Search Results (419)

The role of rhizosphere bacteria in facilitating plant invasion is increasingly acknowledged, yet the influence of specific microbial functional traits remains insufficiently understood. This study addresses this gap by isolating two bacterial strains, Bacillus sp. ScRB44 and Pseudomonas sp. ScRB22, from the rhizosphere of the invasive weed Solidago canadensis. We assessed their nitrogen utilization capacity and indoleacetic acid (IAA) production capabilities to evaluate their ecological functions. Our three-stage experimental design encompassed strain promotion, nutrient stress, and competition phases. Bacillus sp. ScRB44 demonstrated robust IAA production and significantly improved the nitrogen utilization efficiency, significantly enhancing S. canadensis growth, especially under nutrient-poor conditions, and promoting a shift in biomass allocation toward the roots, thereby conferring a competitive advantage over native species. Conversely, Pseudomonas sp. ScRB22 exhibited limited functional activity and a negligible impact on plant performance. These findings underscore that the ecological impact of rhizosphere bacteria on invasive weeds is closely linked to their specific growth-promoting functions. By enhancing stress adaptation and optimizing resource allocation, certain microorganisms may facilitate the establishment of invasive weeds in adverse environments. This study highlights the significance of microbial functional traits in invasion ecology and suggests novel approaches for microbiome-based invasive weed management, with potential applications in agricultural soil health improvement and ecological restoration. Full article

Common ragweed, Ambrosia artemisiifolia (Asteraceae), is an invasive weed that causes problems in cropping systems and to human health both in its native range in North and Central America and the introduced range in Europe, Asia, Africa, and Australia. Ophraella communa, an herbivorous chrysomelid beetle from North America, was accidentally introduced into East Asia and Europe, where it significantly reduces weed populations and pollen production. Despite extensive research on its host specificity and risk assessment, the potential environmental risk of this biological control agent in southeastern Central Europe, one of the most heavily invaded areas by A. artemisiifolia, remains to be determined. This literature review attempts to summarize the results of host-range testing conducted so far and identifies plant taxa native to southeastern Central Europe that have not been tested yet. The results suggest that the host range of O. communa is not yet entirely clear, but may include some plant species from the tribes Heliantheae, Inuleae, Anthemideae, Cardueae, Astereae, and/or Coreopsideae. So far, only some of the 21 genera from those tribes with species in southeastern Central Europe have been tested. We therefore suggest further host specificity studies with representatives of these plant genera to fully assess the potential non-target risks by O. communa in agricultural and natural habitats. Full article

Common ragweed (Ambrosia artemisiifolia L.) has been identified as one of the most harmful invasive weed species in Europe due to its allergenic pollen and competitive growth in diverse habitats. In the first part of this review [Common Ragweed—Ambrosia artemisiifolia L.: A Review with Special Regards to the Latest Results in Biology and Ecology], its biological characteristics and ecological behavior were described in detail. In the current paper, control strategies are summarized, focusing on integrated weed management adapted to the specific habitat where the species causes damage—arable land, semi-natural vegetation, urban areas, or along linear infrastructures. A range of management methods is reviewed, including agrotechnical, mechanical, physical, thermal, biological, and chemical approaches. Particular attention is given to the spread of herbicide resistance and the need for diversified, habitat-specific interventions. Among biological control options, the potential of Ophraella communa LeSage, a leaf beetle native to North America, is highlighted. Furthermore, innovative technologies such as UAV-assisted weed mapping, site-specific herbicide application, and autonomous weeding robots are discussed as environmentally sustainable tools. The role of legal regulations and pollen monitoring networks—particularly those implemented in Hungary—is also emphasized. By combining traditional and advanced methods within a coordinated framework, effective and ecologically sound ragweed control can be achieved. Full article

Sorghum halepense (L.) Pers. (common name Johnson grass) is a perennial invasive weed that causes great harm worldwide, and its allelopathy has been demonstrated in a series of experiments. The present study offers new insights into its organ-specific phytochemical profiles using state-of-the-art metabolomic technology and explores the effects of a methanol extract of S. halepense rhizomes (ShER) and its major bioactive compounds (p-hydroxybenzoic acid and chlorogenic acid) on three noxious weed species. The phytotoxic effects of ShER are reflected through the inhibition of seed germination and reduced seedling growth, which are accompanied by changes in the antioxidant system of seedlings. Phytotoxicity is species specific and concentration dependent, and it is more pronounced against Chenopodiastrum murale (L.) S. Fuentes, Uotila & Borsch and Datura stramonium L. than highly tolerant Amaranthus retroflexus L. Catalase (CAT) is most likely the major mediator in the removal of reactive oxygen species, which are generated during germination and early seedling growth of Ch. murale exposed to ShER. The results of the present study imply the high potential of ShER in the management of amaranthaceous and solanaceous weeds, such as Ch. murale and D. stramonium, respectively. The present study offers an environmentally friendly solution for the biological control of weeds belonging to the families Amaranthaceae and Solanaceae. Also, the results of this research highlight the possibility of effective management of S. halepense by using it as a feedstock for bioherbicide production. Full article

Phewa Lake, Nepal’s second-largest natural lake, is under increasing ecological stress due to sedimentation, shoreline encroachment, and water quality decline driven by rapid urban growth, fragile mountainous catchments, and changing climate patterns. This study employs an integrated approach combining sediment yield estimation from its catchment using RUSLE, shoreline encroachment analysis via satellite imagery and historical records, and identification of pollution sources and socio-economic factors through field surveys and community consultations. The results show that steep, sparsely vegetated slopes are the primary sediment sources, with Harpan Khola (a tributary of Phewa Lake) contributing over 80% of the estimated 339,118 tons of annual sediment inflow. From 1962 to 2024, the lake has lost approximately 5.62 sq. km of surface area, primarily due to a combination of sediment deposition and human encroachment. Pollution from untreated sewage, urban runoff, and invasive aquatic weeds further degrades water quality and threatens biodiversity. Based on the findings, this study proposes a way forward to mitigate sedimentation, encroachment, and pollution, along with a sustainable revitalization plan. The approach of this study, along with the proposed sustainability measures, can be replicated in other lake systems within Nepal and in similar watersheds elsewhere. Full article

The wild tomato (Solanum sisymbriifolium) is a globally distributed shrubby weed with both negative and positive impacts, including its invasive properties and the potential for pharmaceutical and traditional medicinal uses. Despite its ecological significance, the plant’s reproductive biology and pollination ecology remain poorly understood. This study aimed to investigate the floral biology, pollination ecology, and plant reproduction of the weed species. Some flower traits, such as flowering intensity, flower display size, and pollen and ovule production, peaked during spring, summer, and the monsoon, while flower longevity and stigmatic receptivity were the longest in winter. The plant species was self-compatible (ISI = 0.02), heavily depended on pollinators (IDP = 0.72), and experienced minimal pollination limitation (D = 0.10) under open-pollination conditions. Flower visitors’ traits (e.g., abundance, diversity, and richness) were higher in the spring, summer, and the monsoon, and these were lower in winter. The vital pollination service was provided by Amegilla zonata, Ceratina binghami, Lasioglossum cavernifrons, Nomia (Curvinomia) strigata, Tetragonula pagdeni, Xylocopa aestuans, Xylocopa amethystina, Xylocopa fenestrata, and Xylocopa latipes. Reproductive success, as indicated by fruit and seed set, varied seasonally, being higher during the spring–monsoon period and lower in winter. These findings support effective management of this weed species and help conserve the associated bee populations. Full article

Remotely sensed cropland abandonment monitoring is crucial for providing spatially explicit references for maintaining sustainable agricultural practices and ensuring food security. However, abandoned cropland is commonly detected based on multi-date classification or the dynamics of a single vegetation index, with the interactions between vegetation and soil time series often being neglected, leading to a failure to understand its full-life-cycle succession processes. To fill this gap, we propose a new full-life-cycle modeling framework based on the interactive trajectories of vegetation–soil-related endmembers to identify abandoned and reclaimed cropland in Jinan from 2000 to 2022. In this framework, highly accurate annual fractional vegetation- and soil-related endmember time series are generated for Jinan City for the 2000–2022 period using spectral mixture models. These are then used to integrally reconstruct temporal trajectories for complex scenarios (e.g., abandonment, weed invasion, reclamation, and fallow) using logistic and double-logistic models. The parameters of the optimization model (fitting type, change magnitude, start timing, and change duration) are subsequently integrated to develop a rule-based hierarchical identification scheme for cropland abandonment based on these complex scenarios. After applying this scheme, we observed a significant decline in green vegetation (a slope of −0.40% per year) and an increase in the soil fraction (a rate of 0.53% per year). These pathways are mostly linked to a duration between 8 and 15 years, with the beginning of the change trend around 2010. Finally, the results show that our framework can effectively separate abandoned cropland from reclamation dynamics and other classes with satisfactory precision, as indicated by an overall accuracy of 86.02%. Compared to the traditional yearly land cover-based approach (with an overall accuracy of 77.39%), this algorithm can overcome the propagation of classification errors (with product accuracy from 74.47% to 85.11%), especially in terms of improving the ability to capture changes at finer spatial scales. Furthermore, it also provides a better understanding of the whole abandonment process under the influence of multi-factor interactions in the context of specific climatic backgrounds and human disturbances, thus helping to inform adaptive abandonment management and sustainable agricultural policies. Full article

In recent years, land degradation has become a major challenge for human society, with negative impacts on the natural habitat, the economy, and human well-being. A variety of anthropogenic and natural factors are exacerbating the processes of land degradation in the era of climate change. Land restoration is an important and proactive strategy to combat this negative situation. Among the many approaches, the use of vegetation plays a central role in restoring soil health, preventing erosion, promoting biodiversity, and improving water retention. Therefore, the identification of new plant species that have the properties to contribute to land restoration is a necessity today. The plant proposed in this conceptual review for land restoration is the cup plant (Silphium perfoliatum L.). After a brief presentation of the agronomy, adaptability, and multiple uses of this plant species, its potential to provide important ecosystem services useful for land restoration to combat land degradation is herein emphasized. Recent studies have shown that this plant has great potential for phytoremediation of soils contaminated with heavy metals (Zn, Pb, Cr, Cd, Ni, Hg, and Co), especially in post-mining areas where pollution exceeds ecological limits. Most studies have shown that the accumulation of heavy metals is higher at the lamina stage. There is also some evidence that the cup plant thrives in flood-prone areas and contributes to their restoration. Cup plant cultivation can also reduce greenhouse gasses and increase the organic carbon content of the soil. Another method of land restoration related to the establishment of the cup plant in a given area is the suppression of weeds, particularly the prevention of the invasion of exotic weed species. Further research under different soil–climatic conditions is needed to investigate cup plant cultivation as a promising strategy for land restoration in a time when the climate is constantly changing. Full article

Noxious weeds (NWs) are increasingly recognized as a significant threat to the native alpine grassland ecosystems of the Qinghai–Tibetan Plateau (QTP). However, large-scale quantification of their continuous fractional cover remains challenging. This study proposes a pixel-level estimation framework utilizing time-series Sentinel-2 imagery. A Dynamic Mask Non-Stationary Transformer (DMNST) model was developed and trained using multi-temporal multispectral data to map the spatial distribution of NWs in the Three-River Headwaters Region. The model was calibrated and validated using field data collected from 170 plots (1530 quadrats). The results demonstrated that both the dynamic masking module and the non-stationary normalization significantly enhanced the prediction accuracy and robustness, particularly when applied jointly. The model performance varied across different combinations of spectral bands and temporal inputs, with the optimal configurations achieving a test R² of 0.770, MSE of 0.009, and RMSE of 0.096. These findings underscore the critical role of the input configuration and architectural enhancements in accurately modeling the fractional cover of NWs. This study confirms the applicability of Sentinel-2 time-series imagery for modeling the continuous fractional cover of NWs and provides a scalable tool for invasive species monitoring and ecological risk assessment in alpine ecosystems. Full article

Oxalis pes-caprae is one of the most widespread invasive plants in the Mediterranean areas, especially in central and southern Italy, Sicily, and Sardinia. It is an herbaceous species of South African origin, very common in uncultivated areas, in meadows, and at the edges of roads but also in vegetable gardens and fields, where it can become a weed. Its negative impact on the economic sector is significant due to the presence of large quantities of oxalates, which are toxic and dangerous for grazing livestock; the ingestion of high amounts of oxalates causes the accumulation of oxalate crystals, which can lead to kidney failure and anuria. This work represents a descriptive, field-based case report of epidemiological relevance, describing two cases of acute and chronic poisoning by Oxalis pes-caprae found in two different sheep farms in southern Sardinia. In February 2024, the sudden death of about 40 animals was reported in a sheep farm. On another farm, seven animals died (between March and July 2024), while others showed poisoning symptoms such as weight loss, submandibular edema, and a barrel-shaped abdomen. This manuscript aims to highlight the damage caused by poor attention in pasture management and the importance of seasonal risk management; it is necessary to pay attention to the herbaceous species present in pastures, especially in our region, where climatic temperatures no longer respect seasonality and herbaceous species that normally grow in spring are easily found also in the winter months. Full article

Amaranthus retroflexus L. is widely regarded as one of the world’s most invasive weeds, often linked to significant agricultural losses due to its resilience and herbicide resistance. However, unlike other amaranth species already recognized for their health benefits, A. retroflexus remains largely overlooked as a potential nutritional and pharmacological resource. This study investigates whether this abundantly growing plant could be repurposed as sustainable food. We focused on three main questions: Can weed be transformed into a food source? Does A. retroflexus offer comparable nutritional value as its relatives? And how can it be harvested safely for human use? Mineral content, total antioxidant capacity, and polyphenol content were analyzed across different plant parts. Results revealed high levels of essential minerals, antioxidants, and other bioactive compounds, suggesting strong potential as a nutrient-dense food. However, traces of heavy metals—such as lead, cadmium, and arsenic—were detected in some samples, emphasizing the need for controlled cultivation. Overall, the findings support the safe and sustainable valorization of A. retroflexus in food and pharmaceutical applications. Full article

The wooly cupgrass (Eriochloa villosa) is an invasive weed species originating from East Asia that rapidly expanded into agricultural and disturbed land. Its tolerance to herbicides and ecological adaptations enable it to become persistent and difficult to remove with limited control methods. This review synthesizes existing research on its distribution, biology, biochemistry, ecology, management and agricultural impact. Lipid synthesis inhibitor herbicides are reported to provide good results when applied early. Others such as Nicosulfuron and Foramsulfuron, although still effective in many populations, have been linked to emerging resistance in others. Chemical control is still widely used and developing resistance is an increasing concern, so various other control methods are also discussed and encouraged. Row crops such as corn (Zea mays) and soybeans (Glycine max) are particularly vulnerable. Despite being problematic, this species presents potential as a medicinal plant as well as in phytoremediation. Regardless, numerous research gaps remain, particularly in chemical control, its economic impact, biochemical properties, community dynamics and distribution. We aim to provide a comprehensive basis for future research with a focus on interdisciplinary approaches in order to contain its spread as much as possible, as well as explore the benefits it may provide. Full article

Hydrilla, an invasive submerged macrophyte that is classified as a noxious weed in the U.S., can quickly spread into extensive monospecific infestations, excluding other native macrophytes and disrupting entire lake ecosystems. In Florida, infestation has increased tenfold in just three years, consuming over 60% of total management costs and requiring millions of dollars in annual control efforts. Traditional monitoring methods, such as field sampling, provide accurate localized assessments but are expensive and time-consuming. This study leverages Sentinel-2 satellite imagery, introducing the Submerged Aquatic Vegetation Index for Hydrilla (SVI_H), a novel three-band index utilizing the green (G, 560 nm), red-edge 1 (RE1, 705 nm), and shortwave infrared 1 (SWIR1, 1610 nm) bands to distinguish hydrilla from water and emergent aquatic vegetation (EAV) in two Florida lakes. The index, coupled with other vegetation indices, was validated using in situ measurements of hydrilla abundance levels, confirming its strong ability to accurately distinguish hydrilla. At the highest abundance level, SVI_H produced the highest Mathew correlation coefficients (MCCs), i.e., >0.86 for Lake Yale (2021), and >0.60 (2020) and >0.68 (2021) for Lake Apopka, using three thresholding methods. For Apopka (2022), other tested indices such as MFI and FAI yielded high MCC values along with high recall using incremental search threshold. However, these indices could not distinguish EAV from SAV in the eastern regions of Lakes Apopka and Yale, where EAV was dominant. These findings encourage the use of SVI_H for routine hydrilla detection and mapping, facilitating improved management, conservation efforts, and targeted herbicide applications. Full article

Water hyacinth (Eichhornia crassipes) is a globally invasive aquatic weed with high biomass productivity and nutrient content, offering potential as a low-cost organic soil amendment. This review synthesizes findings from 35 studies identified through a structured Web of Science search, examining its use as mulch, compost, biochar, and foliar extract. Reported agronomic benefits include improvements in soil organic carbon, nutrient availability (particularly nitrogen and potassium), microbial activity, and crop yields. However, most studies are short-term and conducted under greenhouse or pot conditions, limiting field-scale generalizability. Additionally, reporting of compost composition and contaminant levels is inconsistent, raising concerns about food safety. While logistical and economic feasibility remain underexplored, emerging evidence suggests that with proper processing, water hyacinth amendments could reduce fertilizer dependence and contribute to circular bioeconomy goals. Future research should prioritize field trials, standardized production protocols, and life cycle assessments to evaluate long-term performance, risks, and climate benefits. Full article

Antigonon leptopus Hook. & Arn., commonly known as the chain of love, is a fast-growing leafy vine characterized by its pink or white heart-shaped flowers and is considered among the most invasive vine species in Guam. In Guam, the vine is considered to be a weed, but worldwide it is utilized in different folk medicine practices, such as for alleviating colds and tending to wounds. As a resource, A. leptopus is underutilized in Guam, prompting the search for possible pharmacological properties. A. leptopus contains a wide range of phytochemicals, including alkaloids, terpenoids, flavonoids, phenols, tannins, saponins, glycosides, and amino acids, which have been found to have many bioactive properties, including antioxidant, antimicrobial, antidiabetic, anti-inflammatory, and anticancer activities. Extraction methods varied according to specific research objectives, but overall, the most common methods involved were maceration, Soxhlet extraction, and hot extraction techniques. The application of green extraction methods, such as the use of supercritical CO₂, is currently lacking for this species. A. leptopus may serve as a promising source of bioactive compounds for the pharmaceutical and nutraceutical industries. Full article