Abstract
Laurus nobilis L. is considered one of the extant relic species of the late Tertiary Eurasian lauriphyllous forest belt, persisting in the Mediterranean vegetation. During the last decades, lauriphyllous species, including L. nobilis, are spreading in southern Europe, apparently favored by warmer and more humid environmental conditions due to suggested trends in climate change. Considering its biogeographical importance, however, few works focused on its ecology and coenology in S-Europe.
We investigate the ecology and rejuvenation of L. nobilis in the Italian forests, taking into account a selection of environmental factors and human impact. We analysed a national dataset of phytosociological relevés in stands with L. nobilis in order to describe the coenology of the species along geographical and topographical gradients in Italy. Ellenberg indicator values combined with climate data are applied to the classification in order to gain more insight into the ecology of Laurus. Additionally, we sampled 34 forests stands in central Italy, in order to assess the patterns of its rejuvenation.
Our results show that L. nobilis occurs in a wide range of distinct plant communities. Abundant regeneration is recorded especially in (1) Quercus ilex evergreen forests and (2) in deciduous mesophilous forests dominated by S-European oaks (Carpinus betulus, Quercus petraea, Fagus sylvatica). An increasing “Laurophyllisation“ was detected by high rejuvenation of Laurus in stands where only few older individuals of the species were formerly scattered in the canopy. We suggest that changes in forest use and abandonment of forest grazing might major explanations for the local spread of L. nobilis.