Historical ecology of Mediterranean forests: Land use legacies on current understorey plants differ with time since abandonment and former agricultural use

Juliet Abadie (1) , Jean-Luc Dupouey (2) , Aline Salvaudon (3) , S. Gachet (4) , Noémie Videau (5) , Catherine Avon (6) , Jérôme Dumont , Thierry Tatoni (4) , Laurent Bergès (7)

1 RECOVER - Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience
2 SILVA - SILVA
3 PNRL - Parc Naturel Régional du Luberon
4 IMBE - Institut méditerranéen de biodiversité et d'écologie marine et continentale
5 ONF - Office nationale des Forets Guadeloupe
6 Semperfloris
7 UR LESSEM - Laboratoire des EcoSystèmes et des Sociétés en Montagne

Questions: Land use legacies in current forest understorey vegetation, thoroughly studied in temperate regions, were investigated in a Mediterranean context. We tested the effect of three historical variables on current forest plant communities and traits: forest temporal continuity (ancient: forested before 1860, recent: reforested after 1860, and very recent forest: reforested after 1958) and type of land use in 1860 and 1958 (forest, pasture or arable land). Location: The Regional Natural Park of Luberon (southeastern France). Methods: We used a comprehensive vegetation plot database (473 species in 1,429 plots). Species’ response to historical variables was tested with logistic regressions, and the relationship between plant traits and historical variables was analysed with RLQ and fourth‐corner analyses. Results: Among all studied species, 250 responded to forest temporal continuity, 208 to 1860 land use, and 246 to 1958 land use. Species associated with ancient forests were more frequently forest specialists or forest edge species, shade‐tolerant and perennials, while species associated with recent and very recent forests were more frequently annuals, anemochorous and heliophilous species. Species exhibited different traits and ecological preferences according to the type of land use prior to forest: therophytes were more frequent on former arable land while chamaephytes were more frequent on former pasture. Trait responses to 1860 and 1958 land uses were globally consistent. Conclusions: The effect of forest temporal continuity and past land use on forest understorey communities was consistent with other studies in northern Europe or northern America, which suggests that the same ecological processes apply in temperate lowland and Mediterranean regions. This study highlights a succession of plant communities in the long term and different trajectories of succession according to the type of former agricultural use. The long‐term legacies of past land use in current forest plant communities highlight the importance to preserve ancient forests, where typical forest species can be maintained.

Mots clés: agricultural use; ancient forest; ecological preference; forest continuity; historical ecology; life‐history traits; mediterranean forest; recent forest; secondary succession

Domaines: Biodiversité et Ecologie; Sylviculture, foresterie

Juliet Abadie, Jean-Luc Dupouey, Aline Salvaudon, S. Gachet, Noémie Videau, et al.. Historical ecology of Mediterranean forests: Land use legacies on current understorey plants differ with time since abandonment and former agricultural use. Journal of Vegetation Science, 2021, 32 (1), pp.1-13. ⟨10.1111/jvs.12860⟩. ⟨hal-03168867⟩