© 2023 The Authors. Conservation Biology published by Wiley Periodicals LLC on behalf of Society for Conservation Biology. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited., The Environmental Impact Classification for Alien Taxa (EICAT) is an important tool for biological invasion policy and management and has been adopted as an International Union for Conservation of Nature (IUCN) standard to measure the severity of environmental impacts caused by organisms living outside their native ranges. EICAT has already been incorporated into some national and local decision-making procedures, making it a particularly relevant resource for addressing the impact of non-native species. Recently, some of the underlying conceptual principles of EICAT, particularly those related to the use of the precautionary approach, have been challenged. Although still relatively new, guidelines for the application and interpretation of EICAT will be periodically revisited by the IUCN community, based on scientific evidence, to improve the process. Some of the criticisms recently raised are based on subjectively selected assumptions that cannot be generalized and may harm global efforts to manage biological invasions. EICAT adopts a precautionary principle by considering a species’ impact history elsewhere because some taxa have traits that can make them inherently more harmful. Furthermore, non-native species are often important drivers of biodiversity loss even in the presence of other pressures. Ignoring the precautionary principle when tackling the impacts of non-native species has led to devastating consequences for human well-being, biodiversity, and ecosystems, as well as poor management outcomes, and thus to significant economic costs. EICAT is a relevant tool because it supports prioritization and management of non-native species and meeting and monitoring progress toward the Kunming–Montreal Global Biodiversity Framework (GBF) Target 6., M.V. was supported by the Spanish Ministerio de Ciencia e Innovación project PREABROAD (EUR2022-134026) and RADIOPOPO (PID2021-122690OB-I00). S.B., M.V., B.G., J.M.J., and G.V. acknowledge funding by the Belmont Forum-BiodivERsA International joint call project InvasiBES and by the national funders Spanish Ministry of Science and Innovation (PCI 2018–092939 and PCI 2018–092986), Swiss National Science Foundation (31003A_179491 and 31BD30_184114), and German Federal Ministry of Education and Research (16LC1803A). G.B. and E.T. acknowledge the support of NBFC to the University of Florence and University of Sassari, funded by the Italian Ministry of University and Research, PNRR, Missione 4 Componente 2, ‘Dalla ricerca all'impressa’, Investimento 1.4, Project CN00000033. P.P. and A.N. were supported by EXPRO grant 19–28807X (Czech Science Foundation) and long-term research development project RVO 67985939 (Czech Academy of Sciences). M.G. was supported by the core research group Forest biology, Ecology, and Technology (P4-0107, Slovenian Research Agency) and by the Administration of the Republic of Slovenia for Food Safety, Veterinary Sector and Plant Protection (contracts C2337-22-000020 and C2337-23-000026). W.R. was supported by the project National Focal Point Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation and Technology(, Austria). H.E.R. was supported by the Natural Environment Research Council (NERC) award NE/R016429/1 under the UK-SCAPE program delivering National Capability., Peer reviewed

Confidence in predictions of non-native species' spread relies on the niche conservatism hypothesis, which poses that climatic niches are preserved over time and space. Because plants introduced through the same introduction pathway (gardening, unintentional) tend to share some features of the introduction process and biological attributes, the extent of niche conservatism might be influenced by how and when species of particular attributes have been introduced. We compared the realized climatic niches between the native (global) and invaded ranges (mainland Spain), through ordination and kernel smoothers. We calculated niche conservatism metrics (i.e. overlap, unfilling, stability, expansion and pioneering), for a set of 158 plant species. Niche conservatism metrics were then related to a plant's introduction pathway, minimum residence time, growth form and native climatic niche breadth. On average, niche stability accounted for 75% of niche occupancy, while around 61% of species showed some degree of niche shift, which were mostly of small magnitude. The climatic niche was most conserved for annual and perennial herbs, plants introduced a long time ago, and those with broad climatic niches in their native range. Introduction pathways had a non-significant effect. Niche conservatism metrics were neither explained by interactions of minimum residence time with introduction pathways nor with growth form. Native climatic niche breadth was the most important correlate of niche conservatism metrics. Synthesis. Non-native plants largely occupy similar climatic conditions in their invaded and native range, a pattern that co-occurred with frequent and mostly small niche shifts. These results largely support the niche conservatism hypothesis. This boosts confidence in predictive models of non-native plants' spread. This study highlights that niche conservatism is better explained by a plant's ability to cope with broad climatic conditions, rather than by its introduction history or growth form., M. Riera was supported by a doctoral grant (FPU18/05806), a short stay grant (EST21/00611), funded by the Ministry of Science, Innovation and Universities; and by the EXOCAT project (http://exocat.creaf.cat/), funded by the Departament d'Acció Climàtica, Alimentació i Agenda Rural from the Autonomous government of Catalonia (Generalitat de Catalunya). Y. Melero is ascribed to the Serra Húnter Programme, a program funded by the Autonomous government of Catalonia (Generalitat de Catalunya), and was supported by a Severo Ochoa Excellence Postdoctoral Fellowship (CEX-2018-000828-S), funded by the Ministry of Science, Innovation and Universities. M. Vilà was partially supported by the project RADIOPOPO (PID2021-122690OB-I00) funded by MCIN/AEI/10.13039/501100011033/FEDER, UE., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX-2018-000828-S), Peer reviewed

[EN]
The introduction of alien species constitutes a global change phenomenon promoted directly or indirectly
by human activities. Many alien species are introduced for specific purposes, often aesthetic, such as
ornamental plants or as pets. They can also arrive as stowaways or contaminants of commercial products, or
simply disperse through large transportation pathways ithat connect previously isolated geographical areas.
The establishment and subsequent expansion of exotic species can lead to biological invasions, which
depends both on the species biological traits and on whether they find favorable environmental conditions
in the area of introduction. Invasive species have an impact on biodiversity and the properties of native
ecosystems. Consequently, they modify the environmental services that nature provides, and affect our
quality of life through changes that can affect public health and socioeconomic sectors such as agriculture,
fisheries or tourism. To mitigate these impacts, the most effective management measures must include the
prevention and early detection of potentially invasive alien species., [ES]
La introducción de especies exóticas constituye un fenómeno de cambio global impulsado directa o
indirectamente por las actividades humanas. Muchas especies exóticas se introducen por sus usos, muchas
veces estéticos, tal es el caso de las plantas ornamentales o las mascotas. También pueden llegar como
polizones o contaminantes de productos comerciales, o sencillamente dispersarse a través de grandes vías de
transporte que conectan áreas geográficas originalmente aisladas. El establecimiento y posterior expansión
de las especies exóticas puede dar lugar a invasiones biológicas, cuyo desarrollo depende tanto de los rasgos
biológicos de las especies, como de que encuentren unas condiciones ambientales favorables en el área de
introducción. Las especies invasoras ocasionan impactos en la biodiversidad y en las propiedades de los
ecosistemas nativos. En consecuencia, modifican los servicios ambientales que la naturaleza nos brinda y
afectan a nuestra calidad de vida mediante cambios que pueden repercutir en la salud pública y en sectores
socioeconómicos como la agricultura, la pesca o el turismo. Para paliar los impactos que ocasionan, las
medidas de gestión más efectivas deben contemplar la prevención y la detección precoz de especies exóticas
potencialmente invasoras., Este artículo se incluye en el marco de los proyectos RADIOPOPO (PID2021-122690OB-I00),
InvaNET (RED2022-134338-T), DYNAMO
(PID2023-152653OA-C22) financiados por MCIN/
AEI/10.13039/ 501100011033 y por FEDER/UE,
Bexyl (Projecto 101060593) financiado por la EU
en la convocatoria HORIZON-CL6-2021-FARM2FORK-01-04 y DesFutur financiado por la Fundación Biodiversidad (PRTR/ NextGenerationEU).
Agradecemos a R. Morón una lectura crítica de una
primera versión del manuscrito y a M. Delibes las sugerencias y correcciones realizadas., Peer reviewed

[EN] Urban green spaces provide valuable ecosystem services and benefit biodiversity. Yet, the use of ornamental plants in public gardens is also the main pathway for the introduction of exotic species in natural habitats. Understanding which are the plant traits that influence the introduction of exotic species is key for preventing their invasion. In this study, we compared aesthetic traits of woody ornamental plant based on whether they are native or exotic in Spain; and according to their invasion status (i.e. non-established, naturalized and invasive). For this purpose, we gathered data on 12 aesthetic traits related to colour, shape, texture and type of aerial organs from 342 ornamental woody species, cultivated in 59 parks belonging to 27 cities across peninsular Spain. We did not find any differences for colour and type traits, except for invasive species having more bipinnated leaves and less simple leaves than the rest. Nevertheless, exotic species differ from natives according to the shape of their flowers, fruits and canopies, and to the texture of their barks. Among exotic species, non-established species differ from the naturalized ones on the shape of their leaves and the texture of their barks. In conclusion, our study demonstrates the existence of traits influencing the choice for ornamental exotic plants. However, these traits might not be useful for distinguishing their invasive potential., [ES] Los ecosistemas urbanos aportan servicios ecosistémicos valiosos, además de beneficios para la biodiversidad. Sin embargo, el uso de plantas ornamentales en los parques urbanos es también la principal vía de introducción de especies exóticas en los espacios naturales. Por tanto, entender cuáles son los rasgos que influencian la introducción de especies exóticas potencialmente invasoras es clave para prevenir sus impactos. En este estudio, hemos comparado rasgos estéticos de plantas leñosas ornamentales según si son nativas o exóticas en España; y según su grado de invasión (no establecidas, naturalizadas e invasoras). Para ello, recopilamos datos de 12 rasgos estéticos relacionados con el color, la forma, la textura y el tipo de los órganos aéreos de 342 plantas leñosas ornamentales cultivadas en 59 parques de 27 ciudades de toda España peninsular. No hemos encontrado diferencias para los rasgos relacionados con el color y el tipo, excepto en el caso de las especies invasoras donde, en comparación con el resto de exóticas, un mayor número de especies presentan hojas bipinnadas y menos especies presentan hojas simples. No obstante, las especies exóticas se diferencian de las nativas por la forma de sus flores, frutos y copas, así como por la textura de sus cortezas. Entre especies exóticas, las especies no establecidas se diferencian de las naturalizadas por la forma de sus hojas y la textura de sus cortezas. En conclusión, nuestro estudio demuestra la existencia de rasgos que influyen en la elección de las plantas ornamentales exóticas. Sin embargo, estos rasgos pueden no ser útiles para distinguir su potencial invasor., Esta investigación ha estado financiada por el proyecto RADIOPOPO (PID2021-122690OB-I00) financiada por MCIN/AEI/10.13039/501100011033/FEDER, UE. Agradecemos al repositorio TRY (Ref. 31914) y sus colaboradores por proporcionar parte de la información necesaria para la toma de datos de este estudio; así como a Álvaro Bayón por la ayuda en la concepción de la metodología., Peer reviewed

We explored pollinator dynamics and their floral visits to ornamental plants over 12 consecutive months in 15 parks in the Mediterranean city of Seville (Spain), Agencia Estatal de Investigación: PID2021-122690OB-I00, Peer reviewed

Many pollinators persist in urban green spaces though these are typically designed to support human recreation rather than for biodiversity conservation. Investigating the role of ornamental plants in supporting pollinators is key to reconciling urban planning and nature conservation.
We explored pollinator dynamics and their floral visits to ornamental plants over 12 consecutive months in 15 parks in the Mediterranean city of Seville (Spain).
We observed 8422 floral visitors from 155 species in 62 plant taxa (74% non-native). Pollinators were represented by wild bees (42%), honeybees (37%), flies (18%), butterflies (2%) and beetles (1%). Pollinators were present all year round and showed two peaks: first, between late winter and early spring; and second, in early summer for wild bees or early autumn for flies and butterflies.
Honeybee visits, but not wild bee, fly or butterfly visits, increased with floral availability per plant taxon. Both native and non-native plants attracted pollinators. However, visitation rates and species richness of each pollinator group varied between native and non-native plants throughout the year.
In Mediterranean climates, the combination of native and non-native ornamental plants in city parks can provide flower resources all year round for pollinators to thrive. Urban planners should balance recreation and conservation goals and prioritise non-invasive combinations of native and non-native plants that are valuable to pollinators across all seasons., This research was supported by the project RADIOPOPO (PID2021-122690OB-I00) funded by MCIN/AEI/10.13039/501100011033/FEDER, UE and the Severo Ochoa project of excellence (Ref. CEX2024-001498-S)., Peer reviewed

The study was conducted between October 2021 and September 2022 in 15 urban green areas (i.e., parks) within the city of Seville, in southern Spain. In this city, owing to gardening and consistently warm temperatures throughout the year, floral resources are available nearly year-round. In each park, a 20 m-wide sampling transect which covered the entire park area was established and within it, flowering ornamental woody plant species (both native and non-native) were sampled once a month. In sum, in each park flowering plant species which attracted pollinators were sampled across the entire area of the park. Each month, for each plant species, pollinators were sampled in two censuses located in two randomly selected plants along the park. In a census, a 10-minute pollinator observation over a 1 m2 area of the flowering plant species was conducted. Within a census any Hymenoptera, Diptera (>3 mm size), Lepidoptera and Coleoptera (>3 mm size) that contacted any reproductive part of a flower was identified and counted, avoiding double counting. Most specimens were identified visually in the field to the lowest possible taxonomic level, except 7.5% of them that were captured for identification in the laboratory with the help of an expert (Francisco P. Molina). Total sampling was 258 hours across 64 days., Overall, the plant-pollinator analyses were based on 62 plant taxa (44 non-native and 16 native). Although our aim was to focus at the plant species resolution level, we grouped 17 plant taxa by genus because there was a mix of species and hybrids with cryptic floral traits, which we assumed were equally attractive to pollinators. These plants were visited by 8422 pollinators belonging to 173 pollinator taxa (99 Hymenoptera, 57 Diptera, 12 Lepidoptera, 5 Coleoptera), 71% identified at the species level.
In some parks and months, no plant-pollinator interactions were recorded or only a single plant taxon was involved, precluding network construction. To address this limitation, we grouped sampling months by plant flowering phenology, using the. Jaccard similarity index (‘vegdist’ function, vegan R package) to quantify compositional dissimilarities in flowering taxa across months. This analysis identified four distinct temporal clusters of three consecutive months: (1) February–April, (2) May–July, (3) August–October, and (4) November–January. We used these periods in subsequent analyses to construct four temporal networks per park, except for Álvaro Diamantino (periods 1 and 4) and Miguel Mañara parks (periods 2-4), where plant diversity was insufficient (< 2 taxa).
To estimate sampling completeness of interaction diversity for each park and period, we used the Chao1 estimator of species richness. We calculated sampling completeness as the ratio of the observed and to estimate richness of pollinators, using the iNext R package., This research was supported by the project RADIOPOPO (PID2021-122690OB-I00)
funded by MCIN/AEI/10.13039/501100011033/FEDER, UE., Datospolinizadores_parquesSevilla.csv; Table_interactions.csv; Beta_diversity_ms.R; Betweenness_centrality_ms.R; Co_flowering_ms.R; Network_parameters_ms.R; Sampling_completeness_ms.R, Peer reviewed

Pollination sustains biodiversity and ecosystem functioning, yet it is increasingly threatened by biological invasions. Non-native plants frequently integrate into plant-pollinator networks, generating both positive and negative effects on native plants. However, most current knowledge derives from static or short-term studies of communities invaded by a few species, offering limited understanding of plant-pollinator dynamics in systems where many non-native species coexist under favorable environmental conditions. Here, we examined plant-insect pollinator networks in urban green areas of a Mediterranean city as a model system to evaluate the role of non-native plants in structuring plant-pollinator networks over the course of one year. We compared native and non-native plants in terms of (i) species-level parameters (normalized degree, strength, specialization, contribution to nestedness, and module roles), (ii) modularity and co-flowering patterns, (iii) persistence of interactions, and (iv) beta-diversity metrics. Non-native plants showed greater specialization and among-module connectivity, whereas native species exhibited greater species strength and within-module connectivity. Native–non-native pairs within modules co-flowered more often, suggesting simultaneous interactions that may foster both competition and facilitation. In contrast, non-native–non-native pairs displayed asynchronous flowering, potentially sustaining shared pollinators over longer periods and mitigating competition. Despite these differences, both groups contributed similarly to temporal network connectivity, and interaction turnover was unaffected by the proportion of non-native species. Overall, these findings reveal that while native and non-native plants play distinct roles in structuring plant-pollinator networks, they do not differ in their contribution to maintaining temporal connectivity. Our study underscores the importance of incorporating temporal and multispecies approaches when assessing the ecological consequences of biological invasions., This research was supported by the project RADIOPOPO (PID2021-122690OB-I00) funded by Agencia Estatal de Investigación (MCIN/AEI/10.13039/501100011033/FEDER, UE)., Peer reviewed

Armenia is a small mountainous country that has been at the crossroads of numerous human migrations and trade for millennia. The number of alien plant species has increased exponentially over the last century. The article analyses 113 plant alien species, which are recorded in natural and semi-natural habitats (62 casual, 25 naturalised and 26 invasive). Most species are casual phanerophytes, while naturalised and invasive alien species are predominantly therophytes. The floristic regions richest in alien species in Armenia are Yerevan, Idjevan and Lori. The three primary regions of origin are North America, East Asia and Europe, and the main introduction pathways are ornamental, natural dispersal and forestry. Casual species are primarily found in urban and semi-urban habitats, whereas naturalised and invasive species thrive mainly in natural areas (i.e., forests, shrublands and wetlands). A weed risk assessment conducted on the alien species indicates that all naturalised species and nearly half of the casual species have the potential to invade the country., This research was supported by the Higher Education and Science Committee of MESCS RA (Research project N° 21AG-1F004). MV was partially supported by project RADIOPOPO (PID2021-122690OB-I00) funded by the Spanish Ministerio de Ciencia e Innovación., Peer reviewed

Confidence in predictions of non-native species' spread relies on the niche conservatism hypothesis, which poses that climatic niches are preserved over time and space. Because plants introduced through the same introduction pathway (gardening, unintentional) tend to share some features of the introduction process and biological attributes, the extent of niche conservatism might be influenced by how and when species of particular attributes have been introduced. We compared the realized climatic niches between the native (global) and invaded ranges (mainland Spain), through ordination and kernel smoothers. We calculated niche conservatism metrics (i.e. overlap, unfilling, stability, expansion and pioneering), for a set of 158 plant species. Niche conservatism metrics were then related to a plant's introduction pathway, minimum residence time, growth form and native climatic niche breadth. On average, niche stability accounted for 75% of niche occupancy, while around 61% of species showed some degree of niche shift, which were mostly of small magnitude. The climatic niche was most conserved for annual and perennial herbs, plants introduced a long time ago, and those with broad climatic niches in their native range. Introduction pathways had a non-significant effect. Niche conservatism metrics were neither explained by interactions of minimum residence time with introduction pathways nor with growth form. Native climatic niche breadth was the most important correlate of niche conservatism metrics. Synthesis. Non-native plants largely occupy similar climatic conditions in their invaded and native range, a pattern that co-occurred with frequent and mostly small niche shifts. These results largely support the niche conservatism hypothesis. This boosts confidence in predictive models of non-native plants' spread. This study highlights that niche conservatism is better explained by a plant's ability to cope with broad climatic conditions, rather than by its introduction history or growth form.