Invasive Plant Research Articles

Exploration of endophytic and rhizospheric bacteria of invasive plant Xanthium strumarium L. reveals their potential in plant growth promotion and bacterial wilt suppression.

Plant-associated microbiome plays important role in maintaining overall health of the host plant. Xanthium strumarium displaying resilience to various environmental fluctuations may harbor some bacterial isolates which can help this plant to grow worldwide. The present study aims to isolate endophytic and rhizospheric bacteria from X. strumarium and assess their plant growth-promoting and Ralstonia solanacearum antagonism activity. From a total of 148 isolated bacteria, 7 endophytic and 2 rhizospheric bacterial isolates were found to endow with significant in vitro plant growth promotion activities. The 16S rRNA gene sequence similarity of the 7 endophytic isolates has revealed these bacteria belonging to 5 genera viz. Curtobacterium, Pantoea, Pseudomonas, Microbacterium and Paracoccus whereas, the two rhizospheric isolates were identified as species of Ralstonia pickettii and Priestia megaterium. Maximum growth promotion was observed using the strains Pseudomonas fluorescens XSS6 and Microbacterium hydrothermale XSS20 in the assay conducted on tomato plants. In the in planta inhibition assay of R. solanacearum carried out in tomato seedlings using root bacterization method, Pseudomonas fluorescens XSS6 and Panotea vagans XSS3 showed antagonistic activity with biocontrol efficacy of 94.83% and 83.96%, respectively. GC-MS analysis detected several known antimicrobial compounds in the extract of the culture supernatant of Pseudomonas fluorescens XSS6 and Panotea vagans XSS3 strains, which may contribute to the inhibition of R. solanacearum by these strains. The results of our study indicated that the bacteria associated with X. strumarium exhibit multiple plant-beneficial effects. These bacteria have the potential to be developed as effective biofertilizers and biological control agents, promoting sustainable agriculture practices.

Increasing invasive liana cover following tree mortality and containment treatments associated with a fungal pathogen

Abstract Tree-afflicting pests, such as insects and pathogens, could change forests in ways promoting invasions by non-native plants. After tree death associated with the fungal pathogen oak wilt (Bretziella fagacearum (Bretz) Z.W. de Beer, Marincowitz, T.A. Duong & M.J. Wingfield) and its attempted containment (severing root connectivity and sanitation removal of infected trees), we examined change in cover of the non-native liana Oriental bittersweet (Celastrus orbiculatus Thunb.; hereafter Celastrus) at 28 sites in temperate black oak (Quercus velutina Lam.) forests, Ohio, USA. During our five-year study spanning 2020 to 2024, Celastrus cover increased significantly (P < 0.05) through time at oak wilt sites but not in untreated reference forest sites without evidence of oak wilt. Celastrus cover increased by an order of magnitude, up to an average of 32× among oak wilt treatments up to 10 years old. By 2024, Celastrus cover ranged from 6-22% on average in 5-10-year-old oak wilt treatments, compared with 1% cover in reference forest. Results indicate that non-native plant invasion accelerated following disturbance associated with a fungal pathogen and its attempted containment, and more generally, suggest that tree-afflicting pests can promote invasive plants in forests. Co-management of tree-afflicting pests and non-native plants may become increasingly important to ensure forests recovering from tree mortality are dominated by native plants.

PATTERNS IN SELFED SEED PRODUCTION AND GERMINATION IN AMUR HONEYSUCKLE (LONICERA MAACKII)

Abstract Amur honeysuckle (Lonicera maackii) is an aggressive invader of forests throughout the eastern United States. While self-pollination has been identified as an important trait of invasive plant species, this trait is understudied, and Amur honeysuckle is anecdotally described as lacking this characteristic. To examine the ability of Amur honeysuckle to self-pollinate, we selected 171 individual shrubs distributed across nine sites. Each site was grouped into one of three invasion types: heavy, light, and sprouting (sites on which a basal cutting treatment previously occurred, but Amur honeysuckle was allowed to reestablish). We compared the number of berries, seeds per berry, and seed germination rates of self- and open-pollinated flowers by pairing branches covered with pollination bags prior to flower emergence with uncovered branches on the same individual shrub. Out of 171 individuals, 48 produced berries from self-pollination within pollination bags (28%), with 48% of bagged branches exhibiting some degree of necrosis or chlorosis, presumably due to increased temperature and humidity. Berries from self-pollination produced 1.5 ± 1.4 (mean ± 1 SD) seeds per berry, whereas berries resulting from open-pollination produced 3.3 ± 1.5 seeds per berry. In a germination trial, 47.3% of self-pollinated seeds germinated, compared to 41.7% of open-pollinated seeds. This study has shown that Amur honeysuckle can self-pollinate and set viable seed, providing the species with an important mechanism to increase population abundance during the early stages of invasion.

Climate Change and Plant Foods: The Influence of Environmental Stressors on Plant Metabolites and Future Food Sources

Climate change is reshaping global agriculture by altering temperature regimes and other environmental conditions, with profound implications for food security and agricultural productivity. This review examines how key environmental stressors—such as extreme temperatures, water scarcity, increased salinity, UV-B radiation, and elevated concentrations of ozone and CO2—impact the nutritional quality and bioactive compounds in plant-based foods. These stressors can modify the composition of essential nutrients, particularly phytochemicals, which directly affect the viability of specific crops in certain regions and subsequently influence human dietary patterns by shifting the availability of key food resources. To address these challenges, there is growing interest in resilient plant species, including those with natural tolerance to stress and genetically modified variants, as well as in alternative protein sources derived from plants. Additionally, unconventional food sources, such as invasive plant species and algae, are being explored as sustainable solutions for future nutrition.

Biological insights into alleviating heavy metal toxicity through the simultaneous supply of biochar biofilters derived from the Mikania micrantha and molybdenum nanoparticles

Cadmium (Cd) contamination in the environment is widespread, making it crucial to reduce Cd accumulation in cereal crops like wheat. However, strategies that not only mitigate Cd pollution but also address other environmental challenges, such as invasive species management, remain unclear. This study introduces an innovative approach combining molybdenum nanoparticles (Mo NPs, 1 µM) and biochar biofilters derived from the invasive plant Mikania micrantha (IPMM), targeting the biochemical and molecular responses of wheat under Cd stress (100 µM). Our findings showed that this novel combination significantly improved wheat physiological characteristics, growth, root architecture, elemental profile, osmoregulation, carotenoid, chlorophyll, gas exchange, and photosynthetic efficiency. Remarkably, simultaneous supply of IPMM biochar biofilters and Mo NPs substantially modulated the Cd translocation, reducing its accumulation in root (30.54%) and shoot (53.59%). Additionally, this strategy not only preserved mesophyll cell structures and the membrane integrity, but also strengthened and activated the oxidative defense systems through the regulation of genetic expressions. This synergistic approach advances the Cd alleviating techniques and offers a sustainable solution for utilizing invasive plants as a potential resource. By addressing both heavy metal pollution and ecological challenges, it provides a promising solution for safer crop production in Cd-contaminated environments.Graphical

An Updated Environmental Resistance Model for Predicting the Spread of Invasive Species

ABSTRACTAimPredictive models on invasive species spread can assist in identifying large‐scale invasion risk. Environmental resistance (ER) models, which predict spread based on ecological similarity to already‐invaded communities, offer one approach. However, gaps remain in understanding how different ER measurements perform across different taxa and how they can be integrated with future global change. Here, we aim to discern the primary drivers of invasion spread by comparing different ER models and then use the best models to forecast future invasion dynamics.LocationEastern US.Taxa1873 invasive plants and animals.MethodsWe developed different ER measurements, including biotic similarities among native plants in their species and phylogenetic assemblages, and functional traits, and abiotic similarities in climate, soil, and human disturbances. We obtained the best ER model for each invasive species to evaluate their potential invasion extents; and we further predicted their future range shifts under climate change.ResultsNative plant similarities provided the best proxy measure of ER for both invasive plants and animals. Invasion hotspots were identified in urban and coastal areas, and the predicted potential invasion ranges under current conditions extended from these hotspots to the neighboring areas. The invasion range for most invasives was predicted to increase under future climate change, with Arthropoda and Tracheophyta generally expanding the most among all taxa. The invasives that are predicted to expand their range in the future have already occupied larger areas than the invasives whose ranges are predicted to contract.Main ConclusionsThese results highlight the importance of maintaining diverse native communities in invasion control and raise the concern of increased invasion risk in the future. Our findings call for more efforts on invasion monitoring in areas near large cities, and increased capacity for early detection and rapid response to prevent the current invasives spreading more widely.

Mitigating the Negative Impact of Certain Erosion Events: Development and Verification of Innovative Agricultural Machinery

This paper aims to solve the problem of erosion sediment that negatively affects the quality of fallowed soil through the development of a new type of agricultural machinery. The transported erosion sediment will be quantified locally to evaluate the danger of these negative effects on the fallowed soil and on the functionality of the grass cover. Subsequently, a new type of machinery will be proposed for the remediation of eroded sediment and conservation of the fallowed soil. In various fallow research areas with different management methods (such as biobelts, grassed valleys, and grassed waterways), agricultural land affected by eroded sediment was examined, and appropriate machinery was designed to rehabilitate the stands after erosion events. By identifying the physical and mechanical properties of the soil, as well as the eroded and deposited sediment/colluvium, the shape, material, attachment method, and assembly of the working tool for the relevant mobile energy device were designed. The developed tool, based on a plow–carry system using a tractor, features flexible tools that separate the eroded sediment from the fallow land surface, transfer it over a short distance, and accumulate it in a designated area to facilitate subsequent removal with minimal damage to the herbaceous vegetation. The calculated erosion event was 196.9 m3 (179.0 m3 ha−1), corresponding to 295 tons (268.5 t ha−1) deposited from the area of 90 ha. Afterward, the proposed machinery was evaluated for the cost of the removal of the eroded sediment. Based on experience from the field, we calculated that 174 m3 per engine hour results in EUR 0.22 m−3. From the performed experiment, it is evident that the proposed machinery offers a suitable solution for eroded sediment removal locally, which prevents further erosion and subsequent sediment deposition in water bodies where the costs for sediment removal are higher. Moreover, we have proven the potential negative impact of invasive plant species because their seeds were stored in the sediment. Finally, it is credible to state that the proposed agricultural machinery offers an effective solution for the eroded sediment relocation, which subsequently can be used for other purposes and monetized. This results in an increase in the profitability of the erosion sediment removal process, which is already in place at the source before further transportation to aquatic systems where the costs for removal are significantly higher.

Invasive Plants Do Not Exert Univocal Responses on Soil Abiotic and Biotic Characteristics

Invasive Plants Do Not Exert Univocal Responses on Soil Abiotic and Biotic Characteristics

A Local and Historical Perspective on Disaster Risk Reduction: Tunja, Colombia Case Study

Abstract This autoethnographic study presents a historical perspective on disaster risk reduction (DRR) at the local level, with the case study of the city of Tunja in Colombia. We analyze the impact that colonization, the independence period, and recent history have had on the creation and reduction of disaster risks in this city. We offer a holistic perspective that shows the interactions of the impact of inequality on Indigenous populations, lack of urban planning, deforestation and the planting of invasive plant species, among other factors, which in combination with natural hazards, such as heavy rainfall, increase disaster risks. We conclude that although the Sendai Framework for Disaster Risk Reduction 2015–2030 is a fundamental instrument to promote risk reduction, in the local context of Tunja, the framework as such is not seen as a guide or parameter. The Colombian Disaster Risk Management Law is the main guide to advance risk reduction. This study demonstrates how DRR is not an isolated process, but a process that encompasses the general well-being of the population. We demonstrate from our lived perspective how access to public education and school feeding, as well as other social protection measures, increase the resilience of the population, making them better able to cope with adversity due to different hazards. This local perspective, with a historical review of a small city in the middle of the Andes, demonstrates the importance of continuing to prioritize and invest in measures that contribute to the population’s well-being as a way to reduce disaster risks, including adapting to our changing climate.

Effects of plant invasion and land use change on soil labile organic carbon in southern China’s coastal wetlands

Effects of plant invasion and land use change on soil labile organic carbon in southern China’s coastal wetlands

Compounds Involved in the Invasive Characteristics of Lantana camara.

Lantana camara L. is native to tropical America and has naturalized in many other tropical, subtropical, and temperate regions in Asia, Africa, Oceania, North and South America, and Europe. L. camara infests diverse habitats with a wide range of climatic factors, and its population increases aggressively as one of the world's 100 worst invasive alien species. Its infestation reduces species diversity and abundance in the natural ecosystems and reduces agricultural production. The life history characteristics of L. camara, such as its high reproductive ability and high adaptive ability to various environmental conditions, may contribute to its ability to infest and increase its population. Possible evidence of the compounds involved in the defense functions of L. camara against natural enemies, such as herbivore mammals and insects, parasitic nematodes, pathogenic fungi and bacteria, and the allelochemicals involved in its allelopathy against neighboring competitive plant species, have accumulated in the literature over three decades. Lantadenes A and B, oleanonic acid, and icterogenin are highly toxic to herbivore mammals, and β-humulene, isoledene, α-copaene thymol, and hexadecanoic acid have high insecticidal activity. β-Caryophyllene and cis-3-hexen-1-ol may function as herbivore-induced plant volatiles which are involved in sending warning signals to undamaged tissues and the next plants of the same species. Farnesol and farnesal may interrupt insect juvenile hormone biosynthesis and cause abnormal metamorphosis of insects. Several triterpenes, such as lantanolic acid, lantoic acid, pomolic acid, camarin, lantacin, camarinin, ursolic acid, and oleanonic acid, have demonstrated nematocidal activity. Lantadene A, β-caryophyllene, germacrene-D, β-curcumene, eicosapentaenoic acid, and loliolide may possess antimicrobial activity. Allelochemicals, such as caffeic acid, ferulic acid, salicylic acid, α-resorcylic acid, p-hydroxybenzoic acid, vanillic acid, unbelliferone, and quercetin, including lantadenes A and B and β-caryophyllene, suppress the germination and growth of neighboring plant species. These compounds may be involved in the defense functions and allelopathy and may contribute to L. camara's ability to infest and to expand its population as an invasive plant species in new habitats. This is the first review to focus on how compounds enhance the invasive characteristics of L. camara.

Predicting suitable habitats for the Brazilian peppertree biological control agent Pseudophilothrips ichini (Thysanoptera: Phlaeothripidae) in Florida

ABSTRACT Invasive plants are rapidly entering new ecosystems due to globalisation, increased trade, and frequent disturbances of natural habitats. Schinus terebinthifolia Raddi, known as the Brazilian peppertree, is a particularly aggressive invasive shrub in Florida, Hawaii, Texas, and California. Due to its aggressive growth and the damage it can cause to ecological systems, it is considered one of the worst upland invasive species in the state of Florida, prompting extensive biological control efforts. The classical biological control agent, Pseudophilothrips ichini, was approved for release in Florida in 2019, with over 6 million thrips released to date. However, the establishment and persistence of these thrips have been inconsistent, and little research has been conducted to understand these patterns. Here, we employ ecological niche modelling as a tool to predict suitable habitats for Brazilian peppertree and P. ichini. Ecological niche models were calibrated using location data of both organisms from their native ranges and bioclimatic data from WorldClim. These models accurately predicted the potential distribution of Brazilian peppertree (AUCtraining = 0.914, AUCvalidation = 0.913) and P. ichini (AUCtraining = 0.934, AUCvalidation = 0.918). The projections indicated that most of Florida is climatically suitable for the Brazilian peppertree, aligning with its known distribution. However, discrepancies were observed between the projected and actual distribution of P. ichini, suggesting that additional environmental or biotic factors may influence their establishment. Further research is necessary to refine these models and enhance the integration of P. ichini into pest management programmes to better conserve time, resources, and funds.

Latitudinal variation in leaf functional traits of an invasive salt-marsh plant and its relationship with growth performance

Latitudinal variation in leaf functional traits of an invasive salt-marsh plant and its relationship with growth performance

Ethnobotany of vascular plants use, conservation and management practice in the homegardens by the people of Dawuro in Southwestern Ethiopia

BackgroundHomegardens (HGs) are well-time-honored traditional land use systems in small plots of land with purposely designed intricate structure and a mixture of planted vascular plants (VPs) for different purposes. Hence, the present study was initiated to investigate the ethnobotanical information of vascular plants of homegardens and their use, conservation and management practice by the people of Dawuro in southwestern Ethiopia.MethodsA total of 162 farmer informants were selected and interviewed within a distance of < 2 km, 2–4 km and > 4 km between the natural forest and homegardens, and 0.8–1 km between the homegardens. Quadrats of three 5 m × 10 m were laid (except front yard) around each living houses. Shannon–Wiener diversity index was used for analysis of diversity.ResultsThere were 345 vascular plants in the homegardens distributed in 252 genera and 79 families. The most frequently recorded plant families were Fabaceae with 38 (11%), Asteraceae 33 (10%), and Lamiaceae 26 (7.5%). The species richness recorded per homegardens ranged from 13 to 59. Ensete ventricosum, Persea americana, Colocosia esculenta, Coffea arabica, Solanum capsicoides, and Ocimum basilicum were the most frequently occurred species. The homegarden was enset-based agrobiodiversity system providing food, medicine and other uses where the highest, 290 species were for medicine. Men are responsible for planting and propagating large-sized plant species in the homegardens, while small-sized were managed by women and children. The α-diversity (H’) ranged from 1.4 to 3.4 and the gamma diversity was 4.2. Culture has positive effect on diversity however, the diversity of species is affected by distance from natural forest (x2 = 14.825, df = 4, p = 0.005) at P < 0.05 level.ConclusionAwareness raising designed and executed by farmer experts and researchers focusing on managing homegarden is necessary to fill the observed gaps in knowledge and attitude of the new generation. The enset-based homegarden management knowledge and practice as well as avoiding the diseases and other constraints of enset should be given attention. Furthermore, decisions on avoiding the growth and management of invasive exotic plant species like eucalyptus tree in the homegardens have to be made.

Invasive plant species and their impact on forest composition and regeneration in tropical deciduous forests of Palamau Tiger Reserve, Eastern India

Invasive plant species and their impact on forest composition and regeneration in tropical deciduous forests of Palamau Tiger Reserve, Eastern India

Grazing can reduce wildfire risk amid climate change.

Over half of Earth's land surface is covered with fire-prone vegetation, with grassy ecosystems-such as grasslands, savannas, woodlands, and shrublands-being the most extensive. In the context of the climate crisis, scientists worldwide are exploring adaptation measures to address the heightened fire risk driven by more frequent extreme climatic conditions such as droughts and heatwaves, as well as by non-native plant invasions that increased fuel loads and altered fire regimes. Although fire is intrinsic to grassy ecosystems, rising exposure to wildfire smoke harms human health and the environment. Here, we argue that grazing management in grassy ecosystems could help reduce wildfire risk and its consequences.

Detection of an invasive plant (Cissus verticillata) in the largest mangrove system on the eastern Pacific coast—a remote sensing approach

The identification and monitoring of invasive plant species utilizing spaceborne sensors have posed substantial challenges over the past few decades, mainly due to a scarcity of state-of-the-art sensors, limited digital processing capabilities, and the presence of a phenological spectral feature that is not readily detectable by conventional methods. The invasive plant Cissus verticillata, first detected in 2017, has affected the largest mangrove system on the eastern Pacific coast—Marismas Nacionales—spreading rapidly and aggressively through the mangrove canopy, and causing degradation and even mortality, mainly of Rhizophora mangle, by obstructing the sunlight over the canopy. The purpose of this study was to isolate the multispectral signal from Cissus verticillata by using a cloud computing approach with Google Earth Engine and generate a comprehensive map of the entire mangrove system by means of a novel dense time series of Sentinel-2 data. Results indicate that the optimal period for detecting Cissus verticillata is between October and December. Furthermore, this species is expanding its range along the riverbanks in the central region of Marismas Nacionales, with its coverage increasing from 426.16 ha in 2019 to 838.08 ha in 2021. These areas were verified with a field endeavor and have signified a substantial development, given that the plant had not been previously identified in this region with conventional field methods due to logistical constraints. The findings and approach of this study will contribute to the decision-making required to manage this invasive plant.

In the weeds: Thinking through anthropological and other social science approaches to invasive plant species and their control

As climate change and biodiversity loss dismantle the world's ecosystems, we are becoming a planet of weeds. The spread of invasive plant species poses acute challenges to human and non-human life, threatening biodiversity, economic livelihoods, and human health. In anthropology, there has been an embrace of the concept of “weediness” as generative in recent years, both as a way to think through unexpected flourishings amidst the ruins of capitalism, and to challenge an anthropocentric view of vegetal value. However, in contexts where the spread of invasive plant species threatens livelihoods, lifeworlds, biodiversity and ecosystems, there is an urgent need to take seriously the negative consequences of weedy proliferation, something that is perhaps best achieved through a vegetal political ecology approach. This paper traces recent developments in anthropological and social science scholarship related to invasive plants and the techniques used to control them. Literatures investigating the role that weeds play in the social world, across anthropology, geography, critical plant studies and related disciplines are brought into conversation with toxicities literatures to think about how the histories and futures of weeds and their control sit in (and shape) landscapes and bodies in uneven ways.

The Invasive Plant Maeopsis eminii: A Key Dietary Resource for Primates in the Tropical Rainforests of West Java, Indonesia

The Invasive Plant Maeopsis eminii: A Key Dietary Resource for Primates in the Tropical Rainforests of West Java, Indonesia

Seasonal and Altitudinal Effects on Chemical Composition and Rumen Degradability of Blackberry Leaves in Northwestern Italian Alps.

The blackberry poses a threat as an invasive plant in various regions worldwide, where it aggressively competes with native species and risks delicate ecosystems. Livestock grazing has emerged as a potential strategy to mitigate its spread. This study investigated the effects of seasonal variations and altitude on the chemical composition and in vitro degradability of blackberry leaves. The leaves accessible to goats were collected in the Northwestern Italian Alps across all seasons at three altitudes (low: 450 m, medium: 700 m, high: 1000 m). The findings indicated that blackberry leaves can serve as a cost-effective, high-protein, and high-fiber feed for ruminants in these regions. However, the goats exhibited a limited capacity for fiber degradation. Furthermore, the nutritional value of these leaves was significantly influenced by the season, altitude, and their interaction. Spring leaves had the highest protein content (241.9 g/kg dry matter) and the best digestibility, with lower lignin levels (69 g/kg dry matter). At higher altitudes, lignin content decreased significantly during winter compared to the other seasons, resulting in a significant increase in fiber degradability. These insights offer crucial guidance for optimizing the utilization of the blackberry plant in goat feeding systems and underscores the necessity of considering both seasonal and altitudinal factors in grazing management practices.