Search Results (415)

Asclepias syriaca L.is a perennial broad-leaved species native to North America. It has become established in many regions of Europe, and has spread with increasing rapidity in recent decades. Its reproductive behaviour allows this species to proliferate rapidly. The selected grasslands are located in the Carpathian Basin in Hungary, in the area of Kiskunság National Park, near Lake Kolon. In the framework of the research, in two consecutive years (2021 and 2022), and in two different seasons (spring and autumn), we examined the percentage cover of vascular plant species in the stands degraded by A. syriaca and the natural control (without A. syriaca), and their seasonal and interannual dynamics. Between the A. syriaca-degraded and natural control stands, there was no significant difference in the number of species in the spring and autumn of any of the examined years. Surprisingly, in the spring, the degraded stands were somewhat richer in vascular plant species. In autumn, the control stands had more vascular plant species, but to a lesser extent. The Shannon diversity was higher in the A. syriaca-dominated stands than in the control in all recording periods. Simpson diversity showed a similar pattern to Shannon diversity, with one exception in spring 2022. In the case of the social behaviour type, it can be clearly seen that the alien competitor (AC) species dominated in spring and autumn in both years in the stand dominated by A. syriaca. In the natural control stand, specialists (S) and competitors (C) dominated in both years and in both seasons. The negative effect of the invasive species on the number and diversity of species was presumably significantly reduced by the significant drying of the study area experienced in recent years. Full article

The number of alien species introduced into South Korea continues to increase over the years. In particular, several plants have been introduced as ornamentals. Ludwigia peploides, which is native to the Americas and Australia, is believed to have been planted as an ornamental aquatic plant called “water primrose” and “primrose”. It spread to natural ecosystems through rivers, and its distribution is gradually expanding in Suwon, Hwaseong, Busan, and Jeju. However, there has been no specific study on the ecological risk of L. peploides introduced into South Korea. This study, therefore, investigates the distribution status and ecological risks of L. peploides in South Korea through field surveys and allelopathic material analysis, as well as assessing abiotic risk factors. The distribution was confirmed at a total of 19 sites, with high-density mats of a single species forming along the water’s edge and on the water surface. The maximum distribution area was 13,922 m² in Chilgok Reservoir in Anseong. Stems and plant fragments transported along waterways were continuously forming colonies through vegetative propagation. When evaluating the overall risk, it is determined that L. peploides has a high potential to cause significant damage to the ecosystem if not managed promptly. Therefore, continuous monitoring is necessary to effectively manage and prevent the habitat expansion of L. peploides. The results of this study are expected to aid in the identification of the current distribution and potential ecological risks of L. peploides in South Korea, providing essential data for ecological risk assessment and the development of effective management strategies. Full article

Research Highlights: Environmental abiotic stressors generate secondary stresses in plants, such as osmotic and oxidative stresses, which negatively influence their normal growth, development, and metabolism. Research about other non-enzymatic components with antioxidant capacity has recently focused on polyphenols. However, their role as indicators of drought and shade tolerance in woody species leaves and roots has been poorly explored or was limited to leaves only. Background and Objectives: Under a scenario of increasing drought, understanding the seedling responses in terms of total polyphenols and their antioxidant activity, in particular at the fine root system level, may help to elucidate the native–alien species interaction. Materials and Methods: At the beginning of July, 5-month-old native Quercus robur and alien Quercus rubra seedlings were transferred indoors to the growth chamber and subjected to progressive soil drying for 21 days. Results: The decrease in soil water content was more pronounced for Q. robur (9%) than for Q. rubra (34% of field capacity). Leaf water potential significantly decreased over time in Q. robur but did not differ from the control in Q. rubra. The total polyphenol concentration in Q. robur was markedly lower in the leaves and significantly higher in the fine roots than in Q. rubra. For the leaves, both species showed markedly higher values if well-watered, and the values significantly decreased in response to drought only in Q. rubra. In contrast, the fine root values for both species were markedly higher if droughted and decreased significantly in time only in Q. robur. Differently from the polyphenol concentration, the antioxidant capacity of Q. rubra was always higher in both the leaves and fine roots. Conclusions: The higher antioxidant activity of the alien species Q. rubra revealed by this work, combined with its isohydric behaviour, could further shed some light on our understanding of its competitive performance at the seedling stage against the native Q. robur. Full article

Glossy buckthorn (Frangula alnus Miller) is an invasive alien plant species (IAPS) rapidly expanding in North America but is largely understudied compared to the common buckthorn (Rhamnus cathartica). Our study investigated the effects of a 27-year-old F. alnus invasion on native understory plant and saprophagous macroarthropod communities in a wet deciduous woodland in Southern Québec, Canada. We hypothesized a decreased taxonomic diversity and a change in community composition of both indicator taxa with increasing F. alnus density. The understory plant and saprophagous macroarthropod communities were characterized, respectively, through vegetation surveys and pitfall trapping across a density gradient of 43 plots invaded by F. alnus. Our results demonstrated that F. alnus did not exert a strong influence on species community composition, although the homogenization of understory plant communities was observed. Despite several decades of F. alnus invasion at our study site, the consequences on the selected indicator taxa were overall relatively small, suggesting that the magnitude of effects is variable. We suggest that further investigation at a larger scale should be performed to evaluate the effect of F. alnus on a broad diversity of indicators and understand any context dependency. Full article

The solanum fruit fly Bactrocera latifrons (Diptera: Tephritidae) is an invasive alien insect that causes huge economic losses to pepper and other solanaceous plant industries. It is mainly distributed in South and Southeast Asia, SW Europe, Western USA, and in some African countries. However, the potential global geographical distribution of B. latifrons is unknown. Therefore, in this study, based on the current (1981–2010) and future (2040–2059) climatic scenarios determined using the CNRM-CM5, Access1.0, GFDL-ESM-2M, and NorESM1-M models, we used a species distribution model (CLIMEX 4.0) to project the potential global geographic distribution of B. latifrons to prevent further invasion and harm. In the current climate scenario, South America (1286.06 × 10⁴ km²), Africa (1435.47 × 10⁴ km²), and Oceania (410.66 × 10⁴ km²) have the largest proportions of suitable land areas for B. latifrons colonization. Under all four future climate models, the global potential suitable area for Bactrocera latifrons is projected to decrease and shift towards higher latitudes. This study provides an important baseline upon which researchers, quarantine personnel, and governments can develop the appropriate control strategies against B. latifrons. Full article

Invasive plant species pose a significant threat to global biodiversity and ecosystems. Climate changes favor the spread of non-native plants, whether voluntary or accidentally introduced into a new environment, as these plants possess a greater ability to adapt to changing environments. The spreading of these alien species has a negative impact also on agro-ecosystems, on agricultural yields, and on the nutritional quality of food crops. The high metabolic plasticity of these plants helps them to adapt to new ecosystems, enabling them to succeed in competing with crops. In particular, many alien plants are producers of alkaloids. These molecules represent the main chemical defense to biotic stressors and also the major risk for human health. In this review, we focused on invasive plants producing tropane alkaloids (TAs) and pyrrolizidine alkaloids (PAs). We explored the potential role of these molecules in the fitness of invasive plants in the context of climate change and reviewed the knowledge regarding their biosynthesis steps and examined the mechanism of toxicity when accidentally ingested. Finally, we summarized the most efficient analytical and molecular methods to detect either alkaloid contamination or the presence of invasive plant contaminants, which are the source of these molecules, in food crops. Possible solutions and precautions to ensure food safety have been also proposed. 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

Argemone ochroleuca Sweet is an alien invasive weed dominating most cultivated lands, however, the phytochemicals present in this plant and the effects of these on the germination and growth of economically important crops such as maize are not well-documented. The objective of the study was to characterize the phytochemistry of the shoots and roots of A. ochroleuca and determine whether the extracts could inhibit the germination of maize seeds. The shoots and roots of A. ochroleuca were extracted in water, hexane, and acetone. Ten maize seeds were used in the germination bioassay. A phytochemical analysis was conducted using gas chromatography-mass spectrometry (GC-MS). The effects of the A. ochroleuca water, hexane, or acetone extracts on maize seed germination were concentration and plant-part dependent. The highest reduction was recorded from the water extract with 82%. Identified compounds with high percentages in A. ochroleuca were 9,12-octadecadienoic acid (Z,Z) and 9,12,15-octadecatrienoic acid, (Z,Z,Z)-. The present study indicated that A. ochroleuca extracts suppress the germination of maize seeds, likely due to the presence of both the identified and potentially unidentified phytochemicals that were not detected by the selected method. There is, however, a need to establish the relationship between the phytochemical compounds and the enzymes responsible for germination. Full article

Being an alien species, Spartina alterniflora has occupied the living space of native animals and plants, causing irreversible damage to the environment. Converting Spartina alterniflora into carbon or its derivatives offers a valuable solution to manage both invasive biomass and an energy shortage. Herein, through a simple activation process, we successfully prepared Spartina alterniflora-derived carbon (SAC) and its N-doped derivative SANC, and used them as metal-free catalysts for an oxygen reduction reaction (ORR). SAC exhibits good electrochemical performance and holds significant potential in catalysis. After N-doping by melamine as a nitrogen source, electronegativity is redistributed in SANC, leading to enhanced performance (a half-wave potential of 0.716 V vs. RHE, and a four-electron transfer pathway with a H₂O₂ yield of only 2.05%). This work presents a straightforward and cost-effective approach to the usage of obsolete invasive biomass and shows great potential in energy generation. Full article

Understanding population genetic structure and its possible causal factors is critical for utilizing genetic resources and genetic breeding of economically important plants. Although Torreya grandis is an important conifer producing nuts in China, little is known about its population structure, let alone the causal factors that shaped its genetic variation pattern and population structure. In this work, we intended to characterize the genetic variation pattern and population structure of the nut-yielding conifer T. grandis throughout its whole geographical distribution and further explore the potentially causal factors for the population structure using multiple approaches. A moderate level of genetic diversity and a novel population structure were revealed in T. grandis based on eleven robust EST-SSR loci and three chloroplast fragments. Alien genetic composition derived from the closely related species T. nucifera endemic to Japan was detected in the Kuaiji Mountain area, where the seed quality of T. grandis is considered the best in China. Demography history and niche modeling were inferred and performed, and the contribution of geographic isolation to its population structure was compared with that of environmental isolation. Significant demographic changes occurred, including a dramatic population contraction during the Quaternary, and population divergence was significantly correlated with geographic distance. These results suggested that early breeding activities and demographic changes significantly contributed to the population structure of T. grandis. In turn, the population structure was potentially associated with the excellent variants and adaptation of cultivars of T. grandis. The findings provide important information for utilizing genetic resources and genetic breeding of T. grandis in the future. 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

This study investigates the potential of the dye extracted from the fruits of the alien invasive plant staghorn sumac (lat. Rhus typhina) as a sustainable and environmentally friendly colorant. By using a range of solvents, including distilled water, methanol, ethanol, propanol, acetonitrile, acetone, and dichloromethane, this study aims to determine the optimum solvent for the extraction of anthocyanin dyes from the fruit of staghorn sumac for the formulation of printing inks and for screen printing on paper and cotton fabric. The colors of the prints made with different dye extracts varied between more or less intense brownish-yellow hues, with the exception of the dye extracts in methanol and ethanol, which gave more brownish-orange hues. All prints showed excellent resistance to rubbing on cotton fabrics as well as to wet ironing. The light fastness of prints made with inks containing dyes extracted from all organic solvents was very good. Good wash fastness of prints on cotton fabrics was only achieved with inks made with dyes extracted in propanol and dichloromethane. The ink made from the dye extracted in propanol proved to be the best choice for printing on cotton fabric due to its uniform, intense, and resilient prints, while the inks made from the dyes extracted in distilled water and ethanol were also a good choice for printing on paper. Full article

Buttonweed (Cotula coronopifolia) is native to South Africa but invasive in wetlands in Europe, North America, and Australasia, where it excludes native plants. Despite being dry-fruited, field studies suggest migratory waterbirds can disperse its seeds via gut passage (endozoochory), aiding its expansion. To explore the potential for endozoochory in different regions and habitats, we collected seeds from six populations in Spain, Sweden, and the UK. Germination was tested under different salinity levels (0, 5, 10, 15 g/L) and simulated gut passage treatments: scarification, acidification, or both. No germination occurred at 15 g/L. Higher salinity reduced and delayed germination, but full gut passage treatment (i.e., both scarification and acidification) increased germinability and accelerated germination. Scarification or acid treatment alone resulted in intermediate germination patterns. There were significant salinity × population and gut passage × population interactions on germinability. The acceleration effect of gut passage on germination was stronger at 5–10 g/L than at 0 g/L. This study highlights how migratory birds can facilitate the spread of alien plants introduced by humans. Endozoochory by waterbirds is an understudied mechanism for the long-distance dispersal of dry-fruited alien plants. Further research on C. coronopifolia, including population genetics, is necessary to understand dispersal mechanisms and facilitate management strategies. Full article

Urban protected biodiversity areas conserve some of the world’s critically endangered and isolated biodiversity while providing essential ecosystem services. However, these urban habitats are threatened by the presence of alien and invasive plants. We studied alien plant species richness and identified the potential predictors in urban protected biodiversity areas in Tshwane Metropolitan Municipality, South Africa. Data on alien plant species were collected through surveys and consultations with protected area managers. We determined the relationship between the observed species richness and potential alien plant species predictors, such as area size, number of visitors, proximity to residential areas, and the year the reserve was proclaimed. We documented 574 records of 189 alien plant species from 60 families across 14 protected areas. Phanerophytes were the most common (46.5%), with many species native to South America, North America, and Africa. Most species have formed naturalised populations (67.7%), followed by invasive populations (20.6%) and casual populations (12%), posing future invasion threats. Most species (55.5%) were introduced as ornamental plants, with many of these species forming invasive populations. Half the recorded species were listed under the NEM:BA A&IS regulations, mostly categorized as 1b. Our findings indicate that the annual number of visitors strongly predicted alien plant species richness in urban protected areas. Additionally, a significant negative correlation was observed between species richness and the proximity to residential areas and years since the proclamation. Understanding the distribution patterns and predictors of species richness is crucial in monitoring invasive alien species and conserving biodiversity in urban environments. Full article