Homeostasis is the adaptability of a species to a changing environment.However,the ecological stoichiometric homeostasis of Robinia pseudoacacia L.in diff erent climatic regions is poorly understood but could provide ...Homeostasis is the adaptability of a species to a changing environment.However,the ecological stoichiometric homeostasis of Robinia pseudoacacia L.in diff erent climatic regions is poorly understood but could provide insights into its adaptability in the loess hilly region.This study sampled 20 year-old R.pseudoacacia plantations at 10 sites along a north–south transect on the Loess Plateau.Variations in the ecological stoichiometric characteristics of leaf and soil carbon,nitrogen,and phosphorus were analysed and homeostatic characteristics of leaf ecological stoichiometric parameters in diff erent climates were identifi ed.Factors aff ecting leaf stoichiometry were assessed.The results show that R.pseudoacacia leaves were rich in nitrogen and defi cient in phosphorous during tree growth and development.Nitrogen and phosphorous levels in the soils of the loess region were lower than the average in soils in the rest of China.All ecological stoichiometric parameters of R.pseudoacacia leaves in two diff erent climates were considered“strictly homeostasis”.Precipitation,available phosphorus,and soil C:P were the main factors aff ecting the variation of C:N:P stoichiometry of R.pseudoacacia leaves.R.pseudoacacia in the loess hilly region has strong ecologically homeostatic characteristics and suggests that it is well-adapted to the area.展开更多
Lectins are natural proteins in animals,plants,and microorganisms and can be divided into 12 families.These lectins play important roles in various environmental stresses.Some polyploid plants show tolerance to enviro...Lectins are natural proteins in animals,plants,and microorganisms and can be divided into 12 families.These lectins play important roles in various environmental stresses.Some polyploid plants show tolerance to environmental stresses and to insect pests.However,the mechanism of stress tolerance is unclear.Tetraploid Robinia pseudoacacia(4×)under salt stress showed higher tolerance than diploid R.pseudoacacia(2×).As lectin can improve stress tolerance,it was questioned whether the stress resistance of polyploid plants was related to the lectin protein.In this study,salt resistance of lectin gene TRpL1 was verified by its over-expression in plants.In addition,salt resistance of lectin protein by E.coli strains was detected.The data revealed that the over-expression transgenic plants of TRpL1 showed better salt tolerance than control plants under salt stress,and the TRpL1-expressing strain also grew better in the medium with added NaCl.Therefore,tetraploid plants can resist salt stress through TRpL1 protein regulation.展开更多
Plantations have been widely established to improve ecosystem services and functioning.Black locust,Robinia pseudoacacia L.is a common,widely planted species to control soil erosion on the Loess Plateau.Previous studi...Plantations have been widely established to improve ecosystem services and functioning.Black locust,Robinia pseudoacacia L.is a common,widely planted species to control soil erosion on the Loess Plateau.Previous studies have focused on economic values but the interactions between soil and plant carbon(C),nitrogen(N)and phosphorus(P)remain unknown.Investigating variations of soil,green and senesced leaf C,N and P levels in R.pseudoacacia along a latitudinal gradient is useful to understanding its ecological functions.The results show that soil C,N and senesced leaf N and P significantly decreased with an increase in latitude,but there were no significant changes in the senesced leaf C and soil P.The resorption efficiency of N was related with latitude and soil N levels,and the relation between green leaf N and soil N was significant.These relations suggest that soil N was the key in affecting green leaf N levels.At higher latitudes,senesced leaves had lower N levels associated with higher N resorption efficiency to maintain a stable N content in green leaves.With a decrease of soil N,R.pseudoacacia can enhance N resorption efficiency to meet the demand of growth.Thus,it is an important species for reforestation,especially in nutrient-poor environments.展开更多
The objective of this study was to isolate lactic acid bacteria(LAB) strains from different origins and to select the best strains for ensiling Robinia pseudoacacia(RB) and Morus alba L.(MB)leaves. The LAB strains wer...The objective of this study was to isolate lactic acid bacteria(LAB) strains from different origins and to select the best strains for ensiling Robinia pseudoacacia(RB) and Morus alba L.(MB)leaves. The LAB strains were inoculated into the extracted liquid obtained from RB and MB leaves to evaluate the fermentation products. 11 LAB strains were selected for further experiments based on the highest products of lactic or acetic acid, including 1 strain of Weissella confusa, 2 of Lactobacillus reuteri and 8 of Lactobacillus plantarum.The API 50 CH fermentation experiment indicated that all of the selected 11 LAB strains utilised most of the carbohydrates. All the strains grew at temperatures between 10 and 45°C and at a p H of 3.5 to 4.5; however, L. reuteri F7 and F8 tolerated a p H as low as 3.0. All 11 LAB strains showed antibacterial activity against Listeria monocytogens, Escherichia coil, Salmonella sp. and Acetobacter pasteurianus; however, after excluding the effect of organic acids, only F7 and F8 still exhibited antibacterial activity. The present study indicated that the selected 11 LAB strains could be used to prepare silages of RB and MB leaves, especially L. reuteri F7 and F8.展开更多
Forest degradation is a worldwide problem,although its causes vary due to geographical and climatic differences and man-made causes.In recent years,the Robinia pseudoacacia forest in the Yellow River Delta has suffere...Forest degradation is a worldwide problem,although its causes vary due to geographical and climatic differences and man-made causes.In recent years,the Robinia pseudoacacia forest in the Yellow River Delta has suffered severe degradation.The causative mechanisms were investigated in the field over two years,and the results show that increased forest degradation was reflected by increased tree mortality,high leaf and soil sodium salt levels and groundwater depth.Average tree diameters decreased,and leaf chlorophyll and soil microbial contents decreased.Redundancy discriminate analysis(RDA)showed that degradation of the forest was correlated positively with soil salt content,but negatively with groundwater depth.Correlation analysis showed that 0.79%–0.95%soil salt content and above 1.20 m groundwater depth caused the death of R.pseudoacacia trees due to localized anthropogenic economic activities,such as rice farming,that disrupted the original water–salt balance.Measures are recommended to prevent further degradation and restore degraded forests.展开更多
Robinia pseudoacacia is an important afforesta-tion tree introduced to China in 1878.In the present study,we examined the genetic diversity among 687 strains rep-resenting four improved varieties and two secondary pro...Robinia pseudoacacia is an important afforesta-tion tree introduced to China in 1878.In the present study,we examined the genetic diversity among 687 strains rep-resenting four improved varieties and two secondary prov-enances,comprising 641 clones and 46 seedlings.Ninety-one simple sequence repeats(SSRs)were selected through segregation analysis and polymorphism characterization,and all sampled individuals were genotyped using well-characterized SSR markers.After excluding loci with non-neutral equilibrium,missing locus data and null alleles,we used 36 primer pairs to assess the genetic diversity of these germplasm resources,revealing vast genetic differentiation among the samples,with an average of 8.352 alleles per locus and a mean Shannon′s index of 1.302.At the popula-tion level,the partitioning of variability was assessed using analysis of molecular variance,which revealed 93%and 7%variation within and among collection sites,respectively.Four clusters were detected using structure analysis,indi-cating a degree of genetic differentiation among the six populations.Insights into the genetic diversity and structure of R.pseudoacacia provide a theoretical basis for the con-servation,breeding and sustainable development in China.展开更多
Robinia pseudoacacia L.(RP)restoration has increased vegetation cover in semi-arid regions on the Loess Plateau of China,but ecological problems have also occurred due to RP restoration,such as reduced soil moisture.F...Robinia pseudoacacia L.(RP)restoration has increased vegetation cover in semi-arid regions on the Loess Plateau of China,but ecological problems have also occurred due to RP restoration,such as reduced soil moisture.Further,it is still uncertain how microbial diversity,composition and assembly processes change with RP restoration in semi-arid regions.Therefore,amplicon sequencing of small subunit ribosomal ribonucleic acid(16S rRNA)and internal transcribed spacer(ITS)genes was performed to study soil bacterial and fungal diversity,composition and assembly processes at four study sites with different stand ages of RP plantations(Y10,RP plantation with stand ages less than 10 a;Y15,RP plantation with stand ages approximately 15 a;Y25,RP plantation with stand ages approximately 25 a;and Y40,RP plantation with stand ages approximately 40 a)along a 40-a chronosequence on the Loess Plateau.The diversity of soil bacteria and fungi increased significantly during the restoration period from 10 to 15 a(P<0.05).However,compared with Y15,bacterial diversity was lower at Y25 and Y40,and fungal diversity remained stable during the restoration period between 25 and 40 a.The relative abundances of Proteobacteria and Ascomycota increased during the restoration period from 10 to 15 a.Conversely,after 15 a of restoration,they both decreased,whereas the relative abundances of Actinomycetes,Acidobacteria and Basidiomycota gradually increased.The variations in soil bacterial communities were mainly related to changes in soil total nitrogen,nitrate nitrogen and moisture contents,while soil fungal communities were mainly shaped by soil organic carbon and nitrate nitrogen contents.Bacterial communities were structured by the heterogeneous selection and stochastic process,while fungal communities were structured primarily by the stochastic process.The RP restoration induced an increase in the relative importance of heterogeneous selection on bacterial communities.Overall,this study reveals the changes in microbial diversity,community composition and assembly processes with RP restoration on the Loess Plateau and provides a new perspective on the effects of vegetation restoration on soil microbial communities in semi-arid regions.展开更多
Background:Afforestation is a common and effective approach used for the restoration of degraded ecosystems worldwide.In China,Robinia pseudoacacia(RP)is among the main non-native tree species and has been widely plan...Background:Afforestation is a common and effective approach used for the restoration of degraded ecosystems worldwide.In China,Robinia pseudoacacia(RP)is among the main non-native tree species and has been widely planted in revegetation of the Loess Plateau.However,owing to uncertainties regarding soil water consumption and carbon sequestration,it is necessary to assess the suitability and sustainability of R.pseudoacacia in restoration.In this study,we aimed to analyse the dynamic effects of R.pseudoacacia forest on soil carbon storage(SCS)and soil water storage(SWS).Specifically,we investigated the association between soil water content(SWC)and soil organic carbon(SOC)and underlying factors in the 0-500-cm profile of a 10-to 50-year-old chronosequence.Results:The results obtained indicated that the dynamics of SWS and SCS on this time scale could be divided into an initial reduction phase(the initial 20 years after afforestation)and subsequent recovery(20-50 years after afforestation).Compared with in the abandoned land(AL),the net accumulation of SCS in R.pseudoacacia forest was 2.51 Mg·ha^(-1)at 50 years after afforestation,whereas there was a 398.76-mm deficit in SWS.Additionally,the natural succession of R.pseudoacacia forest has contributed to the continuous change in stand structure(e.g.vegetation cover(VC),understory vegetation coverage(UVC),and litter biomass(LB)).Conclusions:These findings indicate that vegetation restoration increases carbon sequestration while causing soil water deficit.Furthermore,stand density(SD)was established to make a predominant contribution to the dynamics of SWS and SCS via its effects in altering vegetation,soil,and litter characteristics.Therefore,high-density plantation forests in the Loess Plateau area should be appropriately thinned to reduce the density of forest stands on the basis of soil erosion control and wind and sand fixation,so as to increase carbon sink with lower water consumption,thus realizing the synergistic development of soil carbon sequestration and water connotation.展开更多
Invasive forest species are a recurring problem,which in Portugal assume a somewhat mediatic role,both because of the impacts they cause on biodiversity,but also because they enhance the accumulation of high amounts o...Invasive forest species are a recurring problem,which in Portugal assume a somewhat mediatic role,both because of the impacts they cause on biodiversity,but also because they enhance the accumulation of high amounts of fuel load,increasing the risk of forest fires.However,in some areas of the country,such as the Alentejo(South of Portugal),the scarcity of water did not allow,until now,the dispersion and rapid growth of some of these species,namely Robinia pseudoacacia,which has always remained under control,and it was never a real problem.However,with the growth of intensive farming practices,associated with vineyards,olive groves and almond trees,water and nutrients became available,enabling this species to grow and disperse.This communication presents an observation of several sets of R.pseudoacacia specimens growing with different agricultural holdings,raising the hypothesis that intensive farming practices may,in the short term,contribute to the dispersion of invasive species in regions where they were not a problem,if the situations reported are not followed up and studies are carried out to confirm the observations described.展开更多
Soil water-stable aggregates (WSAs) are the basic unit of soil constitution and can contribute to remaining the stable soil constitution. The objective of this study was to clarify the distribution and stability of WS...Soil water-stable aggregates (WSAs) are the basic unit of soil constitution and can contribute to remaining the stable soil constitution. The objective of this study was to clarify the distribution and stability of WSAs and the soil organic carbon (SOC), the total nitrogen (TN), and the total phosphorus (TP) concentrations in 0 - 20 cm and 20 - 40 cm soil layers under the different ages of Robinia pseudoacacia plantations. The 20, 25, 40, and 50 years-old Robinia pseudoacacia plantations were selected. Stepwise regression analysis showed that >5 mm and 1 - 2 mm WSAs, SOC concentration in 2 - 5 mm WSAs, and TN and TP concentrations in < 0.25 mm WSAs were dominant independent variables affecting aggregate stability and that SOC in 0.25 - 0.5 mm WSAs, TN in <0.25 mm and 1 - 2 mm WSAs and TP in 2 - 5 mm WSAs were dominant independent variables affecting SOC, TN, and TP concentrations in bulk soils.展开更多
The productivity of Robinia pseudoacacia(R.p.) pure forest usually declines at the late growth stage,and reforming it into mixed forests could be a promising way to resolve this problem. When choosing a suitable tree ...The productivity of Robinia pseudoacacia(R.p.) pure forest usually declines at the late growth stage,and reforming it into mixed forests could be a promising way to resolve this problem. When choosing a suitable tree species that can be mixed with R.p., the interspecific relationship is an important issue. Therefore, we gathered the autumn litter fall from R.p. and 10 other species from the Loess Plateau of China were mixed in dual species litterbags(R.p.+each other species) and buried them in soil for a 345 days lab decay incubation. We measured the litter mass loss and nutrient contents to determine whether the nutrient release was affected by mixed species litter decomposition. The impacts of mixed litter decomposition on macro-elements release were more obvious than on micro-elements. The litters with similar substrate quality might show variable impacts on nutrients release in mixed decomposition. The C loss and release of nutrient was improved by descending order when R.p. litter was mixed with Hippophae rhamnoides, Ulmus pumila, Populus simonii, Larix principis-rupprechtii and Quercus liaotungensis(Q.l.). But, except for Q.l., only the other species were recommended as suitable mix-plants for R.p. since promoting a high turnover of the nutrient in the litter compartment and a rapid availability for tree.展开更多
Plants are capable of reducing environmental pollutions through uptaking contaminants in their tissues. In the study site, twenty one-year-old leaves and shoots as well as twenty soil samples were sampled and analyzed...Plants are capable of reducing environmental pollutions through uptaking contaminants in their tissues. In the study site, twenty one-year-old leaves and shoots as well as twenty soil samples were sampled and analyzed by Inductively Coupled Plasma (ICP). We investigated the uptaking ability of lead (Pb) and cadmium (Cd) by the leaves and shoots of Platanus orientalis, Robinia pseudoacacia and Fraxinus rotundifolia in Karaj city, the western Tehran, Iran. We also evaluated the total metal accumulation capacity by using metal accumulation index (MAI). Results indicated that there was no significant difference in uptaking contents of Cd and Pb in the leaves among the trees. However accumulation of Cd in shoots of F. rotundifolia and R. pseudoacacia was significantly higher than that of P. orientalis. The accumulation of Pb in shoots of R. pseudoacacia was significantly higher than the other species. The amount of Pb in the soil of the study area was significantly higher than Cd. Concentrations of Cd and Pb in leaves of the three species are in the ranges of 2.4 2.7 mg Kg-1 and 7.1 14.4 mg Kg-1 , respectively. R. pseudoacacia had the highest MAI value for leaves (2.21) and F. rotundifolia had the highest MAI value for shoots (2.4).展开更多
Preparation of silage is a common method to preserve green forage.It plays an important role in improving forage utili-zation, solving the problem of forage provision and meeting the nutritional needs of livestock in ...Preparation of silage is a common method to preserve green forage.It plays an important role in improving forage utili-zation, solving the problem of forage provision and meeting the nutritional needs of livestock in winter and spring.The effects of various supplements on tetraploid black locust (Robinia pseudoacacia L.) silage were studied by analyzing its color, odor, texture, pH value, the composition and amount of organic acids, the ammonia-N/total-N ratio, crude protein, neutral detergent fibers and acid detergent fibers.Our results show that the silage quality of wilted tetraploid R.pseudoacacia preserved alone is acceptable, while adding brown sugar and Yishengkang to tetraploid R.pseudoacacia foliage improved its quality.The treatments consisting of the tetraploid R.pseudoacacia mixed with 33% and 50% corn stalk achieved the best silage quality in terms of pH value (p<0.01), amount of lactic acid (p<0.01), the ammonia-N/total-N ratio (p<0.01) and the fermentation quality.These treatments also resulted in a high content of crude protein and lower amounts of acid detergent fibers.The treatment consisting of the tetraploid R.pseudoacacia mixed with 20% corn stalk was also good in the quality of its fermentation.展开更多
Heavy metal contamination is one of the most important abiotic stresses affecting physiological activities of plants.We investigated the effects of cadmium(Cd) and lead(Pb) on chlorophyll fluorescence(Fv/Fm,Fo,and Fm)...Heavy metal contamination is one of the most important abiotic stresses affecting physiological activities of plants.We investigated the effects of cadmium(Cd) and lead(Pb) on chlorophyll fluorescence(Fv/Fm,Fo,and Fm),photosynthetic pigments(chlorophyll a and b),and proline in one-year-old seedlings of Robinia pseudoacacia.The seedlings were treated twice over a period of 10 days with Cd and Pb at concentrations of 0,250,500,1000 and2000 mg L-1.Saline solution containing Cd and Pb was sprayed on the leaves.Chlorophyll and proline contents were measured after 10 days.Chlorophyll fluorescence of R.pseudoacacia was affected slightly by high concentrations(1000,2000 mg L-1) of Cd and Pb.Chlorophyll a and a/b increased at 1000 and 2000 mg L-1of Cd and proline content of leaves was similar in all treatments of Cd and Pb.Our results indicated that photosynthetic sensitivity of R.pseudoacacia to Cd and Pb contamination was weak.Photosystem II chlorophyll pigments were not damaged by Pb and Cd stress.We conclude that chlorophyll fluorescence along with chlorophyll and proline contents are useful indicators of Cd and Pb stresses in R.pseudoacacia which widely planted in urban polluted regions in Iran.展开更多
基金supported by the Science and Technology Innovation Program of the Shaanxi Academy of Forestry(SXLK2022-02-03)the National Natural Science Foundation of China(42077452).
文摘Homeostasis is the adaptability of a species to a changing environment.However,the ecological stoichiometric homeostasis of Robinia pseudoacacia L.in diff erent climatic regions is poorly understood but could provide insights into its adaptability in the loess hilly region.This study sampled 20 year-old R.pseudoacacia plantations at 10 sites along a north–south transect on the Loess Plateau.Variations in the ecological stoichiometric characteristics of leaf and soil carbon,nitrogen,and phosphorus were analysed and homeostatic characteristics of leaf ecological stoichiometric parameters in diff erent climates were identifi ed.Factors aff ecting leaf stoichiometry were assessed.The results show that R.pseudoacacia leaves were rich in nitrogen and defi cient in phosphorous during tree growth and development.Nitrogen and phosphorous levels in the soils of the loess region were lower than the average in soils in the rest of China.All ecological stoichiometric parameters of R.pseudoacacia leaves in two diff erent climates were considered“strictly homeostasis”.Precipitation,available phosphorus,and soil C:P were the main factors aff ecting the variation of C:N:P stoichiometry of R.pseudoacacia leaves.R.pseudoacacia in the loess hilly region has strong ecologically homeostatic characteristics and suggests that it is well-adapted to the area.
基金supported by the National Natural Science Foundation of China(32071728)。
文摘Lectins are natural proteins in animals,plants,and microorganisms and can be divided into 12 families.These lectins play important roles in various environmental stresses.Some polyploid plants show tolerance to environmental stresses and to insect pests.However,the mechanism of stress tolerance is unclear.Tetraploid Robinia pseudoacacia(4×)under salt stress showed higher tolerance than diploid R.pseudoacacia(2×).As lectin can improve stress tolerance,it was questioned whether the stress resistance of polyploid plants was related to the lectin protein.In this study,salt resistance of lectin gene TRpL1 was verified by its over-expression in plants.In addition,salt resistance of lectin protein by E.coli strains was detected.The data revealed that the over-expression transgenic plants of TRpL1 showed better salt tolerance than control plants under salt stress,and the TRpL1-expressing strain also grew better in the medium with added NaCl.Therefore,tetraploid plants can resist salt stress through TRpL1 protein regulation.
基金This study was supported by the National Natural Science Foundation of China(41907051 and 41671280)International Partnership Program of Chinese Academy of Sciences(161461KYSB20170013)China Postdoctoral Science Foundation(219M662678).
文摘Plantations have been widely established to improve ecosystem services and functioning.Black locust,Robinia pseudoacacia L.is a common,widely planted species to control soil erosion on the Loess Plateau.Previous studies have focused on economic values but the interactions between soil and plant carbon(C),nitrogen(N)and phosphorus(P)remain unknown.Investigating variations of soil,green and senesced leaf C,N and P levels in R.pseudoacacia along a latitudinal gradient is useful to understanding its ecological functions.The results show that soil C,N and senesced leaf N and P significantly decreased with an increase in latitude,but there were no significant changes in the senesced leaf C and soil P.The resorption efficiency of N was related with latitude and soil N levels,and the relation between green leaf N and soil N was significant.These relations suggest that soil N was the key in affecting green leaf N levels.At higher latitudes,senesced leaves had lower N levels associated with higher N resorption efficiency to maintain a stable N content in green leaves.With a decrease of soil N,R.pseudoacacia can enhance N resorption efficiency to meet the demand of growth.Thus,it is an important species for reforestation,especially in nutrient-poor environments.
基金supported by the Key Technique Project from Henan Province, China (152102110045 and 152102310064)
文摘The objective of this study was to isolate lactic acid bacteria(LAB) strains from different origins and to select the best strains for ensiling Robinia pseudoacacia(RB) and Morus alba L.(MB)leaves. The LAB strains were inoculated into the extracted liquid obtained from RB and MB leaves to evaluate the fermentation products. 11 LAB strains were selected for further experiments based on the highest products of lactic or acetic acid, including 1 strain of Weissella confusa, 2 of Lactobacillus reuteri and 8 of Lactobacillus plantarum.The API 50 CH fermentation experiment indicated that all of the selected 11 LAB strains utilised most of the carbohydrates. All the strains grew at temperatures between 10 and 45°C and at a p H of 3.5 to 4.5; however, L. reuteri F7 and F8 tolerated a p H as low as 3.0. All 11 LAB strains showed antibacterial activity against Listeria monocytogens, Escherichia coil, Salmonella sp. and Acetobacter pasteurianus; however, after excluding the effect of organic acids, only F7 and F8 still exhibited antibacterial activity. The present study indicated that the selected 11 LAB strains could be used to prepare silages of RB and MB leaves, especially L. reuteri F7 and F8.
基金supported by Shandong Provincial“Bohai Granary”Science and Technology Demonstration Project(2019BHLC004)the major projects of science and technology in Shandong province(2017CXGC0313)+3 种基金Agricultural Variety Improvement Project of Shandong Province(2019LZGC009)Shandong Province Natural Science Foundation(ZR2019MC065)the Taishan Scholar Program(tsqn20161058)the Program for Scientific Research Innovation Team in Colleges and Universities of Shandong Province。
文摘Forest degradation is a worldwide problem,although its causes vary due to geographical and climatic differences and man-made causes.In recent years,the Robinia pseudoacacia forest in the Yellow River Delta has suffered severe degradation.The causative mechanisms were investigated in the field over two years,and the results show that increased forest degradation was reflected by increased tree mortality,high leaf and soil sodium salt levels and groundwater depth.Average tree diameters decreased,and leaf chlorophyll and soil microbial contents decreased.Redundancy discriminate analysis(RDA)showed that degradation of the forest was correlated positively with soil salt content,but negatively with groundwater depth.Correlation analysis showed that 0.79%–0.95%soil salt content and above 1.20 m groundwater depth caused the death of R.pseudoacacia trees due to localized anthropogenic economic activities,such as rice farming,that disrupted the original water–salt balance.Measures are recommended to prevent further degradation and restore degraded forests.
基金This work was supported by the Doctoral Scientific Research Starting Foundation of Henan University of Science and Technology(13480089)National Nature Science Foundation of China(31570677)+1 种基金the National Key R&D Program of China(2017YFD0600503)the National Forestry and Grassland Administration of Science and Technology Development Center Project(2016007).
文摘Robinia pseudoacacia is an important afforesta-tion tree introduced to China in 1878.In the present study,we examined the genetic diversity among 687 strains rep-resenting four improved varieties and two secondary prov-enances,comprising 641 clones and 46 seedlings.Ninety-one simple sequence repeats(SSRs)were selected through segregation analysis and polymorphism characterization,and all sampled individuals were genotyped using well-characterized SSR markers.After excluding loci with non-neutral equilibrium,missing locus data and null alleles,we used 36 primer pairs to assess the genetic diversity of these germplasm resources,revealing vast genetic differentiation among the samples,with an average of 8.352 alleles per locus and a mean Shannon′s index of 1.302.At the popula-tion level,the partitioning of variability was assessed using analysis of molecular variance,which revealed 93%and 7%variation within and among collection sites,respectively.Four clusters were detected using structure analysis,indi-cating a degree of genetic differentiation among the six populations.Insights into the genetic diversity and structure of R.pseudoacacia provide a theoretical basis for the con-servation,breeding and sustainable development in China.
基金supported by the National Natural Science Foundation of China(41471437)the National Key R&D Program of China(2016YFA0600801,2017YFC0504504)+1 种基金the West Light Foundation of the Chinese Academy of Science(XAB2016A04)the Key R&D Program of Ningxia Hui Autonomous Region,China(2022BBF02033)。
文摘Robinia pseudoacacia L.(RP)restoration has increased vegetation cover in semi-arid regions on the Loess Plateau of China,but ecological problems have also occurred due to RP restoration,such as reduced soil moisture.Further,it is still uncertain how microbial diversity,composition and assembly processes change with RP restoration in semi-arid regions.Therefore,amplicon sequencing of small subunit ribosomal ribonucleic acid(16S rRNA)and internal transcribed spacer(ITS)genes was performed to study soil bacterial and fungal diversity,composition and assembly processes at four study sites with different stand ages of RP plantations(Y10,RP plantation with stand ages less than 10 a;Y15,RP plantation with stand ages approximately 15 a;Y25,RP plantation with stand ages approximately 25 a;and Y40,RP plantation with stand ages approximately 40 a)along a 40-a chronosequence on the Loess Plateau.The diversity of soil bacteria and fungi increased significantly during the restoration period from 10 to 15 a(P<0.05).However,compared with Y15,bacterial diversity was lower at Y25 and Y40,and fungal diversity remained stable during the restoration period between 25 and 40 a.The relative abundances of Proteobacteria and Ascomycota increased during the restoration period from 10 to 15 a.Conversely,after 15 a of restoration,they both decreased,whereas the relative abundances of Actinomycetes,Acidobacteria and Basidiomycota gradually increased.The variations in soil bacterial communities were mainly related to changes in soil total nitrogen,nitrate nitrogen and moisture contents,while soil fungal communities were mainly shaped by soil organic carbon and nitrate nitrogen contents.Bacterial communities were structured by the heterogeneous selection and stochastic process,while fungal communities were structured primarily by the stochastic process.The RP restoration induced an increase in the relative importance of heterogeneous selection on bacterial communities.Overall,this study reveals the changes in microbial diversity,community composition and assembly processes with RP restoration on the Loess Plateau and provides a new perspective on the effects of vegetation restoration on soil microbial communities in semi-arid regions.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB40020000)the National Natural Science Foundation of China(No.41807011)。
文摘Background:Afforestation is a common and effective approach used for the restoration of degraded ecosystems worldwide.In China,Robinia pseudoacacia(RP)is among the main non-native tree species and has been widely planted in revegetation of the Loess Plateau.However,owing to uncertainties regarding soil water consumption and carbon sequestration,it is necessary to assess the suitability and sustainability of R.pseudoacacia in restoration.In this study,we aimed to analyse the dynamic effects of R.pseudoacacia forest on soil carbon storage(SCS)and soil water storage(SWS).Specifically,we investigated the association between soil water content(SWC)and soil organic carbon(SOC)and underlying factors in the 0-500-cm profile of a 10-to 50-year-old chronosequence.Results:The results obtained indicated that the dynamics of SWS and SCS on this time scale could be divided into an initial reduction phase(the initial 20 years after afforestation)and subsequent recovery(20-50 years after afforestation).Compared with in the abandoned land(AL),the net accumulation of SCS in R.pseudoacacia forest was 2.51 Mg·ha^(-1)at 50 years after afforestation,whereas there was a 398.76-mm deficit in SWS.Additionally,the natural succession of R.pseudoacacia forest has contributed to the continuous change in stand structure(e.g.vegetation cover(VC),understory vegetation coverage(UVC),and litter biomass(LB)).Conclusions:These findings indicate that vegetation restoration increases carbon sequestration while causing soil water deficit.Furthermore,stand density(SD)was established to make a predominant contribution to the dynamics of SWS and SCS via its effects in altering vegetation,soil,and litter characteristics.Therefore,high-density plantation forests in the Loess Plateau area should be appropriately thinned to reduce the density of forest stands on the basis of soil erosion control and wind and sand fixation,so as to increase carbon sink with lower water consumption,thus realizing the synergistic development of soil carbon sequestration and water connotation.
文摘Invasive forest species are a recurring problem,which in Portugal assume a somewhat mediatic role,both because of the impacts they cause on biodiversity,but also because they enhance the accumulation of high amounts of fuel load,increasing the risk of forest fires.However,in some areas of the country,such as the Alentejo(South of Portugal),the scarcity of water did not allow,until now,the dispersion and rapid growth of some of these species,namely Robinia pseudoacacia,which has always remained under control,and it was never a real problem.However,with the growth of intensive farming practices,associated with vineyards,olive groves and almond trees,water and nutrients became available,enabling this species to grow and disperse.This communication presents an observation of several sets of R.pseudoacacia specimens growing with different agricultural holdings,raising the hypothesis that intensive farming practices may,in the short term,contribute to the dispersion of invasive species in regions where they were not a problem,if the situations reported are not followed up and studies are carried out to confirm the observations described.
文摘Soil water-stable aggregates (WSAs) are the basic unit of soil constitution and can contribute to remaining the stable soil constitution. The objective of this study was to clarify the distribution and stability of WSAs and the soil organic carbon (SOC), the total nitrogen (TN), and the total phosphorus (TP) concentrations in 0 - 20 cm and 20 - 40 cm soil layers under the different ages of Robinia pseudoacacia plantations. The 20, 25, 40, and 50 years-old Robinia pseudoacacia plantations were selected. Stepwise regression analysis showed that >5 mm and 1 - 2 mm WSAs, SOC concentration in 2 - 5 mm WSAs, and TN and TP concentrations in < 0.25 mm WSAs were dominant independent variables affecting aggregate stability and that SOC in 0.25 - 0.5 mm WSAs, TN in <0.25 mm and 1 - 2 mm WSAs and TP in 2 - 5 mm WSAs were dominant independent variables affecting SOC, TN, and TP concentrations in bulk soils.
基金supported by the National Science Foundation of China (No. 31070630)
文摘The productivity of Robinia pseudoacacia(R.p.) pure forest usually declines at the late growth stage,and reforming it into mixed forests could be a promising way to resolve this problem. When choosing a suitable tree species that can be mixed with R.p., the interspecific relationship is an important issue. Therefore, we gathered the autumn litter fall from R.p. and 10 other species from the Loess Plateau of China were mixed in dual species litterbags(R.p.+each other species) and buried them in soil for a 345 days lab decay incubation. We measured the litter mass loss and nutrient contents to determine whether the nutrient release was affected by mixed species litter decomposition. The impacts of mixed litter decomposition on macro-elements release were more obvious than on micro-elements. The litters with similar substrate quality might show variable impacts on nutrients release in mixed decomposition. The C loss and release of nutrient was improved by descending order when R.p. litter was mixed with Hippophae rhamnoides, Ulmus pumila, Populus simonii, Larix principis-rupprechtii and Quercus liaotungensis(Q.l.). But, except for Q.l., only the other species were recommended as suitable mix-plants for R.p. since promoting a high turnover of the nutrient in the litter compartment and a rapid availability for tree.
基金The project was financially supported by parks organization of Karaj municipality
文摘Plants are capable of reducing environmental pollutions through uptaking contaminants in their tissues. In the study site, twenty one-year-old leaves and shoots as well as twenty soil samples were sampled and analyzed by Inductively Coupled Plasma (ICP). We investigated the uptaking ability of lead (Pb) and cadmium (Cd) by the leaves and shoots of Platanus orientalis, Robinia pseudoacacia and Fraxinus rotundifolia in Karaj city, the western Tehran, Iran. We also evaluated the total metal accumulation capacity by using metal accumulation index (MAI). Results indicated that there was no significant difference in uptaking contents of Cd and Pb in the leaves among the trees. However accumulation of Cd in shoots of F. rotundifolia and R. pseudoacacia was significantly higher than that of P. orientalis. The accumulation of Pb in shoots of R. pseudoacacia was significantly higher than the other species. The amount of Pb in the soil of the study area was significantly higher than Cd. Concentrations of Cd and Pb in leaves of the three species are in the ranges of 2.4 2.7 mg Kg-1 and 7.1 14.4 mg Kg-1 , respectively. R. pseudoacacia had the highest MAI value for leaves (2.21) and F. rotundifolia had the highest MAI value for shoots (2.4).
基金supported by the State Forestry Administration of China (Nos.2003-5-2 and 2004-04)
文摘Preparation of silage is a common method to preserve green forage.It plays an important role in improving forage utili-zation, solving the problem of forage provision and meeting the nutritional needs of livestock in winter and spring.The effects of various supplements on tetraploid black locust (Robinia pseudoacacia L.) silage were studied by analyzing its color, odor, texture, pH value, the composition and amount of organic acids, the ammonia-N/total-N ratio, crude protein, neutral detergent fibers and acid detergent fibers.Our results show that the silage quality of wilted tetraploid R.pseudoacacia preserved alone is acceptable, while adding brown sugar and Yishengkang to tetraploid R.pseudoacacia foliage improved its quality.The treatments consisting of the tetraploid R.pseudoacacia mixed with 33% and 50% corn stalk achieved the best silage quality in terms of pH value (p<0.01), amount of lactic acid (p<0.01), the ammonia-N/total-N ratio (p<0.01) and the fermentation quality.These treatments also resulted in a high content of crude protein and lower amounts of acid detergent fibers.The treatment consisting of the tetraploid R.pseudoacacia mixed with 20% corn stalk was also good in the quality of its fermentation.
基金supported by Iran Research Institute of Forests and Rangelandsthe Laboratory of Horticultural Sciences of the University of Tehran
文摘Heavy metal contamination is one of the most important abiotic stresses affecting physiological activities of plants.We investigated the effects of cadmium(Cd) and lead(Pb) on chlorophyll fluorescence(Fv/Fm,Fo,and Fm),photosynthetic pigments(chlorophyll a and b),and proline in one-year-old seedlings of Robinia pseudoacacia.The seedlings were treated twice over a period of 10 days with Cd and Pb at concentrations of 0,250,500,1000 and2000 mg L-1.Saline solution containing Cd and Pb was sprayed on the leaves.Chlorophyll and proline contents were measured after 10 days.Chlorophyll fluorescence of R.pseudoacacia was affected slightly by high concentrations(1000,2000 mg L-1) of Cd and Pb.Chlorophyll a and a/b increased at 1000 and 2000 mg L-1of Cd and proline content of leaves was similar in all treatments of Cd and Pb.Our results indicated that photosynthetic sensitivity of R.pseudoacacia to Cd and Pb contamination was weak.Photosystem II chlorophyll pigments were not damaged by Pb and Cd stress.We conclude that chlorophyll fluorescence along with chlorophyll and proline contents are useful indicators of Cd and Pb stresses in R.pseudoacacia which widely planted in urban polluted regions in Iran.
