In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1.

Lakes worldwide have been strongly affected by several types of human-caused alteration, including changes in water level. This also affects deep lakes, including volcanic ones. Volcanic lakes in the Mediterranean area are of great importance for the local economy, but local human activities can threaten their rich biodiversity. As a European biodiversity hotspot and habitat of endemic species, the volcanic Lake Bracciano (Central Italy) is an ecosystem of primary conservation interest threatened by sharply falling water levels, particularly since 2017. It also plays a key role in human wellbeing by providing important ecosystem services including drinking water, fisheries and various recreational opportunities. Although the lake has historically been considered to enjoy good ecological status, various environmental problems, often amplified by water level changes, have arisen during the last two decades. Given this recent rapid evolution, the lake can be considered an example of a valuable ecosystem at risk as a result of increasing anthropogenic pressures. The aim of this review is to examine the changes that have affected the lake in the last 20 years, considerably reducing its capacity to provide ecosystem services, and to review existing and potential threats in order to better inform the management of such resources.

For many species, the Mediterranean region harbors distinct lineages that are of conservation concerns. However, many of these are threatened by habitat degradation and by the introduction of non-native species. Here, we assess the status of the native threespine stickleback (Gasterosteus aculeatus) in the Lake Bracciano region in Italy, where stickleback have been historically present. During a dedicated sampling campaign in summer 2015, surveying the potential habitats that sticklebacks commonly occupy, we could not confirm the presence of this species but found introduced species to be often most abundant. Stickleback are thus likely to either have become extinct over the last decades or be on the verge to extinction in the Lake Bracciano region.