Know more

LERFOB Network: LerFob Experimental Silvicultural Network

Coordination : Champenoux, 54280, France

https://www6.nancy.inrae.fr/silva

http://lerfob.free.fr/IEC/index_forets.php

Maps of "LerFob" network experimental sites (active and completed) distributed by group: hardwoods (left) and softwoods (right) and grouped by forest.

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.

• Compilation of experimental data

The data recorded on all the trees in the permanent plots of the network mainly concern circumference measurements and health status, though one plot provides measurements of total stand height.

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

Depending on the subject of the studies, other measurements are added to the periodic inventories. For example, crown characteristics like branch heightor crown projection) and new technologies such as terrestrial Lidar may be applied.

The Experimental Growth Facility team is in charge of capturing and harmonizing the data files of the active and non-active experimental sites.

• Support for setting up new experiments at the network sites within the framework of projects involving the Silva Team (INRAE).

Network management (i.e. monitoring protocol, data archiving, and 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 responsible for the dendrometric measurements on trees and in the forest stands, stem analysis, retrospective analyses based on annual growth rings, analysis of tree shapes and volumes (terrestrial LIDAR technology), and pedological and ecological surveys.

Access to the network's experimental sites and data is available to researchers from other teams, to answer research or technical questions, within the framework of formal collaborations (collaborative projects or research agreements).

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

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