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Natural ecosystems generally include litter decomposition as part of the natural cycle since the material properties and the environment greatly influence the decomposition rate. The invasion of exotic plants alters the species diversity and growth characteristics of plant communities, but its impact on litter decomposition is unknown in the riparian zone. This study examines how invasive plants affect the early stages of litter decomposition and how species richness impacts them. This experiment involved a random litter mixture of exotic (Alternanthera philoxeroides and Bidens pilosa) and native species in the riparian zone of the Three Gorges Dam Reservoir in China. There were 43 species mixture types, with various species richness ranging from 1 to 6. Litterbags were placed in the hydro-fluctuation zone and terrestrial zone, where they decomposed over the course of 55 days. Invasive plants decompose rapidly compared to native plants (35.71% of the remaining mass of the invasive plant). The invasive plant A. philoxeroides has the potential to accelerate native plant decomposition (0.29 of non-added synergetic effect), but Bidens pilosa cannot. Nonetheless, species richness had little effect on the decomposition rate. These effects are dependent upon differences in chemical functional characteristics among the species. The initial traits of the plants, specifically C, N, and C/N, were significantly and linearly correlated with the loss of mixed litter mass and mixing effect strength (P < 0.01). In addition, submergence decomposition conditions reduce the disturbance of invasive plants and predict decomposition rates based on litter characteristics. Invasive plants can therefore impact the material cycle of an ecosystem. There is a need to examine decomposition time, which may also involve considering other factors. [ABSTRACT FROM AUTHOR]

Exotic plants are plants that are intentionally or unintentionally included in an area. Based on the results of the 2020 survey, one of the exotic plants found in the Donglo Block Rehabilitation Zone area of Meru Betiri National Park (MBNP) is cinderella weed (Synedrella nodiflora). The objective of this study is to determine the distribution pattern and area of cover of exotic S. nodiflora plants in the research location. Data were collected using a combination method of systematic plot transects measuring 2 x 2 meters which were placed along the transect with a total of 415 plots. The data recorded were the coordinate position of each individual S. nodiflora and the area of the cover. Analysis of distribution pattern data using the Morisita index and visualized with a spatial distribution map using Geographic Information System (GIS). Coverage area analysis was carried out by calculating the percent cover of S. nodiflora. The results of the analysis of the Morisita index showed the value of Iδ = 7.13, which indicates that the distribution pattern of the plants is clustered. In addition, the presence of this species in the study area was occupied 41.7% or 0.85 ha of the total area of 2.04 ha. It shows that this species still did not dominate the area, so it can be said that this species has not yet become an invasive species category in the research location.

ABSTRACT Exotic grasses have been introduced into wetlands and can compete with native plants due to their high tolerance of flood and dry periods. Flooding can facilitate seed dispersal of exotic species and reduce the diversity of native species. We compared two grasslands to assess whether seed banks can maintain the diversity of native plants in wetlands with introduced exotic plants. We recorded a total of 136 species and a predominance of annual plants in the seed bank and vegetation together. The seed bank had high species diversity independently of the dominance of the exotic Urochloa humidicola in the vegetation. The seed banks of the native and cultivated grasslands differed significantly with a positive correlation for aquatic plants in the native grassland and negative correlation in the cultivated grassland. The seed bank revealed potential to maintain the diversity of native species in the cultivated grassland since the flood and dry seasons promoted the presence of distinct species in the seed bank, but lower richness in the vegetation reflects a dependence on the germination stage. The seasonality of flood and dry periods influences distinct growth forms, increasing the diversity of the seed bank and the vegetation.

Exotic plant invasions are a major driver of global environmental change that can significantly alter the availability of limiting nutrients such as nitrogen (N). Beginning with European colonization of California, native grasslands were replaced almost entirely by annual exotic grasses, many of which are now so ubiquitous that they are considered part of the regional flora (ânaturalizedâ). A new wave of invasive plants, such as Aegilops triuncialis (Barb goatgrass) and Elymus caput-medusae (Medusahead), continue to spread throughout the state today. To determine whether these new-wave invasive plants alter soil N dynamics, we measured inorganic N pools, nitrification and denitrification potentials, and possible mediating factors such as microbial biomass and soil pH in experimental grasslands comprised of A. triuncialis and E. caput-medusae. We compared these measurements with those from experimental grasslands containing: (1) native annuals and perennials and (2) naturalized exotic annuals. We found that A. triuncialis and E. caput-medusae significantly reduced ion-exchange resin estimates of nitrate (NOâ â») availability as well as nitrification and denitrification potentials compared to native communities. Active microbial biomass was also lower in invaded soils. In contrast, potential measurements of nitrification and denitrification were similar between invaded and naturalized communities. These results suggest that invasion by A. triuncialis and E. caput-medusae may significantly alter the capacity for soil microbial communities to nitrify or denitrify, and by extension alter soil N availability and rates of N transformations during invasion of remnant native-dominated sites.

[Display omitted] • Higher L. major biomass and cover in invaded range compared to the native range. • Reduced overall species richness, and abundance in the invaded range. • Higher L. major damage in the native range compared to the invaded range. • More herbivore association in native range compared to the invaded range. • These findings are consistent with the assumption of Enemy Release Hypothesis. The Enemy Release Hypothesis (ERH) suggests that the absence of natural enemies (herbivores, parasites, and diseases) in non-native environments allow exotic plants to allocate more resources towards growth and reproduction, resulting in increased invasiveness. This study uses the submerged macrophyte Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae), native to Southern Africa, as a case study of this hypothesis. This species is invasive in many parts of the world, including Ireland, the United Kingdom and New Zealand. Here, we investigate the applicability of the ERH in explaining the invasiveness of L. major in New Zealand. This was achieved by comparing L. major biomass and cover, and plant species richness between L. major 's native range in South Africa and its invaded range in New Zealand, where specialist natural enemies were presumed to be lacking. The findings revealed significantly higher L. major biomass (∼100 % increase), cover (∼28 % increase) and shoot production (∼91 % increase) in the invaded range compared to the native range. Additionally, overall species richness and abundance was negatively correlated with L. major abundance in the invaded range. Plants in the native range were associated with more natural enemies and experienced higher levels of damage relative to the invaded sites. Overall, these observations align with the ERH, but should be interpreted with caution as other influential factors such as competition were not measured. Nevertheless, this suggests that L. major could benefit from the integration of biological control measures with the existing methods of control. Two natural enemies, Polypedilum tuburcinatum Andersen (Diptera: Chironomidae) and Hydrellia lagarosiphon Deeming (Diptera: Ephydridae) have already been identified as promising candidates, for biological control of L. major in New Zealand and other regions invaded by this weed. [ABSTRACT FROM AUTHOR]

Numerous studies have highlighted the roles of nutrient availability and fluctuations therein for invasion success of alien plants. Many others also highlighted the role of herbivores in invasion success. However, how herbivory and the level and fluctuations in nutrient availability interact in driving alien plant invasion into native communities remains largely unexplored.We grew eight invasive alien species as target species in pot‐mesocosms with five different synthetic native communities in a three‐factorial design with two levels of nutrient availability (low vs. high), two levels of nutrient fluctuation (constant vs. pulsed) and two levels of above‐ground insect herbivory (with vs. without herbivores). As natural communities have both specialist and generalist herbivores, we simulated this using both a generalist and a specialist herbivorous grasshopper.The relative biomass production of the alien target plants to the total biomass production (i.e. alien biomass/total biomass) decreased in response to an increase in nutrient availability, but increased in response to the presence of herbivores. Furthermore, we found indications that the dominance of the alien target species may depend on interactions of herbivory with changes in nutrient availability and nutrient fluctuations, although these interactions were only marginally significant.Our multi‐trophic multi‐species experiment suggests that herbivory could mediate the interactive effect of nutrient enrichment and variability in nutrient supply on invasion of alien plants into native communities. Therefore, we recommend that studies testing the effects of resources on plant invasion should also consider interactive effects of other trophic levels. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Exotic plants are plants that are introduced intentionally or unintentionally from their original habitat to a new habitat. One of the exotic plants that is potentially invasive is Chromolaena odorata. These plants are found a lot especially in the rehabilitation zone at Donglo Block Resort of Wonoasri, Meru Betiri National Park (MBNP). An initial effort to determine whether this exotic plant was potentially invasive was to use the distribution pattern of a plant population. This study aimed to determine the distribution pattern and area of cover of exotic plants C. odorata in rehabilitation zone at Donglo Block, Resort of Wonoasri MBNP. The sampling of C. odorata used the transect plot method systematically, which carried out in Donglo Block Resort of Wonoasri MBNP. Data analyzed using Morisita index. The map of distribution pattern of C. odorata was created using the Geographic Information System (GIS). Based on the results of the Morisita index, the value (Iδ) = 12.39, which means that C. odorata has a clumped distribution pattern. The distribution pattern of C. odorata can also be seen from the visualization of the spatial distribution map, which shows that the growth of C. odorata in plants or overlaps with each other, hence that it looks clustered. The coverage area of C. odorata in the study location was 596,5 m2 or 29.24% of the total area of the study (20,400 m2). Based on the results of the coverage area of C. odorata, it was indicated that this exotic species is not yet classified as an invasive species in the area.

Context: The presence in several Cuban cities of Amorphophallus Blume ex Decne (Araceae), which has been poorly and unelaborately published in the scientific literature, encouraged researchers to conduct a systematic, phytogeographic, and ethnobotanical study of this plant. Aim: To unveil the nomenclature, taxonomy, phenotypical characterization, differences from akin taxons, distribution, and usefulness of specimens of Amorphophallus Blume ex Decne, currently cultivated in Cuba outside scientific collections. Methods: Specimens kept in gardens of the city of Camagüey were studied using methods such as collection work, descriptor and key comparisons, and scientific description and illustration. Results: The presence in Cuba of genus Amorphophallus Blume ex Decne was confirmed, proving that it is related to other three species: A. paeoniifolius (Dennst.) Nicolson, A. konjac K. Koch, and A. titanum (Becc.) Becc. ex Arcang. The determination of the nomenclature was determined more accurately; the genus and other two species were described. Besides, the analytical key was adjusted to contrast the different Araceae genuses present in the country; another key was presented to contrast the two species described. Aspects related to their usefulness (corroborated or potential) were discussed from different perspectives: food and medicinal properties, and as a nutritional enhacer of soil.

Most studies on forest transition (FT) have focused on temporal patterns of forest cover across whole countries or regions, without much consideration of the local spatio-temporal heterogeneity or the species composition of new forests. We hypothesize that peri-urban forest transitions are driven by processes associated with urban-based economies and functioning, which define spatial characteristics of new forests. We analyzed the patterns of peri-urban forest expansion detected during the past three decades in the Lules watershed, a montane area of ca. 100,000 ha around San Miguel de Tucumán (SMT), an urban center of ca. one million inhabitants in the Andean foothills of subtropical Argentina. New forests (4,600 ha) were observed through the watershed, but they were more frequent at short distances (1–15 km) from the urban and second home residential areas. New forests nearby SMT are characterized by higher plant diversity largely due to a higher proportion of exotic species. In some cases, these exotic species dominated new forests diminishing stand-level biodiversity. Second-home residential areas, a byproduct of the urban centers in intermontane valleys, replicate the spatial patterns of exotic-dominated forest transition observed around SMT. We argue that peri-urban FT provides an early characterization of the future patterns of spontaneous forest transition with increased presence of globalized species which may locally increase species richness. We use the case study to discuss emerging research lines and to emphasize the importance of urban-centered land use policies (e.g., associated to urban-based uses such as recreation or watershed conservation) as key targets for promoting new forests more beneficial for future generations.

The ongoing wide‐scale introduction of nonnative plants across the world may negatively influence native invertebrate fauna, due to a lack of coevolved traits related to the novel plants, e.g., unique phytochemicals or shifted phenology. Nonnative plants, specifically trees, are common in urban environments, areas that already pose novel habitats to plants and wildlife through a wide array of anthropogenic factors. For example, impervious surfaces contribute to increased ambient temperatures, the so‐called urban heat island effect (UHI), which can affect local plant phenology. Yet, few studies have simultaneously studied the effects of urbanization and tree species origin on urban invertebrate communities. We measured the city‐level UHI and phenology of nine native and seven nonnative tree species in five city‐center parks in southern Sweden, as well as four common native species in a rural control forest. We quantified the abundance of invertebrates on a subset of native and nonnative tree species through shake sampling, sticky traps, and frass collection. In the urban environment, nonnative trees hosted significantly fewer invertebrates compared to native trees. Furthermore, the nonnative trees had a delayed phenology compared to native species, while the peak of caterpillars associated with the subset of trees surveyed for this measure was significantly earlier compared to that of the native species studied. The effect of tree species origin on urban invertebrate abundance was of a greater magnitude (effect size) than the effect of urbanization on invertebrate abundance in native tree hosts. Hence, the results indicate that the impact of nonnative vegetation may be a stronger driver of invertebrate declines in urban areas than other factors. As the effect of species origin on tree phenology was at a level comparable to the urban effect, increasing prevalence of nonnative vegetation can potentially obscure effects of urbanization on phenology in large‐scale studies, as well as induce mismatches to invertebrate populations. Since parks harbor a large proportion of urban biodiversity, native trees play a crucial role in such habitats and should not be considered replaceable by nonnative species in terms of conservation value. [ABSTRACT FROM AUTHOR]

Elton's classic diversity-invasibility hypothesis posits that diversity of resident communities increases resistance against invaders. We tested whether the diversity-invasibility relationsip might be mediated by allelopathic effects of the resident species. In a large germination experiment, we exposed seeds of six alien and six native test species to leachates of one, three, six or twelve species. The leachates tended to slightly delay germination, and almost all single-species leachates reduced the proportion of germinated seeds. Nevertheless, the overall effect of the plant leachate mixtures on the proportion of germinated seeds was not significant. This was because a higher diversity of the leachates increased the proportion of germinated seeds, particularly for native test species. Among the six alien test species, it was only the most invasive one that benefited from increased diversity of the leachates, just like the natives did. Overall, our findings suggest that allelopathy of diverse communities does not provide resistance but could actually facilitate the germination of invaders. [ABSTRACT FROM AUTHOR]

Restoration of degraded ecosystems is a global issue, particularly in rural regions where excessive loss of natural vegetation has occurred. We investigated, at both landscape and patch scales, the benefits to butterfly communities of restoration by revegetation (planting trees and shrubs), typical of many rural landscapes in south‐eastern Australia. We surveyed eight pairs of landscapes (200 ha each) dominated either by remnant or restored woody vegetation, along a gradient of wooded cover. In total, 1,683 individuals of 11 butterfly species were recorded by transect counts, with the fauna dominated by four generalist species. At the landscape scale, there were similar patterns of occurrence of butterflies in remnant and restored landscapes: species richness was not related to the gradient in wooded cover, but overall abundance of butterflies increased with wooded cover. At the patch scale there was a similar richness of butterflies in revegetation and remnants (greater than in pasture), with abundance greater in remnants. Individual species showed distinctive responses to patch types (i.e. remnants, revegetation, scattered trees, pasture). In all patch types, the ground layer was dominated by exotic plants and most observations (78%) of butterflies taking nectar were from exotics. Revegetation in farmland created new wooded habitat, at least for common butterfly species, despite the study being undertaken during severe drought. Benefits of revegetation will be enhanced by actions at both the landscape scale (extent, connectivity of habitat), and patch scale (habitat quality) through promoting native ground‐layer species favored for adult foraging and as larval host plants. [ABSTRACT FROM AUTHOR]

Copyright of Archaeologia Lituana is the property of Vilnius University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The soil and its biota can shape the development of colonizing vascular plant communities. Because they occupy soil surfaces where most seeds disperse to, biological soil crusts (biocrusts) are uniquely positioned to influence vascular plant communities established by direct seeding, e.g., for restoration. We created mesocosms of soil overtopped by intact biocrust transplants from the field, varying in key community attributes: total cover, species richness, and proportional cover of mosses relative to lichens. We seeded the same diverse mixture of vascular plants into all mesocosms, including desired native species and problematic exotic invasive species. We tracked plant community development for two full growing seasons, both under ambient outdoor conditions and with supplemental irrigation to remove the influence of water limitation. Under ambient conditions, we found that total biocrust cover suppressed exotic plant emergence and biocrust richness slightly promoted native emergence (r = −0.23 to −0.39) but had weaker and less consistent effects on cover of either native or exotic plants (r ≤ |0.25|). Early emergence events were generally strong drivers of vascular plant recruitment (r = 0.17–0.78) and continued to influence community composition after 2 years, suggesting a priority effect. Biocrust cover also promoted final plant biomass under ambient conditions (r = 0.17–0.33) but did not influence the total cumulative number of native species (r ≤ |0.07|) nor the fecundity of exotics (r ≤ |0.08|). Biocrusts’ influence on total vascular plant biomass was minor. When water was added, biocrust effects sometimes switched from positive or negative to neutral, or vice-versa, indicating that our detection probability of biocrust effects on plants changes with moisture availability. Our results demonstrate that the condition of pre-existing biocrust communities can influence—but not strongly dictate—the outcome of multi-species restoration seedings, mostly positively or neutrally under normal conditions, but switching to potentially negatively under irrigated conditions. Our study also suggests that locations with more intact and richer biocrust communities might be slightly more conducive to successful seeding outcomes, while also providing additional contributions to ecosystem functions. As such, biocrusts, alongside vascular plants, have a role in restoring damaged or degraded ecosystems.

The manuscript presents the first comprehensive assessment of alien vascular plants in Kostroma Oblast (Upper Volga, central European Russia), a region with low human density and high proportions of natural and seminatural habitats (boreal forests). The data set combines literature published for 1866–2020 and direct field observations made in 2011–2020. Among the 1200 vascular taxa listed for this region, 330 are neophytes, including 125 casual and 172 naturalized species, with 21 species considered invasive; 33 casual species recorded for the region have vanished. Additionally, we identified 14 naturalized species as potentially invasive. Overall, naturalized alien plants made up ca. 14% of the vascular flora of Kostroma Oblast. Elodea canadensis, Erigeron canadensis, Heracleum pubescens, Lupinus polyphyllus, and Matricaria discoidea are the most widely distributed invasive species across the region. The majority of naturalized taxa originated from Eurasia (i.e., Europe, the Mediterranean, and Asia), while in invasive flora, there is a clear dominance of species from North America. Biennial/perennial herbs are the most common naturalized plants, followed by annuals, while woody species are poorly represented. Twenty-five naturalized species (ca. 8% of all neophyte taxa) were recorded in at least half of all districts in the region. The number of naturalized species per district was notably uneven, increasing in districts with higher human population densities. Compared to other European regions in Russia, Kostroma Oblast has poor alien and particularly naturalized flora; this condition is linked to the socioeconomic features and climatic conditions of the region. [ABSTRACT FROM AUTHOR]

The novel-weapons and homeland-security hypotheses are based on the idea that aliens and natives are not adapted to each other's allelochemicals as they did not co-evolve. However, as only a few studies have tested this, it remains unclear how important co-evolutionary history is in determining the strength of allelopathic interactions between aliens and natives. Here, we tested for potential pairwise allelopathic effects on each other of five alien and five native herbaceous species in China. We did a germination experiment and a competition experiment. In the germination experiment, we tested whether aqueous extracts of the ten study species had allelopathic effects on each other's seed germination. In the competition experiment, we tested whether the alien and native species differed in their competitive effects and responses, and whether these were changed by the presence of activated carbon—a presumed allelopathy neutralizer– in the soil. Plant extracts had negative allelopathic effects on seed germination. This was particularly the case for extracts from the native species. Moreover, aqueous extracts had slightly stronger negative effects on germination of the aliens than on germination of the natives. In the competition experiment, on the other hand, the natives suffered more from competition than the alien species did, but we could not relate this to allelopathy. Alien plants had negative competitive and allelopathic effects on native plants, but the reverse was also true. These alien-native interactions, however, were not consistently stronger or weaker than native-native or alien-alien interactions. [ABSTRACT FROM AUTHOR]

Grasslands have a long history of invasion by exotic annuals, which may alter microbial communities and nutrient cycling through changes in litter quality and biomass turnover rates. We compared plant community composition, soil chemical and microbial community composition, potential soil respiration and nitrogen (N) turnover rates between invaded and restored plots in inland and coastal grasslands. Restoration increased microbial biomass and fungal : bacterial (F : B) ratios, but sampling season had a greater influence on the F : B ratio than did restoration. Microbial community composition assessed by phospholipid fatty acid was altered by restoration, but also varied by season and by site. Total soil carbon (C) and N and potential soil respiration did not differ between treatments, but N mineralization decreased while extractable nitrate and nitrification and N immobilization rate increased in restored compared with unrestored sites. The differences in soil chemistry and microbial community composition between unrestored and restored sites indicate that these soils are responsive, and therefore not resistant to feedbacks caused by changes in vegetation type. The resilience, or recovery, of these soils is difficult to assess in the absence of uninvaded control grasslands. However, the rapid changes in microbial and N cycling characteristics following removal of invasives in both grassland sites suggest that the soils are resilient to invasion. The lack of change in total C and N pools may provide a buffer that promotes resilience of labile pools and microbial community structure.

Abstract Biological invasions are a leading cause of rapid ecological change and often present a significant financial burden. As a vibrant discipline, invasion biology has made important strides in identifying, mapping, and beginning to manage invasions, but questions remain surrounding the mechanisms by which invasive species spread and the impacts they bring about. Frequent, multiscalar ecological monitoring such as that provided through the National Ecological Observatory Network (NEON) can be an important tool for addressing some of these questions. We articulate a set of major outstanding questions in invasion biology, consider how NEON data science is positioned to contribute to addressing these questions, and provide suggestions to help equip a growing contingent of NEON data users in solving invasion biology problems. We demonstrate these ideas through four case studies examining the mechanisms of plant invasions in the U.S. Intermountain West. In Case Study I, we evaluate the relationships between native species richness, non‐native species richness, and probability of invasion across scales. In Case Studies II and III, we explore the relationship between environmental factors and non‐native species presence to understand invasion mechanisms. Case Study IV outlines a method for improving the ability to distinguish invasive plants from native vegetation in remotely sensed data by leveraging temporal patterns of phenology. There are many novel elements in the NEON sampling design that make it uniquely poised to shed light on the mechanisms that can help us understand invasibility, prediction, and progression, as well as on the variability, longevity, and interactions of multiple invasive species’ impacts. Thus, knowledge gained through analysis of NEON data is expected to inform sound decision‐making in unique ways for managers of systems experiencing biological invasions.

Biological invasions are a leading cause of rapid ecological change and often present a significant financial burden. As a vibrant discipline, invasion biology has made important strides in identifying, mapping, and beginning to manage invasions, but questions remain surrounding the mechanisms by which invasive species spread and the impacts they bring about. Frequent, multiscalar ecological monitoring such as that provided through the National Ecological Observatory Network (NEON) can be an important tool for addressing some of these questions. We articulate a set of major outstanding questions in invasion biology, consider how NEON data science is positioned to contribute to addressing these questions, and provide suggestions to help equip a growing contingent of NEON data users in solving invasion biology problems. We demonstrate these ideas through four case studies examining the mechanisms of plant invasions in the U.S. Intermountain West. In Case Study I, we evaluate the relationships between native species richness, non‐native species richness, and probability of invasion across scales. In Case Studies II and III, we explore the relationship between environmental factors and non‐native species presence to understand invasion mechanisms. Case Study IV outlines a method for improving the ability to distinguish invasive plants from native vegetation in remotely sensed data by leveraging temporal patterns of phenology. There are many novel elements in the NEON sampling design that make it uniquely poised to shed light on the mechanisms that can help us understand invasibility, prediction, and progression, as well as on the variability, longevity, and interactions of multiple invasive species' impacts. Thus, knowledge gained through analysis of NEON data is expected to inform sound decision‐making in unique ways for managers of systems experiencing biological invasions. [ABSTRACT FROM AUTHOR]

1. Urbanisation is one of the main land‐use changes behind global insect collapse. Despite that previous studies have described the negative effects of urbanisation on insect communities, so far there is no synthesis that considers multiple urban drivers, their combined effects, and the role of species traits altogether. 2. Here we developed an integrative framework of the underlying mechanisms behind terrestrial insect species loss in cities by exploring five leading drivers: impervious surfaces, habitat fragmentation, urban heat island, pollution, and exotic plants. For each driver, we identified the main direct and indirect (mediated through species interactions or changes in resources) effects on insect populations and communities, emphasising the role of species traits as moderators of such effects. 3. Body size, mobility, and oviposition/nesting requirements were the traits that frequently defined insect vulnerability to urban drivers. Urban heat island and pollution deserve further research from a community‐level approach. Direct effects of drivers dominated the literature, while most indirect paths were mediated by changes in resources rather than species interactions. 4. In conclusion, our review showed the challenges of recognising particular effects and mechanisms for each urban driver and their combined effects. By doing so, we intended to encourage researchers to address some of the gaps we noticed in order to fully understand how urbanisation is affecting insect communities. Finally, we outlined the main recent urban planning strategies and future challenges in order to successfully conserve urban insect biodiversity. [ABSTRACT FROM AUTHOR]

The biotic resistance hypothesis asserts that native species may hinder the invasion of exotic species, which can occur either directly or indirectly by influencing interactions between exotic and local species. Aphid-tending ants may play a key role in the indirect biotic resistance to plant invasion. Ants may protect aphids, thus increasing their negative effect on exotic plants, but may also deter chewing herbivores, thus benefiting exotic plants. We studied native aphid-tending ants (Dorymyrmex tener, Camponotus distinguendus, and Dorymyrmex richteri) on exotic nodding thistles (Carduus thoermeri), which are attacked by thistle aphids (Brachycaudus cardui) and thistle-head weevils (Rhinocyllus conicus). We evaluated the impact of ants, aphids, and weevils on thistle seed set. We compared ant species aggressiveness towards aphid predators and weevils and performed ant-exclusion experiments to determine the effects of ants on aphid predators and weevils. We analysed whether ant species affected thistle seed set through their effects on aphids and/or weevils. The ant D. tener showed the most aggressive behaviour towards aphid predators and weevils. Further, D. tener successfully removed aphid predators from thistles but did not affect weevils. Excluding D. tener from thistles increased seed set. Analyses supported a negative indirect pathway between the aggressive D. tener and thistle seed set through aphid populations, while the other ant species showed no indirect effects on thistle reproduction. Therefore, aggressive aphid-tending ants may enhance biotic resistance by increasing aphid infestation on exotic invasive plants. This study highlights the importance of indirect biotic resistance in modulating the success of invasive species. [ABSTRACT FROM AUTHOR]

Aim: Climate warming and increasing human disturbance are expected to promote non‐native plant invasions in mountain ecosystems. Although biological invasions are also expected to be modulated by biotic interactions, it is still not clear how invertebrate herbivores can affect plant invasion dynamics. Using a large manipulative experiment, we aimed at testing: (1) the effect of soil disturbance and elevation on native and non‐native plant communities, and (2) the effect of plant‐herbivore interactions, nitrogen deposition, and elevation in driving plant establishment after soil disturbance. Location: European Alps, NE Italy. Taxon: Vascular plants. Methods: We selected remote, uninvaded dry semi‐natural grasslands along the core elevational range of non‐native plants in the European Alps (c. 100–1300 m) and manipulated soil disturbance, nitrogen deposition, and invertebrate herbivory. Then, we followed the natural establishment under real field conditions of both native and non‐native plants over one growing season. We used generalized mixed‐effects models to test the effects of the experimental treatments. Results: Native and non‐native species showed contrasting responses to soil disturbance and elevation. Low elevations and disturbance promoted non‐native success, while affecting native species diversity negatively. Two‐thirds of the experimental sites acquired novel non‐natives after disturbance. Most of the observed non‐natives were not present in the surrounding vegetation as mature plants, indicating that propagules were able to reach even remote natural areas. While current N deposition levels did not affect plant establishment, we found that after disturbance invertebrate herbivory might play an important role in facilitating non‐native invasions by reducing native cover. Main conclusions: Our findings show that highly resistant ecosystems such as continuous grasslands can be easily invaded once the resident vegetation has been removed, and that natural herbivory pressure from invertebrates might amplify the negative effects of disturbance on resident native species irrespective of elevation. Together, these results indicate increasing risks of future plant invasions on mountains under global change. [ABSTRACT FROM AUTHOR]

Introduction: Numbers of alien plant species are rising around the globe, but not all of them become invasive. Whereas introductions have been documented for several decades in some regions of the world, knowledge on alien species in Western Mexico is limited. Here, we study roadside vegetation along an elevational gradient, which includes a protected area. Objective: We analysed the floristic composition of herbaceous alien species, their distribution patterns, and their relationship with various environmental factors. A relative importance value index (IVI) identified the most important and, therefore, probably invasive taxa. Methods: During 2017 and 2018, roadside vegetation was documented with 4-6 transects every 300 altitudinal meters, from 0 to 2 100 m, for a total of 37 transects. Each transect consisted of five 1 m² plots. All herbaceous species were registered and alien taxa identified. A cluster analysis distinguished grouping of species based on elevation. The potentially invasive species were identified by their IVI, based on the sum of relative frequency and density values. The influence of environmental variables was analysed with a canonical correspondence analysis. Results: Most alien species were grasses; other families were represented by one or two species. The species were grouped into three main clusters. The first group included rare species, the second consisted of species restricted to higher altitudes, and the third group were tropical taxa with a distribution from sea level to medium altitudes. The most important potentially invasive species were: Urochloa maxima, Melinis repens, Eragrostis ciliaris and Cynodon dactylon, all African grasses introduced for grazing. The IVI of the species was related to tree cover, leaf litter depth and surface stone cover for some species and, for others, to soil compaction, distance to major roads and elevation. Conclusions: The alien ruderal species clustered according to the general climate (temperate vs. tropical). Grasses of African origin are of highest concern as invasive species. Although most introductions are related to human disturbance, each species becomes dominant under certain environmental conditions. Thus, management programs must be specifically adjusted to each individual invasive alien. [ABSTRACT FROM AUTHOR]

Studies on plant invasions depend on local and regional checklists of the alien flora. However, global overview studies have shown that some regions, including many African countries, remain understudied in this regard. To contribute to filling this gap, here we present the first checklist of alien plants of Sudan and South Sudan (the Sudans). We analysed the taxonomic and geographical composition of the species on this list. Our result show that of the 113 alien species in Sudans (99 in Sudan and 59 in South Sudan), 92 (81.4%) are naturalized and 21 (18.6%) are just casual aliens. The number of naturalized species represent 2.2% of the total flora of the Sudans (4096). The alien species belong to 44 families and 85 genera, and many of them are native to Southern America and Northern America (85.8%). Annual and perennial herbs are the prevailing life forms in the alien flora of the Sudans (68.1%), and, among the casual species, perennial herbs are underrepresented whereas woody tree species are over-represented. Alien plants of the Sudans are mostly used for medicinal and environmental purposes globally. The naturalized plants predominantly occur in man-made disturbed habitats, such as agricultural and ruderal habitats. This first overview of the alien flora of the Sudans should stimulate further research and recording of the alien flora to better understand the drivers and consequences of alien plants in the Sudans. [ABSTRACT FROM AUTHOR]

Context: The presence in Cuba of taxons of Pogostemon Desf. (Lamiaceae), a native genus from Africa, Asia, and Australia, whose previous recorded information was not accurate. Objectives: To report on relocation of a species of this genus, define its nomenclature, contribute with data for identification, and provide arguments of its usefulness. Methods: Study of herbarium specimens, field exploration, sample comparisons with descriptions, analytical keys, and samples incorporated to scientific collections. Results: The presence of Pogostemon cablin (Blanco) Benth (Lamiaceae) was confirmed in the provinces of Sancti Spíritus, Camagüey, Holguín, and Guantánamo, Cuba. This is a promising species for the medical-pharmaceutical industry, and the areas of perfumes and cosmetics. Conclusions: Out of the 34 infra-generic Lamiaceae representatives known to be of exotic origin in the Cuban archipelago, 25 have been unable to naturalize.

Background: Dichrocephala is an Old-World genus of the tribe Astereae within the family Asteraceae. One species, D. integrifolia, has been recently reported as introduced in the New World from a pair of collections from Guatemala. During field work in the state of Chiapas in southern Mexico, the species was found and collected. This is the first record of both the genus and species in Mexico and the second record for these taxa in the Americas. Question: Can D. integrifolia occur in more areas in the New World besides those known from Guatemala and Chiapas? Studied species: Dichrocephala integrifolia Study site and dates: Mexico, Central America, and the Caribbean. Methods: An ecological niche model was made and it was projected into the New World. Results: The ecological niche model predicts the records of D. integrifolia in the New World in addition to other ecologically suitable areas, mostly in pine-oak forests in Mexico and Central America and zones with humid mountain and pine forest in the Caribbean. Moreover, a morphological description and illustrations of the species are provided to help with its identification. Conclusions: It is desirable to avoid the further spreading of D. integrifolia in the New World. Although this species is not considered as invasive, it seems to have a high dispersal potential and the ecological niche modelling indicates larger regions in the Americas that might be affected.

Hiraoka is the created wetland that was constructed in 2000 in an urban park in Sapporo City. We introduced fen and bog plants and monitored the hydrochemical conditions and species assemblage composition four times during the 16 years after construction (YAC). The species richness indices of total, exotics, and annuals resembled those of the target fens within 11 YAC, but the species assemblages did not match the target fens even after 16 YAC, showing that species richness is a less effective way to measure success. The 0.1 m high artificial hummocks enhanced species richness 1.3 to 1.4 times more than the surrounding hollows and increased variety within species assemblages (although these hummocks collapsed before16 YAC). Water level from ground surface (WL) were stable at around 0.00 to +0.05 m, except during several-days floods, when a maximum WL of +0.4 to +0.5 m. Hydrological conditions were, therefore, similar to those natural fens nearby. Mean pH values (min and max) decreased from 6.9 (5.5–9.3) in 1 YAC to 6.2 (5.7–6.9) in 16 YAC and approached those of natural fens. The mean electrical conductivity (166–196 μScm-1) and concentrations of major minerals (Ca2+, Mg2+, and K+) were consistently higher than those of Japanese fens, but dissolved phosphorus (0.00–0.04 mg l−1) and nitrogen (0.12–0.48 mg l−1) were lower. The trajectory of species assemblages quickly approached the target fen at least 5 YAC, but then changed between 5 and 11 YAC, before stagnating. Since mineral content in Hiraoka was near the lower limit of calcareous rich-fens, abundant minerals would be less effective in changing the species assemblage compositions. Due to the dominance of eight initially introduced fen species, the trajectory turned in a different direction. Species assemblages stagnated between initial and target communities before 16 YAC, since the five fen dominants introduced at 8 to 9 YAC had not yet dominated. Accordingly, initial introductions, including species combinations of target fen, can shorten the time required to achieve natural fens. At 16 YAC, large emerged macrophytes did not dominate and did not competitively exclude fen species, probably because the water was oligotrophic and the wetland design did not include open water.

Questions: European woodlands harbor at least 386 alien plant species but the factors driving local invasions remain unknown. By using a large vegetation‐plot database, we asked how local richness and abundance of alien species vary by regions, elevation, climate, soil properties, human disturbance, and habitat types. Location: Western, central and southern Europe. Methods: We linked consolidated data from the European Vegetation Archive (16,211 plots) to a habitat classification scheme, climate, soil properties and human disturbance variables. In addition, we used 250 km × 250 km regional grid cells to test whether local patterns differ among regions. We used generalized additive models (GAMs) and quantile GAMs to explore how relative alien species richness and the sum of alien species covers per plot relate to predictors. Random Forest analyses (RFs) were employed to assess the importance of individual predictors that were not multicollinear. Results: Relative alien species richness and the sum of alien species covers varied across regions and habitat types, with effects being more pronounced at the maximum rather than average responses. Both response variables declined with increasing elevation and distance to the nearest road or railroad and increased with the amount of sealed soil. Maxima in fitted functions matched plots from regional invasion hotspots in northwestern and central Europe. RFs accounted for 39.6% and 20.9% of the total variation in relative alien species richness and the sum of alien species covers, respectively, with region and habitat being the most important variables. Conclusions: The importance of maximum response quantiles and the prevalence of regional hotspots point to invasion debt in European woodlands. As alien plants expand further, their species richness and abundance in woodlands will be likely driven by the shared effects of the introduction and planting history, differences in the invaded habitat types, and dispersal corridors.Using a large vegetation‐plot data set from the European Vegetation Archive, we explored the relationship between the levels of alien plant invasion and environmental variables in European woodlands. Habitat types and regions emerged as the most important predictors, with the latter pointing to regional hotspots of local alien plant invasion and regional invasion debt in woodlands across Europe. [ABSTRACT FROM AUTHOR]

While invasive plant distributions are relatively well known in the eastern United States, temporal changes in species distributions and interactions among species have received little attention. Managers are therefore left to make management decisions without knowing which species pose the greatest threats based on their ability to spread, persist and outcompete other invasive species. To fill this gap, we used the U.S. National Park Service's Inventory and Monitoring Program data collected from over 1,400 permanent forest plots spanning 12 yr and covering 39 eastern national parks to analyze invasive plant trends. We analyzed trends in abundance at multiple scales, including plot frequency, quadrat frequency, and average quadrat cover. We examined trends overall, by functional group, and by species. We detected considerably more increasing than decreasing trends in invasive plant abundance. In fact, 80% of the parks in our study had at least one significant increasing trend in invasive abundance over time. Where detected, significant negative trends tended to be herbaceous or graminoid species. However, these declines were often countered by roughly equivalent increases in invasive shrubs over the same time period, and we only detected overall declines in invasive abundance in two parks in our study. Present in over 30% of plots and responsible for the steepest and greatest number of significant increases, Japanese stiltgrass (Microstegium vimineum) was the most aggressive invader in our study and is a high management priority. Invasive shrubs, especially Japanese barberry (Berberis thunbergii), Japanese honeysuckle (Lonicera japonica), multiflora rose (Rosa multiflora), and wineberry (Rubus phoenicolasius), also increased across multiple parks, and sometimes at the expense of Japanese stiltgrass. Given the added risks to human health from tick‐borne diseases, invasive shrubs are a high management priority. While these findings provide critical information to managers for species prioritization, they also demonstrate the incredible management challenge that invasive plants pose in protected areas, particularly since we documented few overall declines in invasive abundance. As parks work to overcome deferred maintenance of infrastructure, our findings suggest that deferred management of natural resources, particularly invasive species, requires similar attention and long‐term commitment to reverse these widespread increasing invasive trends. [ABSTRACT FROM AUTHOR]

Savitribai Phule Pune University is known for its biodiversity in Pune. In the present study, we have analyzed changes which have occurred on the campus and surrounding area over the last 40 years. Of the 90 bird species reported in the campus and Khadki pond in 1976, we failed to notice 34 species in 2018. A major reason for the decline in bird diversity could be changes in the campus habitat from low scrub jungle, fallow lands and grassland to buildings, roads, and exotic plantations. Increase in human settlement surrounding the campus may also be a contributing factor. Replacing exotic plants by indigenous plant species and control of land use can prevent further loss of biodiversity. [ABSTRACT FROM AUTHOR]

El articulo discute sobre el Robo de néctar en plantas ornamentales en Santa Clara, Cuba. El articulo también discute los efectos del robo de néctar a nivel ecológico,las especies de plantas en que ocurre robo de néctar y las plantas exóticas utilizadas como ornamentales en Cuba. Otros temas relacionados son las plantas exóticas potencialmente invasoras y la conservación de la flora autóctona cubana.

The fern Nephrolepis cordifolia is reported for the first time from the province of Pontevedra (NW Spain). The three populations discovered on Arosa Island consist of dense lawns on two edges and a clearing of tree plantations. It has probably escaped from ornamental cultivation and is invasive due to its good spore dispersal and rapid clonal growth by stolons and tubers. [ABSTRACT FROM AUTHOR]

The Australian tree Lomatia fraseri was recently reported as naturalised on ‘Mowlem Ridge’, near Wainuiomata in the Wellington region of the North Island of New Zealand. Here, we provide more details about this discovery and the presence of the species in New Zealand. The identification of these plants as L. fraseri is supported by the abundant hairs on the underside of the leaves (although these are absent in some plants), hairy flower tepals (also absent in some plants) and the narrowly ovate or narrowly elliptic, dentate leaves of the adults. Occasional juveniles have pinnatifid rather than the usual unlobed leaves, a variation consistent with Australian reports. Lomatia fraseri clearly fulfils the criteria for the Naturalised category in New Zealand. It is intensively established on Mowlem Ridge, where many thousands of plants extend over more than 2 km on a ridgeline firebreak through regenerating forest dominated by Leptospermum scoparium (mänuka). Scattered plants have also been found at least 2.5 km to the east. In addition, self-sown seedlings of L. fraseri have been reported near Christchurch in the South Island. Currently, the Wainuiomata population of L. fraseri is not being actively controlled. We suggest this may be regretted given that L. fraseri has the potential to establish widely throughout New Zealand, based on its demonstrated invasiveness and its broad indigenous distribution in southeastern Australia. Furthermore, that L. fraseri remained undetected for long enough to become so well established, despite being so close to a major population centre and being an utterly distinctive tree, raises the question of whether governmental agencies should be doing more biosecurity surveillance. [ABSTRACT FROM AUTHOR]

About 27 % of available water in South Africa is utilised in the urban environment. Estimates for South Africa place ornamental landscape water use as high as 50 % of urban water use. South Africa's average annual rainfall is approximately 495 mm. Rainfall patterns are erratic with periodic droughts of anticipated increased frequency. Ornamental landscapes require additional watering to minimise impacts of dry periods. These landscapes are often over- rather than under-watered. One method of reducing urban ornamental landscape water use is to group plants according to predefined hydrozones to optimise water use through improved site maintenance, landscape design and irrigation application. Currently no extensive researched database of commonly grown ornamental landscape plants linked to hydrozones exists for South Africa. To produce such a plant database, an analysis determining the hydrozone rating of plants sold in South African nurseries was undertaken. The result of this study is a database of plant species suitable for ornamental landscape hydrozones (high, medium, low and very low water requirements) and linked to a plant factor. This provides South African Green Industries Council members, especially landscapers with a database to assist in selecting the most appropriate plants for each hydrozone for their ornamental landscapes and gardens. The database will support South African ornamental landscape water use models. [ABSTRACT FROM AUTHOR]

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