Invasive Alien Plant Species Research Articles

Invasive Alien Plant Species Assessment in Semi-Arid Ecosystems: A Case Study from Southern Haryana, India

Forests of Southern Haryana are incredibly rich in medicinally important plant species but anthropogenic activities and invasive alien plant species are putting a huge stress on these forests. In order to comprehend the ecology of invasive alien plant species, the current study was carried out in the semi-arid forests of Southern Haryana districts, namely Charkhi Dadri and Mahendergarh. During the study, different analytical parameters were calculated such as density(D), basal area (B.A) and importance value index(IVI) along with different diversity indices such as Shannon-weiner index(H'), Simpson index(CD), Pielou index(d) and Margalef index(E). A total of 19 alien plants were recorded with family Asteraceae dominating with 5 species followed by family Solanaceae and Malvaceae. Some of the alien plants were turned out as deadly invasive such as Parthenium hysterophorus, Prosopis juliflora, Chenopodium murale and Croton bonplandianus with high value of IVI, affecting the survival and growth of important native plant species. Thus, the present study is carried out in the field of phytosociology in forests of Southern Haryana. Appropriate strategies must be implemented in this direction to retain the natural ecology of the area.

Climatic zone effects of non-native plant invasion on CH4 and N2O emissions from natural wetland ecosystems

Plant invasion can significantly alter the carbon and nitrogen cycles of wetlands, which potentially affects the emission of greenhouse gases (GHGs). The extent of these effects can vary depending on several factors, including the species of invasive plants, their growth patterns, and the climatic conditions prevailing in the wetland. Understanding the global effects of plant invasion on the emission of methane (CH4) and nitrous oxide (N2O) is crucial for the climate-smart management of wetlands. Here, we performed a global meta-analysis of 207 paired case studies that quantified the effect of non-native plant invasion on CH4 and N2O emissions in tropical/sub-tropical (TS) and temperate (TE) wetlands. The average emission rate of CH4 from the TS wetlands increased significantly from 337 to 577 kg CH4 ha−1 yr−1 in areas where native plants had been displaced by invasive plants. Similarly, in TE wetlands, the emission rates increased from 211 to 299 kg CH4 ha−1 yr−1 following the invasion of alien plant species. The increase in CH4 emissions at invaded sites was attributed to the increase in plant biomass, soil organic carbon (SOC), and soil moisture (SM). The effects of plant invasion on N2O emissions differed between TS and TE wetlands in that there was no significant effect in TS wetlands, whereas the N2O emissions reduced in TE wetlands. This difference in N2O emissions between climate zones was attributed to the depletion of NH4+ and NO3− in soils and the lower soil temperature in temperate regions. Overall, plant invasion increased the global net CH4 emissions from natural wetlands by 10.54 Tg CH4 yr−1. However, there were variations in CH4 emissions across different climatic zones, indicated by a net increase in CH4 emissions, of 9.97 and 0.57 Tg CH4 yr−1 in TS and TE wetlands, respectively. These findings highlight that plant invasion not only strongly stimulates the emission of CH4 from TS wetlands, but also suppresses N2O emissions from TE wetlands. These novel insights immensely improve our current understanding of the effects of climatic zones on biogeochemical controlling factors that influence the production of greenhouse gases (GHGs) from wetlands following plant invasion. By analyzing the specific mechanisms by which invasive plants affect GHG emissions in different climatic zones, effective strategies can be devised to reduce GHG emissions and preserve wetland ecosystems.

Print Quality of Coated Paper from Invasive Alien Plant Goldenrod

When designing products with a shorter lifespan, such as packaging and graphic products, sustainability and circular economy are particularly important. The use of an alternative fiber source for papermaking, such as collected biomass from invasive alien plant species (IAPS), is a good example of sustainable natural resource management, where IAPS are seen as a potential source of various new products. The aim of the present study was to analyze the printability of paper made from the IAPS Goldenrod. CMYK prints were made using inkjet digital technology, and their print quality was determined. IAPS Goldenrod paper, with its natural brownish color, low gloss, high voluminosity, high surface roughness and porosity, shows inferior print quality compared to recycled office paper. In order to improve the printability of this paper, surface coating using three different wet film depositions was applied. The results indicate that the smallest coat weight used suppresses the color and inferior properties of IAPS Goldenrod paper efficiently, resulting in similar printability for both the analyzed papers. Only a small difference in print quality between coated IAPS Goldenrod and recycled paper was determined, suggesting that low-value, non-demanding graphic products and packaging could be made from the coated IAPS Goldenrod paper.

Vascular Plant Species Inventory of Mexico's Revillagigedo National Park: Awareness of Alien Invaders as a Sine Qua Non Prerequisite for Island Conservation.

The Revillagigedo Archipelago, located in the Eastern Pacific Ocean, stands out for its unique biological richness and endemism. These islands remained uninhabited until the second half of the twentieth century, allowing a better conservation status than on other oceanic islands. However, the continuous introduction of potentially invasive alien plant species, and the lack of adequate control or eradication actions, jeopardize the conservation and restoration of these islands' fragile ecosystems. We present the most complete vascular plant species inventory and an updated list of alien plant species of the Revillagigedo Archipelago, which was compiled through an extensive review of national and international plant collections and other sources. Our 272 species list includes 106 alien plant species (39.3%; 104 in Socorro, and 16 in Clarion): 67 (24.8%) are naturalized, 14 (5.2%) are casual aliens, and 25 (9.3%) subsist under cultivation. The documented alien species belong to 73 families. Annual and perennial herbs are the prevailing life forms in the alien flora, while naturalized species are primarily native to North America. The number of introduced species has increased significantly since the islands became inhabited. Many of the recently introduced species pose a major invasion risk like on other islands of the world.

An Ecological Assessment of Invasive Alien Plant Species in Jokhar Lake Area of Kailali District, Nepal

Invasive alien plant species (IAPS) have been creating adverse impacts on native diversity. Diversity of Nepal’s wetland ecosystems are also threatened by several IAPS but the related studies are very scarce. This study has assessed the status of IAPS found in Jokhar Lake of Kailali district, Nepal. The IAPS survey was carried out by sampling 30 plots of (1×1)m2 each in and around the lake area. A total of 17 species of IAPS were reported from the study site. Most of the IAPS were the members of the family Asteraceae. The diversity of IAPS in the lake represents about 65% of the total IAPS in Nepal. Around the lake periphery, Ageratum houstonianum and Argemone mexicana and inside the lake Eichornia crassipes and Pistia stratiotes were major IAPS. The natural beauty of the lake has been ruined by these IAPS. A detailed study on the impacts and ecology of these IAPS in the lake and lake periphery is still lacking. Hence, it is recommended that the IAPS in the lake area should be controlled to conserve the native diversity and the natural beauty of the lake.

Distribution and Management of the Invasive Swietenia macrophylla King (Meliaceae) at the Foot of a Protected Area in Luzon Island, Philippines

Invasive alien plant species (IAPS) pose one of the most significant threats to native biodiversity. Swietenia macrophylla, or big leaf mahogany, is among the most threatening invasive plants in the Philippines. This article aimed to formally document the presence of S. macrophylla along the edges of Mt. Banahaw de Nagcarlan, a protected area on Luzon Island, Philippines. The study also sought to identify the management strategies being implemented by various government institutions to address big leaf mahogany and other invasive plants. A total of 1591 individuals of S. macrophylla were documented in mixed land-use areas and roadsides. These were found to have been introduced by the Department of Environment and Natural Resources in 1991 as a reforestation species. Fortunately, no individuals were observed beyond the buffer zone towards the protected area. The identification of management strategies for big leaf mahogany and other IAPS revealed that there is no established approach specifically addressing the presence of S. macrophylla at the site. However, some institutions advocate for the conservation of native plants through tree planting activities and educational campaigns. Furthermore, no collaborative efforts were observed among stakeholders and institutions. The results of this study highlight the urgent need to manage the S. macrophylla population. Planning and enforcement of strategies require collaborative efforts among stakeholders to prevent its entry into the protected area and ensure the preservation of native biodiversity.

Using Plant Functional Traits to Define the Biomass Energy Potential of Invasive Alien Plant Species.

The eradication of invasive alien plant species (IAPS) is mandatory worldwide, but the resulting biomass is still considered waste. The energy use of biomasses obtained from IAPS eradication may represent ecological and economic benefits, creating synergies with restoration projects. We evaluated whether the growth forms and functional types identified using the functional space of 63 IAPS corresponded to a possible bioenergy use through multivariate analysis techniques. We extracted leaf and nutrient traits and Grime's CSR plant strategies from an existing database. We calculated the carbon-to-nitrogen ratio (C:N) and gross heating value (GHV) as indicators of biochemical or thermal processes, respectively. For 10 species, we measured the above-ground biomass C:N and GHV (including leaves, stems and branches) and correlated them with those of leaves and with plant adaptive strategies. We identified four groups of IAPS indicative of the main trade-offs between plant economics and size variation, which respectively correlated with C:N and GHV. Herbaceous IAPS were better suited to biochemical processes, and woody IAPS to thermal ones. Overall, Grime's CSR strategies were the best tool to define the IAPS bioenergy potential. In the long term, competitive and ruderal IAPSs can represent a reusable feedstock until their complete eradication.

INTEGRATED APPROACH TO ACCOUNTING ENVIRONMENTAL FACTORS IN MODELS OF THE CURRENT DISTRIBUTION AND CLIMATIC DYNAMICS OF AMBROSIA ARTEMISIIFOLIA L. IN THE CAUCASUS

Current climate change, habitat degradation and road network development contribute to the invasion of alien plant species in areas of more northern latitudes and higher altitudes. Using the maximum entropy method (Maxent), we built the spatial distribution models of Ambrosia artemisiifolia , considering abiotic, biotic and anthropogenic factors, and area accessibility. Maps of the species current distribution in the Caucasus and its range dynamics according to the climate change scenarios were constructed. The most important variables determining A. artemisiifolia spatial localization in the region were as follows: distance to roads (not more than 0-5 m), terrain roughness (gentle areas) and humidity (climate from semi-arid to pergumid). The 0-5 m distance is also characterized by the area accessibility factor (species dispersal capacity), which contributed about 47% to the final model. Species dispersal beyond roadsides was hindered by forests and meadows with the probability of A. artemisiifolia occurrence not exceeding 0.01%. The species core ranges were predicted in foothills and low mountains of the Western and Central Caucasus, Western and Central Transcaucasia, the northwestern Lesser Caucasus and the Caspian Sea coast. The species invasion in highlands could occur along the gentle river valleys that concentrate the main mountain roads. According to the pessimistic and optimistic climate change scenarios, by 2100 the decline in optimal A. artemisiifolia habitats will be 87 and 27%, respectively, and will affect mainly the plain areas of the currently most humid regions. The main core ranges were predicted in the middle mountains and highlands of the Caucasus.

Integrating Locals’ Importance-Performance Perception of Adaptation Behaviour into Invasive Alien Plant Species Management Surrounding Nyika National Park, Malawi

Invasive species are a huge concern to environmental management across the world because they threaten ecosystems, habitats, and species biodiversity, with largely permanent consequences. This study investigates the aspects of community capital and community resilience for the management of Invasive Alien Plant Species (IAPS) under importance-performance analysis in communities surrounding Nyika National Park (Mhuju and Ntchenachena) in Malawi. The study used the binary logistic regression model to determine the locals’ management and adaptation behaviours to IAPS. The findings show that although both IAPS management and adaptation were considered highly important, their performance was only rated at a low level, indicating a significant gap between the importance of eight management and adaptation behaviours for IAPS and their actual performance. The results also show that IAPS management strategies such as ‘’promoting community awareness of common IAPS and their impacts on livelihood” and “incorporating IAPS issues into the school curriculum” are useful in nurturing the locals’ management behaviour. Furthermore, we have identified the following characteristics as having a significant influence on the locals’ participation in IAPS impact reduction and adaptation: (1) age, (2) residential area, (3) understanding the IAPS impacts, (4) membership of farmers’ club or Village Natural Resource Management Committee (VNRMC), and (5) discussion of IAPS in farmer club or VNRMC. These findings provide empirical evidence to policy makers for an effective IAPS management strategy.

Exploring the capability of high-resolution satellite data in delineating the potential distribution of common invasive alien plant species in the Tshivhase Tea Estate

Invasive alien plants (IAPs) continue to exert significant impacts on agriculture in many countries, resulting in food insecurity. IAPs reduce agricultural production through competition and parasitism with planted crops. More recently, the IAPs continue to extend their plasticity to tea plantations, especially in tropical and subtropical areas. This study thus aimed at exploring the potential of SPOT 7 and Sentinel 2 satellite data in mapping the occurrence and co-occurrence of three common IAPs Solanum mauritianum, Lantana camara, and Chromolaena odorata in the Tshivhase Tea Estate in Limpopo Province, South Africa. The stepwise logistic regression models were generated for Solanum mauritianum and Lantana camara occurrence as well as the observed and conditional co-occurrence probability of S. mauritianum (P1), L. camara (P2) and C. odorata (P3). From the remote sensing indices, the Brightness Index (BI) was significant in most SPOT 7 stepwise logistic regression models at p<0.05 whereas the blue, red, and near infrared (NIR) bands and standard deviation (STDv) variables were significant at p<0.05 in most of the Sentinel 2 models. The SPOT 7 model performed Sentinel-2 models, thus resulting in the area under the curve (AUC) of 0.96 for the conditional co-occurrence of S. mauritianum (P1) and L. camara (P2). The Sentinel 2 model yielded an AUC of 0.83. The SPOT 7 model performed superior in mapping the conditional co-occurrence of S. mauritianum and L. camara than the Sentinel 2 model. These results suggest that high spatial resolution satellite images like SPOT 7 can delineate the potential distribution of IAPs in the tea plantation and thus assisting in management strategies geared towards IAP’s elimination and control.

Diversity and distribution of invasive alien plant species along elevation gradient in Makawanpur district, central Nepal

Diversity and distribution of invasive alien plant species along elevation gradient in Makawanpur district, central Nepal

Biochemical characterization and mycorrhizal fungal community of plant species in the Brazilian seasonal dry forest.

Invasive alien plant species (IAPS) have the ability to change the biochemical properties and the arbuscular mycorrhizal fungal (AMF) community structure in their rhizosphere. Organic acids, microbial activity, and AMF play a key role in the invader's spread and also has interactions with the soil chemical factors. Our aim here was to assess the rhizosphere's biochemical factors, AMF community composition, and soil chemical properties associated with Cryptostegia madagascariensis (IAPS) and Mimosa tenuiflora (endemic plant species) from the Brazilian Seasonal Dry Forest. The highest values of total glomalin (5.87 mg g-1 soil), root colonization (54.5%), oxalic and malic acids (84.21 and 3.01 μmol g-1 , respectively), microbial biomass C (mg kg-1 ), Na+ (0.080 cmolc kg-1 ), Ca2+ (7.04 cmolc kg-1 ), and soil organic carbon (4.59 g kg-1 ) were found in the rhizosphere of C. madagascariensis. We found dissimilarities on AMF community structure considering the studied plant species: (i) Racocetra coralloidea, Dentiscutata heterogama, Dentiscutata cerradensis, Gigaspora decipiens, and AMF's richness were highly correlated with the rhizosphere of M. tenuiflora; and (ii). The rhizosphere of C. madagascariensis was highly correlated with the abundance of Claroideoglomus etunicatum, Rhizoglomus aggregatum, Funneliformis mosseae, and Funneliformis geosporum. The results of our study highlight the importance of considering C. madagascariensis as potential hosts for AMF species from Glomerales, and a potential plant species that increase the bioavailability of exchangeable Na and Ca at semi-arid conditions.

Genetic differences among Ailanthus altissima collections across and outside Italy by a Citizen science approach and their susceptibility to the candidate mycoherbicide Verticillium dahliae Kleb.

Ailanthus altissima (Mill.) Swingle is considered one of the worst invasive alien plant species (IAPS) in Europe, able to cause several disturbances to ecosystems and economic issues. To date, the control methods applied are often ineffective, restricted or under assessment by the scientific community, as in the case of Verticillium dahliae (a promising biological control agent to counteract this species). Citizen science initiatives aim to involve the public in the research process to generate genuine outcomes and, in the case of invasive species, represent a valuable additional tool in their earlier detection, monitoring and management. Here, seventy-two citizens were recruited to recognize and record A. altissima across and outside Italy, as well as to collect leaf and seed samples to allow professional scientists to perform the molecular characterization of the Italian (and more) gene pool and, subsequently, test the susceptibility of these provenances to V. dahliae. The collected material matched the identification for the 97% of the cases, and included 129 accessions divided in four genetic groups (with a high percentage of variability, as typically observed for other IAPS subjected to frequent movements and the constant supply of new propagules). Verticillium dahliae inoculation of plants from different provenances selected for each genetic group, revealed a very high mortality (≥93%) independently to the origin area. These outcomes confirm the high susceptibility of A. altissima to the fungal pathogen, and lead to speculate that V. dahliae seems to have no limits in counteracting Ailanthus populations, at least at the Italian level.

Responses of three invasive alien aquatic plant species to climate warming and plant density.

Climate warming may impact plant invasion success directly, as well as indirectly through changes among interactions within plant communities. However, the responses of invasive alien aquatic species to plant density and rising temperatures remain largely unknown. We tested the effects of plant density and neighbour plant identity at different temperatures to better understand the performance of a community of invasive species exposed to climate warming. A microcosm experiment was conducted with three invasive aquatic plants species-Elodea canadensis, Egeria densa and Lagarosiphon major-, at mono and polycultures with low and high plant density, at 16°C, 19°C and 23°C. The results clearly demonstrated that rising temperature influenced, either as a single parameter or as a combined factor, at least one of the measured traits of the three invasive species. Leaf area of E. densa, root number of L. major and growth of E. densa and L. major were influenced by temperature, plant density and neighbour identity. Plant density influenced all traits with the exception of leaf area of E. canadensis and lateral branch production of E. densa. Neighbour identity had no effect on growth rate and leaf area of E. canadensis, on lateral branch and roots production of E. densa and on leaf area of L. major. These findings establish that rising temperature could enhance competition or facilitation among E. canadensis, L. major and E. densa and could cancel the beneficial effects of the presence of a neighbour species; however, the magnitude of this effect was strongly dependent on plant density. Rising temperature due to climate change will likely play a crucial role in interactions between invasive species within plant communities and in the further spread of these invasive aquatic plants.

Identification of Invasive Aliens Plant Species in Cultivated Area of Kamojang Crater at Ibun District, Bandung Regency, West Java

The Cultivated Area in Kamojang Crater, Ibun District, Bandung Regency is part of a single landscape mountain, adjacent to conservated and protected areas which has high biodiversity. This study aims to identify invasive alien plants species in cultivated areas, adjacent to conservation and protected areas. The method used is a descriptive qualitative study with the sampling line transect in 500 meter radius of four location, namely near Nature Reserves (NR), near Nature Tourism Parks (NTP), agriculture (A) and near Protected Forests (PF), and this study has done up at July until November, 2022. The results showed that in the cultivated area in Kamojang Crater, Ibun District, Bandung Regency found 41 families and 96 species of understorey, with the highest number being from the Asteraceae, Poaceae and Fabaceae. Diversity of understorey was categorized as high (H'=3.428), evenly distributed (E=0.738), high species richness (R=13.503) and no dominant species (C=0.165). Several understorey, namely 8 orders, 10 families, and 29 species were categorized as invasive aliens plant species, with the highest important values index being Ageratina riparia (99,642%), Imperata cylindrica (72,919%), Paspalum notatum (31,155%), Chromolaena odonata (31,074%), Etlingera elatior (27,905%), Ageratum conyzoides (20,179%), Lantana camara (19,029%), Amaranthus hybridus (18,818%), Pennisetum purpureum (15,120%), Mimosa pudica (15,031%), Crassocephalum crepidioides (14,037%), and Axonopus compresus (10,671%).

Review of plant communities of the class Polygono arenastri–Poëtea annuae in the Russian Federation

The article provides an overview of plant communities of the Polygono arenastri–Poëtea annuae class in the Russian Federation. The class includes annual anthropogenic vegetation of trampled habitats of localities and their environs. The vegetation of the Polygono arenastri–Poëtea annuae class is cosmopolitan and widespread in Eurasia, North and South America, and Africa. On the territory of the Russian Federation, the class is distinguished by a rather large syntaxonomic diversity. Based on the cluster analysis of 643 complete geobotanical releves from different geographically distant parts of the Russian Federation, 6 associations (Polygonetum arenastri, Sclerochloo durae–Polygonetum arenastri, Poo annuae–Coronopodetum squamati, Poëtum annuae, Matricario discoideae–Polygonetum arenastri, Rumici acetosellae–Spergularietum rubrae), 10 subassociations and 8 variants belonging to the 1st order and 2 unions of the class were identified. Of these, 3 associations (Sclerochloo durae–Polygonetum arenastri, Poo annuae–Coronopodetum squamati and Rumici acetosellae–Spergularietum rubrae) were given from literary sources (prodrome of syntaxa) without analyzing specific releves. Diagnostic species of higher units for the Russian Federation were also redesigned. The central association of the class is Polygonetum arenastri. Its area covers the entire territory of the country. The DCA ordination of communities revealed that the main factors influencing the differentiation of communities are the degree of humidification, which is largely related to the climatic characteristics of the regions, including the degree of local humidification in specific habitats, as well as the richness of soils. The invasion of alien plant species, which become dominant and sodominant in the individual syntaxa, also plays an important role. Similar species: Cuscuta campestris and Hordeum jubatum.

Comparative Analysis of Rhizosphere Fungi in Ageratina Adenophora and Associated Native Species in Far-Western Nepal

Root exudates play a significant role in influencing the rhizosphere microbes. Fungi are an important group of microbes that are influenced by plant root exudates. As invasive alien plant species secretes several allelochemicals and impact soil microbes, this study compared the fungal community in one of the invasive weeds Ageratina adenophora with native species (Rubus ellipticus, Shorea robusta and Imperata cylindrica) in far-western Nepal. The rhizosphere soil was sampled by uprooting respective plants, and the soils were cultured using Czapek Dox Agar and PDA media. A total of 49 fungal species were identified from the plant rhizospheres. A. adenophora altered the species richness, occurrence and frequency of fungi in soil. The pathogenic fungi Aspergillus niger, Myrothecium sp., Phoma sp., Rhizoctonia sp., Pythium oligandrum, Verticillium spp. were the most frequently occurring rhizosphere fungi in all plants and they showed their host specificity in the rhzosphere. The fungi species such as Paecilomyces lilacinus, Aspergillus flavus, Myrothecium sp., Penicillium citrinum, P. chrysogenum, Rhizoctonia sp., Mucor circinelloides, Hypocrea sp., Trichoderma hypoxylon, T. sparsum, Gliocladium sp., Hypomyces sp., Aspergillus niger and M. circinelloides were common in all native plants. Even minor variations in the physicochemical properties of soil can change the presence of fungal species in the root zone, as indicated by the analysis of soil chemicals.

Sentinel-2 Time Series and Classifier Fusion to Map an Aquatic Invasive Plant Species along a River—The Case of Water-Hyacinth

Freshwater ecosystems host high levels of biodiversity but are also highly vulnerable to biological invasions. Aquatic Invasive Alien Plant Species (aIAPS) can cause detrimental effects on freshwater ecosystems and their services to society, raising challenges to decision-makers regarding their correct management. Spatially and temporally explicit information on the occurrence of aIAPS in dynamic freshwater systems is essential to implement efficient regional and local action plans. The use of unmanned aerial vehicle imagery synchronized with free Sentinel-2 multispectral data allied with classifier fusion techniques may support more efficient monitoring actions for non-stationary aIAPS. Here, we explore the advantages of such a novel approach for mapping the invasive water-hyacinth (Eichhornia crassipes) in the Cávado River (northern Portugal). Invaded and non-invaded areas were used to explore the evolution of spectral attributes of Eichhornia crassipes through a time series (processed by a super-resolution algorithm) that covers March 2021 to February 2022 and to build an occurrence dataset (presence or absence). Analysis of the spectral behavior throughout the year allowed the detection of spectral regions with greater capacity to distinguish the target plant from the surrounding environment. Classifier fusion techniques were implemented in the biomod2 predictive modelling package and fed with selected spectral regions to firstly extract a spectral signature from the synchronized day and secondly to identify pixels with similar reflectance values over time. Predictions from statistical and machine-learning algorithms were ensembled to map invaded spaces across the whole study area during all seasons with classifications attaining high accuracy values (True Skill Statistic, TSS: 0.932; Area Under the Receiver Operating Curve, ROC: 0.992; Kappa: 0.826). Our results provide evidence of the potential of our approach to mapping plant invaders in dynamic freshwater systems over time, applicable in the assessment of the success of control actions as well as in the implementation of long-term strategic monitoring.

Smart(phone)-Monitoring (SPM): An Efficient and Accessible Method for Tracking Alien Plant Species

The invasion of alien plant species outside of their home range constitutes an emerging problem threatening native plant diversity. The expansion of alien species is often favored in anthropogenic habitats, such as roads and urbanized areas, which allow the rapid colonization of new sites by these species. The development of suitable monitoring methods is fundamental both to keep pace with the fast expansion dynamics of these species and to enable appropriate and prompt control strategies. In this work, an efficient, accessible, and cost-effective method for monitoring alien plants using a smartphone is proposed (smartphone-monitoring—SPM). Using smartphones with a geolocation system, geographic coordinates of images matched to single plant records can be easily acquired and structured into exportable databases in a few steps. We tested the SPM method on three black-listed alien plants, Ailanthus altissima (Mill.) Swingle, Arundo donax L., and Robinia pseudoacacia L., along the road network and in major urban centers of the Tuscany region (central Italy).

Distribution Patterns and Determinants of Invasive Alien Plants in China.

In recent years, invasive alien plants (IAPs) have caused serious ecological disasters and economic losses in China. This study combined three IAP species richness-related indices (species richness of IAPs, first records of IAPs, and the relative species richness of IAPs), as well as indices reflecting distribution and dispersal patterns (average similarity coefficient of IAPs) and invasiveness (average risk score of IAPs), to conduct an integrated regional-invasion risk assessment based on the principal component analysis (PCA) method. Partial least-squares (PLS) regression was conducted to explore the explanatory power of 12 environmental and anthropogenic factors on different invasion indices. The results indicated that coastal provinces and Yunnan had high IAP introduction risk, as well as high synthetic-risk scores. The dispersal of IAPs in mid-latitude provinces should be particularly prevented. For species richness of IAPs, more environmental factors with variable importance for the project (VIP) values higher than 1 were retained in the optimal model, reflecting the importance of environmental filtering on IAPs. Visitors were the most important predictor for first records of IAPs. Compared to species richness (R2 = 79.5%), first records were difficult to predict (R2 = 60.4%) and were influenced by anthropogenic factors. There was spatial distribution congruence of various families of IAPs. Generally, the correlations of the residuals of species richness were still significant, with 0.421 (p < 0.05) as the lowest Pearson correlation coefficient, which indicated that external factors could not fully explain the spatial distribution congruence. These findings could enrich the relevant research on IAP invasion mechanisms and provide suggestions for regional IAP detection and response.