Search Results (370)

Acacia mearnsii De Wild. has been introduced to over 150 countries for its economic value. However, it easily escapes from plantations and establishes monospecific stands across plains, hills, valleys, and riparian habitats, including protected areas such as national parks and forest reserves. Due to its negative ecological impact, A. mearnsii has been listed among the world’s 100 worst invasive alien species. This species exhibits rapid stem growth in its sapling stage and reaches reproductive maturity early. It produces a large quantity of long-lived seeds, establishing a substantial seed bank. A. mearnsii can grow in different environmental conditions and tolerates various adverse conditions, such as low temperatures and drought. Its invasive populations are unlikely to be seriously damaged by herbivores and pathogens. Additionally, A. mearnsii exhibits allelopathic activity, though its ecological significance remains unclear. These characteristics of A. mearnsii may contribute to its expansion in introduced ranges. The presence of A. mearnsii affects abiotic processes in ecosystems by reducing water availability, increasing the risk of soil erosion and flooding, altering soil chemical composition, and obstructing solar light irradiation. The invasion negatively affects biotic processes as well, reducing the diversity and abundance of native plants and arthropods, including protective species. Eradicating invasive populations of A. mearnsii requires an integrated, long-term management approach based on an understanding of its invasive mechanisms. Early detection of invasive populations and the promotion of public awareness about their impact are also important. More attention must be given to its invasive traits because it easily escapes from cultivation. Full article

A virome survey of banana plantations and their surrounding plants was carried out at nation-wide level in Malawi using virion associated nucleic acids (VANA) high throughput sequencing (HTS) on pooled samples and appropriate alien controls. In total, 366 plants were sequenced, and 23 plant virus species were detected, three species on banana (275 plants) and 20 species in surrounding plants (91 plants). Two putative novel virus species; ginger tymo-like virus and pepper derived totivirus were detected and confirmed by RT-PCR on ginger and pepper. Nine known virus species and detected a host plant was identified for two of them. No viral exchange between banana and surrounding plants was observed. Results from the VANA protocol, applied to pooled banana samples, were compared with previous targeted PCR results obtained from individual banana samples. HTS test detected better BanMMV than IC-(RT)-PCR on individual samples (better inclusivity) but detected with much lower sensitivity BBTV and BSV species, often with less than 10 reads per sample. Detection of novel and known viruses and new host plants calls for strengthened sanitory and phytosanitory measures within and beyond banana production systems. Our research confirms that HTS sensitivity depends on sampling, pooling protocol and targeted virus species. Full article

The invasion of alien species has emerged as a global ecological challenge and invasive species can seriously threaten the habitats of native plants and intensify interspecific competition, ultimately exerting significant impacts on local ecosystems. Therefore, it is necessary to implement effective prevention and control strategies to reduce these impacts and maintain ecological stability. Against this backdrop, it is especially critical to analyze the influencing factors of invasive alien species and predict their future trends. Given China’s vast territory, complex natural geography, and diverse climatic conditions, the problem of invasive alien species in China is particularly severe, and scientific countermeasures are urgently required. Up to now, the number of invasive alien plant species in China has exceeded 520. Based on the number of invasive plant species in each province of China, this study analyzes the intrinsic connection between various influencing factors and invasive species, and through correlation analysis identifies the influencing factors, which are then used to analyze and predict the future invasion risks that each region may face. Full article

Islands subjected to anthropogenic disturbance are highly susceptible to alien plant invasions. However, the alien floral diversity of China’s islands has been insufficiently studied, hindering its control. Weizhou Island (northern South China Sea) has experienced long-term human exploitation. We inventorized its alien, naturalized, and invasive vascular plants (based on herbarium specimen data for 2018–2024 and surveys of 112 plots); analyzed species composition, origins, life forms, and habitats; and conducted an invasive species risk assessment. This identified 203 aliens, including infraspecific and hybrid taxa, 129 (63.5%) naturalized and 71 (55.0% of the naturalized species) invasive. The aliens were dominated by the Fabaceae, Asteraceae, and Euphorbiaceae, particularly genera such as Euphorbia, Senna, and Portulaca, originating primarily in North America, Oceania, and Africa. Perennial herbs were the most common lifeform, followed by annual herbs and shrubs. Invasion hotspots were primarily abandoned farmland, roadsides, and agricultural lands. Using the Analytic Hierarchy Process, we classified the 71 invasive species as representing high-risk, moderate-risk, and low-risk (20, 16, and 35 species, respectively). Bidens pilosa, Ageratum conyzoides, Opuntia dillenii, and Leucaena leucocephala pose severe threats to the island ecosystem. This first complete inventory of the alien flora on Weizhou Island offers critical insight into the management of invasive alien plants in island ecosystems. Full article

Integrating nature-based solutions into sustainable urban design has become increasingly important in response to rapid urbanization and climate-related environmental challenges. As part of these solutions, green walls not only enhance the thermal and acoustic performance of buildings but also contribute to urban ecosystem health by supporting biodiversity. In this context, the careful selection of plant species is essential to ensure ecological efficiency, resilience, and low maintenance. This study presents a model for selecting plant species suitable for natural green walls in Mediterranean cities, with a focus on habitats protected under Directive 92/43/EEC. The selection followed a multi-phase process applied to the native flora of Italy, using criteria such as chorological type, life form, ecological indicator values, altitudinal range, and habitat type. Alien and invasive species were excluded, favoring only native Mediterranean species adapted to local pedoclimatic conditions and capable of providing ecosystem, esthetic, and functional benefits. The outcome of this rigorous screening led to the identification of a pool of species suitable for green wall systems in Mediterranean urban settings. These selections offer a practical contribution to mitigating the urban heat island effect, improving air quality, and enhancing biodiversity, thus providing a valuable tool for designing more sustainable and climate-adaptive buildings. 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

Resprouting is a vital mechanism that enables plants to recover from severe damage caused by environmental or physical disturbances by using non-structural carbohydrates (NSCs), as reflected in their respiration activity. In this study, we focused on resprouting activity and carbon allocation at the organ level in the resprouter species R. pseudoacacia L. We compared the changes in biomass production, NSCs concentration, and respiration rates in each organ (leaf, stem, and root) of five- or six-year-old R. pseudoacacia L. between partial and complete stem loss (tall-stump, TS, and short-stump, SS, respectively) at 2, 4, 9, and 14 months after cutting. TS had greater resprout biomass than SS within two months after cutting, whereas SS experienced a loss of root NSCs before recovery. Compared to TS, SS had higher leaf respiration rates, likely for storage replenishment, whereas root respiration rates remained similar across treatments. The TS maintained NSCs levels during resprouting. However, the SS experienced temporary depletion and recovered within 14 months. Our findings provide new insights into the physiological characteristics of resprouters and invasive alien species with respect to organ loss and offer a novel understanding of efficient storage use during stress and low-cost carbon use for storage replenishment through rapid organ regrowth. Full article

This paper provides data on non-native fungus-like organisms (Oomycota, kingdom Stramenopila), their diversity, and distribution in Lithuania and is an addition to a previously published checklist of alien true fungi (Chytridiomycota, Ascomycota, and Basidiomycota; kingdom Fungi). All available published data were summarized, and the analysis showed that approximately 25% of recorded Lithuania stramenopilous fungus-like organism species are alien. The compiled list represented herein includes 54 species of alien terrestrial and aquatic stramenopilous fungus-like organisms (Oomycota). Most alien Oomycota are obligate pathogens of terrestrial plants. Aquatic organisms are represented by one alien dangerous crayfish pathogen, Aphanomyces astaci, which is currently noted as extinct in Lithuania. The taxonomy of the listed alien species of Oomycota has been revised, and the species names have been adjusted to reflect current nomenclature changes. The taxonomical and ecological analysis demonstrated the prevalence of terrestrial parasitic Peronosporales reported in Lithuania Oomycota and the highest diversity of alien species belonging to the Peronospora genus. The chronology of appearance, distribution within the country, and current status of these non-native organisms were assessed, and some of the most economically or ecologically important harmful invasive species were discussed. 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

Butterflies have nectar-feeding preferences based on various floral characteristics, including flower shape, size, color, fragrance, and nectar composition, which in turn affect their survival, reproduction, and roles in pollination. The National Botanical Garden (NBG) in Lalitpur, Nepal, holds a variety of flowering plants and butterfly populations, providing a suitable study site to test the hypotheses on floral preferences of butterflies. This study assessed the floral preferences of the butterfly community in the NBG based on flower color, the origin of flowering plants (native and alien), and the type of plants (herbs and shrubs). It also tested the association between butterfly proboscis lengths and corolla tube lengths of flowers. Data were collected from 10 blocks (each 5 × 5 m²) through direct observation during the spring and autumn seasons, from March to October 2022. A total of 24 species of butterflies were recorded during the study period, with the chocolate pansy (Junonia iphita) being the most abundant. The relative abundance of pink flowers was higher in the NBG, but the butterflies’ visitation frequency was significantly higher on yellow flowers (p < 0.05) than on other colors. The visitation frequencies of butterflies significantly varied with the flowers’ origin and types. Butterflies visited flowers of alien origin more frequently than native ones (p < 0.05) and those of herbs over shrubs (p < 0.05). Flowers from alien plants, such as Calluna vulgaris and Viola tricolor, were among the most frequently visited. The proboscis length of butterflies showed a significantly strong positive correlation with the corolla tube length of flowers (τ = 0.74, p < 0.001). These results can inform conservation practices and garden management strategies aimed at supporting butterfly diversity through the intentional selection of floral resources. Full article

Leucaena leucocephala (Lam.) de Wit is listed in the world’s 100 worst alien invasive species because of the risks it poses to native plant communities. Life history traits, such as high growth and reproductive rates, and a high capacity to adapt to different environmental conditions may contribute to its invasive properties. Biotic stressors, such as herbivores, pathogens, and competing plant species are known to exert significant selective pressure on the plant’s survival, distribution, and abundance. L. leucocephala has been reported to contain several compounds involved in the defense functions against these biotic stressors. A large amount of L-mimosine, a non-protein amino acid, was found in all plant parts of L. leucocephala, including its flowers. L-Mimosine is toxic to herbivorous mammals and insects, parasitic nematodes, pathogenic fungi, and neighboring competing plant species by inactivating various essential enzymes and blocking DNA replication, and/or inducing oxidative stress conditions. Several flavonoids, polyphenolic compounds, and/or derivatives of benzoic and cinnamic acids are toxic to parasitic nematodes, pathogenic fungi and bacteria, and competing plant species by disrupting plasma membrane structures and functions, and various metabolic processes. These compounds may represent the invasive traits of L. leucocephala that have undergone natural selection during the evolution of the species. They may contribute to the defense functions against the biotic stressors, and increase its survival, distribution, and abundance in the introduced ranges. This is the first review to focus on the compounds involved in the defense functions against biotic stressors. Full article

Invasive alien plant species, while ecologically and economically problematic, represent an underutilized source of bioactive phytochemicals with promising phytopharmaceutical applications. This study investigates the LC-DAD-MS phenolic profiles of 70% ethanol and 80% methanol leaf and flower extracts of Ailanthus altissima (Mill.) Swingle and Helianthus tuberosus L., collected in the Istria region of Croatia, alongside their antioxidant capacities using ABTS, DPPH, and FRAP assays. Both species exhibited high levels of flavonoids and phenolic acids, with consistently higher concentrations in leaf versus flower tissues and in ethanolic versus methanolic extracts. Strong correlations (r > 0.9) between total phenolics and antioxidant activity confirmed the functional significance of these compounds. With a targeted metabolomics approach, in A. altissima, 51 phenolics were identified in leaves and 47 in flowers, with ellagitannins predominating; vescalagin isomers reached 94 mg/g DW in leaves and 82 mg/g DW in flowers. H. tuberosus extracts contained 34 phenolics in leaves and 33 in flowers, with hydroxycinnamic acids and flavonols dominating; 5-caffeoylquinic acid was the principal compound (25 mg/g DW in leaves, 2 mg/g DW in flowers). The identified phytochemicals are known for their potent antioxidant, anti-inflammatory, anticancer, antimicrobial, and metabolic-regulating properties. Additionally, four leaf-specific compounds were identified in each species, indicating potential for targeted extraction. These findings advance the phytochemical characterization of invasive taxa and highlight their potential as sources of natural antioxidants for functional food and pharmaceutical development. Full article

Biological invasions are one of the main causes of biodiversity loss globally, affecting the quality of ecosystem services, the economy, and public health. Research on the presence, distribution, impacts, and introduction pathways of invasive alien species is essential for understanding and tackling the invasion process. Continental, coastal, and marine aquatic ecosystems of the Yucatan Peninsula concentrate a high number of native species; however, the states that are in the region (Campeche, Yucatan, and Quintana Roo) also have the largest loss of natural capital at the national level. The presence of aquatic invasive species has contributed to this downward trend, mainly in protected areas. For this research, an analysis of the national biodiversity information system, the global biodiversity information facility, and the specialized scientific literature was carried out to determine the presence of aquatic invasive species within the protected areas of the Yucatan Peninsula and adjacent marine zone. The results indicated that there are 22 documented aquatic invasive species in 25 protected areas, which were classified into the following taxonomic groups: marine macroalgae (3 species), plants (2), inland and marine fish (11), crustaceans (2), mollusks (2), and hydrozoans (2). A total of 15 of these species had a very high invasiveness score, 6 had a high score, and 1 had a medium score. This research will be useful in strengthening regional public policy and guiding decision makers on the management of aquatic invasive species, mainly for those that are seriously affecting aquatic ecosystems, such as Pterygoplichthys disjunctivus and P. pardalis in freshwater protected areas and Pterois volitans in marine protected areas. Efficient management strategies will be a key element in the protection of biodiversity and ecosystem services, and for sustainable regional development. Full article

This study evaluated the floristic characteristics and ecological conditions of disturbed sites within the Baekdudaegan Protected Area by analyzing species occurrence and ecological indices according to the region and disturbance type. A total of 515 vascular plant species were recorded, including rare species, alien species, and Korean endemic plants. To assess ecological patterns, the Naturalization Index (NI), Urbanization Index (UI), and Sørensen similarity index were applied. The results showed that Mt. Seoraksan, Mt. Deogyusan, and Mt. Taebaeksan had relatively high NI and UI values, while Mt. Jirisan showed a comparatively low UI value. Among disturbance types, the hiking trail (HT) type, located in a high-altitude area with limited accessibility, also recorded lower values. Floristic similarity with reference ecosystems was higher in Mt. Jirisan, Mt. Deogyusan, and Mt. Taebaeksan, whereas Mt. Seoraksan exhibited the lowest similarity. The overall similarity between disturbance types was low, and the composition of plant species varied across disturbance types. These results suggest that differences in disturbance intensity, driven by the disturbance type and topographic conditions, influences the floristic composition. The findings of this study can serve as baseline data for developing site-specific restoration strategies for disturbed sites in the future. Full article

Invasive plants can significantly alter the composition and functioning of soil ecosystems, which in turn affects soil fauna such as microorganisms; mesofauna including mites, springtails, nematodes, and insects; and other invertebrates. We used clusters of three different tree species to investigate how they affect the composition of belowground soil nematode communities. The clusters included Acer negundo (L.) (an invasive, non-native species), Fraxinus excelsior (L.), and Alnus glutinosa (Gaertn.) (both as native representatives) in floodplain forest habitats of the Morava River. We investigated the families, genera, trophic groups, and functional guilds of soil nematodes in each tree cluster to assess the usefulness of nematodes as indicators of the impact of alien tree species on native communities. The study was complemented by measuring basic soil physico-chemical properties. The data show that nematode communities were not sensitive to A. negundo invasion, as clusters of invasive trees had similar nematode abundance, genus richness, diversity, family and genus composition, and trophic structure compared to species-specific clusters of two native tree species. A cumulative total of 96 nematode genera, belonging to 52 families, were recorded in the investigated floodplain forest sites. The most abundant families across all clusters were Alaimidae, Cephalobidae, Hoplolaimidae, and Rhabditidae for all tree clusters. Among the genera, Helicotylenchus, Pratylenchus, Paratylenchus (as obligate plant parasites), Filenchus, and Malenchus (as facultative plant parasites), as well as Acrobeloides, Eucephalobus, Plectus, and Rhabditis (as bacterivores), were the most dominant taxa. The measured soil properties did not differ significantly among tree species (p < 0.05). Nevertheless, redundancy analysis identified a significant correlation between soil moisture content and abundance of several nematode genera, nematode trophic groups, and functional guilds. The results indicate that the presence of invasive ash-leaved maple trees in the studied floodplain forests had no adverse effect on the diversity and functional structure of soil nematode communities. This study offers initial insights into nematode communities in Acer negundo invaded habitats, but further studies are needed to verify these findings. Full article