Search Results (107)

Biological invasions are a primary driver of biodiversity loss, with significant socio-economic repercussions. Therefore, understanding the factors influencing the assembly of invasive insect assemblages in Biodiversity Conservation Priority Areas is essential for formulating effective management strategies. This study examined the invasive alien insect fauna across three such regions in Guangxi, China, from April to November 2022, employing a systematic grid-based sampling design that encompassed 84 grids. A total of nineteen invasive alien insects from seven orders were identified, with Coleoptera (26.3%), Hymenoptera (21.1%), and Diptera (15.8%) being the most prevalent. Bactrocera cucurbitae Bezzi, 1913 (57.1% occurrence frequency) and Blattella germanica Linnaeus, 1767 (53.6%) were the most frequently observed species. Species richness exhibited significant variation among the three areas, peaking in the Western Guangxi and Southern Guizhou Limestone Area. The assemblages’ composition displayed high beta diversity, as indicated by a total Sørensen dissimilarity of 0.645, primarily driven by species turnover (0.474) rather than nestedness (0.171), which suggests the presence of distinct species assemblages across the areas. Generalized linear mixed models and Canonical Correspondence Analysis identified precipitation and temperature as the primary factors influencing species richness and assemblages’ composition, respectively. Hierarchical partitioning indicated that climatic variables, specifically precipitation (48.0%) and temperature (32.0%), collectively accounted for the majority of the variation in species richness, significantly surpassing the impact of local land cover (20.0%). In contrast, contemporary anthropogenic land use factors exhibited no significant effect. Our findings illustrate that while human activities serve as the ultimate drivers of species introductions, the subsequent assembly of invasive insect assemblages within these Biodiversity Conservation Priority Areas are predominantly shaped by climatic conditions. This highlights the essential role of climate suitability in determining the success of post-introduction establishment. Therefore, we recommend the incorporation of high-resolution climate-matching models into biosecurity screening and monitoring frameworks for Biodiversity Conservation Priority Areas, with targeted surveillance efforts directed toward regions exhibiting the highest climatic suitability. Full article

Invasive alien species such as Lantana camara L. impact native species and soil properties, but context-specific effects in transfrontier conservation areas remain poorly understood. Understanding these effects is essential for biodiversity conservation and management. We assessed associations between L. camara presence and native woody species composition and structure, as well as soil nutrients, in protected and communal areas within the Kavango–Zambezi Transfrontier Conservation Area (KAZA TFCA), Zimbabwe. The study hypothesised that invasion effects on vegetation are stronger in communal areas due to higher disturbance, and that soil changes are influenced by land-use intensity. We used stratified random sampling to select 60 plots across invaded and uninvaded sites. Woody vegetation was assessed for species composition and richness, stem density, canopy cover %, height, and diameter at breast height. Soil samples were analysed for nitrogen, organic carbon, phosphorus, potassium, and pH. The presence of L. camara was negatively associated with native species richness, density, height, and canopy cover %, with stronger effects in communal plots. Invaded plots had lower pH (e.g., 6.1 in Park areas) and higher levels of some soil nutrients, particularly phosphorus and organic carbon, though patterns varied by land-use type. These results suggest that anthropogenic disturbance amplifies invasion impacts. We conclude that L. camara reduces native vegetation diversity and structure in this species-rich transfrontier area. Management should prioritise control at communal edges to support woody species resilience, ecosystem services, and biodiversity, with strategies adapted to local land-use conditions. Full article

Invasive alien species (IAS) not only threaten biodiversity and ecosystems but also play a significant role in the spread of infectious diseases; however, the epidemiological role of many IAS remains poorly understood. This study presents the first systematic review of major pathogens reported in 22 IAS of concern to the European Community. Given the breadth of available data, we relied on a literature search including studies reporting natural infections in target IAS, excluding experimental infections and non-target species. A total of 541 publications between 1963 and 2023 were analyzed, identifying 472 pathogens, of which 64 were classified as high-priority based on key global and European frameworks. IAS with broader distribution and higher research effort were associated with greater pathogen richness, suggesting potential epidemiological relevance but also highlighting detection bias. A composite Host–Pathogen Influence Index (HPI-IAS) revealed spatial heterogeneity in epidemiological pressure across Europe, with Poland, Germany, Italy, and France identified as areas of elevated epidemiological concern. These findings underscore the urgent need for coordinated, cross-border monitoring strategies at the European level and contribute to a broader understanding of IAS-related infectious disease ecology within a One Health framework. Full article

Ports and recreational marinas are established hotspots for the introduction and secondary spread of non-indigenous species (NIS), mainly via vessel transport and biofouling on artificial substrates. In the AlienPorts project, we surveyed fouling and associated macrobenthic assemblages in four major Greek marinas across distinct marine regions—Rhodes (Levantine), Heraklion and Piraeus–Zea (Aegean), and Patra (Ionian)—from 2021 to 2022, applying two complementary protocols: (i) photoquadrat surveys and (ii) scraped assemblage sampling. The photoquadrats recorded twelve NIS and seven cryptogenic species, which were dominated by sessile fouling taxa, especially ascidians. The scraped samples revealed 106 polychaete and amphipod species, including 25 taxa (23 NIS, two cryptogenic). Six of the polychaetes are new NIS for the Mediterranean, and thirteen of the taxa are newly recorded as NIS in Greek waters. Heraklion had the highest NIS richness (18 NIS + two cryptogenic), while the other marinas hosted approximately ten NIS/cryptogenic taxa. In contrast, NIS often dominated the population densities, with Zea being the most impacted based on the NIS to native species ratios for both diversity and abundance. The two methods detected largely distinct biodiversity components and shared only one NIS, underscoring a strong complementarity. The multivariate analyses confirmed significant differences among marinas (ANOSIM, p < 0.01). These results support integrated, multi-method monitoring to enhance the early detection and impact assessment under MSFD Descriptor 2. Full article

Invasive alien plants (IAPs) pose a severe and escalating threat to biodiversity and ecosystem services in China. However, a systematic nationwide assessment that identifies invasion hotspots, quantifies their overlap with protected area networks, and pinpoints critical conservation gaps is still lacking. This hinders the development of spatially targeted management strategies. To address this, we developed an integrated analytical framework coupling the Maximum Entropy (MaxEnt) model with the InVEST habitat quality model. Using a high-resolution, county-level distribution database of 293 IAPs, we mapped potential species richness and habitat degradation across China. The geo-detector model was further employed to identify the primary environmental factors and their interactions. Spatial overlay analysis was conducted to delineate core invasion habitats (areas of high invasion suitability and high degradation) and assess their coverage within China’s national nature reserves. Nighttime light intensity (DMSP, 34.39%), annual precipitation (Bio12, 14.16%), and mean diurnal range (Bio2, 11.82%) were the factors with the highest contribution in the model, highlighting the statistical interaction between anthropogenic pressure and climatic conditions. The core invasion habitat spanned 20.10 × 10⁴ km², predominantly (66.04%) concentrated in high-intensity human disturbance zones. Notably, only 11.18% of this core habitat falls within existing national nature reserves, revealing a vast conservation gap of 17.85 × 10⁴ km². Our results indicate a profound spatial mismatch between invasion hotspots and the current protected area network in China. We prioritize southeastern coastal urban agglomerations-characterized by high anthropogenic pressure (DMSP), high precipitation (Bio12), and low diurnal temperature range (Bio2)-for immediate monitoring and intervention. This integrated assessment provides a national-scale, spatially explicit prediction of invasion risk for 293 plant species in China, and offers an evidence-based decision-support tool for optimizing invasive species management and biodiversity conservation. Full article

Biological invasions are among the most pervasive threats to biodiversity, ecosystem functioning, and human well-being. Despite international policy efforts, the number of introductions continues to rise worldwide. Mountains, once considered resistant to biological invasions due to harsh climates and isolation, are becoming increasingly vulnerable. Human activities—tourism, infrastructure development, and land-use change—combined with climate warming, are creating new pathways and suitable conditions for non-native plants to spread upslope. Global evidence shows a rapid increase in alien species richness in mountain ecosystems, with some taxa shifting elevation by hundreds of meters. The problem of biological invasions becomes critical when considering that mountains harbor nearly a quarter of the planet’s total biodiversity. This issue is even more concerning in biodiversity hotspots such as the Mediterranean Basin, where mountains present an exceptionally high rate of endemism and have served as glacial refugia. The Pyrenees exemplify this dynamic: historically shaped by millennia of human activity, they now face growing pressures from tourism and climate change. Recent cataloging efforts reveal 771 alien taxa, surpassing figures for larger ranges like the Alps. These findings challenge long-held assumptions about mountain resilience and underscore the urgent need for coordinated monitoring, early detection, and management strategies—including citizen science initiatives—to mitigate ecological impacts and protect mountain biodiversity under accelerating global change. Full article

Invasive alien plant species pose significant threats to biodiversity and the ecological functioning of ecosystems, necessitating targeted clearing strategies. This study investigated the short-term recovery of native vegetation following the control of Lantana camara and Chromolaena odorata in communal lands of Manzini, Eswatini. Nineteen sites were sampled across cleared and uncleared areas to assess changes in species diversity and veld condition. Cleared sites showed slightly reduced heterogeneity (D′ = 0.722) and higher diversity (H′ = 2.081) compared to uncleared sites (D′ = 0.732) and diversity (H′ = 2.032). Sites free from invasive alien plants had higher species richness (EXP (H′) = 35.693) than invaded sites (EXP (H′) = 28.237). Although statistical analyses showed no significant differences in stem counts between cleared and uncleared sites, effect sizes indicated potential practical significance for C. odorata. The Veld Condition Index (VCI) revealed high spatial variability with no consistent trend associated with clearing. Findings emphasise the complexity of early post-clearing dynamics and the importance of site-specific follow-up and monitoring. Full article

Invasions by alien plants are major global drivers of ecosystem changes and loss of biodiversity. Guangxi is an ecological barrier in southern China that is increasingly being affected by invasive alien plant species. We comprehensively reviewed the literature, compiling and analyzing the long-term changes in species composition, native range, life forms, municipal-scale patterns, and correlates of invasive alien plant richness in Guangxi at three time points (1973, 2010, and 2023). Over the 50-year period, the number of invasive alien plant species markedly increased from 31 species in 1973 to 84 in 2010 and 158 in 2023; the number of families, genera, and species increased 2.05-, 3.75-, and 5.10-fold, respectively. Species native to North America consistently dominated the invasive flora, followed by those native to Africa. The number of species native to South America and Asia increased in the records from 2010 to 2023. Annual herbaceous plants accounted for the largest proportion of invasive species throughout the study period and showed the largest absolute increase in species number. However, no substantial temporal shifts in the overall life-form composition were detected. At the municipal scale, the invasive alien plant richness exhibited pronounced spatial heterogeneity. The invasive alien plant richness was highest in Guilin and Baise in 1973, in Guilin in 2023, followed by Nanning and Baise. Correlation analyses based on 2023 data revealed a significant positive association between invasive alien plant richness and tourism intensity, whereas relationships between population size, gross domestic product, and climatic variables were weak or nonsignificant. Overall, our results document the continued expansion and the spatial differentiation of invasive alien plants in Guangxi over the 50-year period of 1973–2023. These patterns primarily reflect the accumulation in the number of recorded invasive species under a consistent classification framework and should be interpreted with caution given the potential variation in survey effort among periods and cities. The results provide a descriptive baseline for the provincial-scale monitoring, risk assessment, and management of invasive alien plants. Full article

The biotic resistance hypothesis proposes that species-rich communities are more resistant to biological invasions due to the less available resources for invaders. The variation in available soil resources may affect the invasion resistance of community, but there is little evidence. Using invasive Solanum rostratum Dunal, a noxious invader in infertile habitats, and six co-occurring non-invasive species, we conducted a field experiment by testing the relationship between relative growth performance of invasives and richness of resident non-invasives, and the effects of available soil water and nutrients on the relationship. We found that relative aboveground biomass (hereafter relative biomass), relative coverage, community-weighted means (CWM) of specific leaf area (SLA), and photosynthetic rate (P_mass) of S. rostratum decreased with increasing resident non-invasive species richness. In contrast, for the non-invasive species, the CWM of SLA and P_mass significantly increased with increasing resident species richness. However, the available soil water and nutrients exerted limited effects on the relative biomass and coverage of S. rostratum. The piecewise structural equation model showed that non-invasive species richness has not only direct negative effects, but also indirect negative effects through promoting non-invasive biomass on the relative biomass of S. rostratum. Our findings indicate that the higher resident species richness is fundamental to resist invasion of alien S. rostratum, which operates through increasing biomass and resource acquisitive traits of a non-invasive community. Additionally, soil available resources exert limited effects on the invasion resistance. This study suggests the importance of conservation of biodiversity in preventing biological invasions. Full article

Due to global warming and intensified anthropogenic impacts, mountainous areas are increasingly being colonised by alien plant species. The diversity patterns of these species have not been sufficiently studied in the Central Balkans. The aims of this study were to determine the occurrence and richness of alien plant species in relation to habitat type and geological substrates, and to identify the factors with the greatest influence on the composition and abundance of these species on Zlatibor Mountain (Central Balkans). This area is known as an important tourist centre and a large mountainous massif in Serbia. Principal Component Analysis (PCA) and distance-based Redundancy Analysis (db-RDA) were employed to examine the influence of environmental factors on the abundance and composition of 18 alien plant taxa. Data on altitude, habitat type, bedrock type, bioclimatic variables, and indicator values (light regime, soil moisture, acidity, nitrogen and temperature) of dominant plant species within the habitats were used as explanatory variables. Erigeron annuus, Reynoutria × bohemica, Robinia pseudoacacia, and Erigeron canadensis were the most common alien taxa and had the highest abundances. Residential and tourist facilities and the peripheries of asphalt roads are the habitat types where most alien species occur, while the lowest number of species was found in natural and semi-natural herbaceous habitats. Most taxa were found on serpentine substrates, while the number of taxa was lower on siliceous and carbonate substrates. This study emphasises the predominant role of habitat type in the partitioning of ecological niches of alien plant species. Furthermore, habitat type has a much greater influence on species composition and abundance than climatic factors and bedrock type, suggesting that the diversity pattern of alien plant species is related to the type and intensity of anthropogenic influences. Our results provide a useful basis for developing effective strategies to protect native habitats from invasion by alien plants. Full article

The Mystras UNESCO World Heritage Site (MUWHS) is a medieval historical area located on a small hill facing Sparta in the Mediterranean hotspot of the Peloponnese and receives a high number of visitors annually. The main aim of this study is the inventory and analysis of plant species composition and diversity of the Mystras archaeological area, with emphasis on different aspects of its flora, on the specialist endemic plants, and on the generalist ruderal and alien taxa. A high plant species richness was observed, and 321 vascular plant taxa were registered. Most of the taxa are Mediterranean or have a more widespread distribution, and half of them are ruderals. Concerning endemism, 14 Greek and 7 Balkan endemic taxa were registered. As anticipated, the most species-rich plant families recorded in the study area are Asteraceae, Fabaceae, and Poaceae. The total flora is predominantly composed of therophytes, reflecting the site’s Mediterranean climate and disturbance-adapted ecological conditions while the endemic flora is mostly composed of hemicryptophytes. Comparisons of MUWHS plant diversity with four other archaeological sites of the same floristic region of Greece, the Peloponnese, highlighted its high α-diversity on all aspects of its flora and its floristic dissimilarity from the other areas and, additionally, the high plant species richness that is comprised in all five of them. Comparisons of the flora of MUWHS with other Greek and Mediterranean archaeological areas showed significant similarities in the floristic elements considered as deteriogenic for the protected walls and monuments. The findings of our study underscore the urgent need to prioritise the sustainable conservation of archaeological sites such as Mystras. These landscapes are not only cultural monuments but also reservoirs of biodiversity and ecological value. Effective management must, therefore, adopt an integrated approach that balances the preservation of historical structures with the protection of native flora and ecological processes. Full article

A comprehensive floristic study on the vascular flora of the 11 Italian volcanic lake calderas is presented. Despite encompassing one of the Mediterranean’s major freshwater systems, floristic research in these areas has proved fragmented and often outdated. By integrating literature data with original data from new floristic surveys, a total of 1182 spontaneous plant taxa were recorded, including 152 alien plants. Six taxa represent regional novelties and 102 are new for the study area, while 48 taxa reported before 1950 were not confirmed locally. From a conservation perspective, 27 taxa of national interest were reported, including two species classified as Critically Endangered (Isoëtes sabatina, Vicia incisa) and four Endangered (Carex vulpina, Baldellia ranunculoides, Hippuris vulgaris, Hydrocotyle vulgaris) according to IUCN criteria, along with 50 taxa listed on regional red lists. Floristic richness varies notably, from 124 taxa in the caldera of Lake Giulianello to 756 in Lake Bracciano, reflecting differences in caldera size, degree of anthropogenic impact and availability of previous botanical data. These results significantly enrich the floristic knowledge of the calderas of Italian volcanic lakes and may represent a solid reference for future naturalistic research in these areas. Full article

Arundo donax L. has been introduced in markets worldwide due to its economic value. However, it is listed in the world’s 100 worst alien invasive species because it easily escapes from cultivation, and forms dense monospecific stands in riparian areas, agricultural areas, and grassland areas along roadsides, including in protected areas. This species grows rapidly and produces large amounts of biomass due to its high photosynthetic ability. It spreads asexually through ramets, in addition to stem and rhizome fragments. Wildfires, flooding, and human activity promote its distribution and domination. It can adapt to various habitats and tolerate various adverse environmental conditions, such as cold temperatures, drought, flooding, and high salinity. A. donax exhibits defense mechanisms against biotic stressors, including herbivores and pathogens. It produces indole alkaloids, such as bufotenidine and gramine, as well as other alkaloids that are toxic to herbivorous mammals, insects, parasitic nematodes, and pathogenic fungi and oomycetes. A. donax accumulates high concentrations of phytoliths, which also protect against pathogen infection and herbivory. Only a few herbivores and pathogens have been reported to significantly damage A. donax growth and populations. Additionally, A. donax exhibits allelopathic activity against competing plant species, though the allelochemicals involved have yet to be identified. These characteristics may contribute to its infestation, survival, and population expansion in new habitats as an invasive plant species. Dense monospecific stands of A. donax alter ecosystem structures and functions. These stands impact abiotic processes in ecosystems by reducing water availability, and increasing the risk of erosion, flooding, and intense fires. The stands also negatively affect biotic processes by reducing plant diversity and richness, as well as the fitness of habitats for invertebrates and vertebrates. Eradicating A. donax from a habitat requires an ongoing, long-term integrated management approach based on an understanding of its invasive mechanisms. Human activity has also contributed to the spread of A. donax populations. There is an urgent need to address its invasive traits. This is the first review focusing on the invasive mechanisms of this plant in terms of adaptation to abiotic and biotic stressors, particularly physiological adaptation. Full article

Agrobiodiversity decline depends on wider-scale landscape ecological traits. Studying inter-scale patterns helps in understanding context-specific farm-scale biodiversity issues and needs. In this study, we investigated the drivers of agrobiodiversity in four Po Plain sites (northern Italy), an intensively impacted agricultural district. Farm-scale floristic–vegetational indicators reflecting anthropic disturbance (biological forms, chorological traits, and maturity traits) were studied for their relationship with species richness and phytocoenosis α-diversity values. Their correlation with local- and extra-local-scale landscape ecology traits was also studied. Species richness and α-diversity were negatively related to floristic contamination and therophytes; they tended to increase with the Eurasiatic and phanerophyte ratio, suggesting a role of disturbance conditions on diversity values. Extra-local/local scale showed similar relationships with farm-scale floristic–vegetational traits; correlation was higher for local scale. Species richness and α-diversity tended to increase with higher landscape natural components, landscape diversity, biological territorial capacity, and connectivity. These landscape traits also tended to be positively related to Eurasiatic, hemicryptophyte, chamaephyte, phanerophyte, and maturity values, while they were negatively related to adventitious, wide distribution, aliens, and therophytes. Corridors’ ecological quality apparently influenced disturbance-related species amount. Maps representing these inter-scale biodiversity facets are provided (land-use-based support ecosystem service maps integrated with landscape diversity maps). The detected patterns orient context-specific multi-scale biodiversity support. They confirm the theoretical frameworks and should be validated on wider datasets to strengthen their representativeness. Full article

Global changes, such as atmospheric nitrogen deposition, can facilitate alien plant invasions, which are often attributed to the increase in soil nitrogen availability. However, few studies have considered the effects of global change-driven alterations in soil nitrogen forms, especially under conditions with interspecific competition. In this study, we first determined the differences in growth, biomass allocation, and photosynthesis under different nitrogen forms and addition levels between three noxious invasive species (Xanthium strumarium, Ambrosia trifida, and Bidens frondosa) and their respective related natives grown with and without interspecific competition and then assessed the interspecific difference in nitrogen form preference using the ¹⁵N labeling technique. Interspecific competition significantly decreased the positive responses of growth to nitrogen addition for all three natives, while increasing the responses for all three invaders, particularly under nitrate addition. When grown in competition, all invaders showed significant growth advantages over their related natives in most cases, and responded more positively to the addition of nitrate relative to ammonium, while the natives responded more positively to ammonium addition. These findings indicate that the invaders prefer nitrate, while the natives prefer ammonium. Consistently, the growth advantages are more pronounced for the invaders under nitrate relative to ammonium addition, indicating that nitrate-rich habitats may be more vulnerable to the invaders. When grown in monoculture, however, the growth advantage of the invaders became smaller or even disappeared. Nitrogen form preference also disappeared in Siegesbeckia glabrescens (native) and Bidens frondosa (invasive). Interestingly, the native plant Xanthium sibiricum showed significantly higher total biomass than its invasive congener under ammonium addition in both mixed and monoculture conditions. Our ¹⁵N labeling experiment showed that all six species preferred nitrate over ammonium, although this was not significant for two natives (S. glabrescens and X. sibiricum), which is not completely consistent with the results from our nitrogen addition experiment. Our results indicate that global change-driven alterations in soil nitrogen forms, particularly the shift from ammonium to nitrate, may facilitate alien plant invasions. Planting patterns significantly affect the responses of invasive and native species to nitrogen forms and addition levels, with mixed-culture experiments providing better insights into the invasiveness of alien species. Full article