Superabsorbents such as cross-linked PAM （polyacrylamides） are frequently used to increase water availability to plants. Commercial PAM providers suggest that besides its increasing water availability, PAMs also inc...Superabsorbents such as cross-linked PAM （polyacrylamides） are frequently used to increase water availability to plants. Commercial PAM providers suggest that besides its increasing water availability, PAMs also increase nutrient availability to plants. To test this premise, four application rates （0.0 g·kg^-1, 0.33 g·kg^-1, 1.66 g·kg^-1, 3.33 g·kg^-1 and 6.66 g·kg^-1） ofa PAM were mixed with sandy and loamy soils to evaluate its effect on nutrient leaching and retention in these soils. Miscible displacements of chloride were conducted on columns of PAM-soil mixtures and results were evaluated by an equilibrium CDE （convection dispersion equation） model. Increasing the PAM rates up to 1.66 g·kg^-1 resulted in increased early appearance and dispersive transport of chloride in sand. In addition, increasing the PAM rates gradually caused increased tailing of the breakthrough curves of chloride in both soils. These suggested that PAM increased preferential transport of chloride while it increased retention of chloride in soils. Effect of PAM on preferential transport and retardation of CI was greater in sand than loam.展开更多
The interaction of Pb Cd can be observed not only in the uptake process of elements by plants and in their influence on the growth, but also in rhizosphere. The changes in extractable Cd and Pb concentrations in the ...The interaction of Pb Cd can be observed not only in the uptake process of elements by plants and in their influence on the growth, but also in rhizosphere. The changes in extractable Cd and Pb concentrations in the rhizosphere soil of rice plants, root exudates from wheat and wheat plant and their complexing capacity with Pb and Cd were investigated under different Pb and Cd treatments. Results showed that the concentration of extractable Cd in the rhizosphere of rice in red soil was markedly increased by Pb Cd interaction. It increased by 56% in the treatment with Pb and Cd added against that in the treatment with only Cd added in soil. The considerable differences in both composition and amount of root exudate from wheat and rice were found among different treatments. Pb and Cd might be complexed by root exudates. The concentrations of free Pb and Cd in the solution were increased markedly by adding root exudate from wheat and decreased by that from rice due to Pb Cd interaction. The distribution patterns of Pb and Cd in roots were affected by Pb Cd interaction, which accelerated transport of Pb into internal tissue and retarded accumulation of Cd in external tissue.展开更多
A study on the effect of Pb-Cd interaction on plant growth and on the chemistry of elements in plants was conducted under greenhouse condition with red soil-wetland rice system in different growth stage. The results s...A study on the effect of Pb-Cd interaction on plant growth and on the chemistry of elements in plants was conducted under greenhouse condition with red soil-wetland rice system in different growth stage. The results showed that Pb-Cd interactions on growth and metal uptake varied with different growth stageS and chemical compounds added. The plant height and the root weight were markedly affected by Pb-Cd interiction in the young stage but not in the ripening stage of rice at the treatments of PbCl_2 and CdCl_2 added. However, the weight of rice straw in the ripening stage was significantly effected by Pb-Cd interaction with the treatments of Pb(OAc)_2 and CdCl_2. The chemistry of elements in plants also depended on Pb-Cd interaction in varying degrees on account of different plant parts and growth stage. It seems that Pb-Cd interaction occurred not only in roots but also in other parts of wetland rice.展开更多
The ability to manage and restore plant communities in the face of human-induced landscape change may rely on our ability to predict how species respond to environmental variables.Understanding this response requires ...The ability to manage and restore plant communities in the face of human-induced landscape change may rely on our ability to predict how species respond to environmental variables.Understanding this response requires examining factors or their interactions that have influence on plant and resource availability.Our objective was to analyze the relationships between changes in plant abundance and the interaction among environmental habitat factors including soil, geological(rock type), and other environmental variables in the Longhushan karst mountains ecosystem.Species density and dominance were examined using ANOVA, ANCOVA,and Generalized Linear Models to establish the single or combined effects of these groups of factors.The results showed that trends in abundance were mainly affected by rock type(related to the percentage content of dolomite and calcite), soil characteristics in association with topography.Both plant indices were higher in dolomite dominated areas and varied positively with moisture, and elevation, but negatively with organic matter, while density also increased with slope degree.The results demonstrate that significant variations in species abundance was produced with the combination of variables from soil, geological, andenvironmental factors, suggesting their interaction influence on plants.We postulate that spatial variations in plant abundance in karst ecosystem depends on the carbonate rock type in addition to water and nutrient availability which are mainly controlled by topography and other factors such as soil texture and temperature.The study suggests that in karst areas carbonate rock type, in addition to local environmental variables, should be taken into account when analyzing the factors that have impact on plant communities.展开更多
Changes in soil chemistry after invasion by bracken(Pteridium aquilinum)have been studied in heathlands,but comparable studies in meadows are lacking.We investigated if bracken invasion into P-deficient meadows alters...Changes in soil chemistry after invasion by bracken(Pteridium aquilinum)have been studied in heathlands,but comparable studies in meadows are lacking.We investigated if bracken invasion into P-deficient meadows alters the soil nutrient-resource pool,as well as the mechanisms behind it linked to soil processes and bracken nutrition.Furthermore,we investigated how community composition responds to differences in soil chemistry before and after the invasion.Soil and plant material sampling,along with vegetation survey,were performed during bracken peak biomass.Data analyses included analysis of variance and canonical correspondence analysis(CCA).Bracken invasion increased soil P availability,soil organic C concentration,as well as C:N,C:S and N:S ratios,while decreasing Fe and Co concentrations.Bracken pinnae were rich in P,and its rhizomes were rich in K,whereas N:P of pinnae and rhizomes was low.CCA showed contrasting abundance patterns of frequent meadow species related to P and K availability.Holcus lanatus exhibited competitive advantage under extremely low P availability.Increase in P availability under bracken may have occurred through promoting the leaching of Fe and Al.By increasing P availability for its growth and increasing N limitation for other species,bracken can gain a competitive advantage from the soil resource-niche perspective.Its ability to increase soil P availability,along with the physiological mechanisms behind its high P acquisition efficiency,seem to differentiate bracken from other species of competitive ecological strategy,which are mainly confined to nutrient-rich environments.This enabled bracken to invade P-deficient meadows.展开更多
Soil biotic communities can strongly impact plant performance.In this paper,we ask the question:how longlasting the effect of the soil microbial community on plant growth is.We examined the plant growth rates at three...Soil biotic communities can strongly impact plant performance.In this paper,we ask the question:how longlasting the effect of the soil microbial community on plant growth is.We examined the plant growth rates at three stages:early,mid and late growth.We performed two growth experiments with Jacobaea vulgaris,which lasted 49 and 63 days in sterilized soil or live soil.In a third experiment,we examined the effect of the timing of soil inoculation prior to planting on the relative growth rate of J.vulgaris with four different timing treatments.In all experiments,differences in biomass of plants grown in sterilized soil and live soil increased throughout the experiment.Also,the relative growth rate of plants in the sterilized soil was only significantly higher than that of plants in the live soil in the first two to three weeks.In the third experiment,plant biomass decreased with increasing time between inoculation and planting.Overall,our results showed that plants of J.vulgaris grew less well in live soil than in sterilized soil.The negative effects of soil inoculation on plant mass appeared to extend over the whole growth period but arise from the negative effects on relative growth rates that occurred in the first weeks.展开更多
Aims Invasive plants may alter soil fungal communities in a way that improves their growth.Nitrogen(N)content of soil affects the symbiosis between plants and arbuscular mycorrhizal fungi(AMF),further determining plan...Aims Invasive plants may alter soil fungal communities in a way that improves their growth.Nitrogen(N)content of soil affects the symbiosis between plants and arbuscular mycorrhizal fungi(AMF),further determining plant growth.Yet,it is unclear whether altered AMF communities change the dependence of invasive and native species on N-form,and whether N forms alter the invasive plant–AMF interaction(PSIM).Methods Two synthetic plant communities,including four Solidago canadensis individuals and four native plant species,were inoculated with AMF spores from S.canadensis-invaded soils and adjacent non-invaded soils,and were provided with nitrate,ammonia or glutamate.After their growth,the performance of the two plant communities in treatments of AMF origin and N forms,and the pathways of the N forms affecting S.canadensis growth and PSIM were evaluated.Important Findings Solidago canadensis had no obvious N-form dependence in any of the AMF inoculations.Native plant species showed weak N-form dependence,but invasive AMF could remove their N-form dependence.In the absence of N,AMF did not affect growth of S.canadensis and the native plants.In contrast,with N addition,invasive AMF significantly increased belowground and total biomass of the invasive plants but not those of the native plants.Positive PSIM of S.canadensis was also evidently greater than that of native plant species and was realized through directly or indirectly regulating phenotypic traits including plant height,leaf number and number of rhizomes.Our findings emphasize the importance of plant–AMF interactions and a unique N-acquisition strategy during plant invasions.展开更多
文摘Superabsorbents such as cross-linked PAM （polyacrylamides） are frequently used to increase water availability to plants. Commercial PAM providers suggest that besides its increasing water availability, PAMs also increase nutrient availability to plants. To test this premise, four application rates （0.0 g·kg^-1, 0.33 g·kg^-1, 1.66 g·kg^-1, 3.33 g·kg^-1 and 6.66 g·kg^-1） ofa PAM were mixed with sandy and loamy soils to evaluate its effect on nutrient leaching and retention in these soils. Miscible displacements of chloride were conducted on columns of PAM-soil mixtures and results were evaluated by an equilibrium CDE （convection dispersion equation） model. Increasing the PAM rates up to 1.66 g·kg^-1 resulted in increased early appearance and dispersive transport of chloride in sand. In addition, increasing the PAM rates gradually caused increased tailing of the breakthrough curves of chloride in both soils. These suggested that PAM increased preferential transport of chloride while it increased retention of chloride in soils. Effect of PAM on preferential transport and retardation of CI was greater in sand than loam.
基金supported by National Natural Science Foundation of China(31872034 and 32171585)Fundamental Research Funds for the Central Universities(2662020ZKPY007 and 2662021JC011)the start-up funding of Huazhong Agricultural University(101-110200201).
文摘The interaction of Pb Cd can be observed not only in the uptake process of elements by plants and in their influence on the growth, but also in rhizosphere. The changes in extractable Cd and Pb concentrations in the rhizosphere soil of rice plants, root exudates from wheat and wheat plant and their complexing capacity with Pb and Cd were investigated under different Pb and Cd treatments. Results showed that the concentration of extractable Cd in the rhizosphere of rice in red soil was markedly increased by Pb Cd interaction. It increased by 56% in the treatment with Pb and Cd added against that in the treatment with only Cd added in soil. The considerable differences in both composition and amount of root exudate from wheat and rice were found among different treatments. Pb and Cd might be complexed by root exudates. The concentrations of free Pb and Cd in the solution were increased markedly by adding root exudate from wheat and decreased by that from rice due to Pb Cd interaction. The distribution patterns of Pb and Cd in roots were affected by Pb Cd interaction, which accelerated transport of Pb into internal tissue and retarded accumulation of Cd in external tissue.
文摘A study on the effect of Pb-Cd interaction on plant growth and on the chemistry of elements in plants was conducted under greenhouse condition with red soil-wetland rice system in different growth stage. The results showed that Pb-Cd interactions on growth and metal uptake varied with different growth stageS and chemical compounds added. The plant height and the root weight were markedly affected by Pb-Cd interiction in the young stage but not in the ripening stage of rice at the treatments of PbCl_2 and CdCl_2 added. However, the weight of rice straw in the ripening stage was significantly effected by Pb-Cd interaction with the treatments of Pb(OAc)_2 and CdCl_2. The chemistry of elements in plants also depended on Pb-Cd interaction in varying degrees on account of different plant parts and growth stage. It seems that Pb-Cd interaction occurred not only in roots but also in other parts of wetland rice.
基金founded by the National Natural Scientific Foundation of China(Grant No.40972218)the Fundamental Research Founds for National University,China University of Geosciences(Wuhan)(Grant Nos.G1323521125,G1323521225,G1323521325)
文摘The ability to manage and restore plant communities in the face of human-induced landscape change may rely on our ability to predict how species respond to environmental variables.Understanding this response requires examining factors or their interactions that have influence on plant and resource availability.Our objective was to analyze the relationships between changes in plant abundance and the interaction among environmental habitat factors including soil, geological(rock type), and other environmental variables in the Longhushan karst mountains ecosystem.Species density and dominance were examined using ANOVA, ANCOVA,and Generalized Linear Models to establish the single or combined effects of these groups of factors.The results showed that trends in abundance were mainly affected by rock type(related to the percentage content of dolomite and calcite), soil characteristics in association with topography.Both plant indices were higher in dolomite dominated areas and varied positively with moisture, and elevation, but negatively with organic matter, while density also increased with slope degree.The results demonstrate that significant variations in species abundance was produced with the combination of variables from soil, geological, andenvironmental factors, suggesting their interaction influence on plants.We postulate that spatial variations in plant abundance in karst ecosystem depends on the carbonate rock type in addition to water and nutrient availability which are mainly controlled by topography and other factors such as soil texture and temperature.The study suggests that in karst areas carbonate rock type, in addition to local environmental variables, should be taken into account when analyzing the factors that have impact on plant communities.
文摘Changes in soil chemistry after invasion by bracken(Pteridium aquilinum)have been studied in heathlands,but comparable studies in meadows are lacking.We investigated if bracken invasion into P-deficient meadows alters the soil nutrient-resource pool,as well as the mechanisms behind it linked to soil processes and bracken nutrition.Furthermore,we investigated how community composition responds to differences in soil chemistry before and after the invasion.Soil and plant material sampling,along with vegetation survey,were performed during bracken peak biomass.Data analyses included analysis of variance and canonical correspondence analysis(CCA).Bracken invasion increased soil P availability,soil organic C concentration,as well as C:N,C:S and N:S ratios,while decreasing Fe and Co concentrations.Bracken pinnae were rich in P,and its rhizomes were rich in K,whereas N:P of pinnae and rhizomes was low.CCA showed contrasting abundance patterns of frequent meadow species related to P and K availability.Holcus lanatus exhibited competitive advantage under extremely low P availability.Increase in P availability under bracken may have occurred through promoting the leaching of Fe and Al.By increasing P availability for its growth and increasing N limitation for other species,bracken can gain a competitive advantage from the soil resource-niche perspective.Its ability to increase soil P availability,along with the physiological mechanisms behind its high P acquisition efficiency,seem to differentiate bracken from other species of competitive ecological strategy,which are mainly confined to nutrient-rich environments.This enabled bracken to invade P-deficient meadows.
文摘Soil biotic communities can strongly impact plant performance.In this paper,we ask the question:how longlasting the effect of the soil microbial community on plant growth is.We examined the plant growth rates at three stages:early,mid and late growth.We performed two growth experiments with Jacobaea vulgaris,which lasted 49 and 63 days in sterilized soil or live soil.In a third experiment,we examined the effect of the timing of soil inoculation prior to planting on the relative growth rate of J.vulgaris with four different timing treatments.In all experiments,differences in biomass of plants grown in sterilized soil and live soil increased throughout the experiment.Also,the relative growth rate of plants in the sterilized soil was only significantly higher than that of plants in the live soil in the first two to three weeks.In the third experiment,plant biomass decreased with increasing time between inoculation and planting.Overall,our results showed that plants of J.vulgaris grew less well in live soil than in sterilized soil.The negative effects of soil inoculation on plant mass appeared to extend over the whole growth period but arise from the negative effects on relative growth rates that occurred in the first weeks.
基金This work was financially supported for the design of the study,the data collection,analysis and interpretation,and writing the manuscript by the National Natural Science Foundation of China(31700476)Natural Science Foundation of Zhejiang Province(LY20C030003,LY19C030002).
文摘Aims Invasive plants may alter soil fungal communities in a way that improves their growth.Nitrogen(N)content of soil affects the symbiosis between plants and arbuscular mycorrhizal fungi(AMF),further determining plant growth.Yet,it is unclear whether altered AMF communities change the dependence of invasive and native species on N-form,and whether N forms alter the invasive plant–AMF interaction(PSIM).Methods Two synthetic plant communities,including four Solidago canadensis individuals and four native plant species,were inoculated with AMF spores from S.canadensis-invaded soils and adjacent non-invaded soils,and were provided with nitrate,ammonia or glutamate.After their growth,the performance of the two plant communities in treatments of AMF origin and N forms,and the pathways of the N forms affecting S.canadensis growth and PSIM were evaluated.Important Findings Solidago canadensis had no obvious N-form dependence in any of the AMF inoculations.Native plant species showed weak N-form dependence,but invasive AMF could remove their N-form dependence.In the absence of N,AMF did not affect growth of S.canadensis and the native plants.In contrast,with N addition,invasive AMF significantly increased belowground and total biomass of the invasive plants but not those of the native plants.Positive PSIM of S.canadensis was also evidently greater than that of native plant species and was realized through directly or indirectly regulating phenotypic traits including plant height,leaf number and number of rhizomes.Our findings emphasize the importance of plant–AMF interactions and a unique N-acquisition strategy during plant invasions.
