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Moso bamboo (Phyllostachys edulis (Carrière) J.Houz.) is a fast-growing species that commonly invades neighboring broadleaf forests and has been widely reported in subtropical forest ecosystems. However, little is known about the effect on soil phosphorus (P) bioavailability and its potential influence factor during the P. edulis expansion. Here, the four soil P bioavailable fractions (i.e., CaCl2-P, Citrate-P, Enzyme-P, and HCl-P), acid phosphatase activity, iron and aluminum oxides (Fed and Ald), and soil total P pool at depths of 0–10 cm, 10–20 cm, and 20–40 cm were measured in three expanding interfaces (a broadleaf forest, a mixed bamboo–broadleaf forest, and a pure P. edulis forest) in subtropical forests of southern China. Regardless of soil depths, the CaCl2-P content was significantly lower in the mixed bamboo–broadleaf forest than the other two forest types, with contents ranging from 0.09 to 0.16 mg/kg, whereas the HCl-P content was significantly lower in the broadleaf forest, with contents ranging from 3.42 to 14.33 mg/kg, and the Enzyme-P content and acid phosphatase activity were notably lower in P. edulis forest with contents of 0.17–0.52 mg/kg and 68.66–74.80 μmol MUF released g−1 min−1, respectively. Moreover, the soil total P pool was enhanced in the mixed bamboo–broadleaf forest in 0–10 cm depth compared to broadleaf and P. edulis forests, with increases of 27.40% and 31.02%, respectively. The redundancy analysis showed that soil pH plays an important role in regulating soil P bioavailability during the P. edulis expansion (p < 0.01). From the above results, the invasion of P. edulis into broadleaf forests has resulted in soil P bioavailability and storage capacity. The results of this study suggest that when P. edulis invades broadleaf forests, it could affect the soil P bioavailability by elevating soil pH, which in turn drives and facilitates the completion of the expansion. This is important for understanding P cycling during the P. edulis forest expansion in subtropical regions. [ABSTRACT FROM AUTHOR]

The invasion of alien plant species threatens the composition and diversity of native communities. However, the invasiveness of alien plants and the resilience of native communities are dependent on the interactions between biotic and abiotic factors, such as natural enemies and nutrient availability. In our study, we simulated the invasion of nine invasive plant species into native plant communities using two levels of nutrient availability and suppression of natural enemies. We evaluated the effect of biotic and abiotic factors on the response of alien target species and the resistance of native communities to invasion. The results showed that the presence of enemies (enemy release) increased the biomass proportion of alien plants while decreasing that of native communities in the absence of nutrient addition. Furthermore, we also found that the negative effect of enemy suppression on the evenness of the native community and the root‐to‐shoot ratio of alien target species was greatest under nutrient addition. Therefore, nutrient‐poor and natural enemies might promote the invasive success of alien species in native communities, whereas nutrient addition and enemy suppression can better enhance the resistance of native plant communities to invasion. [ABSTRACT FROM AUTHOR]

Background and aims: Soil heterogeneity can be caused by plant-soil feedback (PSF), but little is known about how this affects plant growth and the distribution of roots. Moreover, as invasive and native plant species frequently differ in PSF and root-foraging ability, they may differ in their responses to PSF-mediated soil heterogeneity. Methods: We first conditioned soils by 16 plant species (eight confamilial pairs of invasive alien and native species). Then, we grew each species in a homogeneous treatment with unconditioned soil and in three heterogeneous treatments with four patches. In the home-soil treatment, we filled two patches with unconditioned soil and two with soil conditioned by the target species. In the foreign-soil treatment, we filled two patches with unconditioned soil and two with soil conditioned by the other species in a pair. In the home-and-foreign-soil treatment, we filled two patches with home soil and two with foreign soil. Results: Compared to the homogeneous unconditioned soil treatment, PSF negatively affected plant growth. In the heterogeneous treatment with control- and home-soil patches, biomass was reduced more strongly for the invasive species than for the native species. In the heterogeneous treatment with both home- and foreign-soil patches, root biomass of the invasive species was greater in the foreign-soil than in the home-soil patches, whereas the reverse was true for natives. Conclusion: Although invasive species suffered more from conspecific PSF, root foraging allowed them to avoid home soil. In the long term, this could help invasive species gain a competitive advantage over natives. [ABSTRACT FROM AUTHOR]

Invasive species usually benefit more than native species from increases in nutrient availability. Phenotypic plasticity in above‐ground traits has often been used to explain the superiority of invasive species in response to increased nutrient availability. However, it remains largely unclear whether and how root trait plasticity predicts the ascendancy of invasive plants following nutrient enrichment.Using a 3‐year field nitrogen (N) enrichment experiment, we evaluated the effect of N enrichment on the root traits and growth performance of a globally invasive cordgrass, Spartina alterniflora, and a co‐occurring native plant, Phragmites australis.We found that S. alterniflora exhibited high plasticity in root traits in response to N enrichment, whereas the root traits of P. australis largely remained unresponsive to fertilization. Specifically, in response to N enrichment, S. alterniflora decreased soil exploitation with a lower length ratio of lateral to adventitious roots. However, the root traits of S. alterniflora shifted to be more acquisitive under N enrichment with higher root N concentrations and lower root tissue density. Moreover, there were a series of anatomical adjustments in the adventitious roots of S. alterniflora in response to N enrichment, such as a thicker diameter, lower living cortex‐to‐stele ratio and higher xylem‐to‐root area ratio. These plastic adjustments in root traits jointly resulted in fast nutrient uptake and transportation in S. alterniflora, boosting its above‐ground productivity under fertile N conditions.Our study demonstrated that greater plasticity in root traits enables a globally successful invasive species to take advantages of increased nutrient availability, potentially increasing its invasiveness. We suggest that consideration of root traits can improve our understanding of below‐ground mechanisms underlying invasion under global nutrient enrichment. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Transgenerational plasticity (TGP) allows a plant to acclimate to external variable environments and is a potential mechanism that explains the range expansion and invasion success of some exotic plants. Most studies explored the traits of TGP associated with the success of exotic plant invasions by comparison studies among exotic, native, invasive, and noninvasive species. However, studies on the TGP of invasive plants in different resource environments are scarce, and the biological mechanisms involved are not well understood. This study aimed to determine the role of TGP in the invasiveness of Xanthium strumarium in northeast China. We measured the plant morphology of aboveground parts and the growth of three generations of the invader under different environmental conditions. The results showed that the intergenerational plasticity of X. strumarium was stronger under stress conditions. We found that the X. strumarium parent generation (F0) grown under water and/or nutrient deficiency conditions transferred the environmental information to their offspring (F1 and F2). The F1 generation grown under high‐resource conditions has greater height with larger crown sizes, thicker basal diameters, and higher biomass. Both water and nutrients can affect the intergenerational transmission of plant plasticity, nutrients play a more important role compared with water. The high morphological intergenerational plasticity of X. strumarium under a pressure environment can help it quickly adapt to the new environment and accelerate the rapid expansion of the population in the short term. The root:shoot ratio and reproductive and nutrient distribution of the X. strumarium F0 and F1 generations showed high stability when the growth environment of the F0 generation differed from that of the F1 generation. The stable resource allocation strategy can ensure that the obtained resources are evenly distributed to each organ to maintain the long‐term existence of the community. Therefore, the study of intergenerational transmission plasticity is of great significance for understanding the invasion process, mechanism, and prevention of invasive plants. [ABSTRACT FROM AUTHOR]

Copyright of Ecological Applications is the property of Wiley-Blackwell 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 Ecological Applications is the property of Wiley-Blackwell 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 Ecological Applications is the property of Wiley-Blackwell 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.)

Invasive plant species can drive ecosystem change, particularly on oceanic islands that are vulnerable to plant invasions and subsequent biodiversity loss. While invasive species management is vital for habitat restoration, efficacy of management efforts and the ability of native plants to regenerate varies among studies. The aim of this study was to examine the consequences of managing a thicket-forming woody plant species—Psidium cattleyanum Sabine (strawberry guava)—on subtropical forest regeneration, comparing spatial scales and management periods. We surveyed 15 locations on Norfolk Island, an isolated Pacific Island with a high proportion of endemic and threatened species, by establishing paired managed and unmanaged plots to assess changes in species-area relationships, abundance, richness, and composition of the plant community. Total plant richness was higher in managed plots at the largest scale examined (125 m2). However, there was no significant difference between managed and unmanaged plots in the slopes of species-area relationships when canopy, understory, and seedling strata were combined. Stratum-specific analyses revealed that management-driven changes were most evident in the subcanopy strata, which had significantly higher woody plant abundance and richness in managed plots. Compositional dissimilarity between managed and unmanaged plots was greater in locations with higher moisture levels, suggesting that post-management regeneration is related to environmental conditions. This study suggests that P. cattleyanum suppresses plant recruitment and its removal allows for forest regeneration, indicating that management of dominant invasive woody species facilitates plant recruitment on Norfolk Island if nearby native propagule sources are present. [ABSTRACT FROM AUTHOR]

The legacy effects of invasive plant species can hinder the recovery of native communities, especially under nitrogen deposition conditions, where invasive species show growth advantages and trigger secondary invasions in controlled areas. Therefore, it is crucial to thoroughly investigate the effects of nitrogen deposition on the legacy effects of plant invasions and their mechanisms. The hypotheses of this study are as follows: (1) Nitrogen deposition amplifies the legacy effects of plant invasion. This phenomenon was investigated by analysing four potential mechanisms covering community system structure, nitrogen metabolism, geochemical cycles, and microbial mechanisms. The results suggest that microorganisms drive plant–soil feedback processes, even regulating or limiting other factors. (2) The impact of nitrogen deposition on the legacy effects of plant invasions may be intensified primarily through enhanced nitrogen metabolism via microbial anaerobes bacteria. Essential insights into invasion ecology and ecological management have been provided by analysing how nitrogen-fixing bacteria improve nitrogen metabolism and establish sustainable methods for controlling invasive plant species. This in-depth study contributes to our better understanding of the lasting effects of plant invasions on ecosystems and provides valuable guidance for future ecological management. [ABSTRACT FROM AUTHOR]

• Unsuitable agricultural practices in Lesotho have resulted in degradation of its rangelands, which in turn has given rise to pervasive plant invasion. • Rosa rubiginosa invasion negatively affects abundance of herbaceous vegetation, rangeland quality and subsequent livestock production. • Rosa rubiginosa affects soil properties by increasing pH and affecting nutrient concentration. The capacity of many rangelands in Lesotho is compromised due to plant invasion, resulting from unsuitable agricultural practices. Despite a high number and abundance of invasive plants in Lesotho, there are very few studies determining the invasion ecology to inform management interventions. Rosa rubiginosa L. is one of the most common invasive species invading the rangelands of Lesotho and has notable negative ecological impacts. The aim of this study was to assess rangeland condition following the invasion by Rosa rubiginosa and determine the ecological impacts thereof. This was achieved by assessing the herbaceous species cover and abundance, as well as edaphic factors following R. rubiginosa invasion. The results show that R. rubiginosa negatively affects rangelands by reducing the abundance of herbaceous species, including palatable grass species. In addition, it is shown that the plant alters soil conditions by increasing pH by 27% and affecting nutrient availability. This enhances growth of invasive species since they have competitive advantage in accessing available nutrients over native plants. It is therefore recommended that R. rubiginosa should be managed in the rangelands to improve rangeland productivity. [ABSTRACT FROM AUTHOR]

It has long been hypothesised that introduced species can evolve to become better competitors, which in turn will enable some of them to become invasive. The evolution of increased competitive ability hypothesis (EICA) gives a possible answer for why some introduced plants become invasive by stating that they can escape natural coevolved enemies (pests, pathogens and herbivores) in their new environment, thus allowing them to shift resource allocation from producing expensive chemical defences, towards a higher growth rate and competitive ability. In order to test if there is evidence for increased competitive ability in introduced populations, we examined the performance of three Rumex species (R. obtusifolius, R. crispus and R. conglomeratus, Polygonaceae) from their native (United Kingdom) and introduced ranges (New Zealand), when grown alone and in competition with a conspecific from the same or a different provenance. Based on the predictions of EICA, we hypothesised that plants from the introduced provenance would: (i) have a faster growth rate and a larger biomass at harvest; and (ii) would perform better in competition with a conspecific from the native provenance than one from the introduced provenance. Intraspecific competition reduced biomass by as much as 50%. However, contrary to expectations, we found no difference between the performance of plants from native and introduced provenances when grown in direct competition with each other. Plant performance when grown with a conspecific from the same provenance was similar to performance when paired with one from a different provenance, showing that there was no provenance effect. These results were consistent for all three Rumex species. Our findings contradict the predictions of the EICA hypothesis suggesting that other factors are needed to explain the success of Rumex species in New Zealand. [ABSTRACT FROM AUTHOR]

Abstract Understanding the relationship between plant diversity and invasibility is essential in invasion ecology. Species‐rich communities are hypothesized to be more resistant to invasions than species‐poor communities. However, while soil microorganisms play a crucial role in regulating this diversity–invasibility relationship, the effects of plant competition mode and soil nutrient status on their role remain unclear. To address this, we conducted a two‐stage greenhouse experiment. Soils were first conditioned by growing nine native species separately in them for 1 year, then mixed in various configurations with soils conditioned using one, three, or six species, respectively. Next, we inoculated the mixed soil into sterilized substrate soil and planted the alien species Rhus typhina and native species Ailanthus altissima as test plants. We set up two competition modes (intraspecific and interspecific) and two nutrient levels (fertilization using slow‐release fertilizer and nonfertilization). Under intraspecific competition, regardless of fertilization, the biomass of the alien species was higher in soil conditioned by six native species. By contrast, under interspecific competition, the biomass increased without fertilization but remained stable with fertilization in soil conditioned by six native species. Analysis of soil microbes suggests that pathogens and symbiotic fungi in diverse plant communities influenced R. typhina growth, which varied with competition mode and nutrient status. Our findings suggest that the soil microbiome is pivotal in mediating the diversity–invasibility relationship, and this influence varies according to competition mode and nutrient status.

Abstract Plant invasions severely threaten natural ecosystems, and invasive plants often outcompete native plants across various ecosystems. Arbuscular mycorrhizal (AM) fungi, serving as beneficial microorganisms for host plants, can greatly influence the competitive outcomes of invasive plants against native plants. However, it remains unclear how AM fungi alter the competitive balance between native and invasive species. A competitive experiment was conducted using an invasive Eupatorium adenophorum paired with a native congener Eupatorium lindleyanum. Specifically, both species were inoculated with (M+) or without (M−) the fungus Glomus etunicatum under intraspecific (Intra‐) and interspecific (Inter‐) competition. Plant traits were measured and analyzed regarding the growth and nutrition of both species. The results exhibited that the AM fungus significantly increased the height, diameter, biomass, C, N, and P acquisition of both the invasive E. adenophorum and the native E. lindleyanum. The root mycorrhizal colonization and the mycorrhizal dependency of native E. lindleyanum were greater than those of invasive E. adenophorum. Under M+, the Inter‐competition inhibited the growth and nutrition of invasive E. adenophorum compared to the Intra‐ competition. Further, native E. lindleyanum exhibited higher competitiveness than invasive E. adenophorum in growth and nutrition. Meanwhile, the AM fungus significantly improved the competitiveness of native E. lindleyanum over invasive E. adenophorum. In conclusion, AM fungus improved the competitive advantage of native E. lindleyanum over invasive E. adenophorum in growth and nutrition, potentially contributing to native species competitively resisting the invasion of exotic species. These findings emphasize the importance of AM fungi in helping native plants resist the invasion of exotic plants and further contribute to understanding plant invasion prevention mechanisms.

Abstract Rapid evolution may play an important role in the range expansion of invasive species and modify forecasts of invasion, which are the backbone of land management strategies. However, losses of genetic variation associated with colonization bottlenecks may constrain trait and niche divergence at leading range edges, thereby impacting management decisions that anticipate future range expansion. The spatial and temporal scales over which adaptation contributes to invasion dynamics remain unresolved. We leveraged detailed records of the ~130‐year invasion history of the invasive polyploid plant, leafy spurge (Euphorbia virgata), across ~500 km in Minnesota, U.S.A. We examined the consequences of range expansion for population genomic diversity, niche breadth, and the evolution of germination behavior. Using genotyping‐by‐sequencing, we found some population structure in the range core, where introduction occurred, but panmixia among all other populations. Range expansion was accompanied by only modest losses in sequence diversity, with small, isolated populations at the leading edge harboring similar levels of diversity to those in the range core. The climatic niche expanded during most of the range expansion, and the niche of the range core was largely non‐overlapping with the invasion front. Ecological niche models indicated that mean temperature of the warmest quarter was the strongest determinant of habitat suitability and that populations at the leading edge had the lowest habitat suitability. Guided by these findings, we tested for rapid evolution in germination behavior over the time course of range expansion using a common garden experiment and temperature manipulations. Germination behavior diverged from the early to late phases of the invasion, with populations from later phases having higher dormancy at lower temperatures. Our results suggest that trait evolution may have contributed to niche expansion during invasion and that distribution models, which inform future management planning, may underestimate invasion potential without accounting for evolution.

Abstract Background Si can be important for the growth, functioning, and stoichiometric regulation of nutrients for high-Si-accumulating bamboo. However, other trees do not actively take up dissolved silicic acid [Si(OH)4] from the soil, likely because they have fewer or no specific Si transporters in their roots. It is unclear what causes differential growth and C:N:P stoichiometry between bamboo and other trees across levels of Si supply. Results Si supply increased the relative growth rate of height and basal diameter of bamboo saplings, likely by increasing its net photosynthetic rate and ratios of N:P. Moreover, a high concentration of Si supply decreased the ratio of C:Si in bamboo leaves due to a partial substitution of C with Si in organic compounds. We also found that there was a positive correlation between leaf Si concentration and its transpiration rate in tree saplings. Conclusions We demonstrated that Si supply can decrease the ratio of C:Si in bamboo leaves and increase the ratio of N:P without altering nutrient status or the N:P ratio of tree saplings. Our findings provide experimental data to assess the different responses between bamboo and other trees in terms of growth, photosynthesis, and C:N:P stoichiometry. These results have implications for assessing the growth and competition between high-Si-accumulating bamboo and other plants when Si availability is altered in ecosystems during bamboo expansion.

Human landscape-transforming activities contribute to the global change in vegetation in different forms. Hunting is one of the most ancient human landscape-shaping activities. Feeders for hunting are particularly disruptive to vegetation. In the present study, we conducted a vegetation survey in these highly disturbed places. We investigated the vegetation dynamics over several years in the turkey oak–sessile oak zone, in two areas with different moisture and shade conditions (forest and clearing). Important background factors are the changes in precipitation and temperature. Our results confirm that weed infestation is detectable at bait sites over a long period. The seasonal changes in field weed vegetation, as well as the increase in the number and coverage of weed species at the end of summer, resulting from lifestyle characteristics, were generally detectable in all years and locations, especially in the case of open and more strongly degraded clearings. Meteorological factors played a role in the degree of weed infestation in each year. Degradation was more significant in drought years, while regeneration was also observed in wetter periods. At baits located in the clearing, we showed a positive correlation between the amount of summer precipitation and the total coverage of weed species, as well as between the average spring temperature and the coverage of certain weed species. With the drying of the climate, the disturbed areas are constantly losing their natural value, but wetter weather is not an automatic solution either. Considering that there are approx. 30,000 bait sites in the country, and they are used regularly and very intensively, they can serve as major infection hotspots for alien species in a network.

Abstract Plant invasions can have major impacts on ecosystems, both above‐ and belowground. In particular, invasions by legumes, which often host nitrogen‐fixing symbionts (rhizobia), are known to modify soil bacterial communities. Here, we examined the effect of the invasive herbaceous legume Lupinus polyphyllus on the alpha diversity and community composition of soil bacteria. We also explored the relationships between these bacterial communities and vegetation cover, the cover of other (non‐invasive) legumes, or the number of vascular plants present. For this, we sampled rhizosphere soil and surveyed vegetation from ten paired sites (uninvaded versus invaded more than 10 years ago) in southwestern Finland, and identified bacterial DNA using 16S rRNA gene amplicon sequencing. The presence of the plant invader and the three vegetation variables considered had no effect on the alpha diversity of soil bacteria in terms of bacterial richness or Shannon and Inverse Simpson diversity indices. However, the composition of soil bacterial communities differed between invaded and uninvaded soils at four out of the ten sites. Interestingly, the relative abundances of the top bacterial families in invaded and uninvaded soils were inconsistent across sites, including for legume‐associated rhizobia in the family Bradyrhizobiaceae. Other factors—such as vegetation cover, legume cover (excluding L. polyphyllus), number of plant species—also explained a small proportion of the variation in bacterial community composition. Our findings indicate that L. polyphyllus has the potential to modify the composition of local soil bacterial community, at least in sites where it has been present for more than a decade.

Purpose: The invasive weed common ragweed (Ambrosia artemisiifolia [L.]) has become notorious in China as a major weed in agriculture. Soil microbial communities play important roles in invasive plant growth by potentially mediating nutrient cycling in soil. However, knowledge regarding the soil microbial communities in common ragweed remains limited. Methods: In this study, a long-term field experiment was conducted to comparatively study the microbial community compositions in the rhizosphere soil of invasive common ragweed and two native plants, Chenopodium serotinum and Setaria viridis. Results: We found that the bacterial and fungal community compositions differed significantly between common ragweed and two native plants. Invasion by common ragweed selectively accumulated microorganisms, such as Exopiala, RB41, Cnuella, Dinghuibacter and Funneliformis, that can enhance carbon and nitrogen cycling and the absorption of phosphorus in the rhizosphere environment. Moreover, the relative abundances of these microorganisms were significantly related to the soil pH and ammonium contents. Furthermore, we found that microbial inoculants from rhizosphere of common ragweed promote growth of both common ragweed and S. viridis. Conclusions: Our results show that common ragweed constructs a unique rhizosphere microbial community that distinguishes it from local plants, which could contribute to its growth and expansion by providing a stronger ability to use carbon, nitrogen, and phosphorus. This study offers fundamental explanation to explain how the underground microbial community facilitate the invasion of common ragweed on an ecosystem-level. [ABSTRACT FROM AUTHOR]

Although Mediterranean coastal regions in southern Spain have high floristic diversity and numerous Habitats of Community Interest (HCIs) identified by the European Union Directive Council, they are also vulnerable to invasive plants. In our study, we aimed to create a checklist of terrestrial alien taxa in the Iberian area of the Alboran coast, assess each species' current invasion, analyse the influence of environmental attributes on invasion, estimate the richness of alien species per HCI group, and evaluate each species' potential invasiveness based on its reproductive and dispersal attributes. The checklist that we developed includes 123 alien taxa, most belonging to the Asteraceae, Asparagaceae, and Poaceae families. Notably, 20% of the species are super invaders that occupy more than 20% of HCIs. We also identified Aloe vera, Cylindropuntia spp., Agave salmiana, Opuntia spp., and Paspalum spp. as incipient invaders with the potential for future expansion. Although most alien flora in the HCIs are not regulated by Spanish legislation (RDL 630/2013), monitoring and eradication plans are crucial. Advocating the cessation of using those plants in gardens and reducing anthropogenic pressure are also essential, as human activities worsen invasion dynamics and facilitate the introduction and establishment of invasive species. [ABSTRACT FROM AUTHOR]

The commercial cultivation of herbicide-resistant (HR) transgenic soybeans (Glycine max L. Merr.) raises great concern that transgenes may introgress into wild soybeans (Glycine soja Sieb. et Zucc.) via pollen-mediated gene flow, which could increase the ecological risks of transgenic weed populations and threaten the genetic diversity of wild soybean. To assess the fitness of hybrids derived from transgenic HR soybean and wild soybean, the F2 and F3 descendants of crosses of the HR soybean line T14R1251-70 and two wild soybeans (LNTL and JLBC, which were collected from LiaoNing TieLing and JiLin BaiCheng, respectively), were planted along with their parents in wasteland or farmland soil, with or without weed competition. The fitness of F2 and F3 was significantly increased compared to the wild soybeans under all test conditions, and they also showed a greater competitive ability against weeds. Seeds produced by F2 and F3 were superficially similar to wild soybeans in having a hard seed coat; however, closer morphological examination revealed that the hard-seededness was lower due to the seed coat structure, specifically the presence of thicker hourglass cells in seed coat layers and lower Ca content in palisade epidermis. Hybrid descendants containing the cp4-epsps HR allele were able to complete their life cycle and produce a large number of seeds in the test conditions, which suggests that they would be able to survive in the soil beyond a single growing season, germinate, and grow under suitable conditions. Our findings indicate that the hybrid descendants of HR soybean and wild soybean may pose potential ecological risks in regions of soybean cultivation where wild soybean occurs. [ABSTRACT FROM AUTHOR]

Bamboo invasion into broadleaf forests is a common phenomenon in karst areas; however, the effect of bamboo invasion on soil organic carbon (SOC) in karst areas and the mechanism of the effect are not clear. We selected the study site with broad-leaved forests (BF), mixed forests (MF), and pure bamboo (Indosasa shibataeoides McClure) forests (IF). Furthermore, we sampled the soil from 0 cm to 20 cm and 20 cm to 40 cm layers in the region and investigated the soil properties, organic carbon fractions, and microbial communities. At the same time, we sampled the litterfall layer of different stands and determined the biomass. The results showed that bamboo invasion increased the litterfall biomass per unit area of karst forest, increased the bulk weight of the 0–20 cm soil layer, and lowered the soil pH in the 0–20 cm and 20–40 cm soil layers, bamboo invasion consistently increased the content of soil AN and AK, whereas the content of AP was significantly reduced after bamboo invasion. Both active organic carbon groups (MBC, DOC, and EOC) and passive organic carbon groups (Fe/Al-SOC and Ca-SOC) increased significantly after bamboo invasion. The bamboo invasion increased the diversity of soil microorganisms and bacterial communities; the relative abundance of Actinobacteriota increased in MF and IF, while the relative abundance of Firmicutes decreased in IF. The structure of fungal communities was altered during the bamboo invasion, with an increase in the relative abundance of Mortierellomycota and a decrease in the relative abundance of Basidiomycota at the level of fungal phyla. Partial least squares path modeling analysis identified bamboo invasion enhanced SOC sequestration mainly by increasing litterfall biomass and altering the structure of the fungal community, and the effect of bacteria on SOC was not significant. Our study suggests that bamboo invasion of broadleaf forests is more favorable to soil organic carbon sequestration in karst areas. [ABSTRACT FROM AUTHOR]

Invasions by Spartina species pose serious threats to global coastal ecosystems. Although many studies have examined the effectiveness and ecological impacts of invasive Spartina management, no comprehensive global synthesis has been conducted to assess the effects of management on Spartina per se and on wider non-targets. Here, we conducted a global meta-analysis of 3,459 observations from 102 studies to quantify the effects of different management interventions (physical, chemical, biological, and integrated control) on Spartina per se and native biodiversity and environments. We found that physical measures quickly suppressed Spartina but that their effectiveness declined over time. By contrast, chemical measures decreased the abundance and growth of Spartina to a lesser degree in the early stage, but the effectiveness increased over time. Different management measures did not significantly decrease the diversity of native biota on the whole, but native-plant diversity significantly decreased with time after physical control. Different management measures did not affect abiotic factors differently. These results support the use of chemical measures to control invasive Spartina, although their effectiveness would depend on the time since the management intervention. Addressing the problem of Spartina regrowth following physical control requires improved techniques. We hold that initial states of invaders and subsequent environmental changes after management interventions should be weighed in evaluating control efficacy. [ABSTRACT FROM AUTHOR]

The extensive spread of the invasive black cherry, Padus serotina, has been observed on abandoned agricultural land in Central and Eastern Europe. However, the impact of this species on invaded agroecosystems is still unknown, including the possibility of returning these ecosystems to agricultural production. In order to evaluate the selected soil properties of fallows invaded by P. serotina, their texture, field water capacity, reaction, and content of organic carbon, total nitrogen, and available forms of potassium and phosphorus were determined for 100 study plots. Taking into account the influence of soil conditions on floristic composition, the area covered by individual plant species in the study plots was also included in the analysis. A relationship was found between the presence of all the developmental stages of P. serotina and an increase in the phosphorus content in the soil. With the growth of a black cherry shrub layer, the content of soil nitrogen and potassium increased. An increasing proportion of P. serotina in the herb layer contributed to soil acidification and reduced the water content available for plants in the arable layer at 20–40 cm. The possible impact of P. serotina on soil properties may be an additional premise when considering the possibilities and benefits of the recultivation of fallow land invaded by this species. [ABSTRACT FROM AUTHOR]

Oxalis corymbosa and Bidens pilosa were planted under three densities(（300 seeds/m~2（low-density）, 900 seeds/m~2（medium-density） and 1 800 seeds/m~2（high-density））, with monoculture planting pattern and mixture planting pattern, to explore the conspecific density dependence and interaction mechanism between the two species. The experiment was conducted as completely randomized block design. The growth status and survival strategy of plants were indicated by measuring the growth indices and functional traits of plants. The results were as follows: there were significant differences in the growth indices and functional traits between Oxalis corymbosa and Bidens pilosa under the three densities（P＜0.05）, and the negative density dependence found. Under the same density, the growth indices and functional traits of Oxalis corymbosa also had significant differences in monoculture planting pattern and in mixture planting pattern（P＜0.05）, and it was more unfavorable to the growth of Oxalis corymbose in mixture planting pattern. Bidens pilosa also showed similar results. This result showed that there was mutual restriction between Oxalis corymbosa and Bidens pilosa, and the restriction intensity was higher than that of the conspecific negative density dependence. The mutual restriction between invasive plants was conducive to the prevention and control of the reproduction and proliferation of invasive plants. The results of this experiment had a certain guiding significance for the prevention and control of invasive plants. [ABSTRACT FROM AUTHOR]

To understand the disease-mediated invasion of exotic plants and the potential risk of disease transmission in local ecosystems, it is necessary to characterize population genetic structure and spatio-temporal dynamics of fungal community associated with both invasive and co-occurring plants. In this study, multiple genes were used to characterize the genetic diversity of 165 strains of Colletotrichum gloeosporioides species complex (CGSC) isolated from healthy leaves and symptomatic leaves of invasive plant Ageratina adenophora, as well as symptomatic leaves of its neighbor plants from eleven geographic sites in China. The data showed that these CGSC strains had a high genetic diversity in each geographic site (all Hd > 0.67 and Pi > 0.01). Haplotype diversity and nucleotide diversity varied greatly in individual gene locus: gs had the highest haplotype diversity (Hd = 0.8972), gapdh had the highest nucleotide diversity (Pi = 0.0705), and ITS had the lowest nucleotide diversity (Pi = 0.0074). Haplotypes were not clustered by geographic site, invasive age, or isolation source. AMOVA revealed that the genetic variation was mainly from within-populations, regardless of geographic or isolation origin. Both AMOVA and neutrality tests indicated these CGSC strains occurred gene exchange among geographic populations but did not experience population expansion along with A. adenophora invasion progress. Our data indicated that A. adenophora primarily accumulated these CGSC fungi in the introduced range, suggesting a high frequency of CGSC transmission between A. adenophora and co-occurring neighbor plants. This study is valuable for understanding the disease-mediated plant invasion and the potential risk of disease transmission driven by exotic plants in local ecosystems. [ABSTRACT FROM AUTHOR]

Rapid evolution may play an important role in the range expansion of invasive species and modify forecasts of invasion, which are the backbone of land management strategies. However, losses of genetic variation associated with colonization bottlenecks may constrain trait and niche divergence at leading range edges, thereby impacting management decisions that anticipate future range expansion. The spatial and temporal scales over which adaptation contributes to invasion dynamics remain unresolved. We leveraged detailed records of the ~130‐year invasion history of the invasive polyploid plant, leafy spurge (Euphorbia virgata), across ~500 km in Minnesota, U.S.A. We examined the consequences of range expansion for population genomic diversity, niche breadth, and the evolution of germination behavior. Using genotyping‐by‐sequencing, we found some population structure in the range core, where introduction occurred, but panmixia among all other populations. Range expansion was accompanied by only modest losses in sequence diversity, with small, isolated populations at the leading edge harboring similar levels of diversity to those in the range core. The climatic niche expanded during most of the range expansion, and the niche of the range core was largely non‐overlapping with the invasion front. Ecological niche models indicated that mean temperature of the warmest quarter was the strongest determinant of habitat suitability and that populations at the leading edge had the lowest habitat suitability. Guided by these findings, we tested for rapid evolution in germination behavior over the time course of range expansion using a common garden experiment and temperature manipulations. Germination behavior diverged from the early to late phases of the invasion, with populations from later phases having higher dormancy at lower temperatures. Our results suggest that trait evolution may have contributed to niche expansion during invasion and that distribution models, which inform future management planning, may underestimate invasion potential without accounting for evolution. [ABSTRACT FROM AUTHOR]

A fundamental question in ecology is which species will prevail over others amid changes in both environmental mean conditions and their variability. Although the widely accepted fluctuating resource hypothesis predicts that increases in mean resource availability and variability therein will promote nonnative plant invasion, it remains unclear to what extent these effects might be mediated by soil microbes. We grew eight invasive nonnative plant species as target plants in pot-mesocosms planted with five different synthetic native communities as competitors, and assigned them to eight combinations of two nutrient-fluctuation (constant vs. pulsed), two nutrient-availability (low vs. high) and two soil-microbe (living vs. sterilized) treatments. We found that when plants grew in sterilized soil, nutrient fluctuation promoted the dominance of nonnative plants under overall low nutrient availability, whereas the nutrient fluctuation had minimal effect under high nutrient availability. In contrast, when plants grew in living soil, nutrient fluctuation promoted the dominance of nonnative plants under high nutrient availability rather than under low nutrient availability. Analysis of the soil microbial community suggests that this might reflect that nutrient fluctuation strongly increased the relative abundance of the most dominant pathogenic fungal family or genus under high nutrient availability, while decreasing it under low nutrient availability. Our findings are the first to indicate that besides its direct effect, environmental variability could also indirectly affect plant invasion via changes in soil microbial communities. [ABSTRACT FROM AUTHOR]

Biodiversity can provide some resistance to alien species in some cases, but not in others. The observed paradoxical results may be related to several reasons, including variations in abiotic and/or biotic conditions, alien species characteristics and the fact that the species number cannot adequately reflect native community diversity. A comprehensive study that incorporates these elements is lacking.We constructed invasion systems using nine alien plant species and 12 native communities, composed of two diversity levels (three vs. six species), under different nitrogen (N) and arbuscular mycorrhiza fungi (AMF) inoculation conditions. We used this fully crossed factorial experiment, that is, N (low vs. high) × native community diversity (three vs. six species) × AMF (with vs. without), to systematically explore the invasion success in native communities.We found that the species number of native community did not affect invasion success under any of the N or AMF conditions. The effects of N enrichment and AMF inoculation on invasion were not consistent between alien species and native communities based on their phenotypic plasticity of functional traits in response to N enrichment and AMF inoculation. Specifically, the changing of invasion in response to N enrichment and AMF inoculation was associated with the plasticity of plant height and root mass fraction that reflects the competitiveness for the acquisition of light and soil resources.Our results that species number did not capture well the resistance of the native community suggested that the simple expression of species richness is not realistic to describe the invasion resistance of the community. Additionally, the association between functional traits of both alien species and native communities and invasion success suggested that changes in competitive advantage and resource acquisition strategy are more important in explaining changes in invasive success in different N and AMF conditions.Future studies are needed to explore invasion success by systematically considering the characteristics of invasive species and the native community, and the specific abiotic and biotic conditions. Using functional traits may help advance our understanding of plant invasion in broad circumstances and shed light on a generalized framework of biological invasion. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Semi-arid forests of the Aravalli hills are rich in tree diversity, but plant invasions during the last several decades, especially by Prosopis juliflora (Sw.) DC. have affected the vegetation structure and biogeochemical cycles of these forests. We compared carbon (C), and nitrogen (N) concentrations in the fine root, leaf, and soil physicochemical properties under the invasive tree species, P. juliflora, and native, Acacia nilotica (L.) Willd. ex Delile, to evaluate the effect of invasive tree species on total soil C, N concentrations, and C:N ratios. We also analyzed the soil samples for soil organic C (SOC), total N (TN), soil microbial biomass C (MBC), and soil microbial biomass N (MBN) and stocks. Soil physical and chemical properties under the invasive P. juliflora and native A. nilotica trees varied significantly (p < 0.05). The C and N concentrations in the fine root, leaf, soil SOC, TN and MBC, and MBN concentrations were significantly (p < 0.05) higher in P. juliflora than A. nilotica while C:N ratio, and bulk density, exhibited the opposite trends. The C concentrations followed the order fine root > leaf > soil > microbial biomass while for N concentration and C:N ratios, it was leaf > fine root > soil > microbial biomass. The invasive P. juliflora had a lower C:N ratio in leaf, fine root, and soil than the native A. nilotica. The average rhizosphere soil, fine root, and leaf C concentration for P. juliflora were 36.72 ± 0.84 g kg−1, 547.84 ± 18.56 g kg−1, and 534.77 ± 5.12 g kg−1, respectively and were 1.42, 1.16 and 1.04 times higher than for A. nilotica. Similarly, P. juliflora average rhizosphere soil, fine root, and leaf N concentrations were 4.37 ± 0.11 g kg−1, 19.96 ± 0.94 g kg−1, and 23.18 ± 0.84 g kg−1, respectively, and 2.0, 1.27, and 1.85 times, respectively, higher than for A. nilotica. Further, the MBC:SOC or MBN:TN ratios were higher in native A. nilotica, likely indicating higher efficiency of microbes in soil C decomposition. Together, our results indicate that invasive P. juliflora altered the ecosystem processes and increased the soil and microbial C, and N stocks compared to native A. nilotica in the semi-arid forests of the Aravalli hills. [ABSTRACT FROM AUTHOR]

Climate change, microbial endophytes, and local plants can affect the establishment and expansion of invasive species, yet no study has been performed to assess these interactions. Using a growth chamber, we integrated the belowground (rhizosphere soils) and aboveground (mixture of mature leaf and leaf litter) microbiota into an experimental framework to evaluate the impacts of four native plants acting as microbial inoculation sources on endophyte assembly and growth of the invasive plant Ageratina adenophora in response to drought stress and temperature change. We found that fungal and bacterial enrichment in the leaves and roots of A. adenophora exhibited distinct patterns in response to climatic factors. Many fungi were enriched in roots in response to high temperature and drought stress; in contrast, many bacteria were enriched in leaves in response to low temperature and drought stress. Inoculation of microbiota from phylogenetically close native plant species (i.e., Asteraceae Artemisia atrovirens) causes the recipient plant A. adenophora (Asteraceae) to enrich dominant microbial species from inoculation sources, which commonly results in a lower dissimilar endophytic microbiota and thus produces more negative growth effects when compared to non-Asteraceae inoculations. Drought, microbial inoculation source, and temperature directly impacted the growth of A. adenophora. Both drought and inoculation also indirectly impacted the growth of A. adenophora by changing the root endophytic fungal assembly. Our data indicate that native plant identity can greatly impact the endophyte assembly and host growth of invasive plants, which is regulated by drought and temperature. [ABSTRACT FROM AUTHOR]

Background: Si can be important for the growth, functioning, and stoichiometric regulation of nutrients for high-Si-accumulating bamboo. However, other trees do not actively take up dissolved silicic acid [Si(OH)4] from the soil, likely because they have fewer or no specific Si transporters in their roots. It is unclear what causes differential growth and C:N:P stoichiometry between bamboo and other trees across levels of Si supply. Results: Si supply increased the relative growth rate of height and basal diameter of bamboo saplings, likely by increasing its net photosynthetic rate and ratios of N:P. Moreover, a high concentration of Si supply decreased the ratio of C:Si in bamboo leaves due to a partial substitution of C with Si in organic compounds. We also found that there was a positive correlation between leaf Si concentration and its transpiration rate in tree saplings. Conclusions: We demonstrated that Si supply can decrease the ratio of C:Si in bamboo leaves and increase the ratio of N:P without altering nutrient status or the N:P ratio of tree saplings. Our findings provide experimental data to assess the different responses between bamboo and other trees in terms of growth, photosynthesis, and C:N:P stoichiometry. These results have implications for assessing the growth and competition between high-Si-accumulating bamboo and other plants when Si availability is altered in ecosystems during bamboo expansion. Highlights: (1) Silicon (Si) supply improved the relative growth rate of height and basal diameter of bamboo saplings, which was in contrast to our findings for other tree saplings. (2) Si supply altered the photosynthetic gas exchange properties of plants, which in turn altered Si absorption from soil via passively uptake controlled by leaf transpiration. (3) The ratio of C:Si for all tissues in bamboo was much lower than other tree saplings. Specifically, Si supply decreased the ratio of C:Si in bamboo leaves due to a partial substitution of organic C compounds by Si. [ABSTRACT FROM AUTHOR]

Soil microbes can profoundly affect species coexistence and alien plant invasion via plant–soil feedbacks (PSFs). Theoretically, plants can modify soil biotic communities (e.g. fungal and bacterial communities) sequentially via rhizo‐inputs in the growing season and via litter decomposition in the non‐growing season, and in this way affect the performance of plant individuals that establish in the same soil in the following growing season. However, how plants affect soil microbes via sequential rhizosphere and litter inputs and how these soil microbial legacies feedback to subsequent plants remains unclear.Here, we first explored the sequential effects of living individuals and their leaf litter on soil fungal communities, using 42 common alien and native species in China, and then estimated their PSF effects on three common test species.Our results show that living plants growing in field soil developed distinct rhizosphere fungal communities within one season. After the removal of conditioning plants, the fungal communities in these conditioned soils changed more dramatically in the absence than in the presence of leaf litter, suggesting that leaf litter inputs prolonged the species‐specific legacies that conspecific living individuals exerted in the soil. Moreover, leaf litter induced general negative effects on all test species in the second growing season. Conditioning plant origin (native vs. alien) and life cycle (annual vs. perennial), respectively, had a slight or no impact on fungal community composition, and conditioning plant origin did not affect PSF responses of the test species.Synthesis: These findings show that leaf litter prolongs soil fungal legacies of conspecific living individuals, which can lead to carryover effects on heterospecific plant growth in the next season. Our findings highlight the importance of leaf litter for plant–soil interactions and thereby stress the potential importance of plant litter as a driver of plant community dynamics. [ABSTRACT FROM AUTHOR]

Summary: The invasive Australian tree, Acacia saligna , has been the subject of numerous studies investigating its ecological impact. However, the effect of its invasion on the soil free-living nematode population has yet to be researched. In this study, we examined the impact of A. saligna on the soil free-living nematode population in a coastal dune site with a Mediterranean climate during three sampling periods. Soil samples were collected from beneath the canopies of A. saligna trees, the native dominant shrub Retama raetam , and bare soil plots as a control. Our findings reveal that A. saligna increases the density of the soil free-living nematode population and changes its trophic and taxonomic composition. While the nematode diversity and functional index scores did not significantly differ between sampling locations, they did differ between the different sampling times, highlighting the seasonal dynamics of the soil nematode population in Mediterranean sand dunes. [ABSTRACT FROM AUTHOR]

The invasive plant species, Solidago canadensis, often shares a common mycorrhizal network (CMN) with native plant species in southeast China. We ask whether the transfer of carbon (C) and nitrogen (N) among the invasive S. canadensis, the native Kummerowia striata and their CMN could contribute to the invasiveness of S. canadensis.We conducted a microcosm experiment in which a CMN was established on S. canadensis and K. striata. We used 13CO2 pulse‐labelling to quantify the relative contribution of recently fixed C from the two host species to the CMN. We also calculated the relative N distribution to each host species from the CMN.We found that 89% of the recently fixed C in the CMN originated from S. canadensis, while 11% originated from K. striata. We also found that the CMN distributed 77% of the N it absorbed to S. canadensis and 23% to K. striata.Our results suggest that the unequal distribution of N from a CMN to the invasive and native plant species is related to the unequal contribution of C from the plant species. This mechanism could contribute to invasion of native communities by alien species when there is a stoichiometric exchange of limiting nutrients for C, and when alien species contribute more C to the CMN than natives. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Halting biological invasions and rewilding extirpated native fauna are conservation interventions to bolster biodiversity, species interactions, and ecosystems. These actions are often considered separately and the potential for reintroduced wildlife to facilitate invasive plants has been largely overlooked. Here, we investigated the role of Singapore's recolonizing native wild pigs (Sus scrofa) in facilitating an invasive weed Miconia crenata into tropical rainforests, which are normally highly resistant to invasion. We conducted line‐transect surveys in 11 Singaporean rain forests and used generalized linear mixed models to consider the contribution of pigs' soil disturbances, human forest paths, and other environmental covariates, on the density of M. crenata. We found that M. crenata was more abundant at forest edges and invasion into forest interior was facilitated by pigs, paths, and canopy gaps, but that these effects were all additive, not synergistic (i.e., not multiplicative). These results highlight how modern invasions are driven by multiple disturbances as well as propagule pressure (e.g., urban birds dispersing seeds at forest edges where they establish in pig soil disturbances). Singapore's extensive native forest restoration efforts may have provided plentiful edge and secondary forests that are well suited to pigs and M. crenata, which in turn undermine the aims of fostering later‐successional native plant communities. To prevent negative externalities, we suggest that plant restoration and rewilding projects consider the potential role of wildlife in facilitating non‐native plants, and couple these actions with preliminary screening of unintended consequences and continued monitoring, as well as limiting human‐mediated weed invasion to minimize propagule sources. [ABSTRACT FROM AUTHOR]

• Pollination networks have long been studied by quantifying plant-flower visitor species interactions. Despite making considerable contributions, this ignores important steps of pollen movement from anthers to receptive stigmas and neglects the intraspecific variation of the interacting partners. Addressing specialization and niche partitioning regarding heterospecific pollen transport and transfer, is fundamental to untangle the mechanisms behind contrasts seen in the impact of alien species on native communities. • We used two well-sampled datasets on pollen-transport and pollen-transfer networks to test how intraspecific variation in interaction specialisation affects invaded pollination networks. We considered different levels of biological organization: from species- to individual-based networks. • We found significant intraspecific variation in the pollen loads and pollen deposition of the invasive plant Impatiens glandulifera; thus only a few individual pollinators and plant stigmas carried large amounts of alien pollen grains, potentially functioning as super-spreaders driving the invading process. Consequently, most individuals carried only a few, or no alien pollen at all, possibly buffering the negative effects of invasive plants at the population and community levels. • Node and structural specialization were higher for individual-based and pollen-transfer networks, suggesting a lack of dominant, highly generalist links when downscaling from pollen-transport to pollen-transfer, and from species to individual-based networks. • The high specialization, selectiveness and niche partitioning of plants, pollinators and their interaction revealed at the different stages of the pollination process and across distinct levels of biological organization, suggest important mechanisms associated with the (re) organization of population niches. Moreover, these mechanisms provide a promising approach towards a more comprehensive understanding of the dynamics of invasion biology from population to community and ecosystem functioning.

Describing the spatial distribution of communities is crucial to understanding how environmental disturbance can affect biodiversity. Agricultural lands are susceptible to disturbances of anthropogenic origin and have been identified as ecosystems of conservation concern. Such lands are vulnerable to invasions by anthropogenically introduced non-native plants disturbing habitats. This research focused on the invasion-induced taxonomic filtering of birds with shared habitat requirements. The birds were surveyed along a gradient of invasion-altered areas (far from the invasion, uninvaded although susceptible to invaders, and invaded) to identify changes in bird assemblages (ground/herb dwellers, bush foragers, ecotone birds, and tree foragers) caused by this disturbance. Data were collected from 112 sites sampled in southeastern Poland. There were significantly fewer bird species from each assemblage on invaded sites than on uninvaded sites, although exposed to invasion, despite the decrease in the abundance of only ground/herb dwellers. Beta diversity analysis showed that sites with invasion contained bird communities significantly different from those at other sites. Invasion-induced changes resulted in a significant reduction in the diversity of ground/herb dwellers in comparison with uninvaded sites and created a distinctive bush bird assemblage. This was most likely due to the transformation of the grassland layer and the thickening of the shrub layer by plant invaders, which resemble shrubs in morphology. The results indicated the filtering effect of invasion on bird species composition at the level of two habitat assemblages despite the decreases in bird abundance and species diversity of the whole community.

The invasive plant Wedelia trilobata benefits in various aspects, such as nutrient absorption and environmental adaptability, by establishing a close symbiotic relationship with arbuscular mycorrhizal fungi (AMF). However, our understanding of whether AMF can benefit W. trilobata by influencing its metabolic profile remains limited. In this study, Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was conducted to analyze the metabolites of W. trilobata under AMF inoculation. Metabolomic analysis identified 119 differentially expressed metabolites (DEMs) between the groups inoculated with AMF and those not inoculated with AMF. Compared to plants with no AMF inoculation, plants inoculated with AMF showed upregulation in the relative expression of 69 metabolites and downregulation in the relative expression of 50 metabolites. AMF significantly increased levels of various primary and secondary metabolites in plants, including amino acids, organic acids, plant hormones, flavonoids, and others, with amino acids being the most abundant among the identified substances. The identified DEMs mapped 53 metabolic pathways, with 7 pathways strongly influenced by AMF, particularly the phenylalanine metabolism pathway. Moreover, we also observed a high colonization level of AMF in the roots of W. trilobata, significantly promoting the shoot growth of this plant. These changes in metabolites and metabolic pathways significantly affect multiple physiological and biochemical processes in plants, such as free radical scavenging, osmotic regulation, cell structure stability, and material synthesis. In summary, AMF reprogrammed the metabolic pathways of W. trilobata, leading to changes in both primary and secondary metabolomes, thereby benefiting the growth of W. trilobata and enhancing its ability to respond to various biotic and abiotic stressors. These findings elucidate the molecular regulatory role of AMF in the invasive plant W. trilobata and provide new insights into the study of its competitive and stress resistance mechanisms.

Summary: The ecological and evolutionary processes shaping community structure and functions of microbial symbionts are known to be scale‐dependent. Nonetheless, understanding how the relative importance of these processes changes across spatial scales, and deciphering the hierarchical metacommunity structure of fungal endophytes has proven challenging.We investigated metacommunities of endophytic fungi within leaves of an invasive plant (Alternanthera philoxeroides) across wide latitudinal transects both in its native (Argentina) and introduced (China) ranges to test whether metacommunities of fungal endophytes were structured by different drivers at different spatial scales.We found Clementsian structures with seven discrete compartments (distinctive groups of fungal species with coincident distribution ranges), which coincided with the distribution of major watersheds. Metacommunity compartments were explicitly demarcated at three spatial scales, that is, the between‐continent, between‐compartment, and within‐compartment scales. At larger spatial scales, local environmental conditions (climate, soil, and host plant traits) were replaced by other geographical factors as principal determinants of metacommunity structure of fungal endophytes and community diversity–function relationships.Our results reveal novel insights into the scale dependency of diversity and functions of fungal endophytes, which are likely similar for plant symbionts. These findings can potentially improve our understanding of the global patterns of fungal diversity. [ABSTRACT FROM AUTHOR]

Plant invasions can have long-lasting impacts on soil nitrification, which plays a critical role in nutrient cycling and plant growth. This review examines the legacy effects of plant invasion on soil nitrification, focusing on the underlying mechanisms, context dependence, and implications for management. We synthesize literature on the positive, negative and neutral legacy effects of plant invasion on soil nitrification, highlighting the complexity of these effects and the need for further research to fully understand them. Positive legacy effects include increased soil microbial biomass or activity, potentially enhancing nutrient availability for plants. However, negative legacy effects, like reduced nitrifier abundance, can result in decreased soil nitrification rates and nutrient availability. In some cases, changes to nitrification during active invasion appear transitory after the removal of invasive plants, indicating neutral short-term legacies. We discuss the context dependence of legacy effects considering factors, including location, specific invasive plant species, and other environmental conditions. Furthermore, we discuss the implications of these legacy effects for management and restoration strategies, such as the removal or control of invasive plants, and potential approaches for restoring ecosystems with legacy effects on soil nitrification. Finally, we highlight future research directions, including further investigation into the mechanisms and context dependence of legacy effects, and the role of plant–microbe interactions. Overall, this review provides insights into the legacy effects of plant invasion on soil nitrification and their implications for ecosystems. [ABSTRACT FROM AUTHOR]

Fungal communities are essential to the maintenance of soil multifunctionality. Plant invasion represents a growing challenge for the conservation of soil biodiversity across the globe, but the impact of non-native species invasion on fungal diversity, community structure, and assembly processes remains largely unknown. Here, we examined the diversity, community composition, functional guilds, and assembly process of fungi at three soil depths underneath a native species, three non-native species, and a bare tidal flat from a coastal wetland. Plant species was more important than soil depth in regulating the diversity, community structure, and functional groups of fungi. Non-native species, especially Spartina alterniflora, increased fungal diversity, altered fungal community structure, and increased the relative abundance of saprotrophic and pathogenic fungi in coastal wetland soils. Stochastic processes played a predominant role in driving fungal community assembly, explaining more than 70% of the relative contributions. However, compared to a native species, non-native species, especially S. alterniflora, reduced the relative influence of stochastic processes in fungal community assembly. Collectively, our results provide novel evidence that non-native species can increase fungal diversity, the relative abundance of saprotrophic and pathogenic fungi, and deterministic processes in the assembly of fungi in coastal wetlands, which can expand our knowledge of the dynamics of fungal communities in subtropical coastal wetlands. [ABSTRACT FROM AUTHOR]

During spread in the new range, invasive plants may evolve distinctive traits that make them rapidly occupy the suitable and empty sites at the invasion front, such as rapid growth rate and high seed dispersal ability. However, less is known about how competitive ability evolves during range expansion, and no study has examined whether stand biomass (i.e. biomass production of dense monocultural stands, which may indicate the invasion speed and impacts of invasive plants) changes during range expansion. In this study, using 27 populations of an invasive plant, Mikania micrantha, which is expanding its range on Hainan island of China, we examined how competitive ability and stand biomass change along the invasion route. We grew plants of M. micrantha either singly or with common intraspecific competitors originating from different populations in 3 liter pots to evaluate competitive ability, and grew six plants from the same population together in 3 or 11 liter pots to evaluate stand biomass. When grown alone or with competitors, plant biomass and competitive ability did not correlate with distance from invasion center. Stand biomass was negatively correlated with distance from invasion center in 11 liter pots with a thick soil layer, but not in 3 liter pots with a thin soil layer. Stand biomass was negatively correlated with root to shoot ratio (RSR) in 3 liter pots but not in 11 liter pots, possibly because excessive allocation to roots for belowground competition reduced the overall performance at the stand level when soil space was highly limited. Stand biomass was unrelated to competitive ability. Our results indicate that edge populations of invasive plants may have reduced stand level performance in habitats with thick soil layers. In habitats with shallow soil layers, populations of invasive plants may evolve greater allocation to roots and reduced stand level performance. [ABSTRACT FROM AUTHOR]

Plant population spread has fundamental ecological and evolutionary importance. Both determinants of plant population spread, fecundity and dispersal, can be density‐dependent, which should cause feedback between population densities and spread dynamics. Yet it is poorly understood how density‐dependence affects key characteristics of spread: spread rate at which the location of the furthest forward individual moves, edge depth (the geographical area over which individuals contribute to spread) and population continuity (occupancy of the spreading population).We present a general modelling framework for analysing the effects of density‐dependent fecundity and dispersal on population spread and parameterize this framework with experimental data from a common‐garden experiment using five wind‐dispersed plant species grown at different densities.Our model shows that density‐dependent fecundity and dispersal strongly affect all three population spread characteristics for both exponential and lognormal dispersal kernels. Spread rate and edge depth are strongly correlated but show weaker correlations with population continuity. Positive density‐dependence of fecundity increases all three spread characteristics. Increasingly positive density‐dependence of dispersal increases spread rate and edge depth but generally decreases population continuity. Density‐dependent fecundity and dispersal are largely additive in their effect on spread characteristics. For population continuity, the joint effects of density‐dependent fecundity and dispersal are somewhat contingent on the dispersal kernel.The common‐garden experiment and the experimentally parameterized mechanistic dispersal model revealed density‐dependent fecundity and dispersal across study species. All study species exhibited negatively density‐dependent fecundity, but they differed qualitatively in the density‐dependence of dispersal distance and probability of long‐distance dispersal. The negative density‐dependence of fecundity and dispersal found for three species reinforced each other in reducing spread rate and edge depth. The positively density‐dependent dispersal found for two species markedly increased spread rate and edge depth. Population continuity was hardly affected by population density in all study species except Crepis sancta in which it was strongly reduced by negatively density‐dependent fecundity.Synthesis. Density‐dependent fecundity and seed dispersal profoundly alter population spread. In particular, positively density‐dependent dispersal should promote the spread and genetic diversity of plant populations migrating under climate change but also complicate the control of invasive species. [ABSTRACT FROM AUTHOR]

Invasion success of clonal plants is closely related to their unique clonal life history, and clonal division of labor is a crucial clonal trait. However, so far, it is unclear whether invasive alien clonal species generally possess a greater capacity for division of labor than native species and whether this pattern is affected by environmental conditions. To test whether patch contrast affects the differences in the capacity for division of labor between invasive alien and native clonal plants, we selected five pairs of exotic invasive and native clonal plant species that are congeneric and co-occurring in China as experimental materials. We grew the clonal fragment pairs of these invasive and native plants under high, low, or no contrast of reciprocal patchiness of light and nutrient, respectively, with ramet connections either severed (division of labor prevented) or kept intact (division of labor allowed). The results showed that connection significantly decreased the proportion of biomass allocated to roots in distal (younger) ramets, whereas it increased in proximal (older) ramets of all studied plants under high -contrast treatments. This clear pattern strongly indicated the occurrence of division of labor. Furthermore, the connection had a more pronounced effect on the pattern of biomass allocation of invasive alien plants, resulting in a greater increase in biomass for invasive alien plants compared to native plants. These findings suggest that the invasive alien plants possess a greater capacity for division of labor, which may confer a competitive advantage to them over natives, thus facilitating their invasion success in some heterogeneous habitats such as forest edges where light and soil nutrients show a high negative correlation. [ABSTRACT FROM AUTHOR]

Background and aims: Heavy metal (especially for potentially toxic element) contamination in soil has frequently been associated with plant invasion. However, the mechanisms underpinning plant invasion under potentially toxic element contamination remain unclear. Here we studied how differences in clonal traits of invasive and native plants affect their response strategies to stresses of potentially toxic element contamination. Methods: We manipulated clonal integration of two pairs (Alternanthera philoxeroides - A. sessilis, and Sphagneticola trilobata - S. calendulacea) of congeneric invasive and native plants by either severing stolons between ramet pair or not severing, and grew them in soils contaminated by three levels of Cd and three levels of Pb. Results: Our results show that the combination of Cd and Pb contamination decreased plant growth of recipient ramets of Alternanthera species. Under Pb stress, invasive S. trilobata is Pb-hyperaccumulation and benefits more from clonal integration than native S. calendulacea. Similarly, under Cd stress, invasive A. philoxeroides shows higher Cd risk sharing and benefits more from clonal integration than native A. sessilis. In contrast, clonal integration decreased the performance of A. sessilis under high Cd stress. Conclusion: These results suggest that invasive species such as A. philoxeroides and S. trilobata are able to alleviate the toxic effects of Cd and Pb co-contamination via clonal integration, thus becoming more invasive in contaminated environments with potentially toxic elements. [ABSTRACT FROM AUTHOR]

Currently, plant invasions affect native ecosystems across the Earth. Although much attention has already been paid to their effect on local communities, we still lack basic information on the associations between alien and local species. Here, we present the results of our survey of pollinators of the invasive plant Heracleum mantegazzianum (Apiaceae) in central Europe. At 20 sites within the westernmost part of the Czech Republic, which is strongly affected by the invasion of H. mantegazzianum, pollinators on the flowers of H. mantegazzianum were examined and compared to the species composition of pollinators on native vegetation in the surrounding area. While the flowers of H. mantegazzianum were frequently visited by high abundance of insects, the communities of H. mantegazzianum pollinators were relatively species poor, and the proportion of abundances of H. mantegazzianum pollinators was very uneven, with few species of generalist Diptera and the honey bee (Apis mellifera) dominating over all other flower visitors. Significantly larger species of the family Syrphidae visited flowers of giant hogweed than of other plants. Thus, giant hogweed is not a necessary part of flower communities for flower visiting insects, and it should be eradicated because of its negative effects on other plants, landscape and humans. Our results highlight the need for more detailed studies on direct interactions between alien plant species and native pollinator communities as well as indirect interactions between alien plants and native plants through competition for pollinators. [ABSTRACT FROM AUTHOR]

Invasive plants threaten biodiversity worldwide and effective management must control the target invader while conserving biodiversity. Herbicide is often used to control invasive plants, but potential negative impacts on biodiversity have led to spot spraying being recommended over boom spraying to minimize the exposure of nontarget species to chemicals. We examined the influence of herbicide application methods on off‐target plant communities in threatened temperate grasslands of southeastern Australia, where spraying with the broadleaf herbicide fluroxypr is commonly used to control St. John's wort, Hypericum perforatum L. It is well established that fluroxypr effectively controls H. perforatum but few studies have examined its impact on native forbs. A spray drift experiment using water‐sensitive cards indicated that ground surface coverage was higher for spot spraying (91%–99%) than for boom spraying (5%–31%). We established a replicated, 3‐year, before‐after‐control‐impact experiment across 48 1‐m2 quadrats to determine how three herbicide application methods (spot spray, fine boom and coarse boom) affected nontarget native forbs, the group most likely to be affected by broadleaf herbicides. This experiment was conducted in grasslands where H. perforatum was almost absent, so responses would reflect the direct impacts of the chemical, rather than structural changes resulting from removal of the target invader. Spot spraying decreased the probability of occurrence of native leguminous forbs, while increasing the occurrence of exotic leguminous forbs and the richness of all exotic species and exotic annual forbs. Spot spraying reduced the occurrence of the native Desmodium varians and the abundance of the native Chrysocephalum apiculatum. During this 3‐year study, native species appeared to be impacted either directly by fluroxypr or indirectly by increased competition with exotic species. Where herbicide application is deemed crucial in these grasslands, we recommend boom spraying when H. perforatum density is moderate to high. Spot spraying should only be used when the density of H. perforatum is very low. Given the regional variation in H. perforatum density, the spatial scale of invasion, soil depth, and conservation values, we present a decision tree to assist managers in evaluating the costs and benefits of chemical control, indicating situations where alternative or modified methods could be used. [ABSTRACT FROM AUTHOR]