Crude oil pollution is a significant global environmental challenge.The eastern Gansu Province on the Loess Plateau,an important agricultural region containing the Changqing Oilfield,is facing increasing crude oil con...Crude oil pollution is a significant global environmental challenge.The eastern Gansu Province on the Loess Plateau,an important agricultural region containing the Changqing Oilfield,is facing increasing crude oil contamination.Understanding how microbial communities respond to varying pollution levels is critical for developing effective bioremediation strategies.This study examined how different concentrations of crude oil affect soil properties and microbial communities in Qingyang City,eastern Gansu Province,China by comparing lightly polluted(1895.84-2696.54 mg/kg total petroleum hydrocarbons(TPH)),heavily polluted(4964.25-7153.61 mg/kg TPH),and uncontaminated(CK)soils.Results revealed that petroleum contamination significantly increased total organic carbon(TOC),pH,C:N:P ratio,and the activities of dehydrogenase(DHA)and polyphenol oxidase(PPO),while reducing total nitrogen(TN),available nitrogen(AN),total phosphorus(TP),available phosphorus(AP),available potassium(AK),soil organic matter(SOM),soil water content(SWC),the activities of urease(URE)and alkaline phosphatase(APA),and microbial alpha diversity(P<0.050).Light pollution(LP)soils demonstrated an increase in culturable microorganisms,whereas heavy pollution(HP)soils exhibited increased hydrocarbon-degrading microbes and higher expression of key functional genes,such as alkane monooxygenase(AlkB),cytochrome P450 alkane hydroxylases(P450),catechol 2,3-dioxygenase(C23O),and naphthalene dioxygenase(Nah)(P<0.050).Non-metric multidimensional scaling(NMDS)and redundancy analysis(RDA)indicated evident variations in microbial community structure across different oil contamination levels.LP soils were dominated by bacterial genera Pseudoxanthomonas and Solimonadaceae,whereas Pseudomonas,Nocardioides,and hydrocarbon-degrading genera(Marinobacter,Idiomarina,and Halomonas)were predominant in HP soils.The fungal genus Pseudallescheria exhibited the most pronounced abundance shift between LP and HP soils(P<0.050).Environmental factor analysis identified AN,SWC,TN,SOM,and alpha diversity indices(Shannon index and Chao1 index)as the key differentiators of CK soils,whereas the pollutant levels and metal content were characterized in HP soils.Hydrocarbon-degrading microbial abundance was a defining trait of HP soils.Metabolic pathway analysis revealed enhanced aromatic hydrocarbon degradation in HP soils,indicating microbial adaptation to severe contamination.These findings demonstrated that crude oil pollution suppressed soil nutrients while reshaping the structure and function of microbial communities.Pollution intensity directly affected microbial composition and degradation potential.This study offers valuable insights into microbial responses across contamination gradients and supports the development of targeted bioremediation strategies for oil-contaminated loess soils.展开更多
The main purpose of this study was to examine the effects of plant species diversity and functional composition (the identity of the plant functional groups) on ecosystem stability of Stipa, communities in the Inner M...The main purpose of this study was to examine the effects of plant species diversity and functional composition (the identity of the plant functional groups) on ecosystem stability of Stipa, communities in the Inner Mongolia Plateau. The research work was based on a 12-year study (from 1984 to 1995) of species abundance, diversity, and primary productivity of four Stipa communities, i.e. S. baicalensis Roshev., S. grandis P. Smirn., S, krylovii Roshev., and S. klemenzii Roshev. respectively. The Shnnon-Wiener index was used as a measurement of plant diversity, while functional composition was used to differentiate the functional groups that were included in the communities. The plant species of four Stipa communities were classified into functional groups based on the differences in life forms and ecological groups, which influence their performance in resource requirements, seasonality of growth, tolerance to water stress, and life history. Plant species were classified into five functional groups based on their differences in life form, shrubs and half shrubs, perennial bunch grasses, perennial rhizome grasses, forbs, annuals and biennials. Based on their differences in water requirement these species were classified into four functional groups: xerads, intermediate xerads, intermediate mesophytes, and mesophytes. The results showed: 1) Plant species diversity stabilized ecosystem processes. Shannon-Wiener index were 2.401 4, 2.172 0, 1.624 8, 0.354 3 from S. baicalensis community to S. grandis, S. krylovii and S. klemenzii community, respectively. The dynamics of the aboveground net primary productivity (ANPP) for a 12-year's period showed a reverse pattern, the coefficients of variation of the four communities were 21.94%, 20.63%, 29.21% and 39.72% respectively. 2) The Life form functional group component of diversity was a greater determinant of the ecosystem processes than the species component of diversity. The effects of perennial bunch grasses, perennial rhizome grasses and forbs on community stability were highly significant. 3) The ecological group component of diversity was also a great determinant of the ecosystem processes. The effects of xerads, intermediate xerads, and mesophytes on community stability were also very strong.展开更多
Plateaued函数具有很高的非线性度,可以满足相关免疫性、平衡性,在密码函数领域具有重要作用。为此,基于Carlet等提出的单输出Plateaued函数构造方法(FSE’03会议论文集),利用m序列的状态转移矩阵,构造一类多输出Plateaued函数,并参考Jo...Plateaued函数具有很高的非线性度,可以满足相关免疫性、平衡性,在密码函数领域具有重要作用。为此,基于Carlet等提出的单输出Plateaued函数构造方法(FSE’03会议论文集),利用m序列的状态转移矩阵,构造一类多输出Plateaued函数,并参考Johansson方法中的引理5(IEEE Transactions on Information Theory,2003,No.2),提出另一种多输出Plateaued函数的构造方法,由此得到的2种函数适用于S盒、滤波(组合)函数、杂凑函数等的设计。展开更多
Variations in the fractions of biomass allocated to functional components are widely considered as plant responses to resource availability for grassland plants. Observations indicated shoots isometrically relates to ...Variations in the fractions of biomass allocated to functional components are widely considered as plant responses to resource availability for grassland plants. Observations indicated shoots isometrically relates to roots at the community level but allometrically at the species level in Tibetan alpine grasslands. These differences may result from the specific complementarity of functional groups between functional components, such as leaf, root, stem and reproductive organ. To test the component complementary responses to regional moisture variation, we conducted a multi-site transect survey to measure plant individual size and component biomass fractions of common species belonging to the functional groups: forbs, grasses, legumes and sedges on the Northern Tibetan Plateau in peak growing season in 2010. Along the mean annual precipitation (MAP) gradient, we sampled 7o species, in which 2o are in alpine meadows, 20 in alpine steppes, 15 in alpine desert-steppes and 15 in alpine deserts, respectively. Our results showed that the size of alpine plants is small with individual biomass mostly lower than 1.0 g. Plants keep relative conservative component individual responses moisture functional fractions across alpine grasslands at the level. However, the complementary between functional components to variations specifically differ among groups. These results indicate that functional group diversity may be an effective tool for scaling biomass allocation patterns from individual up to community level. Therefore, it is necessary andvaluable to perform intensive and systematic studies on identification and differentiation the influences of compositional changes in functional groups on ecosystem primary services and processes.展开更多
Orthomorphic permutations have good characteristics in cryptosystems. In this paper, by using of knowledge about relation between orthomorphic permutations and multi-output functions, and conceptions of the generalize...Orthomorphic permutations have good characteristics in cryptosystems. In this paper, by using of knowledge about relation between orthomorphic permutations and multi-output functions, and conceptions of the generalized Walsh spectrum of multi-output functions and the auto-correlation function of multi-output functions to investigate the Walsh spectral characteristics and the auto-correlation function characteristics of orthormophic permutations, several results are obtained.展开更多
Complex tibial plateau fractures can seriously affect quality of life and physical and mental health of patients.The anatomical relationship between the proximal tibial bone and soft tissue is complex,resulting in dif...Complex tibial plateau fractures can seriously affect quality of life and physical and mental health of patients.The anatomical relationship between the proximal tibial bone and soft tissue is complex,resulting in different types of tibial plateau fractures.Violent trauma can lead to displaced fracture,serious soft tissue injury,and potentially,dislocation of the knee joint.Therefore,tibial plateau fractures are extremely unstable.AIM To assess the use of locking compression plate(LCP)+T-type steel plate for postoperative weight bearing and functional recovery of complex tibial plateau fractures.METHODS Ninety-seven patients with complex tibial plateau fractures who underwent surgery at our hospital were selected for retrospective study.Forty-nine patients had been treated with LCP+T-type steel plate limited internal fixation(study group),and 48 patients with bilateral ordinary steel plate support(control group).The operation process index,postoperative rehabilitation related index,Rasmussen score of the knee joint,tibial plateau varus angle(TPA),tibial plateau retroversion angle(PA),and surgical complications of the two groups were compared.RESULTS The operation time and intraoperative bone graft volume in the study group were lower than those in the control group(P<0.05).There were no significant differences in surgical bleeding,anterior external incision length,postoperative drainage,hospital stay duration,and fracture healing time between the groups(P>0.05).There was no significant difference in the TPA and PA angle between the groups immediately and 18 mo after surgery(P>0.05).At 12 mo after surgery,the Rasmussen scale score was higher in the study group than in the control group(P<0.05).There was no significant difference in the Rasmussen scale score at 18 mo after surgery,and the radiology score at 12 and 18 mo after surgery,between the two groups(P>0.05).The postoperative complication rate in the study group(3.77%)was lower than that in the control group(15.09%;P<0.05).CONCLUSION LCP+T-type steel plate internal fixation has advantages in terms of minimizing trauma and enabling early postoperative functional exercise,promoting functional recovery and lower limb weight-bearing,and reducing postoperative complications.展开更多
In this paper, the definition of multl-output partially Bent functions is presented and some properties are discussed. Then the relationship between multi-output partially Bent functions and multi-output Bent function...In this paper, the definition of multl-output partially Bent functions is presented and some properties are discussed. Then the relationship between multi-output partially Bent functions and multi-output Bent functions is given in Theorem 4, which includes Walsh spectrum expression and function expression. This shows that multi-output partially Bent functions and multi-output Bent functions can define each other in principle. So we obtain the general method to construct multi-output partially Bent functions from multi-output Bent functions.展开更多
The Qinghai-Tibet Plateau(QTP),also known as the Third Pole of the Earth,is a vital ecological security barrier for China.It is a tremendously sensitive region affected by the impacts of global climate change.The esca...The Qinghai-Tibet Plateau(QTP),also known as the Third Pole of the Earth,is a vital ecological security barrier for China.It is a tremendously sensitive region affected by the impacts of global climate change.The escalating intensity of climate change has presented profound challenges to its ecosystem functions and stability.This study first analyzes the spatiotemporal variations of the QTP ecosystem patterns and the key functions of the Plateau including water conservation,soil conservation,and windbreak and sand fixation from 2000 to 2020.It clarifies the regional differences in ecosystem functions and their importance,further evaluates the stability of ecosystem functions,and lays a scientific foundation for an ecological civilization on the Plateau by implementing conservation and restoration projects.The main results show that:(1)From 2000 to 2020,the wetland area in the QTP increased,while the grassland area significantly decreased.There were improvements in water conservation and windbreak and sand fixation capacities,with annual rates of change being 3.57m~3·ha^(-1)·a^(-1)and 0.23 t·ha^(-1)·a^(-1),respectively.However,the overall soil conservation trend declined during the same period,with an annual change rate of-0.16 t·ha^(-1)·a^(-1).(2)The core areas of water conservation,soil conservation,and windbreak and sand fixation on the QTP accounted for 12.7%,13.9%,and 14.2%of the total area,respectively.The core water conservation areas are mainly the southeastern QTP,Sanjiangyuan,and Naqu,while the core windbreak and sand fixation areas were concentrated in the central and western parts of the Plateau.The core soil conservation areas surrounded the entire interior of the Plateau.(3)From 2000 to 2020,the water conservation,soil conservation,and windbreak sand-fixation function on the QTP had higher stability in the southeastern and central parts,while stability was lower in the western region.Considering the stability assessment and ecological protection and restoration practices,the QTP can be divided into three major categories and 16 ecological functional zones.Differentiated ecological protection and restoration efforts can be implemented based on the different core ecosystem functions and zoning.展开更多
A total of 50 endophytic bacterial isolates were obtained from Kobreasia capillifolia at alpine grasslands in the Eastern Qilian Mountains on the Tibetan Plateau in China. Based on the sequencing and phylogenetic anal...A total of 50 endophytic bacterial isolates were obtained from Kobreasia capillifolia at alpine grasslands in the Eastern Qilian Mountains on the Tibetan Plateau in China. Based on the sequencing and phylogenetic analysis of 16 S r DNA genes, all isolates phylogenetically related closely to Bacillus, Acinetobacter, Stenotrophomonas, Brevundimonas, Arthrobacter, Curtobacterium, Paenibacillus, Plantibacter, Promicromonospora, Serratia, and Microbacterium, among which Bacillus was the predominant genus(47.8% of the total number of endophytic isolates). These isolates possessed different biological functions. In 50 endophytic bacteria, 42 isolates produced indole acetic acid(IAA) on King medium. There were seven isolates showing potency of mineral phosphate solubilization in Pikovaskaia's(PKO) liquid medium. Seven isolates exhibited antagonistic effect against Fusarium avenaceum, Colletotrichum coccodes and Phoma foveata. This was the first report on diversity and plant growth promotion of endophytic bacteria from K. capillifolia on alpine grassland in the Eastern Qilian Mountains, Chain. It is essential for revealing the relationship among plant, microorganism, and the special environment because the potential function of endophytic bacteria made a contribution to the interactions of plants and endophytic bacteria.展开更多
基金supported by the Natural Science Foundation of Gansu Province(23JRRM0752,22JR5RA345,21JR1RM333)the Project of Science and Technology Specialist in Gansu Province(24CXGM002)+2 种基金the National Natural Science Foundation of China(31860148)the Research Fund Project for PhD of Longdong University(XYBYZK2208)the Natural Science Foundation of Longdong University(HXZK2488).
文摘Crude oil pollution is a significant global environmental challenge.The eastern Gansu Province on the Loess Plateau,an important agricultural region containing the Changqing Oilfield,is facing increasing crude oil contamination.Understanding how microbial communities respond to varying pollution levels is critical for developing effective bioremediation strategies.This study examined how different concentrations of crude oil affect soil properties and microbial communities in Qingyang City,eastern Gansu Province,China by comparing lightly polluted(1895.84-2696.54 mg/kg total petroleum hydrocarbons(TPH)),heavily polluted(4964.25-7153.61 mg/kg TPH),and uncontaminated(CK)soils.Results revealed that petroleum contamination significantly increased total organic carbon(TOC),pH,C:N:P ratio,and the activities of dehydrogenase(DHA)and polyphenol oxidase(PPO),while reducing total nitrogen(TN),available nitrogen(AN),total phosphorus(TP),available phosphorus(AP),available potassium(AK),soil organic matter(SOM),soil water content(SWC),the activities of urease(URE)and alkaline phosphatase(APA),and microbial alpha diversity(P<0.050).Light pollution(LP)soils demonstrated an increase in culturable microorganisms,whereas heavy pollution(HP)soils exhibited increased hydrocarbon-degrading microbes and higher expression of key functional genes,such as alkane monooxygenase(AlkB),cytochrome P450 alkane hydroxylases(P450),catechol 2,3-dioxygenase(C23O),and naphthalene dioxygenase(Nah)(P<0.050).Non-metric multidimensional scaling(NMDS)and redundancy analysis(RDA)indicated evident variations in microbial community structure across different oil contamination levels.LP soils were dominated by bacterial genera Pseudoxanthomonas and Solimonadaceae,whereas Pseudomonas,Nocardioides,and hydrocarbon-degrading genera(Marinobacter,Idiomarina,and Halomonas)were predominant in HP soils.The fungal genus Pseudallescheria exhibited the most pronounced abundance shift between LP and HP soils(P<0.050).Environmental factor analysis identified AN,SWC,TN,SOM,and alpha diversity indices(Shannon index and Chao1 index)as the key differentiators of CK soils,whereas the pollutant levels and metal content were characterized in HP soils.Hydrocarbon-degrading microbial abundance was a defining trait of HP soils.Metabolic pathway analysis revealed enhanced aromatic hydrocarbon degradation in HP soils,indicating microbial adaptation to severe contamination.These findings demonstrated that crude oil pollution suppressed soil nutrients while reshaping the structure and function of microbial communities.Pollution intensity directly affected microbial composition and degradation potential.This study offers valuable insights into microbial responses across contamination gradients and supports the development of targeted bioremediation strategies for oil-contaminated loess soils.
文摘The main purpose of this study was to examine the effects of plant species diversity and functional composition (the identity of the plant functional groups) on ecosystem stability of Stipa, communities in the Inner Mongolia Plateau. The research work was based on a 12-year study (from 1984 to 1995) of species abundance, diversity, and primary productivity of four Stipa communities, i.e. S. baicalensis Roshev., S. grandis P. Smirn., S, krylovii Roshev., and S. klemenzii Roshev. respectively. The Shnnon-Wiener index was used as a measurement of plant diversity, while functional composition was used to differentiate the functional groups that were included in the communities. The plant species of four Stipa communities were classified into functional groups based on the differences in life forms and ecological groups, which influence their performance in resource requirements, seasonality of growth, tolerance to water stress, and life history. Plant species were classified into five functional groups based on their differences in life form, shrubs and half shrubs, perennial bunch grasses, perennial rhizome grasses, forbs, annuals and biennials. Based on their differences in water requirement these species were classified into four functional groups: xerads, intermediate xerads, intermediate mesophytes, and mesophytes. The results showed: 1) Plant species diversity stabilized ecosystem processes. Shannon-Wiener index were 2.401 4, 2.172 0, 1.624 8, 0.354 3 from S. baicalensis community to S. grandis, S. krylovii and S. klemenzii community, respectively. The dynamics of the aboveground net primary productivity (ANPP) for a 12-year's period showed a reverse pattern, the coefficients of variation of the four communities were 21.94%, 20.63%, 29.21% and 39.72% respectively. 2) The Life form functional group component of diversity was a greater determinant of the ecosystem processes than the species component of diversity. The effects of perennial bunch grasses, perennial rhizome grasses and forbs on community stability were highly significant. 3) The ecological group component of diversity was also a great determinant of the ecosystem processes. The effects of xerads, intermediate xerads, and mesophytes on community stability were also very strong.
文摘Plateaued函数具有很高的非线性度,可以满足相关免疫性、平衡性,在密码函数领域具有重要作用。为此,基于Carlet等提出的单输出Plateaued函数构造方法(FSE’03会议论文集),利用m序列的状态转移矩阵,构造一类多输出Plateaued函数,并参考Johansson方法中的引理5(IEEE Transactions on Information Theory,2003,No.2),提出另一种多输出Plateaued函数的构造方法,由此得到的2种函数适用于S盒、滤波(组合)函数、杂凑函数等的设计。
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB03030401 & XDA05060700)the National Natural Science Foundation of China (Grant Nos. 41171044, 31070391, 41271067)the General Financial Grant from the China Postdoctoral Science Foundation (Grant No. 2013M530716)
文摘Variations in the fractions of biomass allocated to functional components are widely considered as plant responses to resource availability for grassland plants. Observations indicated shoots isometrically relates to roots at the community level but allometrically at the species level in Tibetan alpine grasslands. These differences may result from the specific complementarity of functional groups between functional components, such as leaf, root, stem and reproductive organ. To test the component complementary responses to regional moisture variation, we conducted a multi-site transect survey to measure plant individual size and component biomass fractions of common species belonging to the functional groups: forbs, grasses, legumes and sedges on the Northern Tibetan Plateau in peak growing season in 2010. Along the mean annual precipitation (MAP) gradient, we sampled 7o species, in which 2o are in alpine meadows, 20 in alpine steppes, 15 in alpine desert-steppes and 15 in alpine deserts, respectively. Our results showed that the size of alpine plants is small with individual biomass mostly lower than 1.0 g. Plants keep relative conservative component individual responses moisture functional fractions across alpine grasslands at the level. However, the complementary between functional components to variations specifically differ among groups. These results indicate that functional group diversity may be an effective tool for scaling biomass allocation patterns from individual up to community level. Therefore, it is necessary andvaluable to perform intensive and systematic studies on identification and differentiation the influences of compositional changes in functional groups on ecosystem primary services and processes.
基金Supported by State Key Laboratory of InformationSecurity Opening Foundation(01-02) .
文摘Orthomorphic permutations have good characteristics in cryptosystems. In this paper, by using of knowledge about relation between orthomorphic permutations and multi-output functions, and conceptions of the generalized Walsh spectrum of multi-output functions and the auto-correlation function of multi-output functions to investigate the Walsh spectral characteristics and the auto-correlation function characteristics of orthormophic permutations, several results are obtained.
文摘Complex tibial plateau fractures can seriously affect quality of life and physical and mental health of patients.The anatomical relationship between the proximal tibial bone and soft tissue is complex,resulting in different types of tibial plateau fractures.Violent trauma can lead to displaced fracture,serious soft tissue injury,and potentially,dislocation of the knee joint.Therefore,tibial plateau fractures are extremely unstable.AIM To assess the use of locking compression plate(LCP)+T-type steel plate for postoperative weight bearing and functional recovery of complex tibial plateau fractures.METHODS Ninety-seven patients with complex tibial plateau fractures who underwent surgery at our hospital were selected for retrospective study.Forty-nine patients had been treated with LCP+T-type steel plate limited internal fixation(study group),and 48 patients with bilateral ordinary steel plate support(control group).The operation process index,postoperative rehabilitation related index,Rasmussen score of the knee joint,tibial plateau varus angle(TPA),tibial plateau retroversion angle(PA),and surgical complications of the two groups were compared.RESULTS The operation time and intraoperative bone graft volume in the study group were lower than those in the control group(P<0.05).There were no significant differences in surgical bleeding,anterior external incision length,postoperative drainage,hospital stay duration,and fracture healing time between the groups(P>0.05).There was no significant difference in the TPA and PA angle between the groups immediately and 18 mo after surgery(P>0.05).At 12 mo after surgery,the Rasmussen scale score was higher in the study group than in the control group(P<0.05).There was no significant difference in the Rasmussen scale score at 18 mo after surgery,and the radiology score at 12 and 18 mo after surgery,between the two groups(P>0.05).The postoperative complication rate in the study group(3.77%)was lower than that in the control group(15.09%;P<0.05).CONCLUSION LCP+T-type steel plate internal fixation has advantages in terms of minimizing trauma and enabling early postoperative functional exercise,promoting functional recovery and lower limb weight-bearing,and reducing postoperative complications.
基金Supported by State Key Laboratory of InformationSecurity Opening Foundation(01-02) the Doctorate Foundation ofInstitute of Information Engineering (YP20014401)HenanInno-vation Project for University Prominent Research Talents(2003KJCX008)
文摘In this paper, the definition of multl-output partially Bent functions is presented and some properties are discussed. Then the relationship between multi-output partially Bent functions and multi-output Bent functions is given in Theorem 4, which includes Walsh spectrum expression and function expression. This shows that multi-output partially Bent functions and multi-output Bent functions can define each other in principle. So we obtain the general method to construct multi-output partially Bent functions from multi-output Bent functions.
基金The Second Tibetan Plateau Scientific Expedition and Research Program,No.2019QZKK0404。
文摘The Qinghai-Tibet Plateau(QTP),also known as the Third Pole of the Earth,is a vital ecological security barrier for China.It is a tremendously sensitive region affected by the impacts of global climate change.The escalating intensity of climate change has presented profound challenges to its ecosystem functions and stability.This study first analyzes the spatiotemporal variations of the QTP ecosystem patterns and the key functions of the Plateau including water conservation,soil conservation,and windbreak and sand fixation from 2000 to 2020.It clarifies the regional differences in ecosystem functions and their importance,further evaluates the stability of ecosystem functions,and lays a scientific foundation for an ecological civilization on the Plateau by implementing conservation and restoration projects.The main results show that:(1)From 2000 to 2020,the wetland area in the QTP increased,while the grassland area significantly decreased.There were improvements in water conservation and windbreak and sand fixation capacities,with annual rates of change being 3.57m~3·ha^(-1)·a^(-1)and 0.23 t·ha^(-1)·a^(-1),respectively.However,the overall soil conservation trend declined during the same period,with an annual change rate of-0.16 t·ha^(-1)·a^(-1).(2)The core areas of water conservation,soil conservation,and windbreak and sand fixation on the QTP accounted for 12.7%,13.9%,and 14.2%of the total area,respectively.The core water conservation areas are mainly the southeastern QTP,Sanjiangyuan,and Naqu,while the core windbreak and sand fixation areas were concentrated in the central and western parts of the Plateau.The core soil conservation areas surrounded the entire interior of the Plateau.(3)From 2000 to 2020,the water conservation,soil conservation,and windbreak sand-fixation function on the QTP had higher stability in the southeastern and central parts,while stability was lower in the western region.Considering the stability assessment and ecological protection and restoration practices,the QTP can be divided into three major categories and 16 ecological functional zones.Differentiated ecological protection and restoration efforts can be implemented based on the different core ecosystem functions and zoning.
基金the National Natural Science Foundation of China(31160122)the Key Laboratory of Grassland Ecosystem(Gansu Agricultural University),Ministry of Education(CYzs-2011011)for financial support
文摘A total of 50 endophytic bacterial isolates were obtained from Kobreasia capillifolia at alpine grasslands in the Eastern Qilian Mountains on the Tibetan Plateau in China. Based on the sequencing and phylogenetic analysis of 16 S r DNA genes, all isolates phylogenetically related closely to Bacillus, Acinetobacter, Stenotrophomonas, Brevundimonas, Arthrobacter, Curtobacterium, Paenibacillus, Plantibacter, Promicromonospora, Serratia, and Microbacterium, among which Bacillus was the predominant genus(47.8% of the total number of endophytic isolates). These isolates possessed different biological functions. In 50 endophytic bacteria, 42 isolates produced indole acetic acid(IAA) on King medium. There were seven isolates showing potency of mineral phosphate solubilization in Pikovaskaia's(PKO) liquid medium. Seven isolates exhibited antagonistic effect against Fusarium avenaceum, Colletotrichum coccodes and Phoma foveata. This was the first report on diversity and plant growth promotion of endophytic bacteria from K. capillifolia on alpine grassland in the Eastern Qilian Mountains, Chain. It is essential for revealing the relationship among plant, microorganism, and the special environment because the potential function of endophytic bacteria made a contribution to the interactions of plants and endophytic bacteria.