Search Results (66)

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

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

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

Disturbed ecosystems are particularly susceptible to biological invasions. Increasing freshwater salinization, caused by anthropogenic factors, can alter the phytoplankton community and favour newly arrived halotolerant species. This study investigates the halotolerance of four Nostocalean cyanobacterial species—the native to Europe, Aphanizomenon gracile, and alien Chrysosporum bergii, Cuspidothrix issatschenkoi, and Sphaerospermopsis aphanizomenoides—using monoculture experiments under varying NaCl concentrations. Additionally, we performed two microcosm experiments to explore shifts in biodiversity in freshwater phytoplankton communities sourced from artificial reservoirs and assess their susceptibility to cyanobacterial invasion under salinity stress. Results showed that all Nostocalean cyanobacteria were halotolerant under mild salinities (up to 1 g/L NaCl), with Chrysosporum bergii and Sphaerospermopsis aphanizomenoides demonstrating the most salt tolerance. In the microcosm experiment, changes in community composition were driven by the halotolerance of dominant groups. Water body 1, dominated by Bacillariophytina, reduced its biomass of phytoplankton at high salinity (5 g/L NaCl), while water body 2, dominated by Chlorophytina, remained stable regardless of disturbance. Both cyanobacteria successfully invaded both halotolerant and halosensitive communities, increasing their dominance as salinity rose. Our findings suggest that anthropogenic stressors such as freshwater salinization can alter the phytoplankton community and increase a competitive advantage to certain taxa, including widespread alien cyanobacteria, potentially promoting invasions and bloom formation. 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

Urban flora is a more and more interesting research subject, in light of the ongoing environmental change and biological homogenisation, since urban contexts are much more diversified that natural ones and, therefore, they offer much more colonisation possibilities to allochthonous species or unexpected refuges for endangered species. We have, therefore, added our own contribution by analysing the spontaneous vascular flora of 7 cities of the Emilia-Romagna Po Plain (northern Italy), one of the more culturally and economically developed areas in Europe. The global floristic list was 1305 species, spanning from 432 to 756 species in each individual city; 219 of them were constantly present in all cities examined. A notable richness in phytosociological classes (43 out of 75 known for the entire national territory) was observed. Therophytes were 35.4% of the spectrum, followed by hemicryptophytes, phanerophytes and geophytes. Eurasian and Mediterranean species dominated (average values 30 and 27%, respectively); exotic species were 26.8%, in line with the strong floristic pollution of Emilia-Romagna, with neophytes always prevailing over archaeophytes. Among neophytes, 44.8% came from the Americas and 26.2% from Asia. Some hydro-hygrophilous and halophilous species were found, owing to the presence of watercourses crossing the urban areas and coastal wetlands bordering one of the towns. The species new for the flora of Italy or Emilia-Romagna were 32, of which 24 were allochthonous. The species protected at a regional or national level were hardly present, which is normal in artificial environments. Despite the inevitable differences in exploration intensity and effort, this synthesis offers a picture of the contribution given by anthropogenic habitats to the global biological richness of the territory. Full article

The Mediterranean coasts are threatened by human activities that alter habitats structure and functionality, modifying vegetation and causing the loss of typical species. The definition of the conservation status of coastal habitats is essential to preserve these fragile environments through planned policies. This study aims to assess the conservation status of the habitats of community interest (sensu EEC Directive 43/92) through the analysis of biodiversity and correlating it with urbanisation. A total of 73 vegetation relevés were carried out, so allowing 13 revealing different habitats to be identified. The total plant species diversity per habitat was measured by means of the H-index, also used to assess naturalness (N), differently considering native, alien, and disturbance species. To correlate the N index with distance from urban centres, a statistical analysis was performed. The analysis showed the highest values of H⁺ were found in habitats 2240, 2110, 2260, and 2230, while lowest values were observed in habitats 2270* and 2240. The habitats 2270* and 2240, the closest to urban centres, have a lower naturalness score than habitats 1420, 2120, 2250*, and 2270*, where higher naturalness scores have been found and therefore lower levels of disturbance. The criteria and methods discussed in this study can be used in coastal management in order to identify the most sensitive habitats and implement an effective conservation strategy. Full article

Invasive alien plants (IAPs) pose a significant threat to island biodiversity and severely impact ecosystems. Understanding the species–area relationship and environmental determinants of growth forms for IAP species on subtropical islands is crucial for establishing an IAP’s early warning mechanism, enhancing island ecological management, and protecting the ecosystems of Fujian and other subtropical islands. The study identified significant species–area relationships for IAPs and different life-form plants (trees, shrubs, and herbs), with slopes of 0.27, 0.16, 0.15, and 0.24, respectively. The small island effect does not apply to all species. Isolation has little effect on species richness, and the IAPs on Fujian islands do not conform to the isolation effect in island biogeography. Landscape factors are the main determinants of IAPs and different life-form species richness, with area, shape index, and perimeter–area ratio being the three primary landscape factors. These environmental factors are closely related to habitat heterogeneity. Besides landscape factors, different life forms respond differently to environmental factors. Climate drives the species richness distribution of shrubs and herbs, while trees are mainly influenced by human activities. Overall, landscape, human disturbance, and climate jointly drive the distribution of IAPs, with landscape factors being the most significant. Full article

Although the effects of invasive alien plants on natural ecosystems are well known, the effects of specific plant species can vary across habitat types and disturbance intensity. This study was carried out to analyze the effects of Lantana camara on associated vegetation and soil physico-chemical properties at invaded and non-invaded sites across three different habitat types (forest edge, fallow land, and roadside) in central Nepal. We sampled 50 pairs of 5 m × 5 m (for shrub species) and 1 m × 1 m (for herbs species) plots at invaded and non-invaded sites in each habitat and recorded community variables for each species within the sampling plots for both wet (monsoon) and dry (pre-monsoon) seasons. Further, we collected soil samples from each quadrat and determined the soil physico-chemical properties. We recorded 137 species of flowering plants (119 from non-invaded and 97 from invaded plots) and classified them in accordance with life form/habit. In invaded sites, we found a significant decline in species diversity as indicated by the Simpson and Shannon diversity indices. Specifically, L. camara reduced the species richness, Simpson index, and Shannon diversity index by 36.84%, 11.84%, and 40.21%, respectively. Soil nutrients such as total nitrogen, soil organic carbon, and available phosphorus were significantly higher in invaded sites than non-invaded ones except for available potassium and soil pH. This study provided evidence that Lantana L. camara has a substantial impact on the understory plant community assemblage and the physico-chemical properties of soil. The results suggest that the protection of native plant community requires management of L. camara by implementing appropriate measures. Full article

Human landscape-transforming activities contribute to the global change in vegetation in different forms. Hunting is one of the most ancient human landscape-shaping activities. Feeders for hunting are particularly disruptive to vegetation. In the present study, we conducted a vegetation survey in these highly disturbed places. We investigated the vegetation dynamics over several years in the turkey oak–sessile oak zone, in two areas with different moisture and shade conditions (forest and clearing). Important background factors are the changes in precipitation and temperature. Our results confirm that weed infestation is detectable at bait sites over a long period. The seasonal changes in field weed vegetation, as well as the increase in the number and coverage of weed species at the end of summer, resulting from lifestyle characteristics, were generally detectable in all years and locations, especially in the case of open and more strongly degraded clearings. Meteorological factors played a role in the degree of weed infestation in each year. Degradation was more significant in drought years, while regeneration was also observed in wetter periods. At baits located in the clearing, we showed a positive correlation between the amount of summer precipitation and the total coverage of weed species, as well as between the average spring temperature and the coverage of certain weed species. With the drying of the climate, the disturbed areas are constantly losing their natural value, but wetter weather is not an automatic solution either. Considering that there are approx. 30,000 bait sites in the country, and they are used regularly and very intensively, they can serve as major infection hotspots for alien species in a network. Full article

Plant invasions threaten the biodiversity of islands, causing serious impacts on their ecosystems. To investigate the distribution patterns of invasive alien plants on subtropical islands, the environmental determinants of species richness, and the growth forms of invasive alien plants, this study analyzed the composition and origin of invasive alien plants on 77 islands in Fujian. The similarity in the distribution of invasive alien plants between islands was assessed using the UPGMA. Moreover, feature selection, best-subset regression, and variance decomposition were performed using 19 environmental variables characterizing climate, anthropogenic disturbance, and landscape/geography, as well as the species richness and growth forms of invasive alien plants. Through the analysis, the main environmental factors affecting the species richness and growth forms of invasive alien plants on the Fujian islands were identified. The results showed 142 species of invasive alien plants in 38 families and 102 genera on 77 islands in Fujian. Annual herbs constituted the most representative growth form of invasive alien plants and tropical America was the main origin of invasive alien plants. The distribution of invasive alien plants across the 77 islands in Fujian showed a high degree of similarity, suggesting a nested pattern in their distribution. The proportions of building and farmland area (BFA), island area (A), and maximum elevation (ME) were the main driving factors of species richness and growth forms for invasive alien plants. In particular, BFA played a key role in driving plant invasion. The results of this study can help establish an early warning mechanism for invasive alien plants and better implement island ecological management, which are important for the protection of subtropical island ecosystems. Full article

The Epidaurus UNESCO World Heritage site (EPD) is a famous archaeological area that is located in a small valley in the Peloponnese and receives more than 250,000 visitors annually. The study of the plant diversity of the site is in the framework of a continuous research project concerning archaeological areas of the Peloponnese and in the context of a project by the Ministry of Culture, Education and Religious Affairs of Greece that started during 2023 to study the biodiversity of the archaeological areas of Greece. The main aim of this study is the exploration and analysis of the plant species composition and diversity of the Epidaurus archaeological area, with an emphasis on endemic plants, on ruderal and alien taxa as well as on environmental and disturbance indicators and the cultural ecosystem services they provide. This study revealed a high species richness consisting of 446 plant taxa. Most of them are Mediterranean and widespread, ruderals and medium disturbance indicators, but there are also 12 Greek endemic taxa. The richest in the taxa families are Asteraceae, Fabaceae and Poaceae. Therophytes predominate in the total flora registered and hemicryptophytes predominate in the endemics. Comparisons of the EPD’s plant diversity with other archaeological areas of Greece and the Mediterranean revealed its richness and unique character. Management and protection in archaeological areas such as the Epidaurus must focus on the sustainable conservation of their relationship with their natural environment. Full article

Grasslands differ in many types depending on the diversity of climatic conditions and substrates. Due to the great wealth of species found in semi-natural grasslands, they conserve an essential part of the biodiversity of the European Union (EEC 43/92), defined as habitats of community interest. Using the region of Calabria (southern Italy) as a case study, this study aims to evaluate how species assemblages and a set of indicators applied to them can be used to analyse and characterize the diversity, ecological features and conservation status of grassland habitats. Vegetation analysis was carried out using the phytosociological method, and habitat ecological characteristics were defined by Ellenberg’s ecological indicator adapted to the Italian flora. Multivariate analysis of the surveys by means of cluster analysis and Principal Components Analysis (PCA) made it possible to define eight habitat groups according to EEC Directive 43/92: 6110 Rocky or basophilous calcareous grasslands of the Alysso-Sedion albi, 6170 Alpine and subalpine calcareous grasslands, 6220*a Pseudo-steppe with grasses and annuals of the Thero-Brachypodietea dominated by a Lygeum spartum, 6220*b Pseudo-steppe with grasses and annuals of the Thero-Brachypodietea dominated by Hyparrhenia hirta, 6210* Semi-natural dry grasslands and scrub facies on calcareous substrates (Festuco-Bromometalia) (*important orchid sites), 6230* Species-rich Nardus grasslands, on siliceous substrates in mountain areas (and submountain areas, in Continental Europe), 6410 Molinia meadows on calcareous, peaty or clayey-siltladen soils (Molinion caeruleae), 6420 Mediterranean tall humid herb grasslands of the Molinio-Holoschoenion, 6430 Hydrophilous tall herb fringe communities of plains and of the montane to alpine levels. Temperature (T) and oisture (U) are the most statistically significant ecological factors in differentiating different habitat types. Analysis of diversity, assessed through Shannon and Evenness indices, showed that it is strongly correlated with habitat diversity as soil moisture increases. The study of ecological characteristics, correlated with biodiversity indices, helps to characterize grassland habitats, providing guidance for the implementation of active conservation policies for these habitats. Full article

The emergence of multidrug-resistant (MDR) microorganisms combined with the ever-draining antibiotic pipeline poses a disturbing and immensely growing public health challenge that requires a multidisciplinary approach and the application of novel therapies aimed at unconventional targets and/or applying innovative drug formulations. Hence, bacterial iron acquisition systems and bacterial Fe^2+/3+-containing enzymes have been identified as a plausible target of great potential. The intriguing “Trojan horse” approach deprives microorganisms from the essential iron. Recently, gallium’s potential in medicine as an iron mimicry species has attracted vast attention. Different Ga³⁺ formulations exhibit diverse effects upon entering the cell and thus supposedly have multiple targets. The aim of the current study is to specifically distinguish characteristics of great significance in regard to the initial gallium-based complex, allowing the alien cation to effectively compete with the native ferric ion for binding the siderophores pyochelin and pyoverdine secreted by the bacterium P. aeruginosa. Therefore, three gallium-based formulations were taken into consideration: the first-generation gallium nitrate, Ga(NO₃)₃, metabolized to Ga³⁺-hydrated forms, the second-generation gallium maltolate (tris(3-hydroxy-2-methyl-4-pyronato)gallium), and the experimentally proven Ga carrier in the bloodstream—the protein transferrin. We employed a reliable in silico approach based on DFT computations in order to understand the underlying biochemical processes that govern the Ga³⁺/Fe³⁺ rivalry for binding the two bacterial siderophores. Full article

Forests are important ecosystems that face threats from climate change and global environmental shifts, with invasive alien plant species being a significant concern. Some of these invasive species have already become established, while others are in the process of naturalisation. Although forests are a relatively stable ecosystem, extreme weather events increase their vulnerability to change, and clearings left after natural disturbances are particularly susceptible to invasion by alien plant species (IAPS). We created risk maps of two species that have spread rapidly in the last decade: American pokeweed (Phytolacca americana) and the tree of heaven (Ailanthus altissima). We prepared a generalised linear model based on the occurrence data collected within the LIFE ARTEMIS project. Eleven environmental variables were used to determine habitat characteristics. We constructed two models for each species: one covering the entirety of Slovenia and the other specifically for the forested areas in Slovenia, with the latter incorporating forest-specific variables (such as forest sanitation felling and monocultures). We observed the presence of both species at lower altitudes and in close proximity to water sources. American pokeweed tends to occur nearer to railways, while the presence of the tree of heaven is associated with areas lacking carbonate parent material and influenced by land use patterns. In forested areas, the occurrence of American pokeweed is influenced by forest habitat characteristics, such as disturbances caused by extreme weather events or the prevalence of Norway spruce monocultures. In contrast, the occurrence of the tree of heaven is influenced by more general environmental variables, such as altitude and proximity to railways. Consequently, we have generated risk maps for the entirety of Slovenia and separately for forested areas, both of which indicate similar levels of risk, particularly for the tree of heaven. The risk map for American pokeweed highlights numerous vulnerable areas, especially forest edges, which are highly susceptible to invasion. Furthermore, there is a higher likelihood of this species occurring in areas that have undergone sanitation felling. This study suggests that the production of risk maps of IAPS could be improved by focussing on habitat types and taking into account habitat-specific variables. This approach could enhance the early detection and management of these invasive species. Full article