Vegetation restoration and reconstruction are effective approaches to desertification control and achieving social and economic sustainability in desert areas.However,the self-succession ability of native plants durin...Vegetation restoration and reconstruction are effective approaches to desertification control and achieving social and economic sustainability in desert areas.However,the self-succession ability of native plants during the later periods of vegetation restoration remains unclear.Therefore,this study was conducted to bridge the knowledge gap by investigating the regeneration dynamics of artificial forest under natural conditions.The information of seed rain and soil seed bank was collected and quantified from an artificial Caragana korshinskii Kom.forest in the Tengger Desert,China.The germination tests were conducted in a laboratory setting.The analysis of species quantity and diversity in seed rain and soil seed bank was conducted to assess the impact of different durations of sand fixation(60,40,and 20 a)on the progress of vegetation restoration and ecological conditions in artificial C.korshinskii forest.The results showed that the top three dominant plant species in seed rain were Echinops gmelinii Turcz.,Eragrostis minor Host.,and Agropyron mongolicum Keng.,and the top three dominant plant species in soil seed bank were E.minor,Chloris virgata Sw.,and E.gmelinii.As restoration period increased,the density of seed rain and soil seed bank increased first and then decreased.While for species richness,as restoration period increased,it gradually increased in seed rain but decreased in soil seed bank.There was a positive correlation between seed rain density and soil seed bank density among all the three restoration periods.The species similarity between seed rain or soil seed bank and aboveground vegetation decreased with the extension of restoration period.The shape of the seeds,specifically those with external appendages such as spines and crown hair,clearly had an effect on their dispersal,then resulting in lower seed density in soil seed bank.In addition,precipitation was a crucial factor in promoting rapid germination,also resulting in lower seed density in soil seed bank.Our findings provide valuable insights for guiding future interventions during the later periods of artificial C.korshinskii forest,such as sowing and restoration efforts using unmanned aerial vehicles.展开更多
[Objectives] Caragana korshinskii resources are rich in Ordos with a large planting area, but they have not been fully and reasonably utilized. This study aims to effectively convert C. korshinskii into high-quality f...[Objectives] Caragana korshinskii resources are rich in Ordos with a large planting area, but they have not been fully and reasonably utilized. This study aims to effectively convert C. korshinskii into high-quality feed, improve the quality of milk and meat of herbivores and increase production. [Methods] The utilization of C. korshinskii in feed was studied in various aspects, the factors were selected, the level was determined, and the multi-factor experiment—orthogonal experiment was conducted. [Results] The effect on the growth of sheep was in the order of silage > C. korshinskii feed > corn stalk silage > hay meal, and the effect on the growth of goats was in the order of hay meal > C. korshinskii feed > silage > corn stalk silage. [Conclusions] From the analysis of the range results, the best level combination was selected: in different growing seasons, C. korshinskii branch and leaf silage in full-bloom stage had the greatest effect on the growth of sheep and goats, and the fattening effect was the best;among the different silage methods of C. korshinskii, the C. korshinskii—corn stalk mixture silage had a good feeding effect for sheep and goats.展开更多
Roots exert pullout resistance under pullout force,allowing plants to resist uprooting.However,the pullout resistance characteristics of taproot-type shrub species of different ages remain unclear.In this study,in ord...Roots exert pullout resistance under pullout force,allowing plants to resist uprooting.However,the pullout resistance characteristics of taproot-type shrub species of different ages remain unclear.In this study,in order to improve our knowledge of pullout resistance characteristics of taproot systems of shrub species,we selected the shrub species Caragana korshinskii Kom.in different growth periods as the research plant and conducted in situ root pullout test.The relationships among the maximum pullout resistance,peak root displacement,shrub growth period,and aboveground growth indices(plant height and plant crown breadth)were analyzed,as well as the mechanical process of uprooting.Pullout resistance of 4-15 year-old C.korshinskii ranged from 2.49(±0.25)to 14.71(±4.96)kN,and the peak displacement ranged from 11.77(±8.61)to 26.50(±16.09)cm.The maximum pullout resistance and the peak displacement of roots increased as a power function(R^(2)=0.9038)and a linear function(R^(2)=0.8242)with increasing age,respectively.The maximum pullout resistance and the peak displacement increased with increasing plant height;however,this relationship was not significant.The maximum pullout resistance increased exponentially(R^(2)=0.5522)as the crown breadth increased.There was no significant relationship between the peak displacement and crown breadth.The pullout resistance and displacement curve were divided into three stages:the initial nonlinear growth,linear growth,and nonlinear stages.Two modes of failure of a single root occurred when the roots were subjected to vertical loading forces:the synchronous breakage mode and the periderm preferential breakage mode.These findings provide a foundation for further investigation of the soil reinforcement and slope protection mechanisms of this shrub species in the loess area of northeastern Qinghai-Tibet Plateau,China.展开更多
Bacterial and fungal communities play critical roles in reestablishing vegetation structure,function and biodiversity in ecosystem restoration in arid and semi-arid areas.However,the long-term successional changes in ...Bacterial and fungal communities play critical roles in reestablishing vegetation structure,function and biodiversity in ecosystem restoration in arid and semi-arid areas.However,the long-term successional changes in bacterial and fungal communities that occur with artificial vegetation development are not fully understood.In this study,we investigated the successional changes in bacterial and fungal communities in Caragana korshinskii Kom.plantation over a period of 50 a(6,12,18,40 and 50 a)and their relationships with key soil environmental factors in a typical agro-pastoral ecotone,northern China.The results showed that bacterial and fungal diversities(α-andβ-diversity)were significantly affected by plantation age;moreover,the change in fungal community was more evident than that in bacterial community.Soil samples from 12 a plantation had the highest(P<0.05)bacterial and fungalα-diversity(i.e.,abundance-based coverage estimator(ACE)and Chao1 index)at 0-10 cm depth compared with other samples.However,soil samples from plantation at the late recovery stage(40-50 a)had the highestα-diversity at 10-20 cm depth.Soil bacterial community was not significantly affected by plantation age at the genus level;but,soil fungal community was significantly affected at the genus level.Overall,Mortierella and Chaetomium were the dominant genera at natural recovery stage(0 a);Inocybe was the dominant genus at the early recovery stage(6-12 a);Inocybe and Mortierella were the dominant genera at the mid-recovery stage(12-40 a);And Mortierella,Cladosporium and Humicola were the dominant genera at the late recovery stage(40-50 a).Redundancy analysis(RDA)showed thatβ-glucosidase activity,total nitrogen and soil organic carbon were closely associated with bacterial community composition,while alkaline phosphatase,urease activity and total nitrogen were associated with fungal community composition,indicating that changes in enzyme activity and soil nutrients were the most important determinants of dominant genera.Furthermore,pathogenic microorganisms(Cladosporium and Humicola)were dominant in soils from 40-50 a plantation,which may affect plant growth,resulting in the decline of C.korshinskii plantation.Overall,the findings of this study improve the understanding of ecological patterns of bacterial and fungal communities in artificial vegetation and provide an important scientific basis for comprehensive ecological restoration management in arid and semi-arid areas.展开更多
In order to study the eco-physiological mechanisms of C. korshinskii adaptation to extreme drought stress, we investigated the variations of water content in soil, leaves, and stems, the chlorophyll a and b and the ca...In order to study the eco-physiological mechanisms of C. korshinskii adaptation to extreme drought stress, we investigated the variations of water content in soil, leaves, and stems, the chlorophyll a and b and the carotenoid content in leaves and stems, as well as changes of chloroplast ultrastructure in 2-year-old C. korshinskii specimens during a progressive soil drought process (by ceasing watering until all leaves were shed) and a subsequent rehydration process. During the dehydration process, the chlorophyll a and b and carotenoid contents in the leaves decreased, as did the carotenoid content in the stems. During the 4-day rehydration process, the chlorophyll a and b and carotenoid contents in the leaves and stems increased and gradually returned to normal levels. During ongoing drought stress, chloroplasts in the leaves broke away from cell walls and appeared in the center of cells. Under severe drought stress, the mesophyll ultrastructure and chloroplast configuration in leaves were irreversibly disturbed, as mani- fested by the inner and outer membranes being destroyed; the thylakoid system disintegrated, the starch grain disappeared, and parts of cell tissue were dismantled into debris. However, the mesophyll ultrastructure and chloroplast configuration in the stems remained complete. This indicates that C. korshinskii utilizes leaf abscission to reduce the surface area to avoid damage from extreme drought stress, and maintains chloroplast integrity and a considerable amount of chlorophyll to enable a rapid recovery of photosynthesis under the rehydration process.展开更多
Caragana korshinskii Kom, which is a kind of excellent shrubs, has strong resistance to windstorms, and it is also a kind of forage that is of high nutritional value as well as a forming fuel conversion resource that ...Caragana korshinskii Kom, which is a kind of excellent shrubs, has strong resistance to windstorms, and it is also a kind of forage that is of high nutritional value as well as a forming fuel conversion resource that is of high caloric. Caragana korshinskii Kom is of high lignifications after growing for a few years and the toughness of it is considerably high. Currently in China, equipments of harvesting and processing for ripe crops can hardly finish the mechanized production for Caragana korshinskii Kom. Friction characteristics of woody material for Caragana korshinskii Kom under different conditions should be given when the relevant operation machinery is designed, which can provide physical parameters for transportation of Caragana korshinskii Kom as well as the designing of relevant machinery. The paper bases on the research of friction characteristics between Caragana korshinskii Kom whose diameter of 7, 10, and 13 mm under sampling directions of 0°, 45°,and 90° and machinery materials that are commonly used such as steel plate, rubber sheet and so on, and meanwhile the test considers factors such as different conditions of Caragana korshinskii Kom, different materials of machines, different angles and so on. The data strongly suggests that the average static, dynamic friction coefficient between Caragana korshinskii Kom and steel plate is 0.399 711 and0.353 022, respectively; The average static and dynamic friction coefficient between Caragana korshinskii Kom and rubber sheet is 0.965 178 and 0.883 667, respectively. The maximum of static and dynamic friction coefficients is when the angle between the direction of sampling and the direction of movement is vertical. As the angle increased, the dynamic and static friction coefficient decreased. The friction coefficient between Caragana korshinskii Kom and steel plate were increased with the increase of the diameter of Caragana korshinskii Kom, but the diameter have no effect on the dynamic friction coefficient between Caragana korshinskii Kom and rubber plate. The conclusion of this paper can provide references for research on machines that are relevant to transportation and particle forming of Caragana korshinskii Kom.展开更多
One of the goals of grazing management in the desert steppe is to improve its ecosystem.However,relatively little is known about soil microbe communities in the desert steppe ecosystem under grazing management.In this...One of the goals of grazing management in the desert steppe is to improve its ecosystem.However,relatively little is known about soil microbe communities in the desert steppe ecosystem under grazing management.In this study,we investigated the diversity and aboveground biomass of Caragana korshinskii Kom.shrub communities in long-term fencing and grazing areas,combined with an analysis of soil physical-chemical properties and genomics,with the aim of understanding how fence management affects plant-soil-microbial inter-relationships in the desert steppe,China.The results showed that fence management(exclosure)increased plant diversity and aboveground biomass in C.korshinskii shrub area and effectively enhanced soil organic carbon(233.94%),available nitrogen(87.77%),and available phosphorus(53.67%)contents.As well,the Shannon indices of soil bacteria and fungi were greater in the fenced plot.Plant-soil changes profoundly affected the alpha-and beta-diversity of soil bacteria.Fence management also altered the soil microbial community structure,significantly increasing the relative abundances of Acidobacteriota(5.31%-8.99%),Chloroflexi(3.99%-5.58%),and Glomeromycota(1.37%-3.28%).The soil bacterial-fungal co-occurrence networks under fence management had higher complexity and connectivity.Based on functional predictions,fence management significantly increased the relative abundance of bacteria with nitrification and nitrate reduction functions and decreased the relative abundance of bacteria with nitrate and nitrite respiration functions.The relative abundances of ecologically functional fungi with arbuscular mycorrhizal fungi,ectomycorrhizal fungi,and saprotrophs also significantly increased under fence management.In addition,the differential functional groups of bacteria and fungi were closely related to plant-soil changes.The results of this study have significant positive implications for the ecological restoration and reconstruction of dry desert steppe and similar areas.展开更多
基金funded by the General Project of Key R&D Plan of Ningxia Hui Autonomous Region,China(2021BEG03008,2022BEG02012)the Science and Technology Innovation Leading Talent Project of Ningxia Hui Autonomous Region(2021GKLRLX13)the National Natural Science Foundation of China(31760707).
文摘Vegetation restoration and reconstruction are effective approaches to desertification control and achieving social and economic sustainability in desert areas.However,the self-succession ability of native plants during the later periods of vegetation restoration remains unclear.Therefore,this study was conducted to bridge the knowledge gap by investigating the regeneration dynamics of artificial forest under natural conditions.The information of seed rain and soil seed bank was collected and quantified from an artificial Caragana korshinskii Kom.forest in the Tengger Desert,China.The germination tests were conducted in a laboratory setting.The analysis of species quantity and diversity in seed rain and soil seed bank was conducted to assess the impact of different durations of sand fixation(60,40,and 20 a)on the progress of vegetation restoration and ecological conditions in artificial C.korshinskii forest.The results showed that the top three dominant plant species in seed rain were Echinops gmelinii Turcz.,Eragrostis minor Host.,and Agropyron mongolicum Keng.,and the top three dominant plant species in soil seed bank were E.minor,Chloris virgata Sw.,and E.gmelinii.As restoration period increased,the density of seed rain and soil seed bank increased first and then decreased.While for species richness,as restoration period increased,it gradually increased in seed rain but decreased in soil seed bank.There was a positive correlation between seed rain density and soil seed bank density among all the three restoration periods.The species similarity between seed rain or soil seed bank and aboveground vegetation decreased with the extension of restoration period.The shape of the seeds,specifically those with external appendages such as spines and crown hair,clearly had an effect on their dispersal,then resulting in lower seed density in soil seed bank.In addition,precipitation was a crucial factor in promoting rapid germination,also resulting in lower seed density in soil seed bank.Our findings provide valuable insights for guiding future interventions during the later periods of artificial C.korshinskii forest,such as sowing and restoration efforts using unmanned aerial vehicles.
基金Supported by Demonstration Project of Forestry and Grassland Science and Technology Popularization by Central Finance[NeiLinCaoKeTui(2021)]Major Project of"Revitalizing Mongolia through Science and Technology"(KJXM-EEDS-2020006)Major Science and Technology Project of Inner Mongolia Autonomous Region(2019ZD007)。
文摘[Objectives] Caragana korshinskii resources are rich in Ordos with a large planting area, but they have not been fully and reasonably utilized. This study aims to effectively convert C. korshinskii into high-quality feed, improve the quality of milk and meat of herbivores and increase production. [Methods] The utilization of C. korshinskii in feed was studied in various aspects, the factors were selected, the level was determined, and the multi-factor experiment—orthogonal experiment was conducted. [Results] The effect on the growth of sheep was in the order of silage > C. korshinskii feed > corn stalk silage > hay meal, and the effect on the growth of goats was in the order of hay meal > C. korshinskii feed > silage > corn stalk silage. [Conclusions] From the analysis of the range results, the best level combination was selected: in different growing seasons, C. korshinskii branch and leaf silage in full-bloom stage had the greatest effect on the growth of sheep and goats, and the fattening effect was the best;among the different silage methods of C. korshinskii, the C. korshinskii—corn stalk mixture silage had a good feeding effect for sheep and goats.
基金funded by the National Natural Science Foundation of China (42002283, 42062019)the Science and Technology Plan Project of Qinghai Province,China (2022-ZJ-Y08)the Second Tibetan Plateau Scientific Expedition and Research (STEP) Program (2019QZKK0905, 2019QZKK0805)
文摘Roots exert pullout resistance under pullout force,allowing plants to resist uprooting.However,the pullout resistance characteristics of taproot-type shrub species of different ages remain unclear.In this study,in order to improve our knowledge of pullout resistance characteristics of taproot systems of shrub species,we selected the shrub species Caragana korshinskii Kom.in different growth periods as the research plant and conducted in situ root pullout test.The relationships among the maximum pullout resistance,peak root displacement,shrub growth period,and aboveground growth indices(plant height and plant crown breadth)were analyzed,as well as the mechanical process of uprooting.Pullout resistance of 4-15 year-old C.korshinskii ranged from 2.49(±0.25)to 14.71(±4.96)kN,and the peak displacement ranged from 11.77(±8.61)to 26.50(±16.09)cm.The maximum pullout resistance and the peak displacement of roots increased as a power function(R^(2)=0.9038)and a linear function(R^(2)=0.8242)with increasing age,respectively.The maximum pullout resistance and the peak displacement increased with increasing plant height;however,this relationship was not significant.The maximum pullout resistance increased exponentially(R^(2)=0.5522)as the crown breadth increased.There was no significant relationship between the peak displacement and crown breadth.The pullout resistance and displacement curve were divided into three stages:the initial nonlinear growth,linear growth,and nonlinear stages.Two modes of failure of a single root occurred when the roots were subjected to vertical loading forces:the synchronous breakage mode and the periderm preferential breakage mode.These findings provide a foundation for further investigation of the soil reinforcement and slope protection mechanisms of this shrub species in the loess area of northeastern Qinghai-Tibet Plateau,China.
基金This work is funded by the National Natural Science Foundation of China(41807518,42171033)the Open Fund of the Key Laboratory of Desert and Desertification,Chinese Academy of Sciences(KLDD-2020-05).
文摘Bacterial and fungal communities play critical roles in reestablishing vegetation structure,function and biodiversity in ecosystem restoration in arid and semi-arid areas.However,the long-term successional changes in bacterial and fungal communities that occur with artificial vegetation development are not fully understood.In this study,we investigated the successional changes in bacterial and fungal communities in Caragana korshinskii Kom.plantation over a period of 50 a(6,12,18,40 and 50 a)and their relationships with key soil environmental factors in a typical agro-pastoral ecotone,northern China.The results showed that bacterial and fungal diversities(α-andβ-diversity)were significantly affected by plantation age;moreover,the change in fungal community was more evident than that in bacterial community.Soil samples from 12 a plantation had the highest(P<0.05)bacterial and fungalα-diversity(i.e.,abundance-based coverage estimator(ACE)and Chao1 index)at 0-10 cm depth compared with other samples.However,soil samples from plantation at the late recovery stage(40-50 a)had the highestα-diversity at 10-20 cm depth.Soil bacterial community was not significantly affected by plantation age at the genus level;but,soil fungal community was significantly affected at the genus level.Overall,Mortierella and Chaetomium were the dominant genera at natural recovery stage(0 a);Inocybe was the dominant genus at the early recovery stage(6-12 a);Inocybe and Mortierella were the dominant genera at the mid-recovery stage(12-40 a);And Mortierella,Cladosporium and Humicola were the dominant genera at the late recovery stage(40-50 a).Redundancy analysis(RDA)showed thatβ-glucosidase activity,total nitrogen and soil organic carbon were closely associated with bacterial community composition,while alkaline phosphatase,urease activity and total nitrogen were associated with fungal community composition,indicating that changes in enzyme activity and soil nutrients were the most important determinants of dominant genera.Furthermore,pathogenic microorganisms(Cladosporium and Humicola)were dominant in soils from 40-50 a plantation,which may affect plant growth,resulting in the decline of C.korshinskii plantation.Overall,the findings of this study improve the understanding of ecological patterns of bacterial and fungal communities in artificial vegetation and provide an important scientific basis for comprehensive ecological restoration management in arid and semi-arid areas.
基金supported by the National Natural Sciences Foundation of China (Nos. 30900171, 91025026)the China Postdoctoral Science Foundation (No. 20090450186)
文摘In order to study the eco-physiological mechanisms of C. korshinskii adaptation to extreme drought stress, we investigated the variations of water content in soil, leaves, and stems, the chlorophyll a and b and the carotenoid content in leaves and stems, as well as changes of chloroplast ultrastructure in 2-year-old C. korshinskii specimens during a progressive soil drought process (by ceasing watering until all leaves were shed) and a subsequent rehydration process. During the dehydration process, the chlorophyll a and b and carotenoid contents in the leaves decreased, as did the carotenoid content in the stems. During the 4-day rehydration process, the chlorophyll a and b and carotenoid contents in the leaves and stems increased and gradually returned to normal levels. During ongoing drought stress, chloroplasts in the leaves broke away from cell walls and appeared in the center of cells. Under severe drought stress, the mesophyll ultrastructure and chloroplast configuration in leaves were irreversibly disturbed, as mani- fested by the inner and outer membranes being destroyed; the thylakoid system disintegrated, the starch grain disappeared, and parts of cell tissue were dismantled into debris. However, the mesophyll ultrastructure and chloroplast configuration in the stems remained complete. This indicates that C. korshinskii utilizes leaf abscission to reduce the surface area to avoid damage from extreme drought stress, and maintains chloroplast integrity and a considerable amount of chlorophyll to enable a rapid recovery of photosynthesis under the rehydration process.
文摘Caragana korshinskii Kom, which is a kind of excellent shrubs, has strong resistance to windstorms, and it is also a kind of forage that is of high nutritional value as well as a forming fuel conversion resource that is of high caloric. Caragana korshinskii Kom is of high lignifications after growing for a few years and the toughness of it is considerably high. Currently in China, equipments of harvesting and processing for ripe crops can hardly finish the mechanized production for Caragana korshinskii Kom. Friction characteristics of woody material for Caragana korshinskii Kom under different conditions should be given when the relevant operation machinery is designed, which can provide physical parameters for transportation of Caragana korshinskii Kom as well as the designing of relevant machinery. The paper bases on the research of friction characteristics between Caragana korshinskii Kom whose diameter of 7, 10, and 13 mm under sampling directions of 0°, 45°,and 90° and machinery materials that are commonly used such as steel plate, rubber sheet and so on, and meanwhile the test considers factors such as different conditions of Caragana korshinskii Kom, different materials of machines, different angles and so on. The data strongly suggests that the average static, dynamic friction coefficient between Caragana korshinskii Kom and steel plate is 0.399 711 and0.353 022, respectively; The average static and dynamic friction coefficient between Caragana korshinskii Kom and rubber sheet is 0.965 178 and 0.883 667, respectively. The maximum of static and dynamic friction coefficients is when the angle between the direction of sampling and the direction of movement is vertical. As the angle increased, the dynamic and static friction coefficient decreased. The friction coefficient between Caragana korshinskii Kom and steel plate were increased with the increase of the diameter of Caragana korshinskii Kom, but the diameter have no effect on the dynamic friction coefficient between Caragana korshinskii Kom and rubber plate. The conclusion of this paper can provide references for research on machines that are relevant to transportation and particle forming of Caragana korshinskii Kom.
基金funded by the National Natural Science Foundation of China(32061123006,32360426).
文摘One of the goals of grazing management in the desert steppe is to improve its ecosystem.However,relatively little is known about soil microbe communities in the desert steppe ecosystem under grazing management.In this study,we investigated the diversity and aboveground biomass of Caragana korshinskii Kom.shrub communities in long-term fencing and grazing areas,combined with an analysis of soil physical-chemical properties and genomics,with the aim of understanding how fence management affects plant-soil-microbial inter-relationships in the desert steppe,China.The results showed that fence management(exclosure)increased plant diversity and aboveground biomass in C.korshinskii shrub area and effectively enhanced soil organic carbon(233.94%),available nitrogen(87.77%),and available phosphorus(53.67%)contents.As well,the Shannon indices of soil bacteria and fungi were greater in the fenced plot.Plant-soil changes profoundly affected the alpha-and beta-diversity of soil bacteria.Fence management also altered the soil microbial community structure,significantly increasing the relative abundances of Acidobacteriota(5.31%-8.99%),Chloroflexi(3.99%-5.58%),and Glomeromycota(1.37%-3.28%).The soil bacterial-fungal co-occurrence networks under fence management had higher complexity and connectivity.Based on functional predictions,fence management significantly increased the relative abundance of bacteria with nitrification and nitrate reduction functions and decreased the relative abundance of bacteria with nitrate and nitrite respiration functions.The relative abundances of ecologically functional fungi with arbuscular mycorrhizal fungi,ectomycorrhizal fungi,and saprotrophs also significantly increased under fence management.In addition,the differential functional groups of bacteria and fungi were closely related to plant-soil changes.The results of this study have significant positive implications for the ecological restoration and reconstruction of dry desert steppe and similar areas.
