Impact of invasive alien plants on native plant communities and Natura 2000 habitats: State of the art, gap analysis and perspectives in Italy.

Invasive alien plants are a major threat to biodiversity and they contribute to the unfavourable conservation status of habitats of interest to the European Community. In order to favour implementation of European Union Regulation no. 1143/2014 on invasive alien species, the Italian Society of Vegetation Science carried out a large survey led by a task force of 49 contributors with expertise in vegetation across all the Italian administrative regions. The survey summed up the knowledge on impact mechanisms of invasive alien plants in Italy and their outcomes on plant communities and the EU habitats of Community Interest, in accordance with Directive no. 92/43/EEC. The survey covered 241 alien plant species reported as having deleterious ecological impacts. The data collected illustrate the current state of the art, highlight the main gaps in knowledge, and suggest topics to be further investigated. In particular, the survey underlined competition as being the main mechanism of ecological impact on plant communities and Natura 2000 habitats. Of the 241 species, only Ailanthus altissima was found to exert an ecological impact on plant communities and Natura 2000 habitats in all Italian regions; while a further 20 species impact up to ten out of the 20 Italian administrative regions. Our data indicate that 84 out of 132 Natura 2000 Habitats (64%) are subjected to some degree of impact by invasive alien plants. Freshwater habitats and natural and semi-natural grassland formations were impacted by the highest number of alien species, followed by coastal sand dunes and inland dunes, and forests. Although not exhaustive, this research is the first example of nationwide evaluation of the ecological impacts of invasive alien plants on plant communities and Natura 2000 Habitats.

Conservation action should come before publication.

With regard to the recent discovery of the red imported fire ant in Sicily (Menchetti et al. 2023), Genovesi et al. highlight the delay in communicating the observation and call on the scientific communities, scientific journals, and local authorities to ensure that new invasive alien species records are immediately reported for enhancing action.

A revision of Hydraena species of the "Haenydra" lineage (Coleoptera, Hydraenidae).

Hydraena Kugelann represents the largest genus within the water beetle family Hydraenidae, and in particular within Hydraeninae, with about 900 species widely distributed all over the world and several hundreds not yet described. In a recent cladistic analysis, based on morphological characters, Hydraena s. l. was split into two subgenera: Hydraenopsis Janssens (Gondwanian) and Hydraena s. str. (Laurasian). Moreover, within Hydraena s. str., some derived and well-supported monophyletic clades were recognised, and defined as "lineages". Among them, the "Haenydra" lineage, previously considered by many authors as a valid genus/subgenus, includes 89 species distributed exclusively in western Palaearctic, from Portugal to Iran, but absent in North Africa. The main aim of the present paper is to provide a revision of the whole lineage, re-examining taxonomy, ecology, and biogeography of all known species. All species were therefore redescribed, also providing information about diagnostic characters, taxonomic and phylogenetic relationships, ecology and biogeography. A faunistic dataset, including all the known published, and many unpublished, localities for each species, with a series of detailed geographic maps for each species and species complex, was herein supplied. Finally, dichotomous keys are provided for identification of males of all the "Haenydra" species.

Introducing the Global Register of Introduced and Invasive Species.

Harmonised, representative data on the state of biological invasions remain inadequate at country and global scales, particularly for taxa that affect biodiversity and ecosystems. Information is not readily available in a form suitable for policy and reporting. The Global Register of Introduced and Invasive Species (GRIIS) provides the first country-wise checklists of introduced (naturalised) and invasive species. GRIIS was conceived to provide a sustainable platform for information delivery to support national governments. We outline the rationale and methods underpinning GRIIS, to facilitate transparent, repeatable analysis and reporting. Twenty country checklists are presented as exemplars; GRIIS Checklists for close to all countries globally will be submitted through the same process shortly. Over 11000 species records are currently in the 20 country exemplars alone, with environmental impact evidence for just over 20% of these. GRIIS provides significant support for countries to identify and prioritise invasive alien species, and establishes national and global baselines. In future this will enable a global system for sustainable monitoring of trends in biological invasions that affect the environment.

Nocturnal activity of a "diurnal" species, the northern chamois, in a predator-free Alpine area.

The reduction of predation risk is widely considered a major factor affecting the nocturnal activity of mammals. Furthermore, on precipitous mountain terrain, moving in very poor light conditions should be avoided by animals with no special eyesight adaptation to darkness. The Northern chamois Rupicapra rupicapra has been for long considered as a diurnal species, with occasional nocturnal movements. For the first time, we have quantified the nocturnal activity of 21 radiotagged female chamois from the Italian Eastern Alps (Paneveggio-Pale di San Martino Natural Park), continuously monitored for two years from sunset to sunrise, with 24h tracking sessions carried out for six months. Large predators were not present in the study site. Despite their mainly diurnal activity pattern, peaks of nocturnal movements were detected throughout the year. The least proportion of active night fixes occurred in January and in July, while the most were in April and in October. The greater nocturnal activity in the warm months compared to cold periods, was probably due to frozen snow cover reducing nocturnal movements. Movements were mainly concentrated in bright moonlight nights, possibly because of the absence of large predators, but more likely because of increased visibility. Changes in activity levels throughout the year may also reflect changes in energy requirements of Northern chamois.

Alien mammals in Europe: updated numbers and trends, and assessment of the effects on biodiversity.

This study provides an updated picture of mammal invasions in Europe, based on detailed analysis of information on introductions occurring from the Neolithic to recent times. The assessment considered all information on species introductions, known extinctions and successful eradication campaigns, to reconstruct a trend of alien mammals' establishment in the region. Through a comparative analysis of the data on introduction, with the information on the impact of alien mammals on native and threatened species of Europe, the present study also provides an objective assessment of the overall impact of mammal introductions on European biodiversity, including information on impact mechanisms. The results of this assessment confirm the constant increase of mammal invasions in Europe, with no indication of a reduction of the rate of introduction. The study also confirms the severe impact of alien mammals, which directly threaten a significant number of native species, including many highly threatened species. The results could help to prioritize species for response, as required by international conventions and obligations.