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. Understanding its current ecology is fundamental for conservation and monitoring issues and to clarify biogeographical aspects. The recent availability of large vegetation databases can elucidate some of these aspects using coenological records. We investigated the ecology of L. nobilis in Italian forests, taking into account a selection of climatic factors extracted from Bioclim. We analysed a national dataset of 804 phytosociological relevés in stands with L. nobilis in order to assess the coenology of the species along geographical and topographical gradients in Italy. Selected clustering and ordination techniques were used in order to obtain a robust classification. Indicator values according to Ellenberg’s approach, modified for Italy, combined with climatic data were applied to the classification to gain deeper insight into the ecology of Laurus. Our results show that L. nobilis occurs in a wide range of distinct plant communities. It is present in zonal evergreen forests, extrazonal mesophilous forests, and azonal riparian forests. The major contribution to this pattern is given by the minimum temperature of the coldest month and by the precipitation regime. This pattern suggests that its relict status is driven more by micro-topographical environmental factors rather than by the current macroclimatic envelope.