the setting up of new experiments on the network sites in the framework of projects involving the Silva Team (INRAE).

Network management (i.e. protocol monitoring, data archiving, design of measurement tools) is entrusted to the Experimental Growth Facility.

This team is composed of 4 permanent staff members: an assistant engineer and 3 technicians under the responsibility of a research engineer. It is competent in dendrometric measurements on trees and forest stands, stem analysis, retrospective analyses based on the reading of annual growth rings, analysis of tree shapes and volumes (terrestrial LIDAR technology), pedological and ecological surveys.

Work description and access modalities

The network's devices and data are open to researchers from other teams, to answer research or technical development questions, within the framework of formalized collaborations (collaborative project or research agreement).

There are no restrictions on access to experimental sites except in the very rare cases where they are in private forest.

Access unit and cost

Variable according to demand, with a case-by-case analysis of costs, for data editing and technical support in the field or laboratory.


No particular equipment