Plant invasion poses a serious environmental challenge to freshwater ecosystems. Heavy metal pollution and nutrient enrichment, particularly nitrogen (N) and phosphorus (P), are two additional critical environmental i...Plant invasion poses a serious environmental challenge to freshwater ecosystems. Heavy metal pollution and nutrient enrichment, particularly nitrogen (N) and phosphorus (P), are two additional critical environmental issues known to influence the growth of invasive plants. Notably, the N/P ratio in the environments is often inconstant;however, whether these variations can cause differential responses in invasive plants remains underexplored, despite its crucial importance for understanding plant invasiveness. In this study, we examined the effects of different N/P ratios (4:1, 16:1, 32:1, 64:1) on the growth of a widespread invasive plant Alternanthera philoxeroides in cadmium (Cd) polluted water, while maintaining either a constant N concentration (2 mmol L^(−1)) or a constant P concentration (0.5 mmol L^(−1)). Two control treatments were also included: one without Cd, N, or P, and another with Cd but without N or P. The addition of N and P did not mitigate the inhibitory effects of Cd on A. philoxeroides growth nor did it enhance its tolerance. However, under conditions of constant N concentration, the N/P ratio of 4:1 significantly increased both the main stem length and the number of nodes in A. philoxeroides under Cd stress, potentially enhancing its expansion and clonal growth. Our results suggest that A. philoxeroides exhibits greater sensitivity to variations in the N/P ratio when N concentration is held constant, compared to when P concentration is constant in Cd polluted water. This study investigated the effects of varying N/P ratios on invasive plants under Cd pollution, which has been underexplored in previous research. The findings provide an experimental basis for controlling and preventing the spread of invasive plants in freshwater systems polluted with Cd and experiencing eutrophication.展开更多
Guangdong has become a major＂window＂ for invasive plants, and the largest zone, where cross-border and intercontinental migration frequencies reach the peak. The invasive plants in Guangdong are dominated by Mikania...Guangdong has become a major＂window＂ for invasive plants, and the largest zone, where cross-border and intercontinental migration frequencies reach the peak. The invasive plants in Guangdong are dominated by Mikania micrantha, Eichhornia crassipes, Alternanthera philoxeroides, Eupatorium odoratum, and Wedelia trilobata. It is an important way for treating the invasive plants by exploring the prevention methods and making ful use of the characteristics of the invasive plants, and it is of great significance to prevent and utilize alien species in a scientific and effective way in order to control the invasive plants with minimal cost.展开更多
[Objective] The aim was to conduct investigation and risk assessment of the alien invasive plants in riparian zone of Dongjiang River.[Method] The field survey was carried out by the combination methods of sampling pl...[Objective] The aim was to conduct investigation and risk assessment of the alien invasive plants in riparian zone of Dongjiang River.[Method] The field survey was carried out by the combination methods of sampling plots investigation and route survey,and the whole Dongjiang River was covered.52 sampling points were set in the main streams,and 87 sampling points in tributaries streams,624 quadrats were set in total;multi-index comprehensive evaluation method was adopted for the risk assessment with 6 first-level indexes and 25 second-level indexes.[Result] Through the investigation on the riparian zone of Dongjiang River for 2 years,51 species of alien invasive plants were found,belonging to 17 families and 38 genera.The risk level assessment results of these 51 species showed that 18 species,such as Ageratum conyzoides,belonged to high-level risk with over 60 points;26 species,such as Chenopodium ambrosioides,were between 30 and 60 points which belonged to middle-level risk;7 species,such as Paspalum dilatatum,with less than 30 points belonged to low-level risk.[Conclusion] Basic data on the protection,water environmental management and functional zoning of riparian zone of Dongjiang River were provided.展开更多
Exotic plant invasions and increased atmospheric carbon dioxide(CO_(2))concentration have been determined to independently affect soil nematodes,a key component of soil biota.However,little is known about the long-ter...Exotic plant invasions and increased atmospheric carbon dioxide(CO_(2))concentration have been determined to independently affect soil nematodes,a key component of soil biota.However,little is known about the long-term effects of these two global change factors and their interactive effects.Over three consecutive years,we cultivated invasive alien plant Xanthium strumarium and its two phylogenetically related natives under both ambient(aCO_(2))and elevated(eCO_(2))atmospheric CO_(2)concentrations,and determined the effects of the invader and natives on soil nematodes under different CO_(2)concentrations and the relevant mechanism.The abundance of total soil nematodes and that of the dominant trophic group(herbivores)were significantly affected by plant species and CO_(2)concentration,and these effects were dependent on the experimental duration,however,the Shannon-diversity of nematodes was not affected by these factors.Under aCO_(2),both invasive and native species significantly increased the total nematode abundance and that of the dominant trophic group with increasing experimental duration,and the amplitude of the increase was greater under the invader relative to the natives.The eCO_(2)increased total nematode abundance(second year)and that of the dominant trophic group(third year)under the invader,but not under the natives(or even decreased)with increasing experimental duration.Root litter had greater effects on soil nematode abundance than leaf litter and root exudates did.This study indicates that eCO_(2)would aggravate effects of invasive plants on soil nematodes by increasing abundance,and these effects would vary with the duration.展开更多
[Objective]This study was to reveal the essence of mechanism about how the alien invasive plants spread.[Method]Species niche and material/energy flow were used as basic research indicators to analyze the intrinsic me...[Objective]This study was to reveal the essence of mechanism about how the alien invasive plants spread.[Method]Species niche and material/energy flow were used as basic research indicators to analyze the intrinsic mechanism of alien plants invasion.[Result]Most of the invasive plants have not been explicitly defined and their effective control methods not brought forward.[Conclusion]Overrun of alien invasive plants depends on whether the niche of a species could be continuously met at spatial level.Based on this we put forward corresponding control measures,proposed an assumption to establish a cylinder-network model and discussed the definition of alien invasive plants.展开更多
Plant invasion refers to the phenomenon that some plants grow too fast due to they are far away from the original living environment or predators, affecting the local environment. With the development of tourism and t...Plant invasion refers to the phenomenon that some plants grow too fast due to they are far away from the original living environment or predators, affecting the local environment. With the development of tourism and trade, the harm caused by invasive plants will be more and more serious. Therefore, it is necessary to ex- plore an effective method for controlling plant invasion through qualitative and quan- titative research. In this paper, the models were established for the early and late harmful plant invasion control. The huge computation was completed by the com- puter programming to obtain the optimal solutions of the models. The real meaning of the optimal solution was further discussed. Through numerical simulations and discussion, it could be concluded that the quantitative research on the invasive plant control had a certain application value.展开更多
Herein,we developed the invasive plant-derived biochar (IPB) functionalized with CaAl-LDH at five mass ratios using a physical mixture method,assessed their adsorption perform for Eu(Ⅲ),and explored the relative mech...Herein,we developed the invasive plant-derived biochar (IPB) functionalized with CaAl-LDH at five mass ratios using a physical mixture method,assessed their adsorption perform for Eu(Ⅲ),and explored the relative mechanisms.Results show that the IPB successfully loaded CaAl-LDH in five composites and their Eu(Ⅲ) sorption affinities were strongly affected by solution p H,contact time,temperature,and the mass ratio of LDH and IPB.All the sorpiton process for Eu(Ⅲ) occurred on the heterogeneous surface of five composites and the boundary layer diffusion limited the chemical sorption rate.Interestingly,the CaAl-LDH/IPB composite with high ratio of IPB had higher sorption capacity than the one with high ratio of LDH due to larger porosity of the former.Three mechanisms containing ion exchange between Al and Eu ions,surface complexation with carboxyl-and oxygen-containing functional groups,and precipitation were involved in the Eu(Ⅲ) sorption,but the dominant sorption mechanism for each CaAl-LDH/IPB composite differed with different mass ratio of CaAl-LDH and IPB.In composite with more IPB (e.g.,CaAl-LDH/IPB-13),both ion exchange and surface complexes dominated the sorption process and the intensity of Eu^3+ was identified with the one of Eu2O3.Whereas in composites with high LDH,ion exchange dominated the sorption and the intensity of Eu^3+ was obviously higher than the one of Eu_2O_3.This research will provide a new perspective for the application of the LDH/biochar materials.展开更多
Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants...Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants may be closely related to the success of the latter.Accordingly,this study examines differences in functional traits and reproductive allocation strategies between native and invasive plants in Eastern China.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants were all notably higher than those of native species.Additionally,the specific leaf area(SLA)values of invasive plants were remarkably lower than those of native species.Plasticity indexes of SLA,maximum branch angle,and branch number of invasive plants were each notably lower than those of native species.The reproductive allocation coefficient was positively correlated with reproductive branch number and the belowground-to-aboveground biomass ratio but exhibited negative correlations with SLA and aboveground biomass.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants may strongly influence the success of their invasions.展开更多
[Objectives]The paper was to investigate the garden greenbelt in 30 sample plots such as parks,roads,communities,etc.in Shijiazhuang City.[Methods]The species,abundance and frequency of weeds in the greenbelt of publi...[Objectives]The paper was to investigate the garden greenbelt in 30 sample plots such as parks,roads,communities,etc.in Shijiazhuang City.[Methods]The species,abundance and frequency of weeds in the greenbelt of public gardens were recorded through point-line-surface investigation,and typical plants were sampled.[Results]There were 56 species of alien invasive plants in garden greenbelts of Shijiazhuang City,belonging to 44 genera and 20 families.In terms of life form,herbaceous plants were absolutely dominant,accounting for 92.8%of the total.The most alien invasive plants were native to America,accounting for 66.1%of the total.In terms of introduction path,the plants introduced artificially and unintentionally accounted for almost half.The species and quantity of alien invasive plants were related to the size of greenbelt area,the length of the build time of the surveyed plot,the composition structure of greenbelt and the level of green management and protection.There was larger distribution of alien invasive plants in the sample plots with large greenbelt area,long build time,herbaceous-dominated greenbelt and low level of green management and protection.Among the 56 alien invasive plants,3 plants were toxic.From the perspective of invasiveness,the alien invasive plants in the garden greenbelt of Shijiazhuang City could be divided into 5 levels:invasive alien species of malignant consequences,invasive alien species of severe consequences,invasive alien species of partial consequences,invasive alien species of average consequences,and invasive alien species to be observed.[Conclusions]This study will provide a reference for the prevention and control of alien plant invasion,and lay a foundation for the prevention and control of existing invasive plants.展开更多
According to the field survey of alien invasive plants of Jinziling,there were 23 kinds of alien invasive plants in the scenic spot.Species with the comprehensive dominance degree higher than 10% were as follows: six ...According to the field survey of alien invasive plants of Jinziling,there were 23 kinds of alien invasive plants in the scenic spot.Species with the comprehensive dominance degree higher than 10% were as follows: six kinds of Asteraceae: Bidens pilosa,Aster subulatus,Ageratum conyzoides,Conyzai canadens,Parthenium hysterophorus,and Conyza sumatrensis; two kinds of Gramineae: Axonopus compressu,Eleusine indica; two kinds of convolvere: Ipomoea nil,Ipomoea purpurea; two kinds of Fabaceae: Cassiae tora,Medicago hispida; one kind of Verbenaceae: Lantana camara; one kind of Euphorbiaceae: Euphorbia hirta.In total,there were 14 kinds of alien invasive plants.In this survey,the dominant species of invasive plants were obtained by statistical analysis of the composition and distribution of the invasive plants,and the invasion trend was predicted,so as to take effective and economical management and control measures.展开更多
Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native plants.However,little is known about how invasive and native ...Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native plants.However,little is known about how invasive and native plants interact with the quantity and activity of nutrient-acquisition agents.Here a pot experiment was conducted with monoculture and mixed plantings of an invasive plant,Xanthium strumarium,and a common native legume,Glycine max.We measured traits related to root and nodule quantity and activity and mycorrhizal colonization.Compared to the monoculture,fine root quantity(biomass,surface area)and activity(root nitrogen(N)concentration,acid phosphatase activity)of G.max decreased in mixed plantings;nodule quantity(biomass)decreased by 45%,while nodule activity in Nfixing via rhizobium increased by 106%;mycorrhizal colonization was unaffected.Contribution of N fixation to leaf N content in G.max increased in the mixed plantings,and this increase was attributed to a decrease in the rhizosphere soil N of G.max in the mixed plantings.Increased root quantity and activity,along with a higher mycorrhizal association was observed in X.strumarium in the mixed compared to monoculture.Together,the invasive plant did not directly scavenge N from nodule-fixed N,but rather depleted the rhizosphere soil N of the legume,thereby stimulating the activity of N-fixation and increasing the dependence of the native legume on this N source.The quantity-activity framework holds promise for future studies on how native legumes respond to alien plant invasions.展开更多
A key scientific challenge relating to the threat of invasive plants on agriculture at the region level is to understand their adaptation and evolution in functional traits.Leaf functional traits,related to growth and...A key scientific challenge relating to the threat of invasive plants on agriculture at the region level is to understand their adaptation and evolution in functional traits.Leaf functional traits,related to growth and resource utilization,might lead to adaptation of invasive plants to the geographical barriers(region or elevation).In the field experiment,we discussed the effects of region and elevation on leaf functional traits on invasive plant Erigeron annuus in farmland habitats in China.We compared leaf size,coefficient of variation(CV)of leaf traits,and fluctuating asymmetry(FA)of E.annuus from three regions(east vs.center vs.west)and two leaf types(vegetative vs.reproductive leaf),and from nine elevations(980-2100 m)in the west region of China.Our results indicated region and leaf type influenced leaf functional traits,and leaf size was significantly higher and CV of leaf traits and FA in reproductive leaves were significantly lower in the east region than in the west and center regions.Elevation and leaf type affected leaf functional traits,and leaf size was significantly higher and CV of leaf traits in reproductive leaves were significantly lower in moderate elevation.E.annuus has higher leaf size and developmental stability(lower CV and FA)in the eastern region due to the longer adaptation period.Therefore,leaf functional traits play an important role in the adaptation of different longitudes and elevations.It can also facilitate the understanding of the invasiveness and adaptation of leaf traits of invasive plants in the agricultural ecosystem during their spread process in China.展开更多
Leaf chemistry plays a central role in structuring phyllosphere microbiomes.Plant populations often evolve genetic differences in leaf chemistry across region due to both abiotic and biotic selection pressures,includi...Leaf chemistry plays a central role in structuring phyllosphere microbiomes.Plant populations often evolve genetic differences in leaf chemistry across region due to both abiotic and biotic selection pressures,including insect herbivory.Plants in invasive populations may reassociate with native specialist insects,providing an ideal system to examine how herbivory-mediated changes in plant chemistry affect phyllosphere microbiome.Here,we conducted a common garden experiment using Ambrosia artemisiifolia populations differing in leaf chemistry and reassociation history with a specialist beetle—Ophraella communa.We found that plant populations with a longer reassociation history exhibited stronger herbivore resistance and supported phyllosphere communities with higher alpha diversity and more complex composition.These changes were associated with shifts in concentrations of plant metabolites and the expression levels of corresponding biosynthetic genes.The abundance of the fungal pathogens,Golovinomyces,decreased with increasing herbivore resistance,while Pestaliopsis showed the opposite trend.Although reassociation history was linked to population latitude,climatic and soil conditions at the sites of origin also contributed to between-population variation in leaf chemistry and phyllosphere fungal community composition.Our study suggests that genetic differences in leaf chemistry among plant populations can strongly affect herbivore resistance and phyllosphere fungal communities.The observed alignment of reassociation history,chemical traits and phyllosphere fungal communities suggests that herbivore-mediated selection may be a key driver of microbial community evolution in invasive plants.展开更多
Plant-soil feedback(PSF)effects of invasive plants are often regulated by abiotic factors,but whether soil water availability alters the impact of PSF on invasive plant growth and foliar herbivory remains unclear.We h...Plant-soil feedback(PSF)effects of invasive plants are often regulated by abiotic factors,but whether soil water availability alters the impact of PSF on invasive plant growth and foliar herbivory remains unclear.We hypothesized that soil water content modifies PSF effects and then affects foliar herbivory.To test this,we established four soil water level treatments(soil surface elevated 0,5,10 or 15 cm above water)to examine their effects on PSF,growth traits,and herbivore resistance in the invasive weed Alternanthera philoxeroides.Results showed PSF was negative when the soil surface was elevated 5 cm above water,but it was positive in other treatments.Soil condition,water treatment and their interactions significantly affected total biomass,leaf and branch numbers.As soil water content decreased,leaf nitrogen content increased,while the leaf C/N ratio decreased.Root nitrogen and C/N ratios were also affected by water treatment.Leaf mass per area and leaf area consumption rate were significantly affected by water content,with foliar herbivory being lowest when water content was at its minimum.Importantly,the effects of water availability on invasive plant performance and foliar herbivore resistance appeared to be stronger than those mediated by soil feedback.These findings suggest that soil water content,as a critical role,modifies the PSF effects on invasive plant performance,thereby indirectly affecting foliar herbivory.展开更多
Terrestrial plants are colonized by various microorganisms in the rhizosphere,phyllosphere and endosphere.Variations of microorganisms between these niches could affect plant performance.While studies have indicated t...Terrestrial plants are colonized by various microorganisms in the rhizosphere,phyllosphere and endosphere.Variations of microorganisms between these niches could affect plant performance.While studies have indicated that microorganisms associated with invasive plants may facilitate their invasion success,niche effects on the composition,function and co-occurrence network of invasive plant microbiomes remain poorly understood.In this study,we investigated the bacterial and fungal communities in the rhizosphere soil,root and leaf endospheres of two invasive plants,Flaveria bidentis and Eclipta prostrata.Flaveria bidentis is a recently introduced species(introduced in 2001),whereas E.prostrata has been invaded in China for over 1000 years.We found that microbial community of F.bidentis and E.prostrata harbored more specialists,fewer unique amplicon sequence variants(ASVs),and lower diversity and network complexity in the leaf endosphere than that in the rhizosphere soil.Moreover,the bacterial and fungal communities in the rhizosphere soil,root and leaf endospheres of F.bidentis were more diverse,included more unique ASVs,and had a higher network complexity than those of E.prostrata.Predicted functional profiles revealed that there were more beneficial bacteria and fewer pathogenic fungi associated with F.bidentis than those with E.prostrata.These results demonstrate that there is a significant niche differentiation in the two invasive plant microbiotas,and this work may also indicate potential impact of residence time of invasive plants on plant-microbe interactions.展开更多
Invasive alien plant species(IAPS)pose severe threats to global biodiversity conservation.Effective management of IAPS requires mapping their distribution and identifying the environmental factors that drive their spr...Invasive alien plant species(IAPS)pose severe threats to global biodiversity conservation.Effective management of IAPS requires mapping their distribution and identifying the environmental factors that drive their spread.The Gaoligong Mountains,a renowned biodiversity hotspot in southwestern China,currently face the dual challenges of IAPS invasion and climate change.However,we know little about the distribution patterns,key environmental drivers,and sensitivity of IAPS to future climate change in this region.In this study,we mapped IAPS richness distribution and identified invasion hotspots throughout the Gaoligong Mountains.In addition,we assessed the relative importance of environmental variables in shaping the spatial distribution of IAPS richness and projected potential shifts in IAPS richness under various climate change scenarios.We identified 161 IAPS,primarily concentrated in the low-elevation tropical and subtropical regions along river valleys,forming belt-like invasion hotspots.The key factors shaping IAPS richness included disturbance complexity,elevation,seasonal precipitation,and vegetation types.Notably,IAPS richness significantly declined with increasing elevation and latitude but increased with higher disturbance complexity.Moreover,IAPS were more prevalent in grasslands and shrublands than in forested areas.Ensemble modeling of future climate scenarios predicted that the distribution of IAPS richness would shift to progressively higher elevations.These findings provide valuable insights for managing IAPS in mountainous regions that play a crucial role in global biodiversity conservation.展开更多
Invasive alien species(IAS)significantly threaten global biodiversity and ecosystem stability.Despite increasing management efforts,a critical knowledge gap existed in understanding commonalities and disparities among...Invasive alien species(IAS)significantly threaten global biodiversity and ecosystem stability.Despite increasing management efforts,a critical knowledge gap existed in understanding commonalities and disparities among national strategies.We analyzed several IAS management lists from 23 countries and the European Union,focusing specifically on vascular plant species within these lists.List composition,characteristics,and associated management measures were analyzed.Key patterns in species prioritization across national lists and intercontinental exchange of invasive alien plants(IAPs)were identified.Pistia stratiotes,Pontederia crassipes,Salvinia molesta,Cabomba caroliniana,Ulex europaeus were identified as globally recognized threats,being listed by at least 33.3%of analyzed countries and invading five or more continents.Aquatic plants were found to be more frequently included in management lists.A significant directional invasion pattern between the Eastern and Western Hemispheres was identified.Species native to Asia were observed to dominate as significant donors of IAPs across continents.The analysis of list management strategies highlighted substantial gaps in achieving Target 6 of the Kunming-Montreal Global Biodiversity Framework,particularly in species prioritization and inclusion of potential IAPs.In response to these challenges,a tiered classification system for invasive alien species list was proposed,encompassing High-Priority,Watchlist,Potential,and Priority Site categories,which aimed at enhancing management effectiveness by tailoring strategies to different invasion stages and ecological contexts.This study could contribute to understanding global IAPs management strategies and serve as a reference for policymakers and conservation managers to identify priority IAPs and refine management approaches.展开更多
Unraveling the legacy effects of long-term climate warming is essential to for an integrated understanding of plant invasion success.However,knowledge regarding how these legacy influences invasive offspring and natur...Unraveling the legacy effects of long-term climate warming is essential to for an integrated understanding of plant invasion success.However,knowledge regarding how these legacy influences invasive offspring and natural enemies remains lacking.This work was built on a long-term warming experiment established in 2012.Here,we selected invasive Solidago canadensis and performed a series of experiments to explore the effects of experimental warming on offspring S.canadensis from its native and invaded range,as well as the legacy effect of warming on three insect species,and three pathogens.The experience of long-term maternal warming facilitated the growth of offspring from invasive S.canadensis,regardless of the presence of insects or pathogens.This experience decreased insect growth when feeding on native S.canadensis,and inhibited pathogens when infecting invasive S.canadensis.Additionally,the presence of natural enemies could modulate the legacy effects of warming and population provenance.These results suggest that long-term climate warming could facilitate invasion success via coordinated increases in growth and defense,and that legacy effects of climate warming and maternal provenance are important for understanding the cascading effects of climate warming.展开更多
Soil microbes are one of the most important determinants of allelopathic effects in the field. However, most studies testing the role of allelopathy in biological invasions did not consider the roles of soil microbes....Soil microbes are one of the most important determinants of allelopathic effects in the field. However, most studies testing the role of allelopathy in biological invasions did not consider the roles of soil microbes. Here we tested the hypothesis that soil microbes which can degrade allelochemicals may accumulate in soils over time by adaptation and therefore increase the degradation of allelochemicals and alleviate the allelopathic effects in biological invasions. As expected, soil microbes signifi- cantly decreased the allelopathic effects of leaf leachates of eight in the nine invasive plant species studied. In addition, Ageratina adenophora showed lower allelopathic effects in soil with long or intermediately invasion history than those in soil with short invasion history. The two main allelo- chemicals of the invader were degraded more rapidly with increasing invasion history in the soil. Correspondingly,biomass and activity of the soil microbes were higher in the soils with long invasion history than in that with short invasion history. Our results indicate that soil microbes may graduaUy adapt to the allelochemicals of Ageratina and alleviate its allelopathic effects and thus support the above hypothesis. It is necessary to consider the effects of soil microbes when testing the roles of allelopathy or the novel weapons hypothesis in biological invasions.展开更多
Climatic warming affects plant growth and physiology,yet how warming alters chemistry in invasive plants and indirectly affects herbivorous insects remains largely unknown.Here,we explored warming-induced changes in l...Climatic warming affects plant growth and physiology,yet how warming alters chemistry in invasive plants and indirectly affects herbivorous insects remains largely unknown.Here,we explored warming-induced changes in leaf chemistry of the invasive plant Alternanthera philoxeroides and its native congener Alternanthera sessilis,and further examined how these changes affected the performance of the herbivores,Cassida piperata and Spodoptera litura.We conducted a simulated warming experiment to address its effects on 13 leaf chemical traits of A.philoxeroides and A.sessilis.We measured growth and development time of two herbivores reared on plants from warming or ambient controls.Warming significantly affected leaf chemistry composition for both the invasive and native Alternanthera.Warming decreased nitrogen concentration in A.philoxeroides and increased total flavonoid and total phenol concentration in A.sessilis.The effects of warming on nutrients(i.e.fructose,sucrose,total soluble sugar and starch)varied with individual chemicals and plant species.Weight of C.piperata pupal and S.litura larval reared on warming-treated A.sessilis significantly decreased compared with non-warmed control,and a similar pattern was observed for weight of S.litura larval feeding on warming-treated A.philoxeroides.In addition,warming-treated A.sessilis significantly prolonged larval development time of S.litura.These results indicate that warming can directly affect the leaf chemistry in both invasive plant and its native congener,but these effects vary by species.Such differences in warming-induced changes in plant chemistry could indirectly affect herbivorous insects associated with the invasive and native plants.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.32101264)the Science and Technology Research and Development Project of Handan(Grant 23422304086)the National College Student Innovation Training Project of China(Grant No.202410103013).
文摘Plant invasion poses a serious environmental challenge to freshwater ecosystems. Heavy metal pollution and nutrient enrichment, particularly nitrogen (N) and phosphorus (P), are two additional critical environmental issues known to influence the growth of invasive plants. Notably, the N/P ratio in the environments is often inconstant;however, whether these variations can cause differential responses in invasive plants remains underexplored, despite its crucial importance for understanding plant invasiveness. In this study, we examined the effects of different N/P ratios (4:1, 16:1, 32:1, 64:1) on the growth of a widespread invasive plant Alternanthera philoxeroides in cadmium (Cd) polluted water, while maintaining either a constant N concentration (2 mmol L^(−1)) or a constant P concentration (0.5 mmol L^(−1)). Two control treatments were also included: one without Cd, N, or P, and another with Cd but without N or P. The addition of N and P did not mitigate the inhibitory effects of Cd on A. philoxeroides growth nor did it enhance its tolerance. However, under conditions of constant N concentration, the N/P ratio of 4:1 significantly increased both the main stem length and the number of nodes in A. philoxeroides under Cd stress, potentially enhancing its expansion and clonal growth. Our results suggest that A. philoxeroides exhibits greater sensitivity to variations in the N/P ratio when N concentration is held constant, compared to when P concentration is constant in Cd polluted water. This study investigated the effects of varying N/P ratios on invasive plants under Cd pollution, which has been underexplored in previous research. The findings provide an experimental basis for controlling and preventing the spread of invasive plants in freshwater systems polluted with Cd and experiencing eutrophication.
基金Guangdong Boluo Agro-technique Extension Center-South China Agricultural Univeristy Cooperation Project(7700-H13510)~~
文摘Guangdong has become a major＂window＂ for invasive plants, and the largest zone, where cross-border and intercontinental migration frequencies reach the peak. The invasive plants in Guangdong are dominated by Mikania micrantha, Eichhornia crassipes, Alternanthera philoxeroides, Eupatorium odoratum, and Wedelia trilobata. It is an important way for treating the invasive plants by exploring the prevention methods and making ful use of the characteristics of the invasive plants, and it is of great significance to prevent and utilize alien species in a scientific and effective way in order to control the invasive plants with minimal cost.
基金Supported by National Water Pollution Control and Management Technology Major Project of ChinaEcological Function Partition Research of Level Three and Level Four in Key Watershed(2012ZX07501002)the Fundamental Work Project of Ministry ofScience and Technology (2006FY111000)~~
文摘[Objective] The aim was to conduct investigation and risk assessment of the alien invasive plants in riparian zone of Dongjiang River.[Method] The field survey was carried out by the combination methods of sampling plots investigation and route survey,and the whole Dongjiang River was covered.52 sampling points were set in the main streams,and 87 sampling points in tributaries streams,624 quadrats were set in total;multi-index comprehensive evaluation method was adopted for the risk assessment with 6 first-level indexes and 25 second-level indexes.[Result] Through the investigation on the riparian zone of Dongjiang River for 2 years,51 species of alien invasive plants were found,belonging to 17 families and 38 genera.The risk level assessment results of these 51 species showed that 18 species,such as Ageratum conyzoides,belonged to high-level risk with over 60 points;26 species,such as Chenopodium ambrosioides,were between 30 and 60 points which belonged to middle-level risk;7 species,such as Paspalum dilatatum,with less than 30 points belonged to low-level risk.[Conclusion] Basic data on the protection,water environmental management and functional zoning of riparian zone of Dongjiang River were provided.
基金supported by the National Key R&D Program of China(2023YFC2604500)the National Natural Science Foundation of China(32171662,32471753 and 32171666)the Natural Science Foundation of Liaoning(2020-MS-199).
文摘Exotic plant invasions and increased atmospheric carbon dioxide(CO_(2))concentration have been determined to independently affect soil nematodes,a key component of soil biota.However,little is known about the long-term effects of these two global change factors and their interactive effects.Over three consecutive years,we cultivated invasive alien plant Xanthium strumarium and its two phylogenetically related natives under both ambient(aCO_(2))and elevated(eCO_(2))atmospheric CO_(2)concentrations,and determined the effects of the invader and natives on soil nematodes under different CO_(2)concentrations and the relevant mechanism.The abundance of total soil nematodes and that of the dominant trophic group(herbivores)were significantly affected by plant species and CO_(2)concentration,and these effects were dependent on the experimental duration,however,the Shannon-diversity of nematodes was not affected by these factors.Under aCO_(2),both invasive and native species significantly increased the total nematode abundance and that of the dominant trophic group with increasing experimental duration,and the amplitude of the increase was greater under the invader relative to the natives.The eCO_(2)increased total nematode abundance(second year)and that of the dominant trophic group(third year)under the invader,but not under the natives(or even decreased)with increasing experimental duration.Root litter had greater effects on soil nematode abundance than leaf litter and root exudates did.This study indicates that eCO_(2)would aggravate effects of invasive plants on soil nematodes by increasing abundance,and these effects would vary with the duration.
基金Supported by Joint Research Fund from National Natural Science Foundation of China(NSFC)-Yunnan Province(U0933601)Students Research Fund from Southwest Forestry University(1001)~~
文摘[Objective]This study was to reveal the essence of mechanism about how the alien invasive plants spread.[Method]Species niche and material/energy flow were used as basic research indicators to analyze the intrinsic mechanism of alien plants invasion.[Result]Most of the invasive plants have not been explicitly defined and their effective control methods not brought forward.[Conclusion]Overrun of alien invasive plants depends on whether the niche of a species could be continuously met at spatial level.Based on this we put forward corresponding control measures,proposed an assumption to establish a cylinder-network model and discussed the definition of alien invasive plants.
文摘Plant invasion refers to the phenomenon that some plants grow too fast due to they are far away from the original living environment or predators, affecting the local environment. With the development of tourism and trade, the harm caused by invasive plants will be more and more serious. Therefore, it is necessary to ex- plore an effective method for controlling plant invasion through qualitative and quan- titative research. In this paper, the models were established for the early and late harmful plant invasion control. The huge computation was completed by the com- puter programming to obtain the optimal solutions of the models. The real meaning of the optimal solution was further discussed. Through numerical simulations and discussion, it could be concluded that the quantitative research on the invasive plant control had a certain application value.
基金supported by the National Nature Science Foundation of China (Nos.31700476,21777102)。
文摘Herein,we developed the invasive plant-derived biochar (IPB) functionalized with CaAl-LDH at five mass ratios using a physical mixture method,assessed their adsorption perform for Eu(Ⅲ),and explored the relative mechanisms.Results show that the IPB successfully loaded CaAl-LDH in five composites and their Eu(Ⅲ) sorption affinities were strongly affected by solution p H,contact time,temperature,and the mass ratio of LDH and IPB.All the sorpiton process for Eu(Ⅲ) occurred on the heterogeneous surface of five composites and the boundary layer diffusion limited the chemical sorption rate.Interestingly,the CaAl-LDH/IPB composite with high ratio of IPB had higher sorption capacity than the one with high ratio of LDH due to larger porosity of the former.Three mechanisms containing ion exchange between Al and Eu ions,surface complexation with carboxyl-and oxygen-containing functional groups,and precipitation were involved in the Eu(Ⅲ) sorption,but the dominant sorption mechanism for each CaAl-LDH/IPB composite differed with different mass ratio of CaAl-LDH and IPB.In composite with more IPB (e.g.,CaAl-LDH/IPB-13),both ion exchange and surface complexes dominated the sorption process and the intensity of Eu^3+ was identified with the one of Eu2O3.Whereas in composites with high LDH,ion exchange dominated the sorption and the intensity of Eu^3+ was obviously higher than the one of Eu_2O_3.This research will provide a new perspective for the application of the LDH/biochar materials.
基金Project(31300343)supported by the National Natural Science Foundation of ChinaProject supported by Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,ChinaProject(12JDG086)supported by Research Foundation for Advanced Talents of Jiangsu University,China
文摘Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants may be closely related to the success of the latter.Accordingly,this study examines differences in functional traits and reproductive allocation strategies between native and invasive plants in Eastern China.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants were all notably higher than those of native species.Additionally,the specific leaf area(SLA)values of invasive plants were remarkably lower than those of native species.Plasticity indexes of SLA,maximum branch angle,and branch number of invasive plants were each notably lower than those of native species.The reproductive allocation coefficient was positively correlated with reproductive branch number and the belowground-to-aboveground biomass ratio but exhibited negative correlations with SLA and aboveground biomass.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants may strongly influence the success of their invasions.
基金Supported by National Key R&D Program(2020YFF0305905-06)Science and Technology Project of Hebei Academy of Sciences(22112)Key Discipline Project of Hebei Academy of Sciences(491-0401-YBN-DDH4).
文摘[Objectives]The paper was to investigate the garden greenbelt in 30 sample plots such as parks,roads,communities,etc.in Shijiazhuang City.[Methods]The species,abundance and frequency of weeds in the greenbelt of public gardens were recorded through point-line-surface investigation,and typical plants were sampled.[Results]There were 56 species of alien invasive plants in garden greenbelts of Shijiazhuang City,belonging to 44 genera and 20 families.In terms of life form,herbaceous plants were absolutely dominant,accounting for 92.8%of the total.The most alien invasive plants were native to America,accounting for 66.1%of the total.In terms of introduction path,the plants introduced artificially and unintentionally accounted for almost half.The species and quantity of alien invasive plants were related to the size of greenbelt area,the length of the build time of the surveyed plot,the composition structure of greenbelt and the level of green management and protection.There was larger distribution of alien invasive plants in the sample plots with large greenbelt area,long build time,herbaceous-dominated greenbelt and low level of green management and protection.Among the 56 alien invasive plants,3 plants were toxic.From the perspective of invasiveness,the alien invasive plants in the garden greenbelt of Shijiazhuang City could be divided into 5 levels:invasive alien species of malignant consequences,invasive alien species of severe consequences,invasive alien species of partial consequences,invasive alien species of average consequences,and invasive alien species to be observed.[Conclusions]This study will provide a reference for the prevention and control of alien plant invasion,and lay a foundation for the prevention and control of existing invasive plants.
基金Supported by the Basic Ability Improvement Project for Young and Middle Aged Teachers in Guangxi(KY2016YB421)the Project for Backbone Teachers of Baise University in 2013(210203009)
文摘According to the field survey of alien invasive plants of Jinziling,there were 23 kinds of alien invasive plants in the scenic spot.Species with the comprehensive dominance degree higher than 10% were as follows: six kinds of Asteraceae: Bidens pilosa,Aster subulatus,Ageratum conyzoides,Conyzai canadens,Parthenium hysterophorus,and Conyza sumatrensis; two kinds of Gramineae: Axonopus compressu,Eleusine indica; two kinds of convolvere: Ipomoea nil,Ipomoea purpurea; two kinds of Fabaceae: Cassiae tora,Medicago hispida; one kind of Verbenaceae: Lantana camara; one kind of Euphorbiaceae: Euphorbia hirta.In total,there were 14 kinds of alien invasive plants.In this survey,the dominant species of invasive plants were obtained by statistical analysis of the composition and distribution of the invasive plants,and the invasion trend was predicted,so as to take effective and economical management and control measures.
基金funded by the National Natural Science Foundation of China(32171746,31870522,42077450,32371786)the leading talents of basic research in Henan Province+3 种基金Funding for Characteristic and Backbone Forestry Discipline Group of Henan Provincethe Scientific Research Foundation of Henan Agricultural University(30500854)Research Funds for overseas returnee in Henan Province,Chinasupported by National Key Research and Development Program of China(2019YFE0117000)。
文摘Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native plants.However,little is known about how invasive and native plants interact with the quantity and activity of nutrient-acquisition agents.Here a pot experiment was conducted with monoculture and mixed plantings of an invasive plant,Xanthium strumarium,and a common native legume,Glycine max.We measured traits related to root and nodule quantity and activity and mycorrhizal colonization.Compared to the monoculture,fine root quantity(biomass,surface area)and activity(root nitrogen(N)concentration,acid phosphatase activity)of G.max decreased in mixed plantings;nodule quantity(biomass)decreased by 45%,while nodule activity in Nfixing via rhizobium increased by 106%;mycorrhizal colonization was unaffected.Contribution of N fixation to leaf N content in G.max increased in the mixed plantings,and this increase was attributed to a decrease in the rhizosphere soil N of G.max in the mixed plantings.Increased root quantity and activity,along with a higher mycorrhizal association was observed in X.strumarium in the mixed compared to monoculture.Together,the invasive plant did not directly scavenge N from nodule-fixed N,but rather depleted the rhizosphere soil N of the legume,thereby stimulating the activity of N-fixation and increasing the dependence of the native legume on this N source.The quantity-activity framework holds promise for future studies on how native legumes respond to alien plant invasions.
基金This study was supported by the National Natural Science Foundation of China(Nos.31770449,31270465)Fundamental Research Funds for the Central Universities(2662020YLPY016,2662016PY064).
文摘A key scientific challenge relating to the threat of invasive plants on agriculture at the region level is to understand their adaptation and evolution in functional traits.Leaf functional traits,related to growth and resource utilization,might lead to adaptation of invasive plants to the geographical barriers(region or elevation).In the field experiment,we discussed the effects of region and elevation on leaf functional traits on invasive plant Erigeron annuus in farmland habitats in China.We compared leaf size,coefficient of variation(CV)of leaf traits,and fluctuating asymmetry(FA)of E.annuus from three regions(east vs.center vs.west)and two leaf types(vegetative vs.reproductive leaf),and from nine elevations(980-2100 m)in the west region of China.Our results indicated region and leaf type influenced leaf functional traits,and leaf size was significantly higher and CV of leaf traits and FA in reproductive leaves were significantly lower in the east region than in the west and center regions.Elevation and leaf type affected leaf functional traits,and leaf size was significantly higher and CV of leaf traits in reproductive leaves were significantly lower in moderate elevation.E.annuus has higher leaf size and developmental stability(lower CV and FA)in the eastern region due to the longer adaptation period.Therefore,leaf functional traits play an important role in the adaptation of different longitudes and elevations.It can also facilitate the understanding of the invasiveness and adaptation of leaf traits of invasive plants in the agricultural ecosystem during their spread process in China.
基金supported by the National Key R&D Program of China(2024YFF1307500)the National Natural Science Foundation of China Grant(U21A20190,32401313)the China Postdoctoral Science Foundation(2023M730967)。
文摘Leaf chemistry plays a central role in structuring phyllosphere microbiomes.Plant populations often evolve genetic differences in leaf chemistry across region due to both abiotic and biotic selection pressures,including insect herbivory.Plants in invasive populations may reassociate with native specialist insects,providing an ideal system to examine how herbivory-mediated changes in plant chemistry affect phyllosphere microbiome.Here,we conducted a common garden experiment using Ambrosia artemisiifolia populations differing in leaf chemistry and reassociation history with a specialist beetle—Ophraella communa.We found that plant populations with a longer reassociation history exhibited stronger herbivore resistance and supported phyllosphere communities with higher alpha diversity and more complex composition.These changes were associated with shifts in concentrations of plant metabolites and the expression levels of corresponding biosynthetic genes.The abundance of the fungal pathogens,Golovinomyces,decreased with increasing herbivore resistance,while Pestaliopsis showed the opposite trend.Although reassociation history was linked to population latitude,climatic and soil conditions at the sites of origin also contributed to between-population variation in leaf chemistry and phyllosphere fungal community composition.Our study suggests that genetic differences in leaf chemistry among plant populations can strongly affect herbivore resistance and phyllosphere fungal communities.The observed alignment of reassociation history,chemical traits and phyllosphere fungal communities suggests that herbivore-mediated selection may be a key driver of microbial community evolution in invasive plants.
基金supported by the Science and Technology Development Plan Project of Jilin Province(grant no.20240304029SF)the Fundamental Research Funds for the Central Universities(grant no.2412022ZD055).
文摘Plant-soil feedback(PSF)effects of invasive plants are often regulated by abiotic factors,but whether soil water availability alters the impact of PSF on invasive plant growth and foliar herbivory remains unclear.We hypothesized that soil water content modifies PSF effects and then affects foliar herbivory.To test this,we established four soil water level treatments(soil surface elevated 0,5,10 or 15 cm above water)to examine their effects on PSF,growth traits,and herbivore resistance in the invasive weed Alternanthera philoxeroides.Results showed PSF was negative when the soil surface was elevated 5 cm above water,but it was positive in other treatments.Soil condition,water treatment and their interactions significantly affected total biomass,leaf and branch numbers.As soil water content decreased,leaf nitrogen content increased,while the leaf C/N ratio decreased.Root nitrogen and C/N ratios were also affected by water treatment.Leaf mass per area and leaf area consumption rate were significantly affected by water content,with foliar herbivory being lowest when water content was at its minimum.Importantly,the effects of water availability on invasive plant performance and foliar herbivore resistance appeared to be stronger than those mediated by soil feedback.These findings suggest that soil water content,as a critical role,modifies the PSF effects on invasive plant performance,thereby indirectly affecting foliar herbivory.
基金supported by the National Natural Science Foundation of China(U21A20190).
文摘Terrestrial plants are colonized by various microorganisms in the rhizosphere,phyllosphere and endosphere.Variations of microorganisms between these niches could affect plant performance.While studies have indicated that microorganisms associated with invasive plants may facilitate their invasion success,niche effects on the composition,function and co-occurrence network of invasive plant microbiomes remain poorly understood.In this study,we investigated the bacterial and fungal communities in the rhizosphere soil,root and leaf endospheres of two invasive plants,Flaveria bidentis and Eclipta prostrata.Flaveria bidentis is a recently introduced species(introduced in 2001),whereas E.prostrata has been invaded in China for over 1000 years.We found that microbial community of F.bidentis and E.prostrata harbored more specialists,fewer unique amplicon sequence variants(ASVs),and lower diversity and network complexity in the leaf endosphere than that in the rhizosphere soil.Moreover,the bacterial and fungal communities in the rhizosphere soil,root and leaf endospheres of F.bidentis were more diverse,included more unique ASVs,and had a higher network complexity than those of E.prostrata.Predicted functional profiles revealed that there were more beneficial bacteria and fewer pathogenic fungi associated with F.bidentis than those with E.prostrata.These results demonstrate that there is a significant niche differentiation in the two invasive plant microbiotas,and this work may also indicate potential impact of residence time of invasive plants on plant-microbe interactions.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(Grant No.2019QZKK0502)National Natural Science Foundation of China(Grant No.U23A20160)Shanghai Science and Technology Innovation Action Plan(Grant No.23015810100).
文摘Invasive alien plant species(IAPS)pose severe threats to global biodiversity conservation.Effective management of IAPS requires mapping their distribution and identifying the environmental factors that drive their spread.The Gaoligong Mountains,a renowned biodiversity hotspot in southwestern China,currently face the dual challenges of IAPS invasion and climate change.However,we know little about the distribution patterns,key environmental drivers,and sensitivity of IAPS to future climate change in this region.In this study,we mapped IAPS richness distribution and identified invasion hotspots throughout the Gaoligong Mountains.In addition,we assessed the relative importance of environmental variables in shaping the spatial distribution of IAPS richness and projected potential shifts in IAPS richness under various climate change scenarios.We identified 161 IAPS,primarily concentrated in the low-elevation tropical and subtropical regions along river valleys,forming belt-like invasion hotspots.The key factors shaping IAPS richness included disturbance complexity,elevation,seasonal precipitation,and vegetation types.Notably,IAPS richness significantly declined with increasing elevation and latitude but increased with higher disturbance complexity.Moreover,IAPS were more prevalent in grasslands and shrublands than in forested areas.Ensemble modeling of future climate scenarios predicted that the distribution of IAPS richness would shift to progressively higher elevations.These findings provide valuable insights for managing IAPS in mountainous regions that play a crucial role in global biodiversity conservation.
基金the Fundamental Research Funds of CAF(CAFYBB2022SY020)the National Natural Science Foundation of China(31872645).
文摘Invasive alien species(IAS)significantly threaten global biodiversity and ecosystem stability.Despite increasing management efforts,a critical knowledge gap existed in understanding commonalities and disparities among national strategies.We analyzed several IAS management lists from 23 countries and the European Union,focusing specifically on vascular plant species within these lists.List composition,characteristics,and associated management measures were analyzed.Key patterns in species prioritization across national lists and intercontinental exchange of invasive alien plants(IAPs)were identified.Pistia stratiotes,Pontederia crassipes,Salvinia molesta,Cabomba caroliniana,Ulex europaeus were identified as globally recognized threats,being listed by at least 33.3%of analyzed countries and invading five or more continents.Aquatic plants were found to be more frequently included in management lists.A significant directional invasion pattern between the Eastern and Western Hemispheres was identified.Species native to Asia were observed to dominate as significant donors of IAPs across continents.The analysis of list management strategies highlighted substantial gaps in achieving Target 6 of the Kunming-Montreal Global Biodiversity Framework,particularly in species prioritization and inclusion of potential IAPs.In response to these challenges,a tiered classification system for invasive alien species list was proposed,encompassing High-Priority,Watchlist,Potential,and Priority Site categories,which aimed at enhancing management effectiveness by tailoring strategies to different invasion stages and ecological contexts.This study could contribute to understanding global IAPs management strategies and serve as a reference for policymakers and conservation managers to identify priority IAPs and refine management approaches.
基金supported by the National Key Research and Development Project(2022YFC2601102)National Natural Science Foundation of China(32301473)Natural Science Foundation Sichuan Province of China(2024NSFSC1230).
文摘Unraveling the legacy effects of long-term climate warming is essential to for an integrated understanding of plant invasion success.However,knowledge regarding how these legacy influences invasive offspring and natural enemies remains lacking.This work was built on a long-term warming experiment established in 2012.Here,we selected invasive Solidago canadensis and performed a series of experiments to explore the effects of experimental warming on offspring S.canadensis from its native and invaded range,as well as the legacy effect of warming on three insect species,and three pathogens.The experience of long-term maternal warming facilitated the growth of offspring from invasive S.canadensis,regardless of the presence of insects or pathogens.This experience decreased insect growth when feeding on native S.canadensis,and inhibited pathogens when infecting invasive S.canadensis.Additionally,the presence of natural enemies could modulate the legacy effects of warming and population provenance.These results suggest that long-term climate warming could facilitate invasion success via coordinated increases in growth and defense,and that legacy effects of climate warming and maternal provenance are important for understanding the cascading effects of climate warming.
基金We are grateful to Da-Wen Li and Ailaoshan Station for Subtropical Forest Ecosystem Studies, Chinese Academy of Sciences for field assistance. This work was supported by the National Natural Science Foundation of China （31100410, 31470575 and 30830027）, the National Key Technology R＆D Program of China （2011BAD30B00）, and Chinese Academy Science 135 Program （XTBG-T01, F01）.
文摘Soil microbes are one of the most important determinants of allelopathic effects in the field. However, most studies testing the role of allelopathy in biological invasions did not consider the roles of soil microbes. Here we tested the hypothesis that soil microbes which can degrade allelochemicals may accumulate in soils over time by adaptation and therefore increase the degradation of allelochemicals and alleviate the allelopathic effects in biological invasions. As expected, soil microbes signifi- cantly decreased the allelopathic effects of leaf leachates of eight in the nine invasive plant species studied. In addition, Ageratina adenophora showed lower allelopathic effects in soil with long or intermediately invasion history than those in soil with short invasion history. The two main allelo- chemicals of the invader were degraded more rapidly with increasing invasion history in the soil. Correspondingly,biomass and activity of the soil microbes were higher in the soils with long invasion history than in that with short invasion history. Our results indicate that soil microbes may graduaUy adapt to the allelochemicals of Ageratina and alleviate its allelopathic effects and thus support the above hypothesis. It is necessary to consider the effects of soil microbes when testing the roles of allelopathy or the novel weapons hypothesis in biological invasions.
基金supported by the National Key Research and Development Program(2017YFC1200104).
文摘Climatic warming affects plant growth and physiology,yet how warming alters chemistry in invasive plants and indirectly affects herbivorous insects remains largely unknown.Here,we explored warming-induced changes in leaf chemistry of the invasive plant Alternanthera philoxeroides and its native congener Alternanthera sessilis,and further examined how these changes affected the performance of the herbivores,Cassida piperata and Spodoptera litura.We conducted a simulated warming experiment to address its effects on 13 leaf chemical traits of A.philoxeroides and A.sessilis.We measured growth and development time of two herbivores reared on plants from warming or ambient controls.Warming significantly affected leaf chemistry composition for both the invasive and native Alternanthera.Warming decreased nitrogen concentration in A.philoxeroides and increased total flavonoid and total phenol concentration in A.sessilis.The effects of warming on nutrients(i.e.fructose,sucrose,total soluble sugar and starch)varied with individual chemicals and plant species.Weight of C.piperata pupal and S.litura larval reared on warming-treated A.sessilis significantly decreased compared with non-warmed control,and a similar pattern was observed for weight of S.litura larval feeding on warming-treated A.philoxeroides.In addition,warming-treated A.sessilis significantly prolonged larval development time of S.litura.These results indicate that warming can directly affect the leaf chemistry in both invasive plant and its native congener,but these effects vary by species.Such differences in warming-induced changes in plant chemistry could indirectly affect herbivorous insects associated with the invasive and native plants.
