Descrizione 1
Alessandro Calabrese, Lucilla Carnevali, Stefania Ercole, Piero Genovesi
The indicator provides an overview of the current presence of alien animal and plant species in Italy through quantitative data, showing the temporal trends of introduction in Italy over the last century, the average annual introduction rate (average number of new alien species introduced each year), the pathways (according to CBD categories), and the distribution of invasive alien species of Union concern. The number of alien species in Italy is progressively and constantly increasing. Based on currently available data, nearly 3,800 exotic species have been introduced into our country, of which 3,659 are currently present in the territory. The average number of species introduced per year has increased exponentially over time, increasing from 6 species/year in the 1970s to 16 species/year in the last decade,reaching nearly 30 species/year in the current decade. The cumulative number of species introduced in Italy since 1900 also confirms this exponential trend, with an increase of over 500% in 120 years.
According to the CBD (Convention on Biological Diversity), an alien (also referred to as exotic, non-native, introduced) species is defined as "a species, subspecies, or lower taxon introduced (due to human action, intentional or accidental) outside its natural past or present distribution, including any part of the species, gametes, seeds, eggs, or propagules of such species that might survive and subsequently reproduce." An invasive alien species is defined as "an alien species whose introduction and/or spread threatens biodiversity." The indicator provides an overview of the current presence of alien animal and plant species in Italy through quantitative data and shows both the trends of alien species introduction in the national territory over the last century and the average annual rate (average number of new alien species introduced each year). The data used for the indicator have been extracted from the National Alien Species Database, created by ISPRA on behalf of MASE, which is constantly updated and available on the website www.specieinvasive.isprambiente.it.
The indicator also includes distributional data related to the six-year reporting pursuant to Article 24 of EU Regulation 1143/14.
The indicator is useful for representing the phenomenon of biological invasions, which cause damage to biodiversity, ecosystem services, human health, and the economy.
On January 1, 2015, Regulation (EU) 1143/2014 of the European Parliament and Council on the prevention and management of the introduction and spread of invasive alien species came into force. The Regulation establishes rules to prevent, minimize, and mitigate the impact on biodiversity, ecosystem services, human health, and the economy due to the intentional or accidental introduction and spread of invasive alien species within the European Union.
The Commission has adopted a list of invasive species of Union concern, which is continuously updated and reviewed at least every six years. The species on this list cannot be intentionally introduced into European territory, nor can they be bred, transported, placed on the market, or released into the environment.
The Regulation establishes the obligation to develop a surveillance system for the early detection and rapid eradication of species of Union concern that are not yet present in the Member State's territory, as well as the obligation to implement effective management measures for species already present. Additionally, each Member State must conduct a thorough analysis of pathways through which invasive exotic species are introduced and spread within its territory, developing and implementing an action plan for the identified priority pathways.
Member States are responsible for adopting the necessary measures to ensure the enforcement of the Regulation and to establish sanctions in case of violations.
Finally, a system of authorizations and special permits is provided to allow certain activities with invasive alien species, such as research or conservation activities. Member States may establish national lists of invasive species, also to introduce prevention and management measures on a national scale.
Legislative Decree No. 230/17, adapting national legislation to the provisions of EU Regulation 1143/2014, entered into force on February 14, 2018, and sets out measures for: official controls necessary to prevent the deliberate introduction of species of Union and national concern, granting derogation authorizations, establishing a national surveillance system, management measures aimed at eradicating or containing species of Union and national concern, and the penalty system for violations of the provisions.
In June 2019, Italy submitted data for the first reporting required under Article 24 of the EU Regulation on invasive alien species of Union concern. The second reporting is scheduled for 2025.
Descrizione 2
Aleffi, Tacchi, Cortini Pedrotti, 2008. Check-list of the Hornworts, Liverworts and Mosses of Italy. Bocconea, 22.
Bartolucci et al., 2018. An updated checklist of the vascular flora native to Italy. Plant Biosystems 152(2): 179-303.
Bartolucci F., Peruzzi L., Galasso G., ... & F. Conti, 2024. A second update to the checklist of the vascular flora native to Italy. Plant Biosystems, An International Journal Dealing with all Aspects of Plant Biology, 158 (2): 219-296, DOI: 10.1080/11263504.2024.2320126
Galasso et al., 2018. An updated checklist of the vascular flora alien to Italy. Plant Biosystems, 152(3), 556-592.
Galasso G., Conti F., Peruzzi L., ... & Bartolucci F., 2024. A second update to the checklist of the vascular flora alien to Italy. Plant Biosystems, An International Journal Dealing with all Aspects of Plant Biology, 158(2), 297-340.
ISPRA (Istituto Superiore per la Protezione e la Ricerca Ambientale) - Banca Dati Nazionale Specie Alloctone
Minelli, Ruffo, La Posta (eds.), 1993-1995. Checklist delle specie della fauna italiana. Fascicoli 1-110. Edizioni Calderini, Bologna
Ruffo, Stoch (eds), 2007. Checklist and distribution of the Italian fauna. Memorie del Museo Civico di Storia Naturale di Verona, 2 serie, Sezione Scienze della Vita, 17 (2006): 1-303 with CD ROM.
Seebens H., Blackburn T.M., Essl F., 2017. No saturation in the accumulation of alien species worldwide. Nature Communications, 8, 14435. http://www.nature.com/articles/ncomms14435
The data used represent an underestimation of the extent of the phenomenon, both due to the limited number of specific studies, particularly in certain geographical areas, and the delay in species identification. For some taxonomic groups, data are still lacking (especially for fungi and lichens).
Gaps need to be filled regarding the dates of introduction of alien species into Italy, at least from after World War II to the present.
Qualificazione dati
The National Alien Species Database can be accessed online at www.specieinvasive.isprambiente.it
National
(Neolithic) - 1500 - 2024 (dates given in bibliographical references)
Qualificazione indicatore
The indicator was developed by calculating various sub-indicators based on data updated in November 2024 from the National Alien Species Database (ISPRA). The processing consists of simple calculation operations. The indicator is based on the entire dataset of alien animal and plant species (not just invasive alien species).
For the calculation of the introduction rate, only alien species that are established across the entire national territory and introduced after 1900 were considered. Species with uncertain status, those considered alien only in a part of the national territory, and species present only occasionally, or that have become extinct or been eradicated after introduction were excluded. Additionally, invertebrates classified as agricultural and/or forest pests, species associated with spatially limited crops (e.g., Heterodera elachista, a Japanese nematode affecting rice and corn cysts, introduced to Italy between 2012 and 2013) were excluded. This decision is based on the fact that EU Regulation 1143/14 explicitly excludes these species from its prohibitions, as they are already covered by other regulatory instruments. The methodology of Seebens et al. (2017) was followed for analyzing introduction dates.
The number of alien species in Italy is particularly high: based on currently available data, more than 3,800 exotic species (or species with uncertain status) have been introduced into the country, of which 3,659 are still present, almost equally divided between plant and animal species. This total also includes species with uncertain status (defined as cryptogenic, mostly belonging to terrestrial arthropods and various marine taxa) and exotic species exotic only in a part of the national territory. It is important to emphasize that these numbers represent an underestimation, particularly for some taxonomic groups (such as fungi, chromists, and protozoa), due in part to the difficulty in promptly detecting new species.
The trend is negative as the number of alien species in Italy continues to increase steadily and progressively: this number has risen from 3,182 species in 2017 to 3,659 species currently present. Moreover, by observing the average annual introduction rate (Figure 2), an exponential growth trend is evident. After an initial phase of relative stability (1900-1950), with average introduction rates below 2 species per year, there followed a period of increasing introduction rates. Initially moderate, this increase became more substantial from the 1970s onward, surpassing 7 species per year and reaching its peak in the current decade, exceeding 30 species per year. The cumulative number of species introduced in Italy since 1900 also confirms this exponential trend, with an increase of over 500% in 120 years (Figure 3).
Dati
Figure 1: Number of Italian allochthonous species, currently present in Italy, belonging to the main taxonomic groups and percentage of allochthonous to the overall total of species, calculated for each group (excluding Fungi and Algae)
ISPRA - National Database of Alien Species. Updated November 2024
Figure: 2 Number of species introduced to Italy since 1900 and average annual rate of new introductions, calculated from 834 species of certain introduction date
ISPRA - National Database of Alien Species. Updated November 2024.
For the calculation of the introduction rate, only alien species (status = 1.0) over the entire national territory were considered: therefore, species with uncertain status (status = 3 or 4) or of alien origin only in a part of the national territory (status = 1.1) were excluded.
Only species that were stably present (occurrence = 2.0, 2.1, 2.2) were considered: all species that were absent (occurrence = 1.0), erroneously reported (occurrence = 1.1), extinct (occurrence = 1. 2), eradicated (occurrence = 1.3), intercepted (occurrence = 1.4), occasionally present (occurrence = 3.0), present in containment structures (occurrence = 4.0), uncertain (occurrence = 5.0), and undefined (occurrence = 9.9).
So-called agricultural and/or forestry pest invertebrates (pest = a, f, a/f), species related to spatially delimited crops (e.g., Heterodera elachista, a Japanese nematode related to rice and corn cysts, which arrived in Italy between 2012 and 2013) were excluded.
Only species with a period or date of introduction after 1900 were considered: records without a date, those with a date only 1500, and those before 1900 were excluded; precise dates, when present, or those contained in the “data_prima” field were chosen.
Figure 3: Cumulative number of allochthonous species introduced into Italy since 1900, calculated from 834 species of certain introduction date
ISPRA - National Database of Alien Species. Updated November 2024.
Figure 4: Distribution of the 30 invasive alien species of EU relevance present in Italy and reported under Article 24 of EU Regulation 1143/14 in June 2019
ISPRA - National Database of Alien Species. Updated November 2024.
The number of alien species in Italy continues to increase progressively and steadily. This increase is linked to the rise in trade exchanges and the development of transportation systems in Europe, particularly after World War II, as well as the lack of effective biosecurity systems to prevent new arrivals.
Figure 1 illustrates the numerical presence of alien and cryptogenic species (including those present occasionally) in Italy, categorized by major taxonomic groups of animals and plants. It also shows the proportion of introduced alien species relative to the total number of species (native + alien) estimated in Italy for each group. Species that are native to one part of Italy but introduced to another have been considered native species.
Compared to the previous dataset from December 2021, the most significant increases in the percentage of alien species relative to the total number of species in the national territory (ranging between 2% and 4%) have been observed in reptiles and birds.
Analysis of the introduction rate (Figure 2) clearly shows that the average number of species introduced per year has increased exponentially over time, reaching 13 species per year from 2000 to2009 and 16 species per year from 2010 to2019. In the first four years of the current decade, the introduction rate has almost doubled (29.2 species per year). It should be noted that the absolute number of new introductions per decade is likely an underestimation due to limited knowledge of species introduction dates in past decades (covering only 20% of the species in the database). In recent years, when species introduction dates are better documented, the underestimation may be due to the challenge of promptly detecting new presences in the territory. For details regarding the methodology used to calculate the introduction rate, refer to the “Processing Methodology Description” section.
Even when calculating the cumulative number of species introduced in Italy since 1900 (Figure 3), the exponential trend of the phenomenon is confirmed: in 120 years, alien species introductions have increased by over 500%. Since 2019, the number of new introductions per year has exceeded 30, with 2020 recording the highest number of new species introductions (n = 36).
In June 2019, the first reporting required under Article 24 of EU Regulation 1143/14 on invasive alien species of Union concern was submitted. The map (Figure 4) shows the distribution of 30 species present in Italy (out of a total of 48 listed species), represented in 10x10 km² grid cells. There is a concentration of species in northern Italy, particularly in the Po Valley, with two additional small hotspots in central Italy, corresponding to the Pontine Plain in Lazio and the Florence area. The second reporting under Article 24 of EU Regulation 1143/14 is scheduled for 2025, providing an opportunity for an update.
The list of invasive alien species of Union concern has been updated twice since the Regulation’s adoption and currently includes 88 species, of which 47 are already present in the natural environment in Italy.