Search Results (96)

Vegetation in residential areas plays a crucial role in biodiverse and sustainable cities as it enhances biological diversity, environmental quality, and the human well-being of city residents. However, the distribution of vegetation among these areas is often unequal, leading to disparities in access to its benefits. To promote a more biodiverse and environmentally just city, we investigated how woody plants (trees, shrubs and vines) vary with socioeconomic level in residential streetscapes of Santiago de Chile. Across the city, we sampled woody plants in 120 plots (11 m radius) located in residential streetscapes of three socioeconomic levels: low, medium, and high. A total of 557 woody plants were identified and measured. Of these, only 9.7% corresponded to native species, whereas 90.3% were introduced species. Wealthier residential areas had higher species richness and abundance of woody plants, as well as plants with greater structural size (revealed by height and crown area). In addition, we found that the composition of woody plants differed among socioeconomic levels: Liquidambar styraciflua, Platanus x hispanica, and Pittosporum tobira were more abundant in high socioeconomic areas; Prunus cerasifera, Citrus limon, and Ailanthus altissima were more abundant in medium socioeconomic areas; Robinia pseudoacacia, Acer negundo, and Schinus areira were more abundant in low socioeconomic areas. Our research highlights that woody plant diversity, abundance, structure, and composition vary with socioeconomic level in residential streetscapes. Key insights for reducing these inequalities and achieve a more environmentally just city include: (a) governance and equity-based investment; (b) prioritizing local native species; (c) promoting the use of non-tree woody plants; and (d) empowering communities through capacity building and stewardship. Full article

Ailanthus altissima (tree of heaven) is among the most abundant and widespread neophytic plants in Austria. The pollen season of Ailanthus usually ranges from the beginning of June until the mid of July, showing one peak period around the mid of June in Vienna (Austria). Over a span of 48 years (1976–2023), pollen data of Ailanthus was gathered from aerobiological samples and assessed for a temporal trend. In addition, weather data from Vienna (temperature, precipitation, relative humidity and sun hours) was incorporated to find possible associations with Ailanthus pollen indices. The change in the pollen season for Ailanthus described in this study has already manifested and is ongoing. Temperature and sunshine hours have a direct impact on the flowering of urban trees, indicating that global climate change may be a major driver towards more intense pollen and allergy seasons. Full article

Eurydema ventralis has recently intensified in Brassica production in Central and Southeastern Europe, increasing the need for alternatives to conventional insecticides. This laboratory study evaluated five locally sourced inert and plant-derived dusts on the mortality and feeding damage of E. ventralis adults and nymphs. The tested materials were diatomaceous earth, zeolite, quartz sand, wood ash of Norway spruce and Ailanthus altissima leaf dust, compared with an untreated control and a lambda-cyhalothrin control. Mortality and feeding damage were recorded over seven days. The insecticide caused complete mortality in both developmental stages. Diatomaceous earth exhibited the highest efficacy among inert dusts, i.e., 78.3% mortality in adults and 55.2% in nymphs, and a feeding damage index of 3.5. Zeolite and wood ash caused moderate mortality (30.4 and 26.1% in adults; 37.9 and 24.1% in nymphs) and feeding indices of 4.5 and 4.5. A. altissima leaf dust caused low mortality (≤14.5%) but reduced feeding damage (3.7), indicating a deterrent or antifeedant effect. Quartz sand showed negligible efficacy. Diatomaceous earth appears most suitable for integration into sustainable Brassica protection, and A. altissima leaf dust may act as a complementary deterrent, though optimized composition and persistence should be further investigated. Full article

In order to tackle the problems caused by invasive alien plant species, it is important to know what the main groups that have the largest influence on the spreading of the species, know and think about them. Nation-wide questionnaire surveys were carried out in Hungary between 2016 and 2019 among three important stakeholder groups (local governments, national park directorates (NPDs), and state forestry units (SFUs)) of tree of heaven (Ailanthus altissima). The aim of the surveys was to reveal the perception of the three groups about Ailanthus altissima, their experiences with eradication, and other needs for its successful management of the species. Besides basic statistical methods, the chi² test, Fisher’s exact test, Cramer’s V value, and Mann–Whitney U test were conducted to compare groups and reveal relationships between different variables. 221 local governments, 10 NPDs, and 110 SFUs filled in the questionnaire. The response rate was quite low for local governments (8.8%) and high for NPDs (100%) and SFUs (97.5%). Our findings show that the species was recognised by only 59% of respondents representing local governments. Further results are presented regardingthis subsample.The negative impacts of Ailanthus altissima were perceived in all three groups at a higher rate (over 95% in all three groups) than positive impacts (local governments: 63%, NPDs: 10%, SFUs: 35%). The two groups managing forest areas (NPDs and SFUs) ranked the problems caused by the species high (the median was −4 for both groups on a −5–+5 scale). Ailanthus altissima was present in the areas of at least 80 percent in each examined group. In areas where the species was present, eradication was applied in a significantly higher percent of NPDs (86%) and SFUs (88%) than regarding local governments (36%), and the same tendency was found for using mechanical and chemical methods (p < 0.05). The two groups managing forest areas also applied biological methods, although at a lower rate (NPDs: 10%, SFUs: 14%). The unit costs and area of eradication varied between NPDs and SFUs, but the difference was not significant between the two groups (p = 0.073 and 0.213, respectively). NPDs used more external funding for eradication than local governments and state forestry units, mostly co-financed by European Union funds (e.g., LIFE and European Regional Development Fund). Information was required by a large percentage of respondents from local governments (75% of those who recognised the species). The need for cooperation between stakeholder groups was indicated by 78% of local governments recognising the species, and was ranked high by the two expert groups as well (medians were 4 for NPDs and 5 for SFUs on a 0–5 scale). Sharing knowledge about and experience with eradication among the two expert groups and transferring knowledge to the local governments are recommended for the successful management of the species. Further research is needed regarding the effectiveness, the environmental impacts, and the costs of eradication, as well as influencing factors. Full article

The availability of phosphorus in the soil has a key role in plant physiological processes, particularly in the adaptive responses of invasive species. This study examined how contrasting soil phosphorus concentrations (low: 9 mg/kg and adequate: 27 mg/kg) influence biomass production, lignin and extractive content, P concentration in leaves, and root exudate composition in two invasive species, Ailanthus altissima and Fraxinus americana. Seedlings were grown in rhizoboxes filled with alkaline soils of two types. Adequate phosphorus concentration increased both aboveground and root biomass in the examined species, while low phosphorus significantly reduced biomass, especially in the aboveground parts, which were 3 to 4 times smaller compared to plants grown under adequate conditions. Low phosphorus concentration increased lignin and extractive content in the stem. Root exudate analysis revealed that low phosphorus availability enhanced the secretion of malate in both species. Ailanthus altissima exhibited higher malate concentrations in root exudates compared to Fraxinus americana under both phosphorus conditions. Ailanthus altissima is more competitive than Fraxinus americana on low-phosphorus alkaline soils. The results reveal how Ailanthus altissima and Fraxinus americana adapt to varying soil phosphorus levels, aiding the development of strategies to manage these invasive species and preserve ecosystem stability. Full article

Invasive non-native plant species are of ecological concern globally, as they may negatively affect biodiversity, the economy, and human health. At the same time, invasive non-native plants comprise an underutilised biomass that contains valuable natural bioactive compounds, which could find various biomedical applications and potential medicinal uses. In this paper, we aimed to systematically review the published data surrounding four selected invasive non-native plant species in a medical and therapeutic context. The search was conducted using PubMed and PRISMA guidelines, and strict criteria were employed to provide a thorough framework for the study selection process. After rigorous screening of the 53 selected articles, we were able to summarise the main findings and current knowledge regarding the valorisation opportunities for the selected plants in a medical context and to identify research gaps and highlight further research opportunities. Finally, we concluded that the selected invasive non-native plant species may provide valuable services in the biomedical field if the focus of future research is concentrated on their potential applicability in clinical settings. Furthermore, the valorisation of invasive non-native plant species may prove to be a viable strategy for controlling their spread. Full article

Two new very-long-chain 5-n-alkylresorcinol (AR) homologues, that is, 5-n-nonacosylbenzene-1,3-diol and 5-n-hentriacontylbenzene-1,3-diol, were isolated from acetone extracts of Ailanthus altissima samaras. These phenolic compounds were detected in nearly equal proportions, although their total content varied considerably between samples from urban-grown trees. No correlation was observed between AR levels and the physiological state of the tree, suggesting that environmental conditions may strongly influence AR biosynthesis in A. altissima. Furthermore, the isolated AR mixture exhibited antifungal activity against soil-borne phytopathogens of the genera Fusarium and Rhizoctonia. Full article

Ailanthus altissima (AA) is an invasive tree species rapidly spreading worldwide, colonizing both urban and agricultural or forestry environments. This three-year study aimed to assess its effects on the growth and yield traits of the Koroneiki olive cultivar under co-cultivation in pots, combined with two irrigation regimes, full and deficit irrigation (60% of full). Within each irrigation regime, olive trees were grown either in the presence or absence (control) of AA. The trial evaluated several parameters, including vegetative growth, yield traits, and oil quality characteristics. Co-cultivation with AA had no significant impact on tree growth after three years, though it significantly reduced oil content per fruit. Antioxidant capacity of the oil improved under deficit irrigation, while AA presence did not significantly affect it, except for an increase in o-diphenol concentration. Neither the fatty acid profile nor squalene levels were significantly influenced by either treatment. Fruit weight and color were primarily affected by deficit irrigation. During storage, olive oil quality declined significantly, with pre-harvest treatments (presence or absence of AA and full or deficit irrigation regime) playing a critical role in modulating several quality parameters. In conclusion, the presence of AA near olive trees did not substantially affect the key quality indices of the olive oil, which remained within the criteria for classification as extra virgin. Full article

Since its introduction into the USA, the spotted lanternfly (SLF), Lycorma delicatula, (White) (Hemiptera: Fulgoridae) has spread across the landscape relatively unchecked. With a wide host range, it is considered a serious pest of native forest species, as well as agricultural crops. Circle traps placed on Ailanthus altissima (Miller) Swingle (Sapindales: Simaroubaceae) are passive traps collecting SLF as they walk up and down the tree trunk. These traps are successful at detecting new populations of SLF, but this can be challenging to implement at a large scale due to costs and host availability. To improve and facilitate SLF trapping practices, we investigated three key trapping components: improved collection containers, placement on alternative hosts, and lure (methyl salicylate) impact. In initial trials comparing collection jars to removable plastic bags, the adult SLF catch was four times higher using the bag design. In a multi-state survey at varying population densities, the bag traps were comparable to the jar traps but were significantly more effective than BugBarrier^® tree bands, especially during the adult stage. Catch and detection in circle traps placed on alternative hosts, Acer spp. L. (Sapindales: Sapindalaceae) and Juglans nigra L. (Fagales: Juglandaceae), were comparable to those placed on the preferred host A. altissima, especially in the earlier life stages. Additionally, detection rates of methyl salicylate-baited traps on all three hosts were comparable to those on non-baited traps. These results suggest that circle traps fitted with bags provide higher trap catch and an improvement in sample quality. In addition, circle traps were equally effective when placed on maple and black walnut, while methyl salicylate lures do not enhance trap catch or detection. Full article

Citizen science data are easily accessible, which has led to their wide use for scientific data collection such as mapping invasive plant species. However, the crowd-sourced nature of citizen science data has led to criticism over the quality of the data owing to the fragmented spatial distribution of the data collection points. Despite inherent limitations, an increasing collection of research indicates that, when appropriately corrected for data quality issues, the data collected by volunteers can serve as a reliable source for identifying and analysing biodiversity patterns. Prior to utilising citizen science data, it is essential to identify its inherent flaws and limitations to develop appropriate strategies for its effective application. One viable approach to validating such data is to compare it with datasets collected by experts, particularly in urban areas where volunteer participation is high. In our comparative analyses, we evaluated the usability of citizen science data (Global Biodiversity Information Facility (GBIF)) for mapping the occurrence density of five invasive plant species (Ailanthus altissima, Asclepias syriaca, Elaeagnus angustifolia, Robinia pseudoacacia, and Solidago spp.) in urban cores and fringes in Hungary by comparison to maps obtained from spatially homogeneous data (EUROSTAT Land Use and Coverage Area Frame Survey (LUCAS)) collected by experts. The results showed that the volunteers collected valuable data on Ailanthus altissima, which is specific to urban areas, but they underestimated Robinia pseudoacacia, which is often planted for economic benefits. In addition, the volunteers collected much more data closer to urban cores. These results suggest that citizen science data may be suitable for mapping urbanophilic species in urban environments. Our research contributes to the assessment and scientific applicability of volunteer-collected data for mapping the distribution of invasive plant species. Full article

Invasive bacteria have caused tremendous losses to global ecosystems and agricultural production, yet effective control measures remain elusive. Plant specialized metabolites are being investigated as an important source of antimicrobial active substances. And Ailanthus altissima is an abundant tree widespread throughout Northeast China. In this study, we identified 21 compounds from A. altissima leaves, including steroids, terpenes, phenolics, and coumarins. Two new steroidal compounds, ailanstigol A (1) and ailanstigol B (2), and one new coumarin (2′R,3′R)-7-(2′,3′,6′-trihydroxy-3′-methylhexyloxy)-6,8-dimethoxycoumarin (3) were isolated. Antibacterial screening revealed that compounds 1 and 2 exhibited inhibitory activity against two invasive bacteria, Xanthomonas oryzae pv. oryzae PXO 71A and PXO 86A and Pseudomonas syringae pv. maculicola ES4326. Further mechanistic screening unveiled that the steroidal compounds 1 and 2 may inhibit bacterial growth and reproduction by reducing cell viability, disrupting the cell membrane and increasing protein leakage, and inhibiting biofilm formation. In summary, our results enriched the known chemical diversity of A. altissima and provided a foundation for investigating the mechanisms by which steroidal compounds inhibit invasive bacterial growth. 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

This study was conducted at a fixed monitoring site in the southern dump of the large-scale Antaibao open-pit coal mine of China Coal Pingshuo, using long-term monitoring methods. Based on data from 2019 and 2024 in the reclaimed area of the Pingshuo open-pit coal mine, all seedlings and saplings within the Robinia pseudoacacia L. + Ulmus pumila L. + Ailanthus altissima (Mill.) Swingle mixed forests were studied to analyze changes in their abundance and the driving factors influencing their survival rates from 2019 to 2024. The main conclusions are as follows: (1) The species composition of seedlings and saplings remained unchanged but the number of seedlings increased significantly. The majority of newly recruited seedlings were U. pumila., accounting for 92.22% of the total new seedlings, whereas R. pseudoacacia had the highest mortality rate among seedlings. The distribution patterns of seedling-to-sapling transition, sapling-to-tree transition, and seedling–sapling mortality were generally consistent with the overall distribution of seedlings and saplings at the community level. (2) At both the community and species levels, the optimal models for seedling and sapling survival were the height model and the biological factor model. Overall, survival rates of both seedlings and saplings showed a significant positive correlation with height. (3) The biological factors affecting the survival of U. pumila saplings were the basal area (BA) at breast height and the number of conspecific adult trees. The former was significantly negatively correlated with U. pumila seedling survival, while the latter was positively correlated. For R. pseudoacacia seedlings, the key biological factors were the number of heterospecific adult trees and the number of heterospecific seedlings. The former was significantly negatively correlated with survival, whereas the latter was significantly positively correlated. The primary factor influencing sapling survival was sapling height, which showed a significant positive correlation. Full article

Invasive species negatively affect ecosystems, economies, and human health by outcompeting native species and altering habitats. Ailanthus altissima, also known as the tree of heaven, an invasive species native to China that has spread to North America and Europe. Commonly found in urban areas and forestland, these invasive plants cause ecological and economic damage to local ecosystems; they are also the preferred host of other invasive species. Ecological stability refers to the balance and harmony in species populations. Invasive species like A. altissima disrupt this stability by outcompeting native species, leading to imbalances, and there was a lack of research and data on the tree of heaven. To address this issue, this study leveraged deep learning and satellite imagery recognition to generate reliable and comprehensive prediction maps in the USA. Four deep learning models were trained to recognize satellite images obtained from Google Earth, with A. altissima data obtained from the Life Alta Murgia project, LIFE12 BIO/IT/000213. The best performing fine-tuned model using binary classification achieved an AUC score of 90%. This model was saved locally and used to predict the density and probability of A. altissima in the USA. Additionally, multi-class classification methods corroborated the findings, demonstrating similar observational outcomes. The production of these predictive distribution maps is a novel method which offers an innovative and cost-effective alternative for extensive field surveys, providing reliable data for concurrent and future research on the environmental impact of A. altissima. Full article

The bioactivity of the Ailanthus altissima crude leaf extract (CLE) and a leaf extract incorporated into a biopolymer matrix (BPM) was tested against Lymantria dispar larvae. The crude leaf extracts and those incorporated into a chitosan–gelatin polymer matrix were examined in choice and non-choice assays at 0.01, 0.05, 0.5, and 1% concentrations for feeding deterrent activity, contact, and digestive toxicity. The CLE exhibited moderate deterrent activity at all concentrations, whereas the BPM showed a very strong deterrent effect at 0.5% and 1% and a strong effect at 0.1% and 0.01%. No significant differences in digestive or contact toxicity were observed between the CLE and BPM groups and the control groups. The BPM also influenced larval behavior after digestion, decreasing consumption and growth and increasing development time. The higher bioactivity of the CLE compared to the control group is attributed to its high content of total phenols, flavonoids, and tannins, whereas the enhanced bioactivity of the BPM is due to its incorporation into the biopolymer matrix. Given its very strong deterrent activity, and absence of contact and digestive toxicity, the BPM can be recommended as a potential environmentally friendly bioproduct for forest pest control after field evaluation. Full article