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Four species of the genus Lepidonotus (Annelida, Polynoidae) have been listed in the Mediterranean, including L. carinulatus (Grube, 1869), L. squamatus (Linnaeus, 1758), L. tenuisetosus (Gravier, 1902) and L. clava (Montagu, 1808), although recent studies confirmed only the presence of the two latter. Based on materials collected in the Radès Area (Gulf of Tunis, Western Mediterranean), we provide a characterization of a population of L. tenuisetosus based on key morphological characters and body width/length relationships and conclude that all previously known Mediterranean reports from Israel, Croatia, Greece, Spain and Turkey did not belong to L. tenuisetosus, but either to L. carinulatus , L. clava or to other, non-identified species. Therefore, our finding represents not only the first correct record of L. tenuisetosus for the Tunisian waters and the Western basin, but for the whole Mediterranean Sea, and allows us to discuss on the possible reasons explaining the presence of this and other species of Lepidonotus in the Mediterranean.

While decision-making can benefit from considering positive and negative outcomes of change, over the past half-century, research on non-native species has focused predominately on their negative impacts. Here we provide a framework for considering the positive consequences of non-native species relative to relational, instrumental, and intrinsic values. We demonstrate that their beneficial outcomes are common and profoundly important for human well-being. Identified benefits include social cohesion, cultural identity, mental health, food and fuel production, regulation of clean waters, and attenuation of climate change. We argue that long-standing biases against non-native species within the literature have clouded the scientific process and hampered policy advances and sound public understanding. Future research should consider both costs and benefits of non-native species.

With the population increasing, fish communities, as important components in the river system, were inescapably impacted by human activities. To investigate these impacts, we characterized the fish community's composition by environmental DNA metabarcoding in the urban and suburban sites along Xiang River in central China. The results showed that 32 species were identified, and most species were from Cypriniform. The analysis indicated no significant differences in fish communities among the three urban areas. However, significant differences were observed between the bank solidified and non-solidified areas, which indicated that the channelization significantly influenced the biodiversity and abundances. An alien species, Clarias gariepinus, was discovered in all examined sites, and it was negatively associated with ten native species. Furthermore, human populations and acidification were also negatively related to diversity. Our findings clearly showed that the consequences of anthropogenic activities shaped ichthyofauna and caused biodiversity loss in the urban river.

Positive interactions have been hypothesized to influence plant community dynamics and species invasions. However, their prevalence and importance relative to negative interactions remain unclear, but are fundamentally important for both theoretical and applied ecology. We examined pairwise biotic interactions using over 50 years of successional data to assess the prevalence of positive interactions and their effects on each focal species (either native or exotic). We found that positive interactions were widespread and the relative frequency of positive and negative interactions varied with establishment stage and between native and exotic species. Specifically, positive interactions were more frequent during early establishment and less frequent at later stages. Positive interactions involving native species were more frequent and stronger than those between exotic species, reducing the impact of invasional meltdown on succession. Our study highlights the role of positive native interactions in shielding communities from biological invasion and enhancing the potential for long-term resilience.

AimMutualistic interactions between plants and animals are fundamental for the maintenance of natural communities and the ecosystem services they provide. However, particularly in human-dominated island ecosystems, introduced species may alter mutualistic interactions. Based on an extensive dataset of plant–frugivore interactions, we mapped and analysed a meta-network across the Caribbean archipelago. Specifically, we searched for subcommunity structure (modularity) and identified the types of species facilitating the integration of introduced species in the Caribbean meta-network.LocationCaribbean archipelago (Lucayan archipelago, Greater Antilles, Lesser Antilles).MethodsWe reviewed published scientific literature, unpublished theses and other nonpeer-reviewed sources to compile an extensive dataset of plant–frugivore interactions. We visualized spatial patterns and conducted a modularity analysis of the cross-island meta-network. We also examined which species were most likely to interact with introduced species: (1) endemic, nonendemic native or introduced species, and (2) generalized or specialized species.ResultsWe reported 3060 records of interactions between 486 plant and 178 frugivore species. The Caribbean meta-network was organized in 13 modules, driven by a combination of functional or taxonomic (modules dominated by certain groups of frugivores) and biogeographical (island-specific modules) mechanisms. Few introduced species or interaction pairs were shared across islands, suggesting little homogenization of the plant–frugivore meta-network at the regional scale. However, we found evidence of “invader complexes,” as introduced frugivores were more likely to interact with introduced plants than expected at random. Moreover, we found generalist species more likely to interact with introduced species than were specialized species.Main conclusionsThese results demonstrate that generalist species and “invader complexes” may facilitate the incorporation of introduced species into plant–frugivore communities. Despite the influx of introduced species, the meta-network was structured into modules related to biogeographical and functional or taxonomic affinities. These findings reveal how introduced species become an integral part of mutualistic systems on tropical islands.1 INTRODUCTIONMutualistic interactions between plants and animals, such as pollinators and frugivores, are critically important for maintaining the functionality of natural communities (Jordano, 1987;Ollerton et al., 2011; Rech et al., 2016). While most flowering plants are dependent on animals for pollination and seed-set (Ollerton et al., 2011; Rech et al., 2016), animal frugivores may ingest or otherwise manipulate and consequently disperse millions of seeds annually (Bueno et al., 2013). Frugivory is thereby crucial for the maintenance of plant diversity (Harms et al., 2000), as it allows plants to populate new sites, maintains gene flow between distinct populations and decreases density-dependent mortality in proximity of the parent individuals (Rogers et al., 2021). In some tropical systems, approximately 90% of all woody plants depend on frugivores for seed dispersal (Almeida-Neto et al., 2008; Howe & Smallwood, 1982). In addition to providing direct dispersal to specific, favourable sites for the plant (Wenny & Levey, 1998), frugivores can enhance the probability of successful germination, for example through the passage of seeds in the intestinal system (e.g. Traveset et al., 2001). The most important frugivore groups are birds, mammals and reptiles with birds and reptiles being particularly important in tropical island ecosystems (Kaiser-Bunbury et al., 2010; Valido & Olesen, 2007).Globally, co-evolved plant–frugivore communities are suffering from an array of drivers associated with global change, such as the introduction of species into new environments, where they become integrated into local communities through species interactions (Gallardo et al., 2016; Vilà et al., 2011). Species communities are thus being altered, which in turn may have consequences for biotic interactions and ecosystem functions, such as seed dispersal (Aslan et al., 2013; Lugo et al., 2012; Traveset & Richardson, 2006; Vizentin-Bugoni et al., 2021). Island ecosystems are particularly vulnerable to the disruption of native plant–frugivore interactions as island mutualists have evolved in isolation, and frequently developed specific traits, such as altered dispersal, or loss of defence traits in plants (Burns, 2019). Furthermore, as islands harbour many endemic species found nowhere else on Earth (Kier et al., 2009; Paulay, 1994), and have experienced disproportionally high extinction rates and numerous extant island species are threatened with extinctions (Blackburn et al., 2004; Fernández-Palacios et al., 2021; Groombridge, 1992), it is especially important to understand how introduced species integrate into island communities (Wood et al., 2017).Introduced species may integrate into existing communities and establish themselves in different ways. For instance, the concept of “invader complexes” suggests that introduced species facilitate the establishment of other introduced species, resulting in groups of introduced species interacting strongly with each other and less with the remaining community (D'Antonio & Dudley, 1993). Alternatively, endemic species that have become superabundant and highly generalized species due to ecological release and density compensation may readily include new arrivals into their interactions and thereby facilitate the establishment of introduced species on islands (Olesen et al., 2002). Furthermore, a growing number of studies show that species with many mutualistic partners (i.e. generalized species irrespectively of being nonendemic native or endemic) are more likely to incorporate new partners into their networks (Bascompte & Stouffer, 2009; Maruyama et al., 2016). In network theory, this is called “preferential attachment” (Newman, 2001), and thus, most generalized species would be expected to interact with introduced species.In addition to understanding which species are responsible for incorporating introduced species into native communities, we have little quantitative understanding of how introduced species affect the structure of native interaction networks and how this varies biogeographically (Fricke & Svenning, 2020). As for other mutualistic networks, plants and frugivores form complex interaction networks with reccurring structural properties (Bascompte & Jordano, 2007). One such property of interaction networks is modularity, which describes how interacting species aggregate into modules consisting of species that interact strongly within the respective module but much less with species of other modules (Thébault, 2013). The modular structure of mutualistic networks may reflect “co-evolutionary units” (Olesen et al., 2007) determined by an array of factors, such as phenological overlap, morphological traits, taxonomic relatedness and biogeography (Araujo et al., 2018; Dalsgaard et al., 2013; Donatti et al., 2011; Martín González et al., 2018; Maruyama et al., 2014; Schleuning et al., 2014). However, it is poorly understood whether introduced species influence the modular structure of mutualistic systems.Here, we present an extensive dataset on plant–frugivore interactions compiled from published and unpublished resources across the islands of the Caribbean archipelago: Lucayan archipelago, Greater Antilles and Lesser Antilles. We use the data to (i) explore the distribution of frugivory records across the Caribbean islands; (ii) assess island connectivity through shared species and interactions; (iii) evaluate the modular structure of the regional plant–frugivore meta-network and (iv) determine whether generalized vs. specialized species and introduced vs. endemic species are more likely to integrate introduced plants and frugivores into native plant–frugivore communities in island systems.2 METHODS2.1 Data collection and study regionAll our data were collected on the Caribbean islands, that is the Lucayan archipelago (The Bahamas and Turks and Caicos), the Greater Antilles (Cuba, Cayman Islands, Jamaica, Hispaniola and Puerto Rico) and the Lesser Antilles (a series of islands from the US and British Virgin Islands in the north to Grenada in the south). We did not include plant–frugivore interactions from islands such as Trinidad and Tobago, Curaçao, and Bonaire just north of South America, as these are continental islands with biotas with strong affinities to the South American mainland (Carstensen et al., 2012; Ricklefs & Bermingham, 2008). The low-lying sedimentary islands of the Lucayan Archipelago are part of the North American platform (Iturralde-Vinent & MacPhee, 1999; Trejo-Torres & Ackerman, 2001), and some of the islands have been interconnected in the Pleistocene (Murphy et al., 2004; Trejo-Torres & Ackerman, 2001). The mostly large and mountainous islands of the Greater Antilles are old with different geological origins (Graham, 2003; Iturralde-Vinent & MacPhee, 1999). The Greater Antilles emerged as fragments in the Eocene about 49 Ma; the geological history of the region has been highly dynamic with some parts connected in the past (Buskirk, 1985; Graham, 2003; Iturralde-Vinent & MacPhee, 1999; Ricklefs & Bermingham, 2008). The current biota of the Greater Antilles was only in small parts formed by vicariance, with dispersal facilitated by the Aves Ridge about 32–35 Ma (Iturralde-Vinent & MacPhee, 1999) or a more likely overwater dispersal at least for the avifauna (Buskirk, 1985; Graham, 2003; Ricklefs & Bermingham, 2008). The Lesser Antilles form a volcanic arc where the North and South American plates subduct under the Caribbean plate and likely originated at least 20 Ma (Ricklefs & Bermingham, 2008). To the east of the volcanic arc are some younger and low-lying islands such as Antigua and Barbuda, which consist of uplifted marine sediments (Ricklefs & Bermingham, 2008; Ricklefs & Lovette, 1999). Some islands were interconnected during the last glacial maximum, but most Lesser Antilles islands have never been interconnected (Ricklefs & Bermingham, 2004, 2008). The isolation of the Caribbean islands from the mainland differs greatly (Carstensen et al., 2012). Bimini in the Bahamas, for instance, is only approx. 87 km from the North American continent and Grenada in the Lesser Antilles is only 137 km from the continental landmass of South America. By contrast, islands such as Grand Turk (993 km) and South Caicos (999 km) are much more isolated from the mainland. On average, the isolation from any continental landmass in the Caribbean is over 500 km (Mean: 593 km ± 248 km SD; see details in Supporting Information Table S1). The distances between single islands are much smaller, for example the distance between Martinique and Dominica and Martinique and Saint Lucia is approx. 40 km. An island size threshold of 10,000 km2 has previously been suggested to be important for islands to be considered sources for colonization (Weigelt & Kreft, 2013), and on average, the islands of the Caribbean are approx. 304 km (±174 km SD) from the nearest island that exceeds 10,000 km2 (Table S1). Given the geological history and isolation of the Caribbean, the biota is characterized by being depauperate with high levels of endemism.To collect data on interactions between plants and frugivores in the Caribbean, we screened the Web of Science (WoS) and Google Scholar search engines. We used the combination of the following search terms: (“frugivory” OR “seed dispersal” OR “seed removal” OR “mutualism”) AND (“Caribbean” OR “Lesser Antilles” OR “Greater Antilles” OR “West Indies” OR “Bahamas” OR “Turks and Caicos” OR “Cayman Islands” OR “Jamaica” OR “Cuba” OR “Hispaniola” OR “Haiti” OR “Dominican Republic” OR “República Dominicana” OR “Puerto Rico” OR “Mona” OR “Virgin Islands” OR “Saint Martin” OR “Anguilla” OR “St. Kitts and Nevis” OR “Antigua” OR “Barbuda” OR “Montserrat” OR “Guadeloupe” OR “Dominica” OR “Martinique” OR “St. Lucia” OR “St. Vincent” OR “Grenadines” OR “Barbados” OR “Grenada”). To also include the grey literature, we contacted local ornithologists and ecologists working in the Caribbean region. This approach allowed us to obtain non-English publications, such as theses and dissertations not available online. We screened each of the studies manually, discarding studies where no appropriate data were presented (e.g. mutualistic interactions in marine environments). Interactions were only included when the respective authors presented original evidence for interaction events, that is evidence of fruits and/or seeds being ingested by frugivores. Thus, we discarded records where interactions between species were speculative (e.g. observation of frugivores on fruiting plant species without any evidence of fruit ingestion).We standardized the species names of plants and frugivores using the R-package taxize (Chamberlain & Szocs, 2013; Global Names Resolver, 2021) and data from the Integrated Taxonomic Information System (ITIS, 2021). We also retrieved information about species taxonomies (i.e. class, order and family) from ITIS. Finally, we compiled information about the native status of species and classified them into nonendemic native (species native to the Caribbean, but also naturally occurring elsewhere), endemic (only occurring within the Caribbean) and introduced (not naturally occurring within Caribbean) species (see details in Supporting Information Text S1). Of the original records, 95 plant (approx. 16% of all reported plants) and one frugivore record were not identified to species level (e.g. only genus name reported) and were thus excluded from data analyses. The final data used in statistical analyses consisted of interactions between 486 plant and 178 frugivore species.2.2 Data analysis2.2.1 Cross-island patterns of shared species and interactionsWe summarized patterns of shared species and interaction pairs across the Caribbean by calculating the proportion of shared species and interaction pairs across all islands. We calculated this proportion as the number of species/interaction pairs found on any two islands, divided by the total number of species/interaction pairs found on the given islands (Fricke & Svenning, 2020). We summarized these patterns separately for all reported records, for endemic, nonendemic native and for introduced plant and frugivore species and interaction pairs, respectively.2.2.2 Modularity of the Caribbean plant–frugivore meta-networkTo detect a modular structure of the meta-network, that is the network of plant–frugivore interactions across all islands, we employed Beckett's DIRT-LPA algorithm in the computeModules function of the R-package “bipartite” (Dormann et al., 2008, 2009). We ran 10 independent runs of the algorithm on the binary meta-network containing interactions between all identified species and identified the run with the single best division into modules, that is the highest degree of modularity Q. For the run with the highest Q value, we recorded the Q value, the number of modules as well as the respective plant and frugivore species in each module (Schleuning et al., 2014) and the islands on which they were recorded. To test whether the identified modular structure of the meta-network differed from random, we compared our results to 100 null models. To this end, we used an algorithm proposed by Patefield (1981) to randomize the interactions between species, using fixed marginal totals to produce networks with randomly associated species without constraining the degree of specialization (Blüthgen et al., 2008; Schleuning et al., 2014). For each of the null models, we applied the same approach as with the original matrix, that is we identified the single best configuration from 10 independent runs (Schleuning et al., 2014). We then tested whether modularity of the original matrix was significantly different from the best 100 null models by looking at the proportion of null modularity values that were greater than the empirical one, that is if .05; Figure S2c) and the frugivore perspective (slope = 0.003, p > .05; Figure S2d).4 DISCUSSIONHere, we present a comprehensive review of published plant–frugivore interactions across the Caribbean archipelago, including the Lucayan archipelago, the Greater and Lesser Antilles. All islands shared species and unique interaction pairs with neighbouring islands and archipelagos, thereby forming a cohesive meta-network. We show that the meta-network of plant–frugivore interactions across the Caribbean was structured into modules, with at least some modules determined by a combination of functional or taxonomic (i.e. certain groups of frugivores) and biogeographical (i.e. island-specific modules) mechanisms. While relatively few species in the dataset were introduced to the Caribbean (16% plant and 8% frugivore species), we found support for the “invader complexes” theory, whereby introduced species facilitate the establishment of other introduced species (D'Antonio & Dudley, 1993; Olesen et al., 2002). Moreover, we found that generalized species were more likely to incorporate introduced species into their interactions, giving support for the “preferential attachment” theory (Newman, 2001). Below, we first discuss the available data on frugivory in the Caribbean, whereafter we discuss how species and interactions are shared across islands. We end by discussing the drivers of modularity and the integration of introduced species into plant–frugivore communities across the Caribbean.4.1 Data on frugivores and their plants in the Caribbean archipelagoAcross all islands, the vast majority of reported frugivores were birds (79%), followed by reptiles (13%) and mammals (8%), of which in turn the majority were bats (71%). These data thus reflect patterns that are typical for oceanic islands, as there is generally a lack of nonvolant, large-bodied, frugivorous mammals which may be ecologically replaced by birds and reptiles (Kaiser-Bunbury et al., 2010). The low number of mammal species in the dataset could also reflect past mammal extinctions particularly on the islands of the Greater Antilles (Turvey et al., 2021), potentially leaving some plants without their main seed dispersers.A large proportion of the plant species (28%) and the majority of frugivore species in the dataset (65%) were classified as endemic to the Caribbean. High degrees of endemism in local species communities are characteristic of island ecosystems (Kier et al., 2009; Paulay, 1994). In a review of plant–frugivore interactions on the Galapagos archipelago, Heleno et al. (2011) found similarly high proportions of endemic frugivores in the species pool (71%), underlining the importance of endemic frugivores for island communities. By contrast, only a few species in the dataset were classified as introduced to the Caribbean (16% plants and 8% frugivores), which was lower than other studies on island ecosystems. Notably on Hawai'i, the proportion of introduced seed disperser species ranged from 50% to 100% for plants and from 60% to 100% for birds (Vizentin-Bugoni et al., 2019). On the Galapagos, the proportion of introduced plants and frugivores was 28% and 23%, respectively (Heleno et al., 2011). However, on the Galapagos, all introduced frugivore species were mammals, whereas in our data, the vast majority of introduced species were birds (86%) and only two species (14%) were mammals (a primate: Chlorocebus pygerythrus and a carnivore: Herpestes javonicus).4.2 Cross-island patterns of shared species and interactionsWhen examining the role of different groups of plants and frugivores in connecting islands and archipelagos, we found that nonendemic native species and interaction pairs were shared most widely across islands (Figure 2), which is expected, as these species are widespread species occurring throughout the Caribbean and the Neotropical mainland. They are thus supposedly good dispersers, and their ranges often occur across multiple islands and cross-borders of archipelagos (Dalsgaard et al., 2014). Although endemic frugivores made up more than 60% of the frugivore species, generally they overlapped much less between islands compared to nonendemic natives, which only accounted for less than 30% of the frugivores in the data (Table 2). This pattern is not surprising, since the distributional ranges of endemic species are per definition confined within limited geographical areas (Kricher, 2011), many species being single-island endemics or occurring on few islands within each of the archipelagoes, that is the Lucayan archipelago, the Greater and Lesser Antilles (Dalsgaard et al., 2014). In the Caribbean, for instance, there is a high number of single-island endemic frugivorous birds, such as various species of parrots like the Saint Vincent Parrot Amazona guildingii (Birds Caribbean, 2021). Introduced plant species were shared widely across the Caribbean (Figure 2), which was expected, as most were agricultural and widely cultivated plants, reflecting that the Caribbean is historically heavily impacted by humans (Kemp et al., 2020; Walters & Hansen, 2013). By contrast, introduced frugivores were reported on few islands only (Table 2), and these islands shared mostly low proportions of introduced frugivores (Table S4); introduced interaction pairs were almost not shared between islands. Globally, a recent study showed how introduced species caused an increase in the proportion of regions sharing species and interactions (Fricke & Svenning, 2020), demonstrating that species introductions led to increasing similarity and homogenization in plant–frugivore communities across the world (Fricke & Svenning, 2020). In the Caribbean, however, given our data, especially nonendemic natives played a bigger role in interconnecting islands.4.3 Modularity of the Caribbean plant–frugivore meta-networkThe Caribbean plant–frugivore meta-network was organized in modules, as are most mutualistic plant–animal interaction networks, both local networks (e.g. Dalsgaard et al., 2013; Dupont & Olesen, 2009; Mello et al., 2011a, 2011b; Olesen et al., 2007) and meta-networks (Araujo et al., 2018; Emer et al., 2018; Martín González et al., 2018). The separation of the meta-network into modules was at least partly driven by functional or taxonomic (i.e. modules dominated by certain species groups) and biogeographical (i.e. island-specific modules) mechanisms. For instance, one module consisted of small- to medium-sized bird species recorded in Jamaica (100% birds; 88% of frugivores recorded in Jamaica; module nine in Figure 4). Another module consisted mostly of various bat species (63% bats) recorded in Cuba (88% of frugivores recorded in Cuba; module one in Figure 4), whereas another module consisted almost exclusively of rock iguanas (Cychlura spp.) found in the Bahamas only (88% Iguanas; 88% of frugivores were recorded on the Bahamas only; module 13 in Figure 4). These modules associated with specific functional/taxonomic groups or specific islands were thus positioned in the periphery of the Caribbean meta-network (Figure 3). The separation into modules according to biogeographical affinities, such as single islands, was expected given that interactions between plants and frugivores are inherently spatial as species must be in the same place to interact (Morales & Vázquez, 2008) and many species are restricted to specific islands. Spatial patterns that correspond to insularity in the broad sense have previously been shown to partially explain the modular structure of mutualistic plant–animal networks in landscape matrices, where species are restricted to different types of patchily distributed habitats (Maruyama et al., 2014). Patterns of modularity have also previously been suggested to be explained by behavioural or functional traits of species (Dicks et al., 2002; Donatti et al., 2011; Maruyama et al., 2014). In plant–frugivore interactions, although plants typically aim to attract functionally diverse seed dispersers (Plein et al., 2013), there is evidence of functional matching between interaction partners, especially with birds (Vollstädt et al., 2017). Morphologically different frugivore species tend to forage on morphologically distinct sets of plant species (Dehling et al., 2016; Gautier-Hion et al., 1985; Lomáscolo et al., 2010; Mello et al., 2011b), which might be reflected in the modules composed primarily of specific frugivore groups with characteristic morphological and functional traits. Bats, for instance, consume different types of fruits than birds and may show a clear separation in their dietary composition (Gorchov et al., 1995). The patterns of modularity we detected were therefore in line with expectations of functional/taxonomic and biogeographical mechanisms as drivers of modularity. However, there were also modules consisting of a mix of species from various islands. One module consisted of about 50% of large parrot species (Amazona spp.), but the frugivores were recorded in the entire Caribbean (module six in Figure 4) and, notably, the module in the centre of the Caribbean meta-network consisted of various types of frugivores occurring throughout the Caribbean, thereby interconnecting islands and archipelagos in the Caribbean meta-network (module seven; Figure 3 and Table S5).4.4 Interactions with introduced speciesRegarding how introduced species were integrated into the meta-network, we found that nonendemic native and endemic plants and frugivores interacted significantly less with introduced frugivore species than expected at random (Figure 4a,b). Among Caribbean frugivores and their fruiting plants, there is therefore no support for the idea that endemic super-generalists are the main facilitators of introduced species, as suggested for pollination networks on tropical islands (Olesen et al., 2002). On the contrary, introduced frugivores were recorded interacting with introduced plants significantly more often than expected at random (Figure 4c). This pattern suggests that introduced frugivores “prefer” to feed on introduced plants, which in turn suggests the presence of “invader complexes,” that is introduced species interacting more among themselves than expected at random, thus facilitating their establishment (D'Antonio & Dudley, 1993). Such facilitation processes between introduced species can lead to “invasional meltdowns,” as large groups of introduced species may have increasingly negative impacts on native communities (Jeschke et al., 2012; Simberloff & von Holle, 1999). Other island ecosystems have been found to be even more dominated by introduced frugivores, notably Hawai'i is almost exclusively dominated by introduced frugivores, as most of the endemic species have gone extinct (Vizentin-Bugoni et al., 2019; Vizentin-Bugoni et al., 2021). These findings from various archipelagos are concerning, regarding the potential impact of introduced species on native ecosystems. Such findings are particularly worrying when considering that on other island ecosystems, introduced species were also more often involved in seed-dispersal interactions (rather than seed/pulp predation) than native species (Heleno et al., 2011; Vizentin-Bugoni et al., 2019, 2021). For many of the interaction records, our data do not distinguish between seed-dispersal interactions or seed/pulp predation events; thus, it is not possible to estimate the effect of introduced species on local native and endemic plant communities in the Caribbean. Nevertheless, in Hawai'i, it was shown that introduced frugivores do not sufficiently replace the species roles of lost seed dispersers, since they preferentially disperse seeds of introduced rather than native plants (Vizentin-Bugoni et al., 2019). This raises the question why introduced plant species seem so attractive. One reason could be that introduced plants may have specific traits, such as longer fruiting duration, which increase the probability of encounters and are therefore more likely to be consumed by frugivores (Heleno et al., 2011; Sperry et al., 2021). In the Caribbean meta-network, many of the observations were from agricultural areas, where agricultural plants such as Mangifera indica (Mango) are often abundant with large crops, and although they are not dispersed by any native frugivore, they do overall attract many frugivores. Fruiting plant and thus resource abundance is in turn linked to increased fruit consumption, because frugivores often track available fruits in the landscape (Quitián et al., 2019), and consequently, the patterns we find may be partially driven by the high abundance of introduced agricultural plants and their crop sizes in human-dominated environments. Such patterns may be more pronounced on densely populated islands than on islands with few people and relatively more protected areas.In addition to “invader complexes,” we found that generalist species, that is species with many interaction partners, were more likely to interact with introduced species, which was consistent for both plants and frugivores (Figure S2a,b). These results are in line with previous findings, underlining the importance of highly generalized species for the establishment of introduced species, especially on islands (Maruyama et al., 2016). This gives support for the “preferential attachment” hypothesis (Newman, 2001), that is that species with wide ecological niches include and facilitate the establishment of new species, such as introduced species on islands. Our finding that generalized species do not have a higher proportion of interactions with introduced partners in their total set of interactions than specialized species (Figure S2c,d) reflects the overall low numbers of introduced species in the Caribbean data. Since only few of the potentially available interaction partners are introduced species, generalized species with many interaction partners would also be expected to have a decreasing proportion of their interactions with introduced species. Thus, although generalized species are likely to incorporate introduced species into their niche (Figure S2a,b), they do not have a specific preference for introduced species (Figure S2c,d).5 CONCLUSIONSBased on a comprehensive review of accessible data on plant–frugivore interactions, we showed that the Caribbean meta-network is structured into modules and demonstrate how introduced species are integrated into native communities in the Caribbean archipelago. These results provide valuable insight into plant–frugivore interactions in insular biodiversity hotspots, showing how insular plant–frugivore systems are susceptible to invasion. Future studies are needed to demonstrate the importance of introduced species as seed dispersers compared with seed/pulp predators (Nogales et al., 2017). Specifically, research quantifying the relative importance of different frugivore groups as seed dispersers and their respective effectiveness is lacking for most plant–frugivore interactions in the Caribbean. This would provide valuable information and could help with the conservation of endemic plants in the Caribbean archipelago. Moreover, we also in general lack information on frugivory in the Caribbean. Kim et al. (2022) reported 4336 species of plants with animal-dispersal syndromes in the Caribbean archipelago, and our dataset represents only 11% of those species with some regional variation (Table S6). For instance, whereas Puerto Rican plants were covered relatively well (31% of the species), plants in Hispaniola (approx. 7%), Jamaica (approx. 8%) and the Lesser Antilles (approx. 9%) were less well represented. There may also be taxonomical differences in sampling completeness. Palms (Arecaceae) are highly diverse in the Caribbean representing 135 species (Roncal et al., 2008), and our dataset had only 23 palm species (17%). Several endemic and highly threatened fleshy-fruited plants do not have any information on the main seed dispersers (e.g. Catesbea spinosa, Brunfelsia portoricensis, Diospyros spp. and many cactus species). We also have limited and incomplete information on the fruit diet of several endemic frugivores (e.g. pigeons, thrashers and thrushes) that could play an important role for seed dispersal of Caribbean plants. There is therefore an urgent need to increment more scientific information on plant–frugivore interactions in the Caribbean, one of the world's insular biodiversity hotspots.ACKNOWLEDGEMENTSThis work is dedicated to our colleague and coauthor Michel Faife-Cabrera who passed away due to Covid-19 complications. M. Galetti thanks CNPq and University of Miami for financial support. M.G.R. Vollstädt, C. N. Kaiser-Bunbury, B. I. Simmons, F. Gonçalves, and B. Dalsgaard thank the Independent Research Fund Denmark (grant no. 0135-00333B). Funding for A. Strong's work was provided by an NSF grant to T. W. Sherry (Tulane University) and R. T. Holmes (Dartmouth College), the Chicago Zoological Society, Sigma Xi Grants-in-Aid-of Research, the World Nature Association, and The Louisiana Educational Quality Support Fund. A. Strong's work benefitted from collaborations with M. Johnson, T. Sherry, A. Sutton and the late R. Sutton. Funding for S. Schubert's work was provided by Rufford Foundation Small Grants 1, 2, & Booster, in addition to the Old Dominion University Paul W. Kirk Jr Student Research Award, a British Ornithologists' Union Student Research Award, and the BirdsCaribbean David S. Lee Fund. J. Salazar's work was funded by FONDOCyT. (Ministerio de Educaciòn Superior, Ciencia y Tecnología), Project 1B4-9. F. L. Tarazona-Tubens is supported by McKight Fellowship. B. I. Simmons was supported by a Royal Commission for the Exhibition of 1851 Research Fellowship. We also thank all researchers who have worked intensively in the Caribbean.CONFLICT OF INTERESTThe authors declare that there is no conflict of interest to report.Open ResearchSupporting InformationREFERENCESBIOSKETCHMaximilian Vollstädt is an ecologist, and a researcher at the University of Copenhagen, Denmark. His research interests include mutualistic interactions in plant-pollinator and plant-seed disperser communities in tropical island ecosystems.Author contributions: M.G.R.V., M.G., B.D. Conceptualization, Methodology; M.G.R.V., B.I.S. Formal analysis, Visualization; M.G.R.V., M.G., C.N.K.B., B.D. Original draft preparation, Writing; All Authors: Writing, Review & Editing.Volume28, Issue11November 2022Pages 2361-2374FiguresReferencesRelatedInformationRecommendedNatural mixing of species: novel plant–animal communities on Caribbean IslandsA. E. Lugo, T. A. Carlo, J. M. WunderleAnimal ConservationFrugivore distributions are associated with plant dispersal syndrome diversity in the Caribbean archipelagosSeokmin Kim, Lilian Sales, Daiane Carreira, Mauro GalettiDiversity and DistributionsInteractions between resource availability and enemy release in plant invasionDana M. BlumenthalEcology LettersHuman disturbances affect the topology of food websFrederico Mestre, Alejandro Rozenfeld, Miguel B. AraújoEcology LettersA general framework for species-abundance distributions: Linking traits and dispersal to explain commonness and rarityThomas Koffel, Kaito Umemura, Elena Litchman, Christopher A. Klausmeier

Many studies have assessed the various responses of alien plants to changes in overall nutrient or different nitrogen (N) availabilities. However, in natural soils, nutrients are present as different elements (e.g., N and phosphorus [P]) and forms (e.g., inorganic and organic). Few studies have explored whether invasive and native species differ in their responses to varying P availability and forms.We grew five taxonomically related pairs of common herbaceous, invasive and native species alone or in competition under six different conditions of P availability or forms and assessed their growth performance.Invasive species overall did not produce more biomass than native species did in the various P conditions. However, the biomass response to organic forms of P was, relative to the response to inorganic forms of P, stronger for the invasive species than that for the native species and agreed with invasive species mainly allocating biomass to the root system under organic P conditions.While invasive species were not more promiscuous than the native species, they took great advantage of the organic P forms. Therefore, the invasion risk of alien species may increase in habitats with more organic P sources.

Aedes koreicus is an invasive mosquito species originating from East Asia. It has recently been introduced into several countries in Southern, Central and Eastern Europe as well as Central Asia in many of which it has successfully established populations. The biology and ecological requirements of the species are largely unknown, but it is considered as a potential vector of pathogens that requires careful monitoring. We report here the first detection of Ae. koreicus in the Czech Republic, based on a citizen report.

Hybridization outcomes vary geographically and can depend on the environment. Hybridization can also reshape biotic interactions, leading to ecological shifts. If hybrids function differently ecologically in ways that enhance or reduce fitness, and those ecological roles vary geographically, ecological factors might explain variation in hybridization outcomes. However, relatively few studies have focused on ecological traits of hybrids. We compared the feeding ecology of Catostomus fish species and hybrids by using stable isotopes (δ

Since Darwin's time, degree of ecological similarity between exotic and native species has been assumed to affect the establishment success or failure of exotic species. However, a direct test of the effect of exotic–native similarity on establishment of exotics is scarce because of the difficulty in recognizing failures of species to establish in the field. Here, using a database on the establishment success and failure of exotic fish species introduced into 673 freshwater lakes, we evaluate the effect of similarity on the establishment of exotic fishes by combining phylogenetic and functional information. We illustrate that, relative to other biotic and abiotic factors, exotic–native phylogenetic and functional similarities were the most important correlates of exotic fish establishment. While phylogenetic similarity between exotic and resident fish species promoted successful establishment, functional similarity led to failure of exotics to become established. Those exotic species phylogenetically close to, but functionally distant from, native fishes were most likely to establish successfully. Our findings provide a perspective to reconcile Darwin's naturalization conundrum and suggest that, while phylogenetic relatedness allows exotic fish species to pre-adapt better to novel environments, they need to possess distinct functional traits to reduce competition with resident native fish species.

Arbuscular mycorrhizal fungi (AMF) provide crucial support for the establishment of plants in novel environments. We hypothesized that the OTU/genus richness and diversity of soil- and root-associated AMF associated with alien plant species in their exotic ranges are lower than those in their native ranges. We examined the root-associated and soil-dwelling AMF of 11 invasive plant species in their native and exotic ranges in the United States and Europe by DNA sequencing of the ITS2 locus. Examined root-associated AMF assemblages were simplified, which manifested as the loss of several AMF genera in the exotic ranges of the plants. These fungal assemblages were also characterized by greater dominance and simplification of the fungal assemblages. The dominant fungal genera were present regardless of whether their host plants were in their native or exotic ranges. Interestingly, both the native and invaded soils hosted diverse local AMF assemblages. Therefore, alien plant invasions were not limited to soils with low AMF diversity. Some AMF taxa could be context-dependent passengers rather than drivers of alien plant invasions. Further studies should identify functions of AMF missing or less abundant in roots of plants growing in exotic ranges.

Numerous anthropogenic factors, historical and contemporary, have contributed to declines in the abundance and diversity of freshwater fishes in North America. When Europeans first set foot on this continent some five hundred years ago, the environment was ineradicably changed. Settlers brought with them diseases, animals, and plants via the Columbian Exchange, from the old world to the new, facilitating a process of biological globalization. Invasive species were thus introduced into the Americas, displacing native inhabitants. Timber was felled for ship building and provisioning for agriculture, resulting in a mass land conversion for the purposes of crop cultivation. As European colonization expanded, landscapes were further modified to mitigate against floods and droughts via the building of dams and levees. Resources have been exploited, and native populations have been overfished to the point of collapse. The resultant population explosion has also resulted in wide-spread pollution of aquatic resources, particularly following the industrial and agricultural revolutions. Collectively, these activities have influenced the climate and the climate, in turn, has exacerbated the effects of these activities. Thus, the anthropogenic fingerprints are undeniable, but relatively speaking, which of these transformative factors has contributed most significantly to the decline of freshwater fishes in North America? This manuscript attempts to address this question by comparing and contrasting the preeminent drivers contributing to freshwater fish declines in this region in order to provide context and perspective. Ultimately, an evaluation of the available data makes clear that habitat loss, obstruction of streams and rivers, invasive species, overexploitation, and eutrophication are the most important drivers contributing to freshwater fish declines in North America. However, pesticides remain a dominant causal narrative in the popular media, despite technological advancements in pesticide development and regulation. Transitioning from organochlorines to organophosphates/carbamates, to pyrethroids and ultimately to the neonicotinoids, toxicity and bioaccumulation potential of pesticides have all steadily decreased over time. Concomitantly, regulatory frameworks designed to assess corresponding pesticide risks in Canada and the USA have become increasingly more stringent and intensive. Yet, comparatively, habitat loss continues unabated as agricultural land is ceded to the frontier of urban development, globalized commerce continues to introduce invasive species into North America, permanent barriers in the form of dams and levees remain intact, fish are still being extracted from native habitats (commercially and otherwise), and the climate continues to change. How then should we make sense of all these contributing factors? Here, we attempt to address this issue.

Soil organic carbon (SOC) in coastal wetlands, also known as "blue C," is an essential component of the global C cycles. To gain a detailed insight into blue C storage and controlling factors, we studied 142 sites across ca. 5000 km of coastal wetlands, covering temperate, subtropical, and tropical climates in China. The wetlands represented six vegetation types (Phragmites australis, mixed of P. australis and Suaeda, single Suaeda, Spartina alterniflora, mangrove [Kandelia obovata and Avicennia marina], tidal flat) and three vegetation types invaded by S. alterniflora (P. australis, K. obovata, A. marina). Our results revealed large spatial heterogeneity in SOC density of the top 1-m ranging 40-200 Mg C ha

In Patagonia (Argentina) two non-native vespid wasps became established in the last decades. Vespula germanica was first detected in 1980 while V. vulgaris arrived some 30 years later. Both species can have a strong negative impact on agriculture, natural environment and on outdoor human activities. Invasion success -the establishment and spread of a species- may be influenced negatively by the degree of interaction with the resident native community, and alien species already present. The sequential arrival of these two wasps allows us to understand key questions of invasion ecology. Additionally, recognizing the outcome of the invasion by vespids in Patagonia -a region lacking native social wasps-, may help plan species-focused mitigation and control strategies. We explored long term species coexistence through the deterministic Lotka-Volterra competition model, using site-specific field data on prey captured (to estimate niche overlap) and current nest densities in sites. Food items carried by workers were similar but there is some degree of segregation. V. germanica nest density in shared sites, and in sites without coexistence, were 3.14 and 3.5 respectively, being higher for V. vulgaris with 4.71 and 5.33. The model predicts stable co-existence of both species in the invaded range, yet a higher abundance of V. vulgaris should be expected. Added to evidence on other foraging behavioral attributes of both wasp species and the invasion patterns observed in other regions, it is likely that the prior presence of V. germanica does not contribute significantly to the biotic resistance of the invaded range for V. vulgaris

Amphibian and reptile diversity from Isla Santay (Durán, Ecuador) has been underestimated due to the lack of monitoring throughout the island. Historically, this island has also been affected by anthropic landscape changes which limit the occurrence of certain species and favors the dispersion of opportunistic or more tolerant species. Such species dynamics tend to be more evident on islands, since their isolation limits species’ mobility. We present an updated checklist of the herpetofauna of Isla Santay Durán, Ecuador, and report for the first time the occurrence of two introduced species, Anolis sagrei Duméril & Bibron, 1837, Brown Anole, and Hemydactylus frenatus Duméril & Bibron, 1836.

Biological invasions are one of the major threats to the ecosystem structure and functioning. After the initial introduction, frequently mediated by human activities, alien species can overcome different biogeographical and ecological barriers and determine severe impacts on native biodiversity and socio-economic activities. The Italian peninsula is located at the intersection of large trade routes within the Mediterranean Sea. Such position, along with the intense commercial activity and the high population density of the Italian coast, are considered important drivers of alien species in Italian marine and transitional ecosystems. The Italian peninsula, however, is also one of the regions with the highest native species richness within the Mediterranean Sea and, therefore, it is crucial to account for both alien and native species diversity when estimating the impact of biological invasion. Yet, such comprehensive information is frequently scattered across several biodiversity information systems and databases. Here, two datasets with alien and native species records in Italian marine and transitional waters are described. These datasets, created for the LifeWatch Italy case study on alien species, are the result of a large-scale collaboration involving experts working across the whole range of taxonomic diversity. The marine dataset includes a total of 12,219 records belonging to 3,772 species gathered from 91 investigated sites and seven EUNIS habitats. The dataset on transitional waters biodiversity includes 3,838 records belonging to 2,019 species found in 23 locations and four EUNIS habitats. Alien species were recorded in both marine and transitional waters, accounting respectively for 140 and 171 biological records belonging to 59 and 97 species. These occurrence data can be used for further research studies or management purposes, including the evaluation of the invasion risk and the formulation of alien species control and management plans. Furthermore, these compiled datasets can be used as input data for the Biotope vulnerability case study of LifeWatch ERIC, which offers a number of ICT services for the calculation of the incidence and of the impact of alien species on European biotopes.

A colonial ascidian of the genus Distaplia caused a mass mortality of the pen shell Atrina maura (Sowerby, 1835) during June 2016 in the southwest of the Gulf of California (Mexico), with a significant socio-economic cost. Tentatively identified in previous works as Distaplia cf. stylifera, a precise taxonomic determination was still lacking. In the present work, based on a detailed morphological study, it is confirmed that this aggressive species is Distaplia stylifera (Kowalevsky, 1874). Originally described from the Red Sea, the species currently has a wide circumtropical distribution (with the exception of the Eastern Pacific to date) and is reported as introduced in parts of its range. The present account thus represents an important range extension of this species. However, when revising the original description and later observations, the reported variability of several characters makes it likely that the binomen is in fact a complex of species, as is common in other ascidians with wide distributions. A complete morphological and genetic study including populations from the entire range of distribution would be necessary to settle the status of D. stylifera. Taxonomic uncertainties hinder a correct interpretation of biogeographical patterns and inference on the origin of the studied population. Nevertheless, the known introduction potential of the species, coupled with an explosive growth in an anthropized environment, and the lack of any previous reports in the Eastern Pacific, strongly suggest that the investigated population represents yet another instance of ascidian introduction. From the point of view of management, its invasive behavior is cause for great concern and warrants mitigation measures.

Invasive species pose a significant threat to biodiversity and agriculture world-wide. Natural enemies play an important part in controlling pest populations, yet we understand very little about the presence and prevalence of natural enemies during the early invasion stages. Microbial natural enemies of fall armyworm Spodoptera frugiperda are known in its native region, however, they have not yet been identified in Africa where fall armyworm has been an invasive crop pest since 2016. Larval samples were screened from Malawi, Rwanda, Kenya, Zambia, Sudan and Ghana for the presence of four different microbial natural enemies; two nucleopolyhedroviruses, Spodoptera frugiperda NPV (SfMNPV) and Spodoptera exempta NPV (SpexNPV); the fungal pathogen Metarhizium rileyi; and the bacterium Wolbachia. This study aimed to identify which microbial pathogens are present in invasive fall armyworm, and determine the geographical, meteorological and temporal variables that influence prevalence. Within 3 years of arrival, fall armyworm was exposed to all four microbial natural enemies. SfMNPV probably arrived with fall armyworm from the Americas, but this is the first putative evidence of host spillover from Spodoptera exempta (African armyworm) to fall armyworm for the endemic pathogen SpexNPV and for Wolbachia. It is also the first confirmed incidence of M. rileyi infecting fall armyworm in Africa. Natural enemies were localised, with variation being observed both nationally and temporally. The prevalence of SfMNPV (the most common natural enemy) was predominantly explained by variables associated with the weather; declining with increasing rainfall and increasing with temperature. However, virus prevalence also increased as the growing season progressed. The infection of an invasive species with a natural enemy from its native range and novel pathogens specific to its new range has important consequences for understanding the population ecology of invasive species and insect–pathogen interactions. Additionally, while it is widely known that temporal and geographic factors affect insect populations, this study reveals that these are important in understanding the distribution of microbial natural enemies associated with invasive pests during the early stages of invasion, and provide baseline data for future studies.

Approximately 17% of the land worldwide is considered highly vulnerable to non-native plant invasion, which can dramatically alter nutrient cycles and influence greenhouse gas (GHG) emissions in terrestrial and wetland ecosystems. However, a systematic investigation of the impact of non-native plant invasion on GHG dynamics at a global scale has not yet been conducted, making it impossible to predict the exact biological feedback of non-native plant invasion to global climate change. Here, we compiled 273 paired observational cases from 94 peer-reviewed articles to evaluate the effects of plant invasion on GHG emissions and to identify the associated key drivers. Non-native plant invasion significantly increased methane (CH

International audience; On the presence of Xylocopa (Koptortosoma) pubescens Spinola, 1838, in metropolitan France (Hymenoptera, Apidae). Xylocopa (Koptortosoma) pubescens Spinola, 1838, species native to Africa and the Middle East, is recorded for the first time in metropolitan France where it has been observed in an urban garden in Ronchin (Nord). To assess its ability to establish and expand, we developed a MAXENT climatic niche model. Ronchin is slightly above the threshold of suitability of X. pubescens. We assume that it should not expand in this unsuitable region. However, the species should be monitored.; Xylocopa (Koptortosoma) pubescens Spinola‚ 1838‚ espèce originaire d’Afrique et du Moyen-Orient‚ est signalée pour la première fois en France métropolitaine où elle a été observée dans un jardin urbain de Ronchin (Nord). Pour évaluer ses capacités d’installation et d’expansion‚ nous avons développé un modèle de niche climatique avec MAXENT. Ronchin est très légèrement au-dessus du seuil favorable à la survie de X. pubescens. Nous supposons qu’elle ne devrait pas se développer dans cette région peu favorable mais l’espèce est à surveiller.

Invasive red lionfish Pterois volitans (Linnaeus, 1758) represent an ongoing ecological threat within temperate and tropical waters. Relatively little is known regarding the overall health of P. volitans and their potential for spreading pathogens in non-native regions. Lionfish collected from inshore reefs of Grenada, West Indies, in 2019 and 2021 were identified as P. volitans based on cytochrome c oxidase subunit 1 barcoding. Gross and microscopic examination of tissues revealed myxozoan plasmodia in the hearts of 24/76 (31.6%) lionfish by histopathology or wet mount cytology. Further histopathologic examination revealed severe granulomatous inflammation and myofiber necrosis associated with developing plasmodia and presporogonic life stages. Fresh myxospores were morphologically and molecularly consistent with Kudoa hypoepicardialis, being quadrate in apical view with 4 valves and 4 equal polar capsules. The spore body was 5.1-7.9 (mean: 6.0) µm long, 8.1-9.8 (8.7) µm wide, and 6.9-8.5 (7.7) µm thick. Polar capsules were 2.3-2.7 (2.5) µm long and 0.9-1.6 (1.3) µm wide. 18S small subunit rDNA sequences were 99.81-99.87% similar to sequence data from the original description of the species. Novel 28S large subunit rDNA and elongation factor 2 data, which did not match any previously reported species, were provided. This is the first account of a myxozoan parasite of P. volitans, a new host record and locality for K. hypoepicardialis, and one of few reports describing pathogen-associated lesions in invasive lionfish.

Exploring how functional traits vary and covary is important to understand plant responses to environmental change. However, we have limited understanding of the ways multiple functional traits vary and covary within invasive species.We measured 12 leaf traits of an invasive plant Chromolaena odorata, associated with plant or leaf economics, herbivore defense, and drought resistance on 10 introduced populations from Asia and 12 native populations from South and Central America, selected across a broad range of climatic conditions, and grown in a common garden.Species' range and climatic conditions influenced leaf traits, but trait variation across climate space differed between the introduced and native ranges. Traits that confer defense against herbivores and drought resistance were associated with economic strategy, but the patterns differed by range. Plants from introduced populations that were at the fast-return end of the spectrum (high photosynthetic capacity) had high physical defense traits (high trichome density), whereas plants from native populations that were at the fast-return end of the spectrum had high drought escape traits (early leaf senescence and high percentage of withered shoots).Our results indicate that invasive plants can rapidly adapt to novel environmental conditions. Chromolaena odorata showed multiple different functional trait covariation patterns and clines in the native and introduced ranges. Our results emphasize that interaction between multiple traits or functions should be considered when investigating the adaptive evolution of invasive plants.

It has been suggested that establishment of one alien invader might promote further invasions. Such a so-called invasional meltdown could be mediated by differences in soil-legacy effects between alien and native plants. Whether such legacy effects might depend on the diversity of the invaded community has not been explored to date. Here, we conducted a two-phase plant-soil feedback experiment. In a soil-conditioning phase, we grew five alien and five native species as invaders in 21 communities of one, two or four species. In the subsequent test phase, we grew five alien and five native species on the conditioned soils. We found that growth of these test species was negatively affected by soils conditioned by both a community and an invader, and particularly if the previous invader was a conspecific (i.e. negative plant-soil feedback). Alien test species suffered less from soil-legacy effects of previous allospecific alien invaders than from the legacy effects of previous native invaders. However, this effect decreased when the soil had been co-conditioned by a multispecies community. Our findings suggest that plant-soil feedback-mediated invasional meltdown may depend on community diversity and therefore provide some evidence that diverse communities could increase resistance against subsequent alien invasions. published

Studies addressing the economic impacts of invasive alien species are biased towards ex-post assessments of the costs and benefits of control options, but ex-ante assessments are also required to deal with potentially damaging invaders. The polyphagous shot hole borer Euwallacea fornicatus (Coleoptera: Curculionidae) is a recent and potentially damaging introduction to South Africa. We assessed the potential impact of this beetle by working across economic and biological disciplines and developing a simulation model that included dynamic mutualistic relations between the beetle and its symbiotic fungus. We modeled the potential growth in beetle populations and their effect on the net present cost of damage to natural forests, urban trees, commercial forestry, and the avocado industry over 10 yr. We modeled high, baseline, and low scenarios using discount rates of 8, 6, and 4%, and a plausible range of costs and mortality rates. Models predicted steady growth in the beetle and fungus populations, leading to average declines in tree populations of between 3.5 and 15.5% over 10 yr. The predicted net present cost was 18.45 billion international dollars (Int. $), or about 0.66% of the country’s GDP for our baseline scenario ($2.7 billion to $164 billion for low and high scenarios). Most of the costs are for the removal of urban trees that die as a result of the beetle and its fungal symbiont, as has been found in other regions. We conclude that an ex-ante economic assessment system dynamics model can be useful for informing national strategies on invasive alien species management.

Invasive plant species (IPS) are often considered weeds that cause high yield losses in crops, negatively affect the environment, and disrupt certain ecosystem services. The negative impact of IPS on biodiversity is increasing and disturbing native vegetation. The management of plant invasions can be divided in two phases (before and after invasion). Prior to introduction it is crucial to develop the knowledge base (biology, ecology, distribution, impact, management) on IPS, prevention measures and risk assessment. After introduction if eradication fails, the monitoring and the integrated management of IPS are imperative to prevent the naturalization and further dispersal. This review uses two major invasive weed species (Amaranthus palmeri S. Wats. and Solanum elaeagnifolium Cav.) as case studies to propose a framework for early detection, rapid herbicide resistance screening, and integrated management. The holistic framework that is presented exploits recent: (i) novel detection tools, (ii) rapid tests and assays for herbicide resistance, and (iii) biology, ecology, distribution traits, and management tools for the IPS. Farmers, advisors, researchers, and policymakers need briefing on IPS growth dynamics, adaptability rates, and response to conventional and novel treatments to prevent new invasions, eradicate isolated stands, and mitigate the impact of invasive weed species in the long term. © 2022 Society of Chemical Industry.

Digitized collections can help illuminate the mechanisms behind the establishment and spread of invasive plants. These databases provide a record of traits in space and time that allows for investigation of abiotic and biotic factors that influence invasive species.Over 1100 digitized herbarium records were examined to investigate the invasion history and trait variation of Microstegium vimineum. Presence-absence of awns was investigated to quantify geographic patterns of this polymorphic trait, which serves several functions in grasses, including diaspore burial and dispersal to germination sites. Floret traits were further quantified, and genomic analyses of contemporary samples were conducted to investigate the history of M. vimineum's introduction and spread into North America.Herbarium records revealed similar patterns of awn polymorphism in native and invaded ranges of M. vimineum, with awned forms predominating at higher latitudes and awnless forms at lower latitudes. Herbarium records and genomic data suggested initial introduction and spread of the awnless form in the southeastern United States, followed by a putative secondary invasion and spread of the awned form from eastern Pennsylvania. Awned forms have longer florets, and floret size varies significantly with latitude. There is evidence of a transition zone with short-awned specimens at mid-latitudes. Genomic analyses revealed two distinct clusters corresponding to awnless and awned forms, with evidence of admixture.Our results demonstrate the power of herbarium data to elucidate the invasion history of a problematic weed in North America and, together with genomic data, reveal a possible key trait in introduction success: presence or absence of an awn.

Biological invasions strongly increased during the last centuries and are challenging environmental managers worldwide. In this context, public acceptance of management measures is a key factor determining the long-term success of the control of invasive species. However, in the case of charismatic and iconic invasive species, the public has often been unwilling to accept strict management measures. Here, we studied the public perception of the Chinese windmill palm (Trachycarpus fortunei) in Switzerland, which is declared as invasive in southern Switzerland but also recognized as iconic. We conducted a nation-wide online survey in the multilingual and multicultural context of Switzerland, investigating the influence of social and cultural factors on the knowledge of, the attitude toward, and the willingness to control the invasive T. fortunei. Results confirm that the knowledge and perception of invasive plants have a strong social and cultural component and may vary greatly as a function of the cultural background, education level, age, and other social characteristics. Furthermore, information on the invasiveness of the focal species provided during the survey significantly affected informants’ perceptions, which are closely related to the acceptance of possible management and control measures. This allows us to highlight the importance of a holistic approach that includes targeted public information when dealing with biological invasions, especially in the case of charismatic and iconic species. Based on the obtained results, we suggest avenues for refining management and control strategies of T. fortunei in Switzerland, many of which generally applicable to other cases of invasive species.

Spodoptera frugiperda has spread to Africa, Asia, and Oceania, posing a serious threat to global agriculture. We estimated the appropriate dose of X-ray sterilization for S. frugiperda using an X-ray irradiation instrument to investigate environmentally acceptable control techniques, laying the framework for future applications of sterile insect technology (SIT) to manage the pest environmentally-friendly.This study is the first to investigate the effects of X-ray irradiation on the growth, development, survival, reproduction, and flight of S. frugiperda. The results showed that irradiation with 50-400 Gy had no significant effect on pupal eclosion, but females were more sensitive than males in terms of reproductive parameters, especially when doses of radiation were 350 Gy. After irradiation with a sub-sterilizing dose of 250 Gy, the parental sterility rate was 85%, and the sterility traits could be passed on to their offspring, resulting in a continuous decrease in the population of FOur laboratory experiments theoretically confirmed the feasibility of SIT for controlling S. frugiperda in the field using X-ray radiation. This study provides a theoretical basis for future regional pest management strategies. © 2022 Society of Chemical Industry.

Invasive alien species (IAS) are a rising threat to biodiversity, national security, and regional economies, with impacts in the hundreds of billions of U.S. dollars annually. Proactive or predictive approaches guided by scientific knowledge are essential to keeping pace with growing impacts of invasions under climate change. Although the rapid development of diverse technologies and approaches has produced tools with the potential to greatly accelerate invasion research and management, innovation has far outpaced implementation and coordination. Technological and methodological syntheses are urgently needed to close the growing implementation gap and facilitate interdisciplinary collaboration and synergy among evolving disciplines. A broad review is necessary to demonstrate the utility and relevance of work in diverse fields to generate actionable science for the ongoing invasion crisis. Here, we review such advances in relevant fields including remote sensing, epidemiology, big data analytics, environmental DNA (eDNA) sampling, genomics, and others, and present a generalized framework for distilling existing and emerging data into products for proactive IAS research and management. This integrated workflow provides a pathway for scientists and practitioners in diverse disciplines to contribute to applied invasion biology in a coordinated, synergistic, and scalable manner.

The wood cricket Nemobius sylvestris (Bosc, 1792) is herein reported in North America for the first time. The species is currently known to be established in the vicinity of Rochester, New York, and Seattle, Washington, indicating two separate introductions. It is unclear when the species was first introduced to the region, nor what its potential ecological effects may be. The presence of this species in the USA was first noted via photos posted to iNaturalist, highlighting the value of citizen/community science platforms in detecting novel introductions.

The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama (Hemiptera: Liviidae) is a destructive, invasive species that poses a serious threat to the citrus industry wherever it occurs. The psyllid vectors the phloem-limited bacteria 'Candidatus Liberibacter americanus' and 'Ca. L. asiaticus', causal agents of the incurable citrus greening disease or huanglongbing (HLB). It is essential to understand which regions and areas are suitable for colonization by ACP to formulate appropriate policy and preventive measures. Considering its biology and ecology, we used a machine learning algorithm based on the MaxEnt (Maximum Entropy) principle, to predict the potential global distribution of ACP using bioclimatic variables and elevation.The model predictions are consistent with the known distribution of ACP and also highlight the potential occurrence outside its current ecological range, that is, primarily in Africa, Asia and the Americas. The most important abiotic variables driving the global distribution of ACP were annual mean temperature, seasonality of temperature and annual precipitation.Our findings highlight the need for international collaboration in slowing the spread of invasive pests like D. citri. © 2022 Society of Chemical Industry.

Macrophytes are an important part of freshwater ecosystems and they have direct and indirect roles in keeping the water clear and providing structure and habitats for other aquatic organisms. Currently, climate change is posing a major threat to macrophyte communities by altering the many drivers that determine macrophyte abundance and composition. We synthesise current literature to examine the direct effects of climate change (i.e. changes in CO2, temperature, and precipitation patterns) on aquatic macrophytes in lakes as well as indirect effects via invasive species and nutrient dynamics. The combined effects of climate change are likely to lead to an increased abundance and distribution of emergent and floating species, and a decreased abundance and distribution of submerged macrophytes. In small shallow lakes, these processes are likely to be faster than in deep temperate lakes; with lower light levels, water level fluctuations and increases in temperature, the systems will become dominated by algae. In general, specialized macrophyte species in high-latitude and high-altitude areas will decrease in number while more competitive invasive species are likely to outcompete native species. Given that the majority of endemic species reside in tropical lakes, climate change, together with other anthropogenic pressures, might cause the extinction of a large number of endemic species. Lakes at higher altitudes in tropical areas could therefore potentially be a hotspot for future conservation efforts for protecting endemic macrophyte species. In response to a combination of climate-change induced threats, the macrophyte community might collapse, which will change the status of lakes and may initiate a negative feedback loop that will affect entire lake ecosystems.

Invasive species tend to possess acquisitive plant traits that support fast growth and strong competitive ability. However, the relevance of symbioses with arbuscular mycorrhizal fungi (AMF) to the fast growing, acquisitive strategy of invasive species is still unclear.We measured AMF colonization in roots of five congeneric pairs of invasive and native eastern North American woody species (10 species total; 4 lianas, 6 shrubs) that were grown in a monoculture common garden experiment in Syracuse, NY. We then examined the relationships of AMF colonization to above and belowground traits of these species.Total AMF colonization and arbuscule colonization were greater in invasive compared to native woody species, a pattern that was more distinct in congeneric shrubs than congeneric lianas. The level of AMF colonization was also positively correlated with traits indicative of rapid plant growth and nutrient uptake.The concordance of a resource-acquisitive strategy with higher AMF colonization suggests that symbioses with AMF may be part of the strategy by which invasive woody plants of eastern North America are able to maintain fast growth rates and outcompete their native counterparts.

Context Habitat loss is a global problem and in Fiji >50% of the land area once covered by forests has been converted to grasslands and agricultural land. About 99% of Fiji’s endemic biodiversity and 80% of the land bird species have been identified as forest species. Aims In this study, we compare forest and grassland sites and test for consistency in avian diversity, abundance, foraging guild, and distribution status (endemic, native, introduced to Fiji) over a 5-year period (2016–2020). Methods We surveyed bird communities using the point count method with a 100 m radius and 7-min observation period per site. Key results A one-way analysis of similarities (ANOSIM) analysis showed significant differences in species composition and bird abundance between the forested habitats and grassland habitats. A general linear model test showed significant differences in foraging guild composition and distribution status between forested and grassland habitats. There were no significant differences between the three forested sites (primary montane forest, secondary old-growth forest, old-growth mahogany plantations with regenerating native species), while grassland sites had stronger annual change in species composition. Implications Forest cover, irrespective of whether these forests are of primary or secondary nature, therefore plays an important role in maintaining the native and endemic land bird species and other biodiversity in oceanic island ecosystems such as Viti Levu Island, Fiji.

Exotic plant invaders pose a serious threat to native plants. However, despite showing inferior competitive ability and decreased performance, native species often subsist in invaded communities. The decline of native populations is hypothesized to be halted and eventually reversed if adaptive evolutionary changes can keep up with the environmental stress induced by invaders, that is, when population extinction is prevented by evolutionary rescue (ER). Nevertheless, evidence for the role of ER in postinvasion persistence of native flora remains scarce. Here, I explored the population density of a native forb, Veronica chamaedrys , and evaluated the changes in the shade-responsive traits of its populations distributed along the invasion chronosequence of an exotic transformer, Heracleum mantegazzianum , which was replicated in five areas. I found a U-shaped population trajectory that paralleled the evolution of plasticity to shade. Whereas V. chamaedrys genotypes from intact, more open sites exhibited a shade-tolerance strategy (pronounced leaf area/mass ratio), reduced light availability at the invaded sites selected for a shade-avoidance strategy (greater internode elongation). Field experiments subsequently confirmed that the shifts in shade-response strategies were adaptive and secured postinvasion population persistence, as indicated by further modeling. Alternative ecological mechanisms (habitat improvement or arrival of immigrants) were less likely explanations than ER for the observed population rebound, although the contribution of maternal effects cannot be dismissed. These results suggest that V. chamaedrys survived because of adaptive evolutionary changes operating on the same timescale as the invasion-induced stress, but the generality of ER for postinvasion persistence of native plants remains unknown.

Wildlands have to be available and provide a tangible experience in cities, not only for biodiversity protection but also for nature experience. They need to support innovation with nature in order to address social, economic and environmental challenges. For that, additional knowledge about different features of the forest, waters and wetlands have to be provided considering local experiences, such as physical and socio-economic context, ecosystem structure and functioning, ecosystem services and disservices, accessibility, social use, existent and perceived risks, maintenance costs, and managing urban-protected areas. Different papers in this chapter aim to contribute to increase the understanding of the wildlands in cities, the main topic being related with ecosystem services provided by urban forest (Antonenko et al.), nature-based solutions applied at city scale (Xu et al.), integration of urban rivers and wetlands in city management (Napieralski, Shirazi et al., Faggi and Breuste) or the challenges of exotic species in urban design (Gavrilidis et al.). The case studies cover a wide range of geographical backgrounds, considering experience from South Asia (Shirazi et al.), China (Xu et al.), South America (Faggi and Breuste), North America (Napieralski), Russia (Antonenko et al.) and Southeastern Europe (Gavrilidis et al.).

The recent integration of citizen science with modern technology has greatly increased its applications and has allowed more people than ever to contribute to research across all areas of science. In particular, citizen science has been instrumental in the detection and monitoring of novel introduced species across the globe. This study provides the first records of Miomantis caffra Saussure, 1871, the South African Mantis, from the Australian mainland and uses records from four different citizen science and social media platforms in conjunction with museum records to track the spread of the species through the country. A total of 153 wild mantises and oothecae were observed across four states and territories (New South Wales, Norfolk Island, Victoria, and Western Australia) between 2009 and 2021. The large number of observations of the species in Victoria and the more recent isolated observations in other states and territories suggest that the species initially arrived in Geelong via oothecae attached to plants or equipment, likely from the invasive population in New Zealand. From there it established and spread outwards to Melbourne and eventually to other states and territories, both naturally and with the aid of human transport. We also provide a comparison of M. caffra to similar native mantises, specifically Pseudomantis albofimbriata (Stål, 1860), and comment on the potential impact and further spread of the species within Australia. Finally, we reiterate the many benefits of engaging directly with citizen scientists in biodiversity research and comment on the decision to include them in all levels of this research investigation.

MDFRC item.1. One of the greatest threats to lotic ecosystems is flow regulation. The impacts of flow regulation on native fish are often mitigated using periodic water allocations, termed environmental flows. The effectiveness of environmental flows has been studied in some systems, but the role of flow conditions prior to water allocation (i.e. antecedent conditions) has rarely been quantified. 2. We evaluated the effects of floodplain inundation due to variable river flows on fish abundance in wetlands of the mid-Murray River, Australia, using a hierarchical multi-species model parameterized to estimate fish abundance while accounting for variable detection. We evaluated the effects of antecedent conditions on three time-scales, including patterns in long-term (5 years prior), medium-term (1 year prior) and short-term (3 months prior) wetland inundations. 3. While species-specific responses to antecedent conditions varied, we found a general divergence in the responses of native and non-native species. Native fish tended to respond positively to consistent frequent inundation of wetlands, while non-native fish tended to respond positively to long- or medium-term dry periods and short-term wet periods. 4. Fish detection probability varied among species, sampling gears, wetland areas and wetlands, indicating that accounting for variable detection can be critical when evaluating patterns in fish abundance. 5. Synthesis and applications. We found that antecedent conditions can be important for determining environmental water allocation policies. Our results indicated that native fish generally responded positively to frequent inundation of wetlands, while non-native species generally responded positively to long dry periods followed by short-term inundation events. For some non-native species, long dry periods not only generated a positive response in abundance, but enhanced the positive response to short-term inundation events. The divergence between native and non-native fishes' responses to antecedent conditions provides opportunities for managers to allocate water to favour native fish assemblages. Future research of environmental flows for managing fish assemblages should consider antecedent conditions and apply models that account for incomplete detection, such as the one developed here, to better inform the management process.

MDFRC item.Literature data are reviewed on the origin, distribution, economic benefits and impacts of common carp Cyprinus carpio L. in the Mediterranean region. Despite the ubiquity of domesticated and feral forms, wild populations of the genetically pure ancestor are still found in confined areas of Thrace and Northern Anatolia, and possibly in eastern parts of Greece. Introductions and translocations throughout the region from at least Roman times have been driven by a combination of historical, economic and cultural motives, which have contributed to the spread of the species into many freshwater systems. Although impacts have been either documented or suspected in most areas of distribution, and intervention by biomanipulation successfully implemented in some water bodies, there is a compelling need for more focused research in more vulnerable areas characterised by drier/warmer and overall more unpredictable climate conditions, which appear to favour successful common carp population dynamics. In contrast to large-scale (i.e. country-wide) control measures, likely to prove unfeasible because of the intrinsically high costs associated and/or loss of revenue from sport fishing and fisheries activities, localised (integrated) management actions, followed by post-intervention monitoring, are likely to benefit targeted water bodies for increased amenity and restoration value.

MDFRC item.Using fish data from an intensive radio-tracking study over three consecutive seasons of microhabitat interaction between introduced pumpkinseed Lepomis gibbosus and native brown trout Salmo trutta in an English stream, constrained additive (CAO) and quadratic ordination (CQO) were used as a novel analytical approach to determine the degree of overlap and repartition in seasonal microhabitat preference between the two species, and to assess the shape of their preference profiles across a microhabitat gradient defined by depth, velocity, substratum, macrophytes, shelters and debris. Both species showed preference for stream pool habitats with instream cover mostly irrespective of season, indicating the existence of a microhabitat overlap. However, a certain degree of microhabitat repartition also was evident, with narrower preference profiles for introduced pumpkinseed relative to native brown trout. Overall, CAO and CQO represent a logical and useful multivariate extension to available modelling approaches in fish-habitat studies due to their ability to provide for a synoptic representation of response profiles for different species over a composite (latent) variable describing (micro) habitat characteristics.

La Trobe University Faculty of Science, Technology and Engineering Murray Darling Freshwater Research CentreMDFRC item.Alterations to the natural hydrologic regime in regulated rivers can disrupt cues that initiate the maturation and spawning of riverine fish, or they can change the conditions which are suitable for the recruitment of larvae into juvenile populations. Observations of fish larvae have the potential to provide insights into the effects of flow regulation, showing whether it has had a greater impact on fish by preventing spawning or by reducing or eliminating recruitment. We investigated historical and current records of native fish in the highly regulated Campaspe River and the moderately regulated Broken River, Murray-Darling Basin, Australia, and compared these with the results from sampling of fish larvae over three consecutive years to assess the likely impact that river regulation has had on fish populations in lowland Australian rivers. Of the 12 native species of fish that have been recorded historically from the Campaspe River, eight still occur, generally in low abundance, but only three of these were recorded as larvae in this experiment. From recent records, ten native fish species are extant in the Broken River from a suite of 15 that have been recorded there; of these, nine were collected as larvae. The presence of Murray cod larvae in this river was a significant finding. Thus, the less regulated Broken River is in a much healthier state than the Campaspe River. The results of sampling in both rivers indicated that most species of fish spawned each year, despite high inter-annual variation in antecedent hydrological conditions. This suggests that for the species present in these two rivers, the hydrology (pattern of daily discharge) during the winter and spring preceding breeding was unlikely to be a cue for final maturation and spawning. These findings are only preliminary, but they may show that river regulation has had more of an impact on post-spawning recruitment than on prevention of spawning. This has important implicatons for the remediation of the effects of river regulation, with targeting of recruitment processes and the factors influencing these, a priority.

The use of native species for timber plantations in the tropics has lately gained interest. Recent studies have shown that native tree plantations can have greater economic, and ecological benefits than non-native plantations. Facilitative nutritional interactions with nitrogen-fixing trees are a common practice used in hopes of enhancing nitrogen input. Dalbergia retusa and Terminalia amazonia are two neotropical species frequently used for timber extraction. In order to understand these species belowground interactions, we worked on 33 plots of the T. amazonia and D. retusa mixtures in the Agua Salud Project Native Species plantations in Panama. The objective of this study was to assess if soil biochemical properties under T. amazonia trees might be influenced by D. retusa in these mixtures. For this, soil samples were collected and analyzed for nitrogen pools, extractable cations and selected phosphorus constituents. Our results showed that nutrient concentrations were not significantly different below D. restusa and T. amazonia trees. Nonetheless, temporal and physicochemical characteristics of the plantation might be influencing the tree performance and should be considered for a better understanding of the nutrient dynamics in native tree plantations.

Species’ life histories determine population demographics and thus the probability that introduced populations establish and spread. Life histories also influence which species are most likely to be introduced, but how such ‘introduction biases’ arise remains unclear. Here, we investigate how life histories affect the probability of trade and introduction in phylogenetic comparative analyses across three vertebrate classes: mammals, reptiles and amphibians. We find that traded species have relatively high reproductive rates and long reproductive lifespans. Within traded species, introduced species have a more extreme version of this same life history profile. Species in the pet trade also have long reproductive lifespans but lack ‘fast’ traits, likely reflecting demand for rare species which tend to have slow life histories. We identify multiple species not yet traded or introduced but with life histories indicative of high risk of future trade, introduction and potentially invasion. Our findings suggest that species with high invasion potential are favoured in the wildlife trade and therefore that trade regulation is crucial for preventing future invasions.

Even though the ecological impacts of invasive alien species (IAS) have been well studied, social aspects of IAS in freshwater ecosystems are still poorly explored. This study aimed to assess the perceptions associated with non-indigenous freshwater fish species (NIFS) among environmental-related professional and non-professional stakeholders in a Mediterranean country that displays high levels of fish species endemism, by using a questionnaire survey approach. Overall, 203 individuals participated, from which, the majority (n = 144) were related to environmental sciences. Most of the respondents perceived NIFS to be a threat of national importance, possibly attributed to the emotional effect of the term non-indigenous (conceived as intruder). However, NIFS were indicated as the least important threat affecting aquatic ecosystems when compared with other pressures. This contrasting perception could be explained by the fact that broad-scale impacts (i.e., climate change) exert stronger reactions compared to NIFS. Interestingly, non-professionals were more successful in identifying NIFS and native species compared to professionals, however both indicated low overall identification success. The majority of the respondents, both professionals and non-professionals, considered that: (a) the official authorities do not implement actions for NIFS management, (b) government spending should be increased to manage NIFS even if it should be reduced for other needs, and (c) early detection is the best way to manage NIFS. The establishment of a nationwide network consisting of all related stakeholders on NIFS issues, aiming to public awareness and preventive management actions to limit the spread and impacts of NIFS should be set as a priority.

The present study adds 19 species (15 Rhodophyta, one Chlorophyta and three Ochrophyta) to the Azorean marine macroalgal flora, increasing the current total of species recorded in this region to 521 (349 Rhodophyta, 76 Chlorophyta and 96 Ochrophyta), and showing that this isolated island group supports a relatively rich marine macroalgal flora. Some species fall within their known overall distributional range, whereas other found here represent a northern or southern extension to their known distribution in the Atlantic. Three species (Antithamnionella elegans, Gymnophycus hapsiphorus and Scytosiphon dotyi) are probable introductions to the Azores, whereas Melanothamnus pseudoforcipatus has an uncertain status. Six of the newly reported species were found as components of the intertidal algal turf samples, which justifies the need for continuing to examine turf samples as new discoveries can be anticipated. This study is a contribution to the project AZORESBIOPORTAL-PORBIOTA (ACORES-010145-FEDER-000072) funded through FEDER (85%) and Regional funds (15%) via Operational Programme Azores 2020. Funding was also provided from National Funds through FCT-Fundação para a Ciência e a Tecnologia, under the projects UID/BIA/00329/2013, 2015-2018 and UID/BIA/00329/2019 and UID/BIA/00329/2020-2023. EC benefitted from a post-doctoral fellowship awarded by ARDITI (Regional Agency for Development of Research, Technology and Innovation of Madeira, Project M1420-09-5369-FSE-000002). ACLP was supported by PhD grant awarded by FRCT-Fundo Regional da Ciência e Tecnologia (M3.1.a/F/083/2015). PDT was supported by Xunta de Galicia 'Axudas de apoio a etapa de formacion posdoutoral' (grant ED481D/2017/011) and `Talento Senior' (grant 03IN858A2019-1630129). info:eu-repo/semantics/publishedVersion

La mayoría de las especies de plantas introducidas en México no han sido evaluadas para priorizar las acciones de gestión para erradicarlas o contenerlas o para mitigar los daños causados por invasiones de plantas nocivas. Se evaluaron 42 taxa (41 especies y una variedad) de malezas introducidas de la familia Leguminosae usando criterios empíricos y derivados de teoría, en el desarrollo de un modelo centrado en el comportamiento de las especies en el extranjero, su tiempo de residencia y las localidades ocupadas, y la presencia en México de los parientes congenéricos nativos y no nativos. Los datos se obtuvieron a partir de fuentes bibliográficas y de la base de datos “Malezas Introducidas en México” que incluye información de 11 herbarios de México. También desarrollamos un proceso de puntuación para calificar la expansión de las introducidas de acuerdo con tiempo de residencia y número de localidades ocupadas. Clasificamos a las leguminosas introducidas en cuatro categorías de prioridad de atención. Albizia lebbeck, Pueraria phaseoloides, Lablab purpureus, Securigera varia, Delonix regia, Clitoria ternatea y Spartium junceum deben recibir prioridad de atención alta; consideramos que ocho especies requieren una atención prioritaria media, y siete atención prioritaria baja. 20 taxa fueron clasificados como no prioritarios. El modelo de evaluación desarrollado todavía necesita un mayor refinamiento, ya que especies aparentemente inocuas obtuvieron puntajes altos y una potencialmente peligrosa (Cassia fistula) se clasificó en la categoría no prioritaria. Esperamos que el presente modelo de evaluación funcionará como una herramienta y con baja dependencia de expertos, para identificar a las especies introducidas que requieren un análisis de riesgo más completo para priorizar esfuerzos para el manejo de las plantas introducidas nocivas.

Interference competition over food and territory can shape population structure and habitat use within and between species. The introduction of invasive species often leads to novel competitive interactions over shared resources and invaders can eventually exclude the native species from preferred habitats. Invasive brook trout (Salvelinus fontinalis) introduced to northern Europe have excluded native brown trout (Salmo trutta) from numerous headwater streams. The fact that invasive brook trout can displace the more aggressive brown trout is puzzling. However, the earlier spawning and hatching of brook trout, compared to brown trout, may lead to unequal competition due to size advantage and prior resident status of brook trout at the fry stage. In this study, we examine the effect of competition between brown trout and brook trout using the natural size distribution of the two species. In two consecutive experiments, we first measured space use and feeding of a fry (age 0+) in the presence of a juvenile (age 1+). In experiment 2, we assessed territorial interactions between the species at the fry stage (age 0+) and if smaller brown trout could compensate the disadvantage by manipulating residence duration. Fry of brook trout feed sooner and spend more time close to the larger individual than brown trout fry. We also found that brook trout fry won most territorial contests against brown trout, and that increased residence duration led to longer and more aggressive interactions. The results suggest that smaller brown trout are displaced to suboptimal habitats in the presence of a larger brook trout. Therefore, the later emergence from gravel beds resulting in the naturally occurring size disadvantage of brown trout at the fry stage may lead to unequal territorial interactions that could explain why brown trout are displaced from preferred habitats in sympatry with brook trout.

Prudent predators catch sufficient prey to sustain their populations but not as much as to undermine their populations' survival. The idea that predators evolve to be prudent has been dismissed in the 1970s, but the arguments invoked then are untenable in the light of modern evolution theory. The evolution of prudent predation has repeatedly been demonstrated in two-species predator-prey metacommunity models. However, the vigorous population fluctuations that these models predict are not widely observed. Here we show that in complex model food webs prudent predation evolves as a result of consumer-mediated ('apparent') competitive exclusion of resources, which disadvantages aggressive consumers and does not generate such fluctuations. We make testable predictions for empirical signatures of this mechanism and its outcomes. Then we discuss how these predictions are borne out across freshwater, marine and terrestrial ecosystems. Demonstrating explanatory power of evolved prudent predation well beyond the question of predator-prey coexistence, the predicted signatures explain unexpected declines of invasive alien species, the shape of stock-recruitment relations of fish, and the clearance rates of pelagic consumers across the latitudinal gradient and 15 orders of magnitude in body mass. Specific research to further test this theory is proposed.

In this study we report the first case of an introduced alien host spider species being parasitized and manipulated by an ichneumonid wasp. Hymenoepimecis bicolor, previously described parasitizing exclusively Trichonephila clavipes (Araneidae), was observed parasitizing the European species Cyrtophora citricola (Araneidae) in southeastern Brazil. The cocoon web built by the parasitized spider is composed of a reduced horizontal sheet, which maintains the radial structure. The reduced number of radii and spirals probably reduce the chances of insect interception by these modified structures. In addition, the density of supporting threads is apparently very different between normal and modified webs. The cocoon web spun by C. citricola lacks the protective barrier structure usually observed in cocoon webs spun by parasitized females of T. clavipes. Our observations are in agreement with several predictions of the ecdysteroid hypothesis and represent an interesting opportunity for further investigation of interactions between these parasitoids and their spider hosts.

Biological invasions pose one of the most severe environmental challenges of the twenty-first century. A longstanding idea is that invasion risk is predictable based on the phylogenetic distance - and hence ecological resemblance - between non-native and native species. However, current evidence is contradictory. To explain these mixed results, it has been proposed that the effect is scale-dependent, with invasion inhibited by phylogenetic similarity at small spatial scales but enhanced at larger scales. Analyzing invasion outcomes in a global sample of bird communities, we find no evidence to support this hypothesis. Instead, our results suggest that invaders are locally more successful in the presence of closely related and ecologically similar species, at least in human-altered environments where the majority of invasions have occurred. Functional trait analyses further confirm that the ecological niches of invaders are phylogenetically conserved, supporting the notion that successful invasion in the presence of close relatives is driven by shared adaptations to the types of niches available in novel environments.

Artificial light at night (ALAN) has been and still is rapidly spreading and has become an important component of global change. Although numerous studies have tested its potential biological and ecological impacts on animals, very few studies have tested whether it affects alien and native plants differently. Furthermore, common plant species, and particularly common alien species, are often found to benefit more from additional resources than rare native and rare alien species. Whether this is also the case with regard to increasing light due to ALAN is still unknown. Here, we tested how ALAN affected the performance of common and rare alien and native plant species in Germany directly, and indirectly via flying insects. We grew five common alien, six rare alien, five common native, and four rare native plant species under four combinations of two ALAN (no ALAN vs. ALAN) and two insect-exclusion (no exclusion vs. exclusion) treatments, and compared their biomass production. We found that common plant species, irrespective of their origin, produced significantly more biomass than rare species and that this was particularly true under ALAN. Furthermore, alien species tended to show a slightly stronger positive response to ALAN than native species did (p = .079). Our study shows that common plant species benefited more from ALAN than rare ones. This might lead to competitive exclusion of rare species, which could have cascading impacts on other trophic levels and thus have important community-wide consequences when ALAN becomes more widespread. In addition, the slightly more positive response of alien species indicates that ALAN might increase the risk of alien plant invasions. published