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ecological characteristics of artificial vegetation communities on excavated slopes at the Xiangjiaba hydroelectric power station

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Journal of Chongqing University 2009年第2期8卷 75-81页

作者：夏振尧许文年 College of Water Resources and Hydroelectric Engineering Wuhan University Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education China Three Gorges University

This paper reports the investigation of artificial vegetation communities on excavated slopes in a construction perturbed area of the Xiangjiaba hydroelectric power station in the Jinsha River Basin, P. R. China. Belt transect and random quadrats were used in sampling and recording the vegetation of the four selected plots on the slopes. The community of each plot was characterized based on the coverage, relative importance value, richness, diversity, evenness of species derived from the survey data. Problems of these communities were identified and corresponding regulation measures were proposed to accelerate the positive succession process of the ecosystem. It is demonstrated that the artificial vegetation restoration on the excavated slope has improved the ecological environment.

关键词： vegetation ecological community artificial vegetation community ecological characteristics regulation analysis

ecological characteristics AND ROLES OF AGRIOPHYLLUM SQUARROSUM,A PIONEER ANNUAL ON SAND DUNES IN HEXI CORRIDOR,CHINA

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ECOLOGICAL CHARACTERISTICS AND ROLES OF AGRIOPHYLLUM SQUARRO...

A study on an oligotrophic bacteria and its ecological characteristics in an arid desert area

第三世界生态高峰会

作者： MA Q.L~(1,2) 1 Gansu key lab of comhating desertification,Gansu Desert Control Research Institute,Wuwei 733000.Gansu province,China 2 Shapotou Desert Research and Experiment Station.Cold and Arid Regins Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou 730000,Gansu province,China

Agriophyllum squarrosum Moq,a therophyte of sandy soils,is considered as the best indicator of the beginning of community succession on shifting sand *** can dominate most of the shifting sand dunes,but its eco-charateristics and roles is known little,so t he experiment was conducted to understand the distribution and growth charateristics,ecological roles of such pioneer annual C4 grasses on shifting sand dunes in Hexi *** experiment was conducted at Minqin Desert Control Comprehensive Experimental Station（38°34′N,102°58′E）.The sampling method was adopted to investigated the distribution of on different land and *** plot size was 2m×2m,The plot number of each site was *** ten sampling plants were selected to observed modules and growth pattern of *** wind breaking and sand stabilizing of *** individual and *** community were observed by the portable wind velocity measuring *** results showed that spatial pattern of *** was clumped pattern under large and small scale at different habitats which were extremely unstable,that was,the surface substrate frequently shifts,the soil water-content was highly variable and the site did not permit the growth of any other plant *** of the elongation of its fine roots,*** were well adapted to dry sandy soil and able to penetrate deep soil layers containing *** biomass and the pod numbers increased under conditions where enough water was *** A,squarrosum had many branches which divaricating place was lower,strong mechanism intensity and strong root system to endure wind erosion in winter and spring seasons,so it could reduce wind velocity *** individual reduced wind velocity obviously,so sands carried by wind current to pileup and form the sandy *** curve of the sandy tongue to the physical volume of *** was conic that equation was y=0.0008x-0.2117x+ 43.509（R=0.964）.Highest an

关键词： Agriophyllum squarrosum pioneer annual Hexi corridor ecological characteristics ecological role

来源： cnki会议评论

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Science China Earth Sciences 2007年第S1期 128-134页

作者： PAN HuiXia, CHENG ZhengMing, ZHANG XueMei, MU ShuYong, QI XiaoLing & WANG Fang Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, ürümqi 830011, China

An oligotrophic bacterium was isolated from the biological soil crust underlayer in the Xinjiang Gurbantunggut Desert. It was numbered SGB-5, G+. Cell size is (0.328-0.746) μm×(0.171-0.240) μm. Raised colony is white, roundness and its diameter is 5 mm. The strain is a facultative aerobe. It was able to grow in conditions of 1―15 mg·C·L?1 culture medium at 10―50℃. The strain’s optimum growth temperature is 37℃. The range of its optimum growth pH is 8―9. A large amount of extracellular mucopolysaccharide was secreted during growth. The chemical composition of this mucopolysaccharide consists of arabinose, X sugar, glucose, galactose and mannitol. Mole ratio of these sugars is 1:14:19:6:14. The viscosity of the mucopolysaccharide can reach 6300 mPa·s, when the strain is cultivated for 72 h. After the culture solution in which viscosity was 1500 mPa·s was sprinkled on the quicksand surface, 6 mm bacteria crust of conglutinating sand was formed. This crust could not only stabilize sand, but could also potentially slow the rate of the soil water evaporation.

关键词： Oligotrophic bacteria ecological characteristics

Flora and ecological characteristics of rare plant communities on the southern slope of Shennongjia Mountain

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Journal of Forestry Research 2002年第1期13卷 21-24,82-83页

作者：邓红兵江明喜吴金清葛继稳中国科学院沈阳应用生态研究所沈阳110016 中国科学院武汉植物研究所武汉430074 湖北省野生动植物保护站武汉430072

According to the investigation of sampling area of 6800 m2 on the south slope of Shennongjia Mountain, there were 126 vascular plant species, belonging to 108 genera and 64 families, in the investigated rare plant communities, of which 9 rare plant species were recorded, accounting for 27.3% of the total rare plants. The communities were about 30 m in height and were divided into three layers as tree layer, shrub layer, and herb layer. The flora of the communities had obvious temperate character. Phanerophytes (accounted for 65.9%), Mesophyllous (62.7%), Papyraceous (84.1%), simple leaf (83.3%), un-entire leaf (69.8%) were dominant in life form, leaf size class, leaf texture, leaf form, and leaf margin respectively. According to important value of species, the communities were divided into three types as Davidia involucrata + Litsea pungens community, Cercidiphyllum japanicum + Padus wilsonii community, and Padus wilsonii + Acer mono community. The indexes of species diversity of tree layer had little difference among communities and evenness was high. The results indicated that the communities had complex structure and relative stability.

关键词： Rare plant community Flora ecological characteristics Shennongjia Mountain

Denitrifying Bacteria in Paddy Soils of the Taihu Lake Basin,China

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Pedosphere 2004年第4期14卷 527-532页

作者： ZHANGHua-Yong LIZhen-Gao PANYing-Hua LILiang-Mo InstituteofSoilScience ChineseAcademyofSciencesNanjing210008（China）.

This study attempted to determine the characteristics of the communities, the ecological factors, and the denitrifying enzyme activity for denitrifying bacteria found in the paddy soils of the Taihu Lake Basin, China. Samples of the six main soil types of the basin were taken from paddy fields with different fertilities. The total numbers of bacteria and denitrifying bacteria in the high fertility soils were much more than those in low fertility soils, and the number of denitrifying bacteria accounted for 49% to 80% of the total number of bacteria. The O2 content was an important ecological factor that affected denitrification. Of test the strains isolated from the paddy soils in the Taihu Lake Basin, some (e.g., Pseudomonas spp.) grew well under low oxygen partial pressure, while others (e.g., Bacillus spp.) had no strict predilection with O2 content. Another critical ecological factor was the nitrogen concentration. Three selected denitrifying bacteria grew better in aculture medium with 135 instead of 276mg L^-1 nitrogen. At the same time 67% of the test strains were able to reduce NO3^- to NO2^- and 56% had N2O reductase.

关键词： denitrifying bacteria ecological characteristics enzyme activity paddysoils

The response of Caragana microphylla seedlings to water table changes in Horqin Sandy Land,China

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Research in Cold and Arid Regions 2015年第1期7卷 88-93页

作者： YunHua Ma TongHui Zhang XinPing Liu Wei Mao XiangFei Yue Naiman Desertification Research Station Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences University of Chinese Academy of Sciences

This paper focuses on the growth response of Caragana microphylla seedlings to changes of artificially controlled water table in Horqin Sandy Land, China. Monitoring results of soil water content shows that soil moisture is closely correlated to groundwater depths. Soil volumetric water increased rapidly when close to water sources and finally stabilized in a saturated state. The soil moisture trend of CK （control） increased gradually at 0-50 cm of soil depth then decreased to 4% below 50 cm soil depth. C. microphylla can adapt to different soil environments by changes in ecological and physiological characteristics. By comparing the ecological characteristics of C. microphylla seedlings at various water tables, we found that a shallow water table of 40 cm depth inhibited seedling groundwater depth of 120 em was more advantageous for plant growth because of weak ecological characteristics. A height and canopy growth of C. microphylla seedlings. During the first two years, the most suitable water depth for root biomass was 120 cm, and 180 cm for root length. The growth of vertical roots is positively correlated with groundwater depth, and root thickness is the determinate factor for root biomass while the fine root is the determinate factor for root length. A thick root would grow much more in a natural drought environment while access to ground water promotes the growth of fine roots.

关键词： water table changes Caragana microphylla seedlings ecological characteristics Horqin Sandy Land

Overview of Pharmaceutical Research on Passiflora foetida L.

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Agricultural Science & Technology 2014年第7期15卷 1113-1116页

作者：张月张小伟司珂瑜胡家华宇磊陈洪卫李洪珠巩江倪士峰西北大学文学院陕西西安710127 西北大学物理学院陕西西安710069 西北大学生命科学学院陕西西安710069 西藏民族学院医学院陕西咸阳712082

Based on extensive literature search,the composition,pharmacology,clini cal applications of Passiflora foetida L,ecological characteristics were summarized with the aim to provide scientific data for further research ... 详细信息

关键词： Passiflora foetida L. Composition Pharmacology Clinical applications Reprehensive dietary ecological characteristics