The Checklist of the Sardinian Alien Flora: an Update

Abstract

Alien plants colonization, due to the fast spreading of highly invasive taxa, is more and more a serious source of concerns for habitat and species conservation. Apart direct in situ intervention, it is of major importance to acquire the best and up to date knowledge about alien taxa that currently threaten the integrity of wild and valuable environments. In this light, here is presented the update to the checklist of alien vascular flora of the island of Sardinia (Italy) on the basis of the new findings, nomenclatural adjustments, and revision of diffusion status of alien taxa. The checklist at present, consists of 541 taxa (84 doubtful) which represent 17% of the whole flora of the island; 22 taxa are new to the island and 7 of them for Italy. Neophytes represent the majority of the whole alien flora (301, 66% of the total) and, in confront to archaeophytes, gather nearly all invasive taxa (54 vs 4). The new findings are all neophytes. Phanerophytes (42%) are the most representative biological form and Americas represents the region that mostly contributes to the Sardinian alien flora (33%). Further analysis highlights that, in terms of number of taxa, highly anthropically impacted environments such as synanthropic (36%) and agricultural (23%) are the eligible habitats for most of the alien species in Sardinia while coastal areas and wetlands, beyond hosting a lower number of taxa, are characterized by the relative highest number of invasives.