Maintaining beneficial, native plant structure and diversity while reducing invasive, nuisance species dominance is an important management domain for natural resource managers. One such vegetation component in North ...Maintaining beneficial, native plant structure and diversity while reducing invasive, nuisance species dominance is an important management domain for natural resource managers. One such vegetation component in North American lakes and reservoirs is submerged aquatic vegetation—a valuable aquatic resource which serves as productive habitat for fish, aquatic macroinvertebrates, and other wildlife. Reservoirs in the southern parts of the United States have experienced varying aquatic plant dominance dynamics due to historical water resource management actions, including drawdowns and introduction of herbivorous fish for the purpose of controlling invasive aquatic vegetation. Some of these management options have also been detrimental to native submerged aquatic vegetation. This paper explores an adaptive management research effort by installing herbivore-protected, fenced-pen submerged aquatic vegetation sites in a high-herbivore reservoir to determine effectiveness of protecting habitat and serving as founder colony sources for propagule spread. Four experimental sites with three management treatments each were planted with American eelgrass. Each site utilized one un-fenced treatment and two treatments with varying mesh sizes for protective fencing-pens. Site integrity, species survival and spread, and grazing were documented. One additional site was installed and planted with other native submerged aquatic vegetation species for nominal species performance descriptions. No plants survived unprotected in the high-herbivore system and plants, in general, performed consistently better within the smaller mesh size. These test planting results were ultimately used to inform adaptive management decision making for plant installation and expansion designs for managing reservoirs invested with Hydrilla, considered one of the most serious invasive aquatic plants in the United States.展开更多
The aim for this present study was to evaluate the antioxidant potential of aqueous extracts (AE), hydro-ethanolic extracts (HE) and ethanolic extracts (EE) obtained from an aquatic plant (<em>L. schlechteri<...The aim for this present study was to evaluate the antioxidant potential of aqueous extracts (AE), hydro-ethanolic extracts (HE) and ethanolic extracts (EE) obtained from an aquatic plant (<em>L. schlechteri</em>) using a simple and fast method that is the CCM. This method revealed the presence of phenolics and flavonoids at different levels but with higher antioxidant activity in EE compared to AE. Among the two families of antioxidants evaluated, the phenolic compounds were found to be higher on the EE (5.85 mgEAG/MS) followed by the HE (5.06 mgEAG/MS) and less and less important on the AE (3.661 mgEAG/MS). While the less significantly elevated flavonoids showed values of 1.146 mgECa/MS for EE, 0.406 mgECa/MS for HE et 0.181 mgECa/MS for AE. However, the anti-free radical activity was also evaluated. Unlike the antioxidant activity, the ant-free radical activity with a greater IC50 was observed on AE with a rate of 66.66 mg/mL, then less on the hydro-ethanolic and ethanolic extracts, respectively at levels of 26.15 mg/mL et 19.18 mg/mL.展开更多
[Objective] The aim was to study the effects of Eichhornia crassipes as an invasive plant on aquatic plants in Dianchi Lake. [Method] Based on the determination of chlorophyll content of phytoplankton and submerged pl...[Objective] The aim was to study the effects of Eichhornia crassipes as an invasive plant on aquatic plants in Dianchi Lake. [Method] Based on the determination of chlorophyll content of phytoplankton and submerged plant (Potamogeton pectinatus) in Dianchi Lake in different months, the effects of E. crassipes on aquatic plants in Dianchi Lake were studied, and the allelopathy effect of root culture solution of E. crassipes on Microcystis aquaticum was discussed. [Result] The growth of E. crassipes in Dianchi Lake reduced the chlorophyll content of phytoplankton and submerged plant (P. pectinatus), and it showed that E. crassipes had certain inhibitory effect on their growth; the culture solution of E. crassipes root inhibited M. aeruginosa growth obviously. [Conclusion] The study could provide scientific references for the prevention and control of ecological safety of E. crassipes.展开更多
To find out the current situation and configuration of aquatic plants in landscape water of Chengdu wetland parks,sample-plot survey of aquatic plants in landscape water in the built wetland parks of Chengdu and urban...To find out the current situation and configuration of aquatic plants in landscape water of Chengdu wetland parks,sample-plot survey of aquatic plants in landscape water in the built wetland parks of Chengdu and urban parks was conducted.The results showed that there are 41 kinds of aquatic plants in the research region,belonging to 23 families.They are mainly hygrophyte and emergent plants,while floating and submerged plants are rarely used.Configuration of aquatic plants is mainly composed of emergent plants,supplemented by floating-leaved and submerged plants,and water landscape is rich.Then,configuration of aquatic plants in wetland parks was analyzed from the ecological function,landscape construction and other aspects,to provide the reference for plant configuration of urban wetland parks.展开更多
Maintaining open flowers is critical for successful pollination and depends on long-term water and carbon balance.Yet the relationship between how flower hydraulic traits are coordinated in different habitats is poorl...Maintaining open flowers is critical for successful pollination and depends on long-term water and carbon balance.Yet the relationship between how flower hydraulic traits are coordinated in different habitats is poorly understood.Here,we hypothesize that the coordination and trade-offs between floral hydraulics and economics traits are independent of environmental conditions.To test this hypothesis,we investigated a total of 27 flower economics and hydraulic traits in six aquatic and six terrestrial herbaceous species grown in a tropical botanical garden.We found that although there were a few significant differences,most flower hydraulics and economics traits did not differ significantly between aquatic and terrestrial herbaceous plants.Both flower mass per area and floral longevity were significantly positively correlated with the time required for drying full-hydrated flowers to 70%relative water content.Flower dry matter content was strongly and positively related to drought tolerance of the flowers as indicated by flower water potential at the turgor loss point.In addition,there was a trade-off between hydraulic efficiency and the construction cost of a flower across species.Our results show that flowers of aquatic and terrestrial plants follow the same economics spectrum pattern.These results suggest a convergent flower economics design across terrestrial and aquatic plants,providing new insights into the mechanisms by which floral organs adapt to aquatic and terrestrial habitats.展开更多
The study aimed to evaluate the ability of some terrestrial and aquatic plants for wastewater purification.Aquatic plants can remove pollutants from wastewater by consuming and accumulating various contaminants in diff...The study aimed to evaluate the ability of some terrestrial and aquatic plants for wastewater purification.Aquatic plants can remove pollutants from wastewater by consuming and accumulating various contaminants in different parts of plants.Different aquatic and terrestrial plants(Rosa sinensis,Typha latifolia,Ocimm bacilicum,Azolla pinnata,and Salvinia molesta)which have the ability to decrease water pollution were utilized in this study.The capability offive different species of plants was investigated by measuring chemical oxygen demand(COD),biological oxygen demand(BOD),electrical conductivity(EC),total dissolved solids(TDS),and pH of the medium.In this research,some aquatic and terrestrial plants were transplanted in wastewater plastic pots containing domestic wastewater with different ratios of 50%and 100%.Then,after 30 days,the physiological and biochemical parameters of plants were calculated to observe the effect of wastewater on plants.Results revealed higher chlorophyll and carotenoids in typha plants treated with 100%wastewater.The highest percentage of elimination in BOD(65%),COD(27%),TDS(72%),EC(83%),and pH(6.8%)was noted with the use of typha and azolla.Intriguingly,total soluble sugars,total free amino acids,and total proteins were found maximum in the hibiscus plant as compared to the other plants under 100%and 50%domestic wastewater treatment,while typha and ocimum showed lower values of these parameters irrespective of wastewater treatments.Moreover,the COD,BOD,TDS,EC,and pH trend was higher in 100%wastewater as compared to 50%wastewater.Taking into account the accumulation capacity of the tested plants especially typha can be efficiently used for the treatment of domestic wastewater.展开更多
Aims Aquatic plants play an important role in freshwater ecosystems.Previous works have largely focused on the functional significance of plant above ground parts,with much less attention on the root structures of aqu...Aims Aquatic plants play an important role in freshwater ecosystems.Previous works have largely focused on the functional significance of plant above ground parts,with much less attention on the root structures of aquatic plants.In this study,we divided 21 aquatic plants(including five introduced plants)into multiple plant groups(different life forms,monocot/eudicot and introduced/native)with the goal of addressing two questions:(i)what root structures do aquatic plants exhibit,and(ii)are there differences among these plant groups?Methods Twenty-one aquatic plants belonging to four life forms(free-float-ing,emergent,floating-leaved and submerged)were collected at the near flowering stage from a typical macrophyte-dominated lake in the yangtze River Basin,China.The following root topological parameters were quantified:altitude(a),path length(pe),magnitude(M),mean topological length(b),topological index(TI)and normed indices qa and qb.Important Findings The root topological indices TI,qa and qb for the 21 aquatic plants were 0.724±0.013,0.290±0.031 and 0.152±0.024(means±S.E.),respectively,revealing a general pattern of dichotomous branching,except for the aquatic root of Myriophyllum aquati-cum(Vell.)Verdc.,which displays herringbone branching.All three topological indices were significantly lower for monocots(TI=0.700±0.130,qa=0.191±0.149 and qb=0.086±0.236)than eudicots(TI=0.752±0.206,qa=0.405±0.569 and qb=0.229±0.393),indicating that the roots of monocots are typi-cally more dichotomous-like than those of eudicots.Among the four life forms,the three topological indices for emergent plants(TI=0.832±0.006,qa=0.616±0.018 and qb=0.381±0.014)were significantly higher than those of the other three life forms.Overall,there was no difference between the topological indices of introduced and native aquatic plants,but the introduced species M.aquaticum and Alternanthera philoxeroides(Mart.)Griseb.had both aquatic and edaphic roots as well as unusual functions,which may help explain their strong viability.展开更多
Certain plants have demonstrated the capability to take up and accumulate metals,thus offering the potential to remediate metal-contaminated water and sediment.Several aquatic species have further been identified whic...Certain plants have demonstrated the capability to take up and accumulate metals,thus offering the potential to remediate metal-contaminated water and sediment.Several aquatic species have further been identified which can take up metal and metal oxide engineered nanoparticles(ENPs).It is important to evaluate if aquatic plants exhibiting potential for metal phytoremediation can be applied to remediation of metallic ENPs.Understanding the interactions between ENPs and aquatic plants,and evaluating possible influences on metal uptake and phytoremediation processes is therefore essential.This review article will address the feasibility of green plants for treatment of ENP-affected aquatic ecosystems.Discussion will include common types of ENPs in current use;transformations of ENPs in aquatic systems;the importance of microorganisms in supporting plant growth;ENP entry into the plant;the influence of microorganisms in promoting plant uptake;and recent findings in phytoremediation of ENP-affected water,including applications to constructed wetlands.展开更多
Aims Pond environmental conditions may differ among years with regards to the season in which ponds begin to fill.We experimen-tally evaluated how seedling emergence,plant growth and phe-nology differed among years in...Aims Pond environmental conditions may differ among years with regards to the season in which ponds begin to fill.We experimen-tally evaluated how seedling emergence,plant growth and phe-nology differed among years in which filling occurred in winter,autumn or spring.Methods We collected sediments from a natural temporary pond and located them in aquariums.They were placed in a climatic chamber that simulated annual variation in field environmental temperatures and light conditions.Aquariums were assigned to one of three treat-ments,which differed in the date on which they were filled with water(autumn,winter and spring).We counted the number of seed-lings of different species emerged and recorded data about the pres-ence of flowers,seeds or spores every week.The experiment was finished in June,when we harvested the plants and estimated their biomass.Important Findings In most species,seedling emergences were primarily related to time after filling,and thus synchronized their life cycles with the unpre-dictably timed wet phase of the ponds.Autumn filling resulted in the highest numbers of seeds/spores.However,winter filling pro-moted plant growth the most.In the spring filling treatment,more terrestrial plant seedlings emerged and fewer seeds/spores were produced.When ponds are flooded earlier,plants may produce a higher number of propagules.However,in years when inundation is delayed to spring and hydroperiods are short,seedling emergence deplete the seed bank and there is little to no seed production,while terrestrial monocots are able to colonize pond basin.展开更多
A series of pot experiments with Alternanthera philoxeroides,Typha latifolia,Sagittaria sagittifolia and Phragmites communis were conducted to assess the phosphorus depletion effect in the rhizosphere.The ratio of roo...A series of pot experiments with Alternanthera philoxeroides,Typha latifolia,Sagittaria sagittifolia and Phragmites communis were conducted to assess the phosphorus depletion effect in the rhizosphere.The ratio of root to shoot,root morphology,phosphorus uptake efficiency and phosphorus utilization efficiency were analyzed.An obvious variation in phosphorus concentrations between the rhizosphere soil and non-rhizosphere soil was observed.The water-soluble P contents in the rhizosphere soil of A.philoxeroides,T.latifolia,S.sagittifolia and P.communis were reduced by 81%,42%,18%and 16%,respectively,compared with that in the non-rhizosphere soil.A.philoxeroides had the highest phosphorus uptake efficiency(1.32 mg/m),while T.latifolia achieved the effective phosphorus depletion by the strong rooting system and the high phosphorus uptake efficiency(0.52 mg/m).T.latifolia not only used phosphorus to produce biomass economically,but also adjusted carbon allocation to the roots to explore the soil for more available phosphorus.A.philoxeroides and T.latifolia were more effective in depleting phosphorus in the rhizosphere than S.sagittifolia and P.communis.展开更多
Tropical lotus(Nelumbo) is an important and unique ecological type of lotus germplasm.Understanding the genetic relationship and diversity of the tropical lotus is necessary for its sustainable conservation and utiliz...Tropical lotus(Nelumbo) is an important and unique ecological type of lotus germplasm.Understanding the genetic relationship and diversity of the tropical lotus is necessary for its sustainable conservation and utilization.Using 42 EST-SSR(expressed sequence tag-simple sequence repeats) and 30 SRAP(sequence-related amplified polymorphism) markers,we assessed the genetic diversity and inferred the ancestry of representative tropical lotus from Thailand and Vietnam.In total,164 and 41 polymorphic bands were detected in 69 accessions by 36 EST-SSR and seven SRAP makers,respectively.Higher genetic diversity was revealed in Thai lotus than in Vietnamese lotus.A Neighbor-Joining tree of five main clusters was constructed using combined EST-SSR and SRAP markers.Cluster Ⅰ included 17 accessions of Thai lotus;cluster Ⅱ contained three Thai accessions and 11 accessions from southern Vietnam;and cluster Ⅲ was constituted by 13 accessions of seed lotus.Consistent with the results from the NeighborJoining tree,the genetic structure analysis showed that the genetic background of most Thai and Vietnamese lotus was pure,as artificial breeding has been rare in both countries.Furthermore,these analyses indicate that Thai and Vietnamese lotus germplasms belong to two different gene pools or populations.Most lotus accessions are genetically related to geographical distribution patterns in Thailand or Vietnam.Our findings showed that the origin or genetic relationships of some unidentified lotus sources can be evaluated by comparing morphological characteristics and the data of molecular markers.In addition,these findings provide reliable information for the targeted conservation of tropical lotus and parent selection in breeding novel cultivars of lotus.展开更多
Coexisting floating-leaved and submerged plants experience similar environmental changes but may evolve different patterns of genetic variation.To compare local-scale genetic variation,we collected samples of floating...Coexisting floating-leaved and submerged plants experience similar environmental changes but may evolve different patterns of genetic variation.To compare local-scale genetic variation,we collected samples of floating-leaved Nymphoides peltata and submerged Myriophyllum spicatum coexisting in a disturbed urban lake in China.At the subpopulation level,using microsatellites,M.spicatum had higher clonal diversity than N.peltata.M.spicatum had 28.4%multilocus genotypes(MLGs)shared between subpopulations,but N.peltata had only one MLG shared between two adjacent subpopulations.N.peltata displayed more genetic variation between subpopulations than within subpopulations,but the reverse was true for M.spicatum.Principal components and Bayesian cluster analyses showed that individuals from each subpopulation of N.peltata tended to have relatively close genetic relationships.For M.spicatum,individuals from each subpopulation were genetically scattered with those from other subpopulations.Our results imply that in unpredictable adverse environments M.spicatum may be less subjected to local-deme extinction than N.peltata because of genetically diverse clones at the subpopulation level.This characteristic means that following adverse events,M.spicatum may rapidly restore subpopulation distributions via recolonization and intense gene flow among subpopulations.展开更多
Elevated evapotranspiration due to warmer air temperature could raise salinity and nutrient levels of some inland wetlands, potentially impacting nitrogen cycling. To characterize the impact of high evapotranspiration...Elevated evapotranspiration due to warmer air temperature could raise salinity and nutrient levels of some inland wetlands, potentially impacting nitrogen cycling. To characterize the impact of high evapotranspiration on soil microbial nitrogen cycling in inland wetlands, we compared freshwater and brackish marsh(or non-marsh) wetlands in terms of sediment ammonia-oxidizing rate(AOR), denitrifying rate(DR), and related microbial communities in a typical inland basin, the Hulun Lake basin, in China. Results showed that marsh ecosystems(ME) exhibited 31% higher AOR and 65% higher DR than non-marsh ecosystems(NE). For NE, freshwater non-marsh wetland exhibited 12% higher AOR than brackish non-marsh wetland. This was probably due to the inhibitory effects of high NH_4~+ and salinity levels on ammonia-oxidizing archaea in brackish non-marsh wetland. Conversely, DR in brackish non-marsh wetland was 23% higher than that in freshwater non-marsh wetland, with total organic carbon(TOC) significantly influencing this difference,suggesting that the higher DR in brackish non-marsh wetland was mainly due to its higher TOC level. For ME, due to the direct and indirect interference of salinity, brackish marsh wetland displayed 26% lower AOR and 19% lower DR than freshwater marsh wetland. Besides, brackish wetlands harbored distinct ammonia-oxidizing and denitrifying microbial communities compared to freshwater wetlands. The assembly of these communities was dominated by stochastic processes, while brackish wetlands exhibited more prominent deterministic processes than freshwater wetlands. Overall, high evapotranspiration altered activities and community characteristics of ammonia oxidizers and denitrifiers in inland brackish wetlands by enhancing salinity and nutrient levels,while emergent plants occurring in ME could mitigate the adverse effects of salt stress of inland brackish wetlands on nitrogen cycling.展开更多
A modularized and air adjustable constructed submerged plant bed(CSPB)which can be used to restore the eutrophic water is introduced in this paper.This plant bed helps hydrophyte grow under poor conditions such as fre...A modularized and air adjustable constructed submerged plant bed(CSPB)which can be used to restore the eutrophic water is introduced in this paper.This plant bed helps hydrophyte grow under poor conditions such as frequently changed water depth,impaired water transparency,algae bloom and substantial duckweed in summer,which are not naturally suitable for growing hydrophyte.This pilot study in Waihuan River of Tianjin,China,revealed that reduction of Chemical Oxygen Demand(COD),Total Nitrogen(TN)and Total Phosphorus(TP)by the use of CSPB could be reached 30%-35%,35%-40%,30%-40%respectively in the growing season(from March to October)and 5%-10%,5%-15%,7%-20%respectively in the winter(from November to February)when the detention time was 6 d.The relationships between the concentration of COD,TN,TP and the detention time fit the first-order kinetic equation well and the coefficients of determination(R^(2))were all above 0.9.The attenuation coefficients k of the kinetic equation were a function of the water temperature.When the water temperature was quite low or quite high,k was not significantly changed with increasing or decreasing water temperature.While when the temperature was in a moderate range,an increase or decrease of water temperature would lead to a rapid increase or decrease in k.展开更多
Engineered nanoparticles(ENPs)threaten the environment through wastewater discharging.Generally,constructed wetlands(CWs)are efficient methods for ENPs removal.However,the biotoxicity of ENPs on plants in CWs is uncle...Engineered nanoparticles(ENPs)threaten the environment through wastewater discharging.Generally,constructed wetlands(CWs)are efficient methods for ENPs removal.However,the biotoxicity of ENPs on plants in CWs is unclear.Here,we investigated the distribution and bio-impacts of different ENPs(Ag NPs,TiO_(2) NPs,and CeO_(2) NPs)in plants under 5-and 60-day exposure to 1 and 50 mg/L concentrations.Results showed that ENPs appeared in the vascular bundle and mesophyll cell space,which induced the variation in antioxidase activities(e.g.,superoxide dismutase[SOD],peroxidase[POD],and catalase[CAT]activities)as well as overproduction of malondialdehyde(MDA).Additionally,Ag NPs inhibited photosynthesis rate and root activity during two exposure phases.CeO_(2) NPs had positive and negative impacts on plants in 5-and 60-day exposure,respectively.Inversely,TiO_(2) NPs enhanced photosynthesis and root activity under 60-day exposure.Finally,the contents of the C,N,and P elements in plants fluctuated in response to ENPs stress.All results have a positive correlation with the wetland performance under ENPs exposure except for TiO_(2) NPs treatment.Overall,our study systematically reveals aquatic plants'responses to ENPs and provides a reference for building ecological treatment systems to purify wastewater containing ENPs.展开更多
Aims Foraging behavior was concerned less in plants especially for clonal aquatic species.The goal of this study was to test the foraging behav-ior and the function of phenotypic plasticity of a clonal submerged plant...Aims Foraging behavior was concerned less in plants especially for clonal aquatic species.The goal of this study was to test the foraging behav-ior and the function of phenotypic plasticity of a clonal submerged plant,Potamogeton maackianus A.Benn in variable manipulative environments.Methods To explore the foraging behavior of a clonal submerged plant,clones of P.maackianus were cultivated in variable environments of different substrate types and light conditions.We measured bio-mass,specific root area(SRA),specific root length(SRL),branch-ing angle of the ramet,chlorophyll content of apical leaves(CCAL),Fv/Fm(chlorophyll fluorescence parameter that indicates maximal photosystem II(PS II)efficiency)and biomass distribution in soil and light contrast treatments after harvest.Important Findings We found that the atypical non-clonal-like foraging behavior homogenized the performance of the stoloniferous clonal spe-cies,P.maackianus,in the measurement of biomass in our study.Substrate type had significant effects on most traits of P.maackianus,except on total biomass,shoot biomass distribution and CCAL.Patchy substrate mediated more root distribution into sand patch rather than into clay patch.Increase of SRA,SRL and Fv/Fm might be adaptive to substrate heterogeneity.Moreover,substrate hetero-geneity induced‘sidewalk’stolon lineage on the edge of sand patch along the patch border.Light condition only had significant effects on branching angle,shoot biomass distribution and Fv/Fm.Shade led to more shoot assignment in light-rich zone than in light-poor zone.Potamogeton maackianus adjusted the branching angle of ramet rather than clonal exploitation in heterogeneous substrates with patchy shade.Moreover,shade led to higher Fv/Fm.A com-promising foraging strategy promoted P.maackianus to escape unfa-vorable environments.Phenotypic plasticity,which maximized the performance of P.maackianus in the measurement of biomass in variable environments,may explain its domination in some shallow lakes of the middle and lower reaches of Yangtze River.展开更多
Benthic macroinvertebrates play key roles in shallow aquatic ecosystems and can contribute substantially to aquatic food webs.However,how macroinvertebrates with different behaviors(for example,pertaining to locomotio...Benthic macroinvertebrates play key roles in shallow aquatic ecosystems and can contribute substantially to aquatic food webs.However,how macroinvertebrates with different behaviors(for example,pertaining to locomotion,foraging and burrowing)impact water quality and primary producers has not been fully explored.Here,we performed two consecutive microcosm experiments to test the effects of(1)macroinvertebrates with different behaviors(a low mobility scraper aquatic snail Bellamya aeruginosa and a high mobility shredder freshwater shrimp Macrobrachium nipponense)and(2)different shrimp biomasses on water clarity and the composition of benthic primary producers.The results showed that presence of snails significantly increased the biomass of filamentous green algae and decreased the biomass of periphyton.In contrast,presence of shrimp significantly decreased the biomass of filamentous green algae and increased the biomass of periphyton,and these effects were biomass dependent.Filamentous green algae disappeared when shrimp biomass reached 9.8 g m^(-2).No interactive effects of snail and shrimp presence were found.This could be attributed to different food preferences by the two consumers,with snails preferring periphyton(mainly diatoms)and shrimp preferring filamentous green algae.The presence of snails decreased water turbidity,while shrimp increased water turbidity,which showed a hump-shaped response to shrimp biomass with a peak at 24.2 g m^(-2).These results are likely because the snail is a low mobility grazer and can filter suspended particles,while the shrimp is a high mobility shredder with burrows,which can strongly disturb sediment.The decrease in water disturbance at high shrimp biomass might be due to food limitation,thus reducing burrowing and foraging activities.Neither snail nor shrimp affected the biomass of H.verticillata,while the biomass of V.spinulosa increased with shrimp biomass.The reason for this could be that shrimp increased nutrient availability and decreased the growth of filamentous green algae that compete with macrophytes.Our study demonstrated that different macroinvertebrates have complementary functions in benthic habitats;thus,maintaining macroinvertebrate diversity is important for shallow aquatic ecosystems.Furthermore,the freshwater shrimp M.nipponense could be a potential consumer to control filamentous green algal blooms in its native range,but their biomass should be taken into consideration.展开更多
文摘Maintaining beneficial, native plant structure and diversity while reducing invasive, nuisance species dominance is an important management domain for natural resource managers. One such vegetation component in North American lakes and reservoirs is submerged aquatic vegetation—a valuable aquatic resource which serves as productive habitat for fish, aquatic macroinvertebrates, and other wildlife. Reservoirs in the southern parts of the United States have experienced varying aquatic plant dominance dynamics due to historical water resource management actions, including drawdowns and introduction of herbivorous fish for the purpose of controlling invasive aquatic vegetation. Some of these management options have also been detrimental to native submerged aquatic vegetation. This paper explores an adaptive management research effort by installing herbivore-protected, fenced-pen submerged aquatic vegetation sites in a high-herbivore reservoir to determine effectiveness of protecting habitat and serving as founder colony sources for propagule spread. Four experimental sites with three management treatments each were planted with American eelgrass. Each site utilized one un-fenced treatment and two treatments with varying mesh sizes for protective fencing-pens. Site integrity, species survival and spread, and grazing were documented. One additional site was installed and planted with other native submerged aquatic vegetation species for nominal species performance descriptions. No plants survived unprotected in the high-herbivore system and plants, in general, performed consistently better within the smaller mesh size. These test planting results were ultimately used to inform adaptive management decision making for plant installation and expansion designs for managing reservoirs invested with Hydrilla, considered one of the most serious invasive aquatic plants in the United States.
文摘The aim for this present study was to evaluate the antioxidant potential of aqueous extracts (AE), hydro-ethanolic extracts (HE) and ethanolic extracts (EE) obtained from an aquatic plant (<em>L. schlechteri</em>) using a simple and fast method that is the CCM. This method revealed the presence of phenolics and flavonoids at different levels but with higher antioxidant activity in EE compared to AE. Among the two families of antioxidants evaluated, the phenolic compounds were found to be higher on the EE (5.85 mgEAG/MS) followed by the HE (5.06 mgEAG/MS) and less and less important on the AE (3.661 mgEAG/MS). While the less significantly elevated flavonoids showed values of 1.146 mgECa/MS for EE, 0.406 mgECa/MS for HE et 0.181 mgECa/MS for AE. However, the anti-free radical activity was also evaluated. Unlike the antioxidant activity, the ant-free radical activity with a greater IC50 was observed on AE with a rate of 66.66 mg/mL, then less on the hydro-ethanolic and ethanolic extracts, respectively at levels of 26.15 mg/mL et 19.18 mg/mL.
基金Supported by Scientific Demonstration Engineering Project in Kunming City (109S010103)
文摘[Objective] The aim was to study the effects of Eichhornia crassipes as an invasive plant on aquatic plants in Dianchi Lake. [Method] Based on the determination of chlorophyll content of phytoplankton and submerged plant (Potamogeton pectinatus) in Dianchi Lake in different months, the effects of E. crassipes on aquatic plants in Dianchi Lake were studied, and the allelopathy effect of root culture solution of E. crassipes on Microcystis aquaticum was discussed. [Result] The growth of E. crassipes in Dianchi Lake reduced the chlorophyll content of phytoplankton and submerged plant (P. pectinatus), and it showed that E. crassipes had certain inhibitory effect on their growth; the culture solution of E. crassipes root inhibited M. aeruginosa growth obviously. [Conclusion] The study could provide scientific references for the prevention and control of ecological safety of E. crassipes.
基金Sponsored by Sichuan Landscape and Recreation Research Center (JGYQ2019018)。
文摘To find out the current situation and configuration of aquatic plants in landscape water of Chengdu wetland parks,sample-plot survey of aquatic plants in landscape water in the built wetland parks of Chengdu and urban parks was conducted.The results showed that there are 41 kinds of aquatic plants in the research region,belonging to 23 families.They are mainly hygrophyte and emergent plants,while floating and submerged plants are rarely used.Configuration of aquatic plants is mainly composed of emergent plants,supplemented by floating-leaved and submerged plants,and water landscape is rich.Then,configuration of aquatic plants in wetland parks was analyzed from the ecological function,landscape construction and other aspects,to provide the reference for plant configuration of urban wetland parks.
基金supported by the National Natural Science Foundation of China(32171507,31870385,31901285)CAS"Light of West China"program。
文摘Maintaining open flowers is critical for successful pollination and depends on long-term water and carbon balance.Yet the relationship between how flower hydraulic traits are coordinated in different habitats is poorly understood.Here,we hypothesize that the coordination and trade-offs between floral hydraulics and economics traits are independent of environmental conditions.To test this hypothesis,we investigated a total of 27 flower economics and hydraulic traits in six aquatic and six terrestrial herbaceous species grown in a tropical botanical garden.We found that although there were a few significant differences,most flower hydraulics and economics traits did not differ significantly between aquatic and terrestrial herbaceous plants.Both flower mass per area and floral longevity were significantly positively correlated with the time required for drying full-hydrated flowers to 70%relative water content.Flower dry matter content was strongly and positively related to drought tolerance of the flowers as indicated by flower water potential at the turgor loss point.In addition,there was a trade-off between hydraulic efficiency and the construction cost of a flower across species.Our results show that flowers of aquatic and terrestrial plants follow the same economics spectrum pattern.These results suggest a convergent flower economics design across terrestrial and aquatic plants,providing new insights into the mechanisms by which floral organs adapt to aquatic and terrestrial habitats.
文摘The study aimed to evaluate the ability of some terrestrial and aquatic plants for wastewater purification.Aquatic plants can remove pollutants from wastewater by consuming and accumulating various contaminants in different parts of plants.Different aquatic and terrestrial plants(Rosa sinensis,Typha latifolia,Ocimm bacilicum,Azolla pinnata,and Salvinia molesta)which have the ability to decrease water pollution were utilized in this study.The capability offive different species of plants was investigated by measuring chemical oxygen demand(COD),biological oxygen demand(BOD),electrical conductivity(EC),total dissolved solids(TDS),and pH of the medium.In this research,some aquatic and terrestrial plants were transplanted in wastewater plastic pots containing domestic wastewater with different ratios of 50%and 100%.Then,after 30 days,the physiological and biochemical parameters of plants were calculated to observe the effect of wastewater on plants.Results revealed higher chlorophyll and carotenoids in typha plants treated with 100%wastewater.The highest percentage of elimination in BOD(65%),COD(27%),TDS(72%),EC(83%),and pH(6.8%)was noted with the use of typha and azolla.Intriguingly,total soluble sugars,total free amino acids,and total proteins were found maximum in the hibiscus plant as compared to the other plants under 100%and 50%domestic wastewater treatment,while typha and ocimum showed lower values of these parameters irrespective of wastewater treatments.Moreover,the COD,BOD,TDS,EC,and pH trend was higher in 100%wastewater as compared to 50%wastewater.Taking into account the accumulation capacity of the tested plants especially typha can be efficiently used for the treatment of domestic wastewater.
基金Special Foundation of National Science and Technology Basic Research(2013FY112300).
文摘Aims Aquatic plants play an important role in freshwater ecosystems.Previous works have largely focused on the functional significance of plant above ground parts,with much less attention on the root structures of aquatic plants.In this study,we divided 21 aquatic plants(including five introduced plants)into multiple plant groups(different life forms,monocot/eudicot and introduced/native)with the goal of addressing two questions:(i)what root structures do aquatic plants exhibit,and(ii)are there differences among these plant groups?Methods Twenty-one aquatic plants belonging to four life forms(free-float-ing,emergent,floating-leaved and submerged)were collected at the near flowering stage from a typical macrophyte-dominated lake in the yangtze River Basin,China.The following root topological parameters were quantified:altitude(a),path length(pe),magnitude(M),mean topological length(b),topological index(TI)and normed indices qa and qb.Important Findings The root topological indices TI,qa and qb for the 21 aquatic plants were 0.724±0.013,0.290±0.031 and 0.152±0.024(means±S.E.),respectively,revealing a general pattern of dichotomous branching,except for the aquatic root of Myriophyllum aquati-cum(Vell.)Verdc.,which displays herringbone branching.All three topological indices were significantly lower for monocots(TI=0.700±0.130,qa=0.191±0.149 and qb=0.086±0.236)than eudicots(TI=0.752±0.206,qa=0.405±0.569 and qb=0.229±0.393),indicating that the roots of monocots are typi-cally more dichotomous-like than those of eudicots.Among the four life forms,the three topological indices for emergent plants(TI=0.832±0.006,qa=0.616±0.018 and qb=0.381±0.014)were significantly higher than those of the other three life forms.Overall,there was no difference between the topological indices of introduced and native aquatic plants,but the introduced species M.aquaticum and Alternanthera philoxeroides(Mart.)Griseb.had both aquatic and edaphic roots as well as unusual functions,which may help explain their strong viability.
基金Support from the Office of the Provost,Ball State University(USA)the University of Siena(Italy)。
文摘Certain plants have demonstrated the capability to take up and accumulate metals,thus offering the potential to remediate metal-contaminated water and sediment.Several aquatic species have further been identified which can take up metal and metal oxide engineered nanoparticles(ENPs).It is important to evaluate if aquatic plants exhibiting potential for metal phytoremediation can be applied to remediation of metallic ENPs.Understanding the interactions between ENPs and aquatic plants,and evaluating possible influences on metal uptake and phytoremediation processes is therefore essential.This review article will address the feasibility of green plants for treatment of ENP-affected aquatic ecosystems.Discussion will include common types of ENPs in current use;transformations of ENPs in aquatic systems;the importance of microorganisms in supporting plant growth;ENP entry into the plant;the influence of microorganisms in promoting plant uptake;and recent findings in phytoremediation of ENP-affected water,including applications to constructed wetlands.
基金This study was funded by the Spanish Ministry of Agriculture,Food and Environment(Project 158/2010).
文摘Aims Pond environmental conditions may differ among years with regards to the season in which ponds begin to fill.We experimen-tally evaluated how seedling emergence,plant growth and phe-nology differed among years in which filling occurred in winter,autumn or spring.Methods We collected sediments from a natural temporary pond and located them in aquariums.They were placed in a climatic chamber that simulated annual variation in field environmental temperatures and light conditions.Aquariums were assigned to one of three treat-ments,which differed in the date on which they were filled with water(autumn,winter and spring).We counted the number of seed-lings of different species emerged and recorded data about the pres-ence of flowers,seeds or spores every week.The experiment was finished in June,when we harvested the plants and estimated their biomass.Important Findings In most species,seedling emergences were primarily related to time after filling,and thus synchronized their life cycles with the unpre-dictably timed wet phase of the ponds.Autumn filling resulted in the highest numbers of seeds/spores.However,winter filling pro-moted plant growth the most.In the spring filling treatment,more terrestrial plant seedlings emerged and fewer seeds/spores were produced.When ponds are flooded earlier,plants may produce a higher number of propagules.However,in years when inundation is delayed to spring and hydroperiods are short,seedling emergence deplete the seed bank and there is little to no seed production,while terrestrial monocots are able to colonize pond basin.
基金This work was supported by the National Natural Science Foundation of China(Grant No.30570340)the National Natural Science Foundation of China-Japan Science and Technology Agency(NSFC-JST)Scientific Cooperation Program(Grant No.50721140017)Scientific and Technical Supporting Programs Funded by Ministry of Science&Technology of China during the 11th Five-year Plan(Grant No.2006BAC10B03).
文摘A series of pot experiments with Alternanthera philoxeroides,Typha latifolia,Sagittaria sagittifolia and Phragmites communis were conducted to assess the phosphorus depletion effect in the rhizosphere.The ratio of root to shoot,root morphology,phosphorus uptake efficiency and phosphorus utilization efficiency were analyzed.An obvious variation in phosphorus concentrations between the rhizosphere soil and non-rhizosphere soil was observed.The water-soluble P contents in the rhizosphere soil of A.philoxeroides,T.latifolia,S.sagittifolia and P.communis were reduced by 81%,42%,18%and 16%,respectively,compared with that in the non-rhizosphere soil.A.philoxeroides had the highest phosphorus uptake efficiency(1.32 mg/m),while T.latifolia achieved the effective phosphorus depletion by the strong rooting system and the high phosphorus uptake efficiency(0.52 mg/m).T.latifolia not only used phosphorus to produce biomass economically,but also adjusted carbon allocation to the roots to explore the soil for more available phosphorus.A.philoxeroides and T.latifolia were more effective in depleting phosphorus in the rhizosphere than S.sagittifolia and P.communis.
基金supported by Shanghai Landscaping Administration Bureau (Grant number G182412)the grant from Zhejiang Humanity Landscape Co.,Ltd.,Hangzhou,China。
文摘Tropical lotus(Nelumbo) is an important and unique ecological type of lotus germplasm.Understanding the genetic relationship and diversity of the tropical lotus is necessary for its sustainable conservation and utilization.Using 42 EST-SSR(expressed sequence tag-simple sequence repeats) and 30 SRAP(sequence-related amplified polymorphism) markers,we assessed the genetic diversity and inferred the ancestry of representative tropical lotus from Thailand and Vietnam.In total,164 and 41 polymorphic bands were detected in 69 accessions by 36 EST-SSR and seven SRAP makers,respectively.Higher genetic diversity was revealed in Thai lotus than in Vietnamese lotus.A Neighbor-Joining tree of five main clusters was constructed using combined EST-SSR and SRAP markers.Cluster Ⅰ included 17 accessions of Thai lotus;cluster Ⅱ contained three Thai accessions and 11 accessions from southern Vietnam;and cluster Ⅲ was constituted by 13 accessions of seed lotus.Consistent with the results from the NeighborJoining tree,the genetic structure analysis showed that the genetic background of most Thai and Vietnamese lotus was pure,as artificial breeding has been rare in both countries.Furthermore,these analyses indicate that Thai and Vietnamese lotus germplasms belong to two different gene pools or populations.Most lotus accessions are genetically related to geographical distribution patterns in Thailand or Vietnam.Our findings showed that the origin or genetic relationships of some unidentified lotus sources can be evaluated by comparing morphological characteristics and the data of molecular markers.In addition,these findings provide reliable information for the targeted conservation of tropical lotus and parent selection in breeding novel cultivars of lotus.
基金Supported by the National Natural Science Foundation of China(No.31600325)。
文摘Coexisting floating-leaved and submerged plants experience similar environmental changes but may evolve different patterns of genetic variation.To compare local-scale genetic variation,we collected samples of floating-leaved Nymphoides peltata and submerged Myriophyllum spicatum coexisting in a disturbed urban lake in China.At the subpopulation level,using microsatellites,M.spicatum had higher clonal diversity than N.peltata.M.spicatum had 28.4%multilocus genotypes(MLGs)shared between subpopulations,but N.peltata had only one MLG shared between two adjacent subpopulations.N.peltata displayed more genetic variation between subpopulations than within subpopulations,but the reverse was true for M.spicatum.Principal components and Bayesian cluster analyses showed that individuals from each subpopulation of N.peltata tended to have relatively close genetic relationships.For M.spicatum,individuals from each subpopulation were genetically scattered with those from other subpopulations.Our results imply that in unpredictable adverse environments M.spicatum may be less subjected to local-deme extinction than N.peltata because of genetically diverse clones at the subpopulation level.This characteristic means that following adverse events,M.spicatum may rapidly restore subpopulation distributions via recolonization and intense gene flow among subpopulations.
基金supported by the Natural Science Foundation of Shandong Province,China(Nos.ZR2022QC146and ZR2021YQ22)the National Natural Science Foundation of China(Nos.31872242,32070405,32270444,and32200349)he Colleges and Universities Youth Innovation Science and Technology Teams Support Program of Shandong Province,China(No.2021KJ015)。
文摘Elevated evapotranspiration due to warmer air temperature could raise salinity and nutrient levels of some inland wetlands, potentially impacting nitrogen cycling. To characterize the impact of high evapotranspiration on soil microbial nitrogen cycling in inland wetlands, we compared freshwater and brackish marsh(or non-marsh) wetlands in terms of sediment ammonia-oxidizing rate(AOR), denitrifying rate(DR), and related microbial communities in a typical inland basin, the Hulun Lake basin, in China. Results showed that marsh ecosystems(ME) exhibited 31% higher AOR and 65% higher DR than non-marsh ecosystems(NE). For NE, freshwater non-marsh wetland exhibited 12% higher AOR than brackish non-marsh wetland. This was probably due to the inhibitory effects of high NH_4~+ and salinity levels on ammonia-oxidizing archaea in brackish non-marsh wetland. Conversely, DR in brackish non-marsh wetland was 23% higher than that in freshwater non-marsh wetland, with total organic carbon(TOC) significantly influencing this difference,suggesting that the higher DR in brackish non-marsh wetland was mainly due to its higher TOC level. For ME, due to the direct and indirect interference of salinity, brackish marsh wetland displayed 26% lower AOR and 19% lower DR than freshwater marsh wetland. Besides, brackish wetlands harbored distinct ammonia-oxidizing and denitrifying microbial communities compared to freshwater wetlands. The assembly of these communities was dominated by stochastic processes, while brackish wetlands exhibited more prominent deterministic processes than freshwater wetlands. Overall, high evapotranspiration altered activities and community characteristics of ammonia oxidizers and denitrifiers in inland brackish wetlands by enhancing salinity and nutrient levels,while emergent plants occurring in ME could mitigate the adverse effects of salt stress of inland brackish wetlands on nitrogen cycling.
基金This work was supported by NSF of Tianjin(Nos.043115111-3,09ZCGYSF00400,200801100)National Key-Projects of Water Pollution Control and Prevention(Nos.2009ZX07209-001 and 2008ZX07314-005-011)the National Natural Science Foundation of China(Grant No.5107906).
文摘A modularized and air adjustable constructed submerged plant bed(CSPB)which can be used to restore the eutrophic water is introduced in this paper.This plant bed helps hydrophyte grow under poor conditions such as frequently changed water depth,impaired water transparency,algae bloom and substantial duckweed in summer,which are not naturally suitable for growing hydrophyte.This pilot study in Waihuan River of Tianjin,China,revealed that reduction of Chemical Oxygen Demand(COD),Total Nitrogen(TN)and Total Phosphorus(TP)by the use of CSPB could be reached 30%-35%,35%-40%,30%-40%respectively in the growing season(from March to October)and 5%-10%,5%-15%,7%-20%respectively in the winter(from November to February)when the detention time was 6 d.The relationships between the concentration of COD,TN,TP and the detention time fit the first-order kinetic equation well and the coefficients of determination(R^(2))were all above 0.9.The attenuation coefficients k of the kinetic equation were a function of the water temperature.When the water temperature was quite low or quite high,k was not significantly changed with increasing or decreasing water temperature.While when the temperature was in a moderate range,an increase or decrease of water temperature would lead to a rapid increase or decrease in k.
基金supported by the National Natural Science Foundation of China(Grant No.51708056)the National Major Project of Pollution Control and Treatment Science and Technology(Grant No.2017ZX07401003-4)Chongqing Talents Plan for Young Talents(No.CQY201905062)。
文摘Engineered nanoparticles(ENPs)threaten the environment through wastewater discharging.Generally,constructed wetlands(CWs)are efficient methods for ENPs removal.However,the biotoxicity of ENPs on plants in CWs is unclear.Here,we investigated the distribution and bio-impacts of different ENPs(Ag NPs,TiO_(2) NPs,and CeO_(2) NPs)in plants under 5-and 60-day exposure to 1 and 50 mg/L concentrations.Results showed that ENPs appeared in the vascular bundle and mesophyll cell space,which induced the variation in antioxidase activities(e.g.,superoxide dismutase[SOD],peroxidase[POD],and catalase[CAT]activities)as well as overproduction of malondialdehyde(MDA).Additionally,Ag NPs inhibited photosynthesis rate and root activity during two exposure phases.CeO_(2) NPs had positive and negative impacts on plants in 5-and 60-day exposure,respectively.Inversely,TiO_(2) NPs enhanced photosynthesis and root activity under 60-day exposure.Finally,the contents of the C,N,and P elements in plants fluctuated in response to ENPs stress.All results have a positive correlation with the wetland performance under ENPs exposure except for TiO_(2) NPs treatment.Overall,our study systematically reveals aquatic plants'responses to ENPs and provides a reference for building ecological treatment systems to purify wastewater containing ENPs.
基金Natural Science Foundation of China(31170339)the Special Foundation of National Science and Technology Basic Research(2013FY112300).
文摘Aims Foraging behavior was concerned less in plants especially for clonal aquatic species.The goal of this study was to test the foraging behav-ior and the function of phenotypic plasticity of a clonal submerged plant,Potamogeton maackianus A.Benn in variable manipulative environments.Methods To explore the foraging behavior of a clonal submerged plant,clones of P.maackianus were cultivated in variable environments of different substrate types and light conditions.We measured bio-mass,specific root area(SRA),specific root length(SRL),branch-ing angle of the ramet,chlorophyll content of apical leaves(CCAL),Fv/Fm(chlorophyll fluorescence parameter that indicates maximal photosystem II(PS II)efficiency)and biomass distribution in soil and light contrast treatments after harvest.Important Findings We found that the atypical non-clonal-like foraging behavior homogenized the performance of the stoloniferous clonal spe-cies,P.maackianus,in the measurement of biomass in our study.Substrate type had significant effects on most traits of P.maackianus,except on total biomass,shoot biomass distribution and CCAL.Patchy substrate mediated more root distribution into sand patch rather than into clay patch.Increase of SRA,SRL and Fv/Fm might be adaptive to substrate heterogeneity.Moreover,substrate hetero-geneity induced‘sidewalk’stolon lineage on the edge of sand patch along the patch border.Light condition only had significant effects on branching angle,shoot biomass distribution and Fv/Fm.Shade led to more shoot assignment in light-rich zone than in light-poor zone.Potamogeton maackianus adjusted the branching angle of ramet rather than clonal exploitation in heterogeneous substrates with patchy shade.Moreover,shade led to higher Fv/Fm.A com-promising foraging strategy promoted P.maackianus to escape unfa-vorable environments.Phenotypic plasticity,which maximized the performance of P.maackianus in the measurement of biomass in variable environments,may explain its domination in some shallow lakes of the middle and lower reaches of Yangtze River.
基金supported by the National Natural Science Foundations of China(Grant No.32001158 and Grant No.31872687)China Postdoctoral Science Foundation(Grant No.2019M652734)the Research funds of The Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control(No.2001K003).
文摘Benthic macroinvertebrates play key roles in shallow aquatic ecosystems and can contribute substantially to aquatic food webs.However,how macroinvertebrates with different behaviors(for example,pertaining to locomotion,foraging and burrowing)impact water quality and primary producers has not been fully explored.Here,we performed two consecutive microcosm experiments to test the effects of(1)macroinvertebrates with different behaviors(a low mobility scraper aquatic snail Bellamya aeruginosa and a high mobility shredder freshwater shrimp Macrobrachium nipponense)and(2)different shrimp biomasses on water clarity and the composition of benthic primary producers.The results showed that presence of snails significantly increased the biomass of filamentous green algae and decreased the biomass of periphyton.In contrast,presence of shrimp significantly decreased the biomass of filamentous green algae and increased the biomass of periphyton,and these effects were biomass dependent.Filamentous green algae disappeared when shrimp biomass reached 9.8 g m^(-2).No interactive effects of snail and shrimp presence were found.This could be attributed to different food preferences by the two consumers,with snails preferring periphyton(mainly diatoms)and shrimp preferring filamentous green algae.The presence of snails decreased water turbidity,while shrimp increased water turbidity,which showed a hump-shaped response to shrimp biomass with a peak at 24.2 g m^(-2).These results are likely because the snail is a low mobility grazer and can filter suspended particles,while the shrimp is a high mobility shredder with burrows,which can strongly disturb sediment.The decrease in water disturbance at high shrimp biomass might be due to food limitation,thus reducing burrowing and foraging activities.Neither snail nor shrimp affected the biomass of H.verticillata,while the biomass of V.spinulosa increased with shrimp biomass.The reason for this could be that shrimp increased nutrient availability and decreased the growth of filamentous green algae that compete with macrophytes.Our study demonstrated that different macroinvertebrates have complementary functions in benthic habitats;thus,maintaining macroinvertebrate diversity is important for shallow aquatic ecosystems.Furthermore,the freshwater shrimp M.nipponense could be a potential consumer to control filamentous green algal blooms in its native range,but their biomass should be taken into consideration.
