Assessment of the Forest History of the Lorraine Plateau

PIs : Jean-Luc Dupouey (UMR 1137 Ecologie et Ecophysiologie Forestières – EEF); Vincent Robin (Laboratoire Interdisciplinaire des Environnements Continentaux – LIEC Université de Lorraine)

Collaborations : Delphine Aran (Laboratoire Interdisciplinaire des Environnements Continentaux – LIEC Université de Lorraine); Sandrine Chauchard, Joseph Levillain, Pierre Montpied (UMR 1137 Ecologie et Ecophysiologie Forestière – EEF); Jean-Claude Gégout (UMR 1092 Laboratoire d’étude des Ressources Forêt-Bois – LERFOB); Vincent Boulanger, Catherine Cluzeau, Nicolas Drapier (Office National des Forêts – ONF)

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Context – On the Lorrain plateau, as in many other regions of France, it is often assumed that forestry has led locally to the partial or total replacement of beech by oaks. Under a silvicultural regime of coppice, in more open stands, and because oak has always had a higher economic value, beech has been progressively expelled. However, we have no direct biological evidence of this substitution of species, even less a measure of its magnitude. If this substitution has indeed taken place, the current distribution of beech and oak trees does not reflect their “real” ecological niche, and this discrepancy is an issue for understanding, and therefore for the management of these species.

Objectives –

• To identify the dominant forest species of the stands prior to the anthropogenic promotion of oaks;
• To test the hypothesis that the beech was replaced by the oaks during the historical period;
• To characterize the ecological limit between beech and oak in plains.

Approach –  We propose an innovative interdisciplinary approach that includes:

• The analysis of databases to characterize the limit of ecological niches, as it appears today, between oaks and beech in plain.
• Pedoanthracology (analysis of soil charcoal) to locally assess the past composition of forests.
• Palynology to evaluate the composition of the past vegetation communities, at the extra-local scale.

Expected results and impacts – Our results will allow:

• to verify whether past action by foresters has led to a long-term substitution between beech and oak, more or less important depending on the degree of soil waterlogging.
• to better define the respective ecological niche of beech and oak trees in a context of clay soils of lowlands, widespread in France.