Introduced Plant Species Research Articles

Response of Native and Non-Native Subarctic Plant Species to Continuous Illumination by Natural and Artificial Light.

This study addressed the following questions: How does continuous lighting (CL) impact plant physiology, and photosynthetic and stress responses? Does the impact of CL depend on the source of the light and other environmental factors (natural vs. artificial)? Do responses to CL differ for native and non-native plant species in the subarctic region and, if differences exist, what physiological reasons might they be associated with them? Experiments were conducted with three plants native to the subarctic region (Geranium sylvaticum L., Geum rivale L., Potentilla erecta (L.) Raeusch.) and three non-native plant species (Geranium himalayense Klotzsch, Geum coccineum Sibth. and Sm., Potentilla atrosanguinea Loddiges ex D. Don) introduced in the Polar-Alpine Botanic Garden (KPABG, 67°38' N). The experimental groups included three species pairs exposed to (1) a natural 16 h photoperiod, (2) natural CL, (3) an artificial 16 h photoperiod and (4) artificial CL. In the natural environment, measurements of physiological and biochemical parameters were carried out at the peak of the polar day (at the end of June), when the plants were illuminated continuously, and in the second week of August, when the day length was about 16 h. Th experiments with artificial lighting were conducted in climate chambers where plants were exposed to 16 h or 24 h photoperiods for two weeks. Other parameters (light intensity, spectrum composition, temperature and air humidity) were held constant. The obtained results have shown that plants lack specific mechanisms of tolerance to CL. The protective responses are non-specific and induced by developing photo-oxidative stress. In climate chambers, under constant environmental conditions artificial CL causes leaf injuries due to oxidative stress, the main cause of which is circadian asynchrony. In nature, plants are not photodamaged during the polar day, as endogenous rhythms are maintained due to daily fluctuations of several environmental factors (light intensity, spectral distribution, temperature and air humidity). The obtained data show that among possible non-specific protective mechanisms, plants use flavonoids to neutralize the excess ROS generated under CL. In local subarctic plants, their photoprotective role is significantly higher than in non-native introduced plant species.

Dietary foundations for pollinators: nutritional profiling of plants for bee health

Human activities, including urban expansion, intensive farming practices, and the application of pesticides have significantly reshaped bee habitats. Understanding the nutritional content of pollen, the primary source of bees’ proteins and lipids, is important for maintaining their diet and health. In this study, we set out to determine the nutritional composition of pollen from various plant families and genera. Our objectives were to analyze the levels of non-esterified fatty acids (NEFAs), amino acids (AAs), protein-to-lipid (P:L) ratios, and omega-6:3 ratios of 57 pollen species native to North America. These data suggest a potential trade-off between NEFA and AA content within pollen, suggesting that a diverse floral diet may benefit bees more than a single pollen source. The AA profiles showed considerable diversity, with all pollen species providing the essential amino acids (EAAs) required for bee health, except for methionine which was lacking in Rhus glabra pollen. The plant family Asteraceae was especially abundant in EAAs. P:L ratios varied widely further emphasizing bees’ need for access to a diverse array of nutritional profiles. There were no overall nutritional differences between pollen from native and introduced plant species. This study highlights the significance of a diverse array of floral resources to meet the comprehensive nutritional needs of bees, contributing to the support of pollinator populations and the broader ecological system.

Seasonal changes in habitat use and behavior of the threatened Pampas meadowlark Leistes defilippii

The Pampas grasslands’ biodiversity is severely threatened by habitat modification, as is the case for the Pampas meadowlark ( Leistes defilippii). Here we study the areas used by the species throughout the year in the Southern Pampas of Argentina, in association with seasonal changes in behavior, in an attempt to provide information for its effective conservation. We selected four grassland sites with livestock activities in which we studied vegetation characteristics and the abundance and behavior of the Pampas meadowlark, during breeding and non-breeding seasons. The species was absent in sites with higher bare ground cover and lower cover of >30 cm vegetation, and with high proportions of forb, shrub or exotic grass species. In those areas where the Pampas meadowlark was present during the breeding season, its abundance was higher where the grassland was entirely dominated by native grasses, and abandoned another site when the grassland became dominated by introduced plant species, after the breeding period. We are the first to report the behavior of a Pampas meadowlark population throughout an entire year with its seasonal changes. Our results and description of the behavior throughout the year highlight the importance of structural heterogeneity of the grasslands, determined by a low intensity of grazing, for the breeding of the Pampas meadowlark. Also, features associated with breeding habitat can’t predict the presence of flocks during the non-breeding season, as noted in our results for vegetation structure, but vegetation composition, food availability and landscape variables could play an important role in determining which areas serve as appropriate habitat during the non-breeding season, when large flocks search the grasslands for food. A better understanding of the habitat requirements and the use of space at different scales by the Pampas meadowlark will allow the identification of the most urgent and effective measures for its conservation.

Genetic and phenotypic differentiation in functional traits of Iris pseudacorus L. in native and introduced Mediterranean climate ranges

Intraspecific variation in functional traits between native and introduced plant species may underlie resilience and invasiveness of introduced species. We explored if observed phenotypic variation of Iris pseudacorus L. between populations in the native vs. introduced ranges results from genetic differentiation and/or phenotypic plasticity. Seeds were collected from populations along estuarine stress gradients within populations in both Guadalquivir Estuary (Andalusia, Spain) and San Francisco Bay-Delta Estuary (California, USA). Genetic analysis was performed on leaf tissue from plants in each seed donor population. Germinants (n = 48: 6 plants × 4 populations × 2 ranges) were grown for 12 months in a common garden experiment (CGE). We then evaluated 25 traits including growth, biomass allocation, morphological and biochemical responses. Geographic range explained relative intraspecific trait variation segregating native from introduced phenotypes. Native plants had lower specific leaf area (− 34%) and carbohydrate concentrations in rhizomes (− 63%) than introduced plants, providing evidence of genetic differentiation. Higher genetic diversity and 27% higher phenotypic variation (CGE) of native vs. introduced plants indicated longer-term adaptive processes in the native range. Genetic distance of introduced populations (field) increased along with their phenotypic distance (CGE), suggesting rapid genetic differentiation. Phenotypic plasticity also explained some observed inter-range differences under field conditions not expressed by plants in the CGE. Management of the introduced I. pseudacorus populations should be established urgently since they represent novel genotypes with key functional traits that can support invasiveness through increased competitive ability and physiological stress tolerances to sea level rise.

The specialised buzz pollination syndrome poses a partial barrier to plant invasions

Abstract Plants that exhibit generalised pollination syndromes have been hypothesised to become invasive more easily compared with specialists, yet the degree to which specialised pollination traits inhibit plant invasions is unknown. One such specialisation is the buzz pollination syndrome, which encompasses specialised floral traits that restrict pollen access (typically poricidal anthers) and benefits from specialised insect behaviour for pollen extraction. We reviewed the literature on buzz pollination of invasive plants to assess whether: (1) plant species exhibiting specialised pollination syndromes are underrepresented as invasive species, and (2) species with specialised pollination syndromes that have become invasive can reproduce in the absence of specialist buzzing pollinators. Synthesis. We found 2.5% (117/4630) of invasive angiosperms have poricidal anthers, which is an underrepresentation of the proportion of global angiosperms that are estimated to have poricidal anthers (6%–10%). Most invasive buzz‐pollinated plants are genetically self‐compatible (97%), but only 43% can set fruit in the absence of a pollinator. Our findings highlight the importance of establishing new pollinator mutualisms for sexual reproduction. However, we identified six non‐buzzing behaviours used to extract pollen from plants with poricidal anthers, which is important where buzzing pollinators may be absent or not attracted to newly introduced plant species.

Shifting the paradigm: The role of introduced plants in the resiliency of terrestrial ecosystems to climate change.

Current ecological communities are in a constant state of flux from climate change and from species introductions. Recent discussion has focused on the positive roles introduced species can play in ecological communities and on the importance of conserving resilient ecosystems, but not how these two ideas intersect. There has been insufficient work to define the attributes needed to support ecosystem resilience to climate change in modern communities. Here, I argue that non-invasive, introduced plant species could play an important role in supporting the resilience of terrestrial ecosystems to climate change. Using examples from multiple taxonomic groups and ecosystems, I discuss how introduced plants can contribute to ecosystem resilience via their roles in plant and insect communities, as well as their associated ecosystem functions. I highlight the current and potential contributions of introduced plants and where there are critical knowledge gaps. Determining when and how introduced plants are contributing to the resilience of ecosystems to climate change will contribute to effective conservation strategies.

DNA metabarcoding analysis of the bare-nosed wombat (Vombatus ursinus) diet.

Wombats are native herbivorous grazers that have adapted to Australia's low-quality forage. Studies on diet selection by bare-nosed wombats (Vombatus ursinus) are limited and are either observational or based on microhistological studies. The current study determined the diet of wombats through DNA metabarcoding across five study sites in New South Wales over a one-year period. Metabarcoding was chosen as it is non-invasive, less time consuming and more specific than traditional techniques. The list of 209 plant species identified as eaten by wombats in this study is much higher than previously reported, with grasses being the most common plant group identified in all samples. Most dietary items identified were introduced plant species. Seasonal differences in plants eaten occurred at four of the five study sites and may reflect dietary abundance and floristic composition at different times of year. Further studies are required to determine if the dietary items differ markedly across the entire range of wombats, and if nutrition influences dietary preferences.

Virome release of an invasive exotic plant species in southern France.

The increase in human-mediated introduction of plant species to new regions has resulted in a rise of invasive exotic plant species (IEPS) that has had significant effects on biodiversity and ecosystem processes. One commonly accepted mechanism of invasions is that proposed by the enemy release hypothesis (ERH), which states that IEPS free from their native herbivores and natural enemies in new environments can outcompete indigenous species and become invasive. We here propose the virome release hypothesis (VRH) as a virus-centered variant of the conventional ERH that is only focused on enemies. The VRH predicts that vertically transmitted plant-associated viruses (PAV, encompassing phytoviruses and mycoviruses) should be co-introduced during the dissemination of the IEPS, while horizontally transmitted PAV of IEPS should be left behind or should not be locally transmitted in the introduced area due to a maladaptation of local vectors. To document the VRH, virome richness and composition as well as PAV prevalence, co-infection, host range, and transmission modes were compared between indigenous plant species and an invasive grass, cane bluestem (Bothriochloa barbinodis), in both its introduced range (southern France) and one area of its native range (Sonoran Desert, Arizona, USA). Contrary to the VRH, we show that invasive populations of B. barbinodis in France were not associated with a lower PAV prevalence or richness than native populations of B. barbinodis from the USA. However, comparison of virome compositions and network analyses further revealed more diverse and complex plant-virus interactions in the French ecosystem, with a significant richness of mycoviruses. Setting mycoviruses apart, only one putatively vertically transmitted phytovirus (belonging to the Amalgaviridae family) and one putatively horizontally transmitted phytovirus (belonging to the Geminiviridae family) were identified from B. barbinodis plants in the introduced area. Collectively, these characteristics of the B. barbinodis-associated PAV community in southern France suggest that a virome release phase may have immediately followed the introduction of B. barbinodis to France in the 1960s or 1970s, and that, since then, the invasive populations of this IEPS have already transitioned out of this virome release phase, and have started interacting with several local mycoviruses and a few local plant viruses.

Feeding of lygaeid bugs (Heteroptera, Lygaeidae) on the common milkweed (Asclepias syriaca L.) in Kaniv Nature Reserve

The paper presents data on the feeding of three species of bugs of the Lygaeidae family: Tropidothorax leucopterus (Goeze, 1778), Lygaeus equestris (Linnaeus, 1758) and L. simulans (Deckert, 1985) on common milkweed (Asclepias syriaca L.) in the conditions of Kaniv nature reserve, located in the forest-steppe zone in the central part of Ukraine. Common milkweed is a dangerous invasive species, a transformer of ecosystems, which poses a threat to local plant and animal communities. There is a problem in finding methods of limiting the spread of populations of this species. Among the factors that contribute to its limitation may be the consumption of common milkweed by animals, in particular by phytophagous insects. The study was conducted during the growing seasons of 2022 and 2023 on the grassland area overgrown with tree and shrub vegetation on the hills on the right bank of the Dnipro River. Tropidothorax leucopterus were feeding on sap from the vegetative body of common milkweed plants, being, for the most part, on the lower surface of the leaves. They formed dense groups, and the number of bugs on one plant could reach up to 100 individuals. Both the nymphs (from June to September) and the adults (from August to October) of this species were noted. During the study, it was also observed feeding of this species on the white swallow-wort (Vincetoxicum hirundinaria Medik.), which is a traditional food object for this insect. But only single individuals of these bugs were found on the white swallow-wort. The representatives of the other two species, Lygaeus equestris and L. simulans, fed on the content of the common milkweed seeds during the fruit opening period. Separate individuals or small groups (up to 20 individuals) were observed, adults and single nymphs were noted. The transition of native phytophagous species to feeding on the common milkweed can facilitate its inclusion in food chains in local ecosystems and limit the spread of this aggressive introduced plant species

Late-Holocene stability and recent changes in small mammal communities in north-central Andean forests of Patagonia

Past and current climatic and environmental changes have contributed to configure actual species distributions and abundances. Knowing their evolution over time allows discrimination between natural and anthropogenic causes in current composition of faunal communities. We evaluate the changes in small mammal assemblages from the north-central Patagonian Andean forests since the Late-Holocene to recent times and their relationship with the environmental modifications driven by human activities. A bone sequence from Población Anticura archaeological site (lower Manso river valley, Río Negro province, Argentina) was studied, which encompasses a time span from the early Late-Holocene (3350 ± 100–2270 ±80 years BP) to final Late-Holocene (1420 ± 70–530 ±50 years BP) and Historical times (480 ± 70–280 ±40 years BP). The species composition indicates that forest environment established in the area from at least the Late-Holocene (dominance of Loxodontomys micropus, with subordinate frequencies of Abrothrix olivacea, A. hirta, Geoxus valdivianus, Irenomys tarsalis, and Paynomys macronyx), with patches of (or near to) open environments (presence of Reithrodon auritus and cavids). It is remarkable the presence of cavids, which increased their abundance in the sequence towards Historical times but disappeared nowadays. The low frequencies (<10%) of the rodent Oligoryzomys longicaudatus along the entire sequence is also relevant, since this rodent is the reservoir of the Andes strain of the Hantavirus (ANDV), which causes pulmonary syndrome. This mouse dominates the small mammal assemblages from forests and ecotonal shrublands of northwestern Patagonia (abundances exceed 50% in owl pellets recently collected from the study area). Current configuration of forest and ecotonal assemblages, particularly the high abundance of O. longicaudatus, should be mainly linked to anthropogenic causes, including the introduction of cattle, land clearing, and the advance of introduced plant species such as the sweet briar ( Rosa eglanteria). Particularly, this exotic shrub offers shelter and additional food for O. longicaudatus, turning their shrublands into spaces of high epidemiological risk.

Studying of the biological characteristics of introduced rare citrus taxa in the humid subtropics of Russia as one of the elements of preserving and increasing plant biodiversity

The study is devoted to the study of the biological characteristics of introduced citrus taxa. The study of the biological characteristics of plants in various soil-climatic zones is of great scientific and practical importance, and is an essential element in preserving and increasing biodiversity by new introduced plant species. As a result of the research, the forms C. maxima ‘Sambokan’, C. × meyeri, C. × limetta ‘Chontipico’ and C. × limonelloides were isolated, which can be recommended for creating plantings in open ground and cultivation structures with uncontrolled conditions in the humid subtropics of Russia. Taxa C. aurantifolia, C. aurantifolia ‘Foro’, C. × limonelloides, C. × meyeri, C. × myrtifolia, C. × latifolia, C. × bergamia, C. × limetta ‘Chontipico’, C. limon ‘Del Brasil’, C. × meyeri, C. medica var. sacrodactylus, distinguished by its decorative qualities, can be recommended as an extension crop in demonstration areas, as well as for the design of winter gardens, terraces and interiors in various rooms.

Habitat restoration to conserve the Little Vermilion Flycatcher on Santa Cruz Island, Galapagos.

The endemic Little Vermilion Flycatcher (LVF), Pyrocephalus nanus, has suffered a drastic decline on Santa Cruz Island, where it was common 30 years ago. Currently, less than 40 individuals remain in the last remnants of natural humid forest in the Galapagos National Park on this island. This small population has low reproductive success, which is contributing to its decline in Santa Cruz. Previous studies have identified Avian Vampire Fly, Philornis downsi, parasitism, changes in food sources, and habitat alteration as threats to this species. In Santa Cruz, invasive plants may strongly affect the reproductive success of the LVF because they limit accessibility to prey near the ground, the preferred foraging niche of these birds. Since 2019, we restored the vegetation in seven plots of one hectare each by removing invasive blackberry plants and other introduced plant species. In all nests that reached late incubation, we also reduced the number of Avian Vampire Fly larvae. In this study, we compared foraging and perch height, pair formation, incubation time and reproductive success between managed and unmanaged areas. As predicted, we found significantly lower foraging height and perch height in 2021 in managed areas compared to unmanaged areas. In 2020, daily failure rate (DFR) of nests in the egg stage did not differ between management types; however, in 2021, DFR in the egg stage was significantly lower in managed areas than in unmanaged areas. The DFR during the nestling stage was similar between managed and unmanaged areas in 2020, but in 2021, only nests in managed areas reached the nestling stage. Females brooded significantly more during the incubation phase in managed areas. Additionally, we found significantly higher reproductive success in managed areas compared to unmanaged areas in 2021, but not in 2020. Habitat restoration is a long-term process and these findings suggest that habitat management positively affects this small population in the long term.

Atta cephalotes (Hymenoptera: Myrmicinae) is colonizing urban areas in Cali, Colombia

Numerous studies have examined the effect of invasive species on biodiversity in urban environments, however, few of them have investigated the role of native species while turning into invasive pests. In Colombia, Atta cephalotes, a native leaf-cutting ant (LCA), has responded successfully to the conversion of natural ecosystems to agricultural-rural environments and, most recently, to residential and urban development. In this study, we illustrate the incidence and distribution of this native ant species in an environment where animal life must face urban disturbs in the physical environment, resource availability, and ecosystem processes associated with human urbanization in Cali, the third most important city in Colombia. For this, A. cephalotes nests were georeferenced in public green areas located in 12 communes across the city of Cali, southern Colombia. Vegetation and soil cover, urban settings, foraging trails and plants foraged by the ants were recorded. A. cephalotes nests were present in all green areas and, even in human dwellings; the ants harvested both native and introduced plant species. Despite being well adapted to strongly modified urban environments, this ant species appears to be dependent on human-subsidized resources. Given the wide distribution of leaf-cutting ants in Latin America, it is plausible to expect that similar processes are underway in other countries where these ants are found. Hence, this study also proposes to alert the academic and social communities to direct future research towards evaluating both the responses and impacts of these ants in relation to changes in the urban landscape.

Alien species of vascular plants of Taimyr

The features of alien plant species distribution in Taimyr district of Krasnoyarsk region are characterized. Totally, 54 alien plant species (5.5 % of the district’s flora) were found in the area, 27 of them were observed by the authors more than once or found in the region for the first time. The general features of the distribution, occurrence and timing of these species are given. For row of species, methods of introduction and assessment of population dynamics (emergence and extinction) are considered. It has been noted that a large part of noted imported species populations are very short-lived (1-2 years, rarely more). It is also discussed whether certain species are alien or natural. A relatively new group of introduced species - those spreading from culture (mainly from lawn mixtures) - has been identified that requires a separate special study. The likelihood of significant introductions of alien species into natural ecosystems, based on available observations, is assessed as low. As a rule, introduced plant species appear only in the early stages of post-anthropogenic succession or under constant influence of technogenic factors, later they are still superseded by the native pioneer erosiophilic species. Nevertheless, the need to monitor the invasion of alien species and the dynamics of their populations remains relevant as a general element in the dynamics of the composition of the Arctic flora.

Peculiarities of Respiration and Photosynthesis Processes of Plants Belonging to the Genera Catalpa L. and Paulownia L. Used in Landscaping of the City of Vanadzor

Key words: global climate change, biodiversity, greening, introduced species The species composition of biodiversity is negatively affected by global climate change. As a result of global warming, changes in the physiological processes of many plant species occur. Due to global warming, it has been recorded that many introduced plant species are well adaptable in the wild and suitable for cultivation. Presumably plants, belonging to the genera Catalpa L. and Paulownia L. are such species of plants. Given the projections of global warming, the selection of plant species for urban greening should prioritize not only their fast growth rate and adaptability but also an examination of their fundamental physiological processes, specifically focusing on photosynthesis and respiration, within the specific urban environment. Based on the research conducted in the city of Vanadzor in June and August 2023, it has been determined that plants from the genera Catalpa L. and Paulownia L. are among the introduced species utilized for the city's landscaping. Previously, plant species belonging to these genera were not used in landscaping. In all likelihood, the climatic conditions of Vanadzor were unfavorable for growing these plants. Due to the increase in average annual temperature, plants belonging to these two genera were discovered in the green spaces of the city of Vanadzor. In the trees belonging to the genus Catalpa L. in the city of Vanadzor, there was a recorded increase in photosynthetic activity by 1.025 times at the end of the growing season. This is significant because the utilization of this plant type for city greening can help reduce CO2 concentration in the atmosphere. On the other hand, the examination of the basic physiological processes in trees belonging to the genus Paulownia L. indicates a high rate of respiration intensity, resulting in the release of CO2 gas into the atmosphere in these plant species. These findings emphasize the need for a scientific approach to landscaping, taking into account the projected climate changes in the city of Vanadzor.

14,000 years of climatic and anthropogenic change in the Afromontane forest of São Tomé Island, Gulf of Guinea

São Tomé (Gulf of Guinea, Central Africa) is a 854 km2 tropical island that had a pivotal role in early European colonial expansion through the Atlantic between the 15th and 16th centuries. Historical sources suggest that native vegetation has been heavily impacted since human arrival (1470 CE) due to monoculture economies and the introduction of mammals and plants, some of which now have established wild populations. The Afromontane forest of São Tomé, located above 800 m.a.sl., is particularly rich in endemic plant species and has remained relatively unaffected by direct human impacts. Here, we explore how environmental change influenced this forest through the study of a sedimentary sequence from the volcanic crater of Lagoa Amélia (1340 m a.s.l.), a palustrine system located at the boundary between submontane (800–1400 m a.s.l.) and mist forest (above 1400 m a.s.l.). We used fossil pollen, non-pollen palynomorphs, sedimentology and charcoal to determine forest dynamics from the Late Pleistocene to the present. From 14,000 to 12,500 cal yr BP the forest was dominated by taxa from higher altitudes, adapted to cooler and drier climates (e.g. Afrocarpus mannii trees and Psychotria nubicola). After 12,500 cal yr BP, a potential uphill migration was identified by an increase in taxa like the trees Symphonia globulifera and Craterispermum cerinanthum. From 11,200 cal yr BP through the rest of the Holocene taxa from lower altitudes became dominant (e.g. Prunus africana, Polyscias, and Sabicea), except at c. 8500 cal yr BP when rapid cooling led to forest opening. Charcoal showed that fires were frequent during the Late Pleistocene (14,000 to 11,200 cal yr BP), becoming rare during the Holocene until anthropogenic fires started at c. 220 cal yr BP. Other recent anthropogenic impacts detected in Lagoa Amélia included the appearance of pollen of introduced plant species (e.g., Cestrum), and the increase in pollen of economically important species (Elaeis guineensis, Zea mays) and in fungal spores related to introduced herbivores. Our results reveal that climate changed the altitudinal distribution of the Afromontane forest in São Tomé during the Late Pleistocene, as observed on the African continent, and that this ecosystem was also strongly impacted by human arrival, through fire, farming, and introduced species.

Introduced plant species in the urban environment of the temperate-continental climate zone under conditions of global warming

Global climate change stimulates migration, which increases the number of introduced plant species, as well as those with a status of rarity, so the aim of the study was to identify highly promising plants of rare and decorative species in Ukraine to overcome the negative impact of the "urban heat island". We selected 40 species of plants native to temperate and continental climates for the study: 24 species are not commonly cultivated in the Polissya and Forest-Steppe regions of Ukraine and 16 species are widespread in this area. To select plants that are effective in reducing the negative effects of the urban heat island, we determined the relative decrease in ambient temperature near the crown of plants using an Elitech RC-4 thermometer and diagnosed the photosynthetic apparatus using a Floratest fluorometer. The analysis was based on the chlorophyll fluorescence induction curve. Among the rare species, the following species proved to be the best in terms of stress resistance, photosynthetic apparatus efficiency and temperature reduction near the crown: Acer mandshuricum, Aesculus pavia, Broussonetia papirifera, Catalpa bignonioides, Corylus colurna, Fagus orientalis, Fagus sylvatica, Prunus padus, Tetradium daniellii, the planting of which will reduce the negative effects of the "urban heat island". In addition, species that are not commonly cultivated in the continental climate zone have proven to be very promising for urban greening in this climate zone: Acer pseudoplatanus, Acer velutinum, Corylus maxima 'Atropurpurea', Fagus sylvatica 'Atropurpurea', Parrotia persica, Phelodendron amurense, Platanus × hispanica, Prunus dulcis, Pterocarya pterocarpa and Tilia platyphyllos. The use of rare species in urban landscaping will also help to preserve biodiversity according to the "Global Biodiversity Strategy".

Hidden cargo: The impact of historical shipping trade on the recent-past and contemporary non-native flora of northeastern United States.

Understanding establishment and spread of non-native plants is important in the face of a homogenizing global flora. While many studies focus on successful, invasive species, fewer have studied failed plant introductions. Until the early 1900s, large quantities of ship ballast, often containing foreign plant propagules, were deposited in New Jersey (USA). The resulting ballast flora is documented in extensive herbarium records, providing us a unique opportunity to analyze successes and failures of novel plant species introductions. We used digitized specimens from 75 herbaria to study 264 non-native species introduced into New Jersey through 19th century ballast deposition. We used spatial (density-based clustering; HDBSCAN) and temporal analyses of species retention and geographic spread to quantify disappearance rate, survival, and dispersion through time and define trajectory groups. Four distinct trajectory groups were identified: waif (only present during import; 32% of species), short-term (disappeared quickly; 20%), established-limited spread (survives locally, 30%), and established-widespread (widespread, 18%). Species disappearance rate was highest during ballast deposition and decreased soon after deposition stopped around 1900. Spatial patterns showed a strong association with 19th century railroads for inland dispersal from ports. The disappearance rate and spatial analyses are robust to herbarium collection bias. This study using New Jersey as a model is one of the few documenting multispecies successes and failures in inadvertent plant introductions. Results reveal distinct trends in species establishment and geographic spread and highlight the utility of herbarium specimens in answering questions that span large time scales.

Adaptive ecological knowledge among the Ndjuka Maroons of French Guiana; a case study of two ‘invasive species’: Melaleuca quinquenervia and Acacia mangium

BackgroundTo understand how local ecological knowledge changes and adapts, here in the case of the recent introduction of plant species, we report the knowledge and perceptions of the Ndjuka (Maroon) of French Guiana concerning two tree species, Acacia mangium and niaouli (Melaleuca quinquenervia), which are categorized as “invasive alien plants” in the savannas of their territory.MethodsTo this end, semi-structured interviews were conducted between April and July 2022, using a pre-designed questionnaire, plant samples and photographs. The uses, local ecological knowledge, and representations of these species were surveyed among populations of Maroon origin in western French Guiana. All responses to closed questions collected during the field survey were compiled into an Excel spreadsheet in order to perform quantitative analyses, including the calculation of use reports (URs).ResultsIt appears that the local populations have integrated these two plant species, which are named, used and even traded, into their knowledge systems. On the other hand, neither foreignness nor invasiveness seem to be relevant concepts in the perspective of the informants. The usefulness of these plants is the determining factor of their integration into the Ndjuka medicinal flora, thus resulting in the adaptation of their local ecological knowledge.ConclusionIn addition to highlighting the need for the integration of the discourse of local stakeholders into the management of "invasive alien species,” this study also allows us to observe the forms of adaptation that are set in motion by the arrival of a new species, particularly within populations that are themselves the result of recent migrations. Our results furthermore indicate that such adaptations of local ecological knowledge can occur very quickly.

Media myopia distorts public interest in US invasive plants

AbstractIntroduced invasive plants are a major environmental problem, but public interest in invasive plants is generally considered low compared to climate change and threatened flagship species, hindering support for effective management and policy. To understand what does drive public interest in invasive plants in the US, we investigated Google Trends search data from 2010 to 2020 for 209 introduced plant species found in the continental US. Using a phylogenetically-controlled structural equation model, we investigated three hypothesized drivers of interest: (1) plant abundance as quantified by national and state-level occurrence records in the Global Biodiversity Information Facility, (2) four key plant traits that might influence plant conspicuousness to the general public: ornamental use, human health risks, monoculture formation, and plants with positive economic value, and (3) media coverage, in particular the volume and sentiment of news articles over the same 10-year period. Public search interest was highest for the most abundant introduced species and those with human health risks, but significantly lower for ornamentals. News coverage was mostly negatively toned and disproportionately focused on a relatively small group of widespread invasive species, with significantly lower and more positively-worded coverage of ornamentals. Ultimately, we suggest that a narrow emphasis on a few highly covered ‘notorious’ invasive plant species, with lower and more positive coverage of ornamental introduced species, could send mixed messages and weaken public awareness of the threats of biological invasions. However, the generally strong linkages between public search interest and media coverage of invasive plants suggests ample opportunity to improve messaging and increase public awareness.