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Relative importance of water, energy, and heterogeneity in determining regional pteridophyte and seed plant richness in China

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Journal of Systematics and Evolution 2011年第2期49卷 95-107页

作者： 1,2.3.Sheng-Bin CHEN § 1 Gao-Ming JIANG 3.Zhi-Yun OUYANG 3.Wei-Hua XU 3.Yi XIAO 1 (State Key Laboratory of Vegetation and Environmental Change, institute of Botany, Chinese Academy of Sciences, beijing 100093. China) 2.(Graduate University of the Chinese Academy of Sciences, beijing 100049, China) 3.(State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences,{3., China) (State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (Graduate University of the Chinese Academy of Sciences Beijing 100049 China) (State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China)

Environmental variables, such as ambient energy, water availability, and environmental heterogeneity have been frequently proposed to account for species diversity gradients. How taxon-specific functional traits define large-scale richness gradients is a fundamental issue in understanding spatial patterns of species diversity, but has not been well documented. Using a large dataset on the regional flora from China, we examine the contrast spatial patterns and environmental determinants between pteridophytes and seed plants which differ in dispersal capacity and environmental requirements. Pteridophyte richness shows more pronounced spatial variation and stronger environmental associations than seed plant richness. Water availability generally accounts for more spatial variance in species richness of pteridophytes and seed plants than energy and heterogeneity do, especially for pteridophytes which have high dependence on moist and shady environments. Thus, pteridophyte richness is disproportionally affected by water-related variables; this in turn results in a higher proportion of pteridophytes in regional vascular plant floras (pteridophyte proportion) in wet regions. Most of the variance in seed plant richness, pteridophyte richness, and pteridophyte proportion explained by energy is included in variation that water and heterogeneity account for, indicating the redundancy of energy in the study extent. However, heterogeneity is more important for determining seed plant distributions. Pteridophyte and seed plant richness is strongly correlated, even after the environmental effects have been removed, implying functional linkages between them. Our study highlights the importance of incorporating biological traits of different taxonomic groups into the studies of macroecology and global change biology.

关键词： habitat heterogeneity pteridophytes seed plants species richness water-energy hypothesis.

The impact of vegetation restoration on erosion-induced sediment yield in the middle Yellow River and management prospect

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Science China Earth Sciences 2005年第6期48卷 724-741页

作者： CHEN Hao1, ZHOU Jinxing2. CAI Qiangguo1, YUE Zhongqi3. LU Zhongchen4, LIANG Guanglin1& HUANG Jianguo5 1. Key Laboratory of Water Cycle and Related Land Surface Processes, institute of Geographic Sciences and Natural Resources Re-search, Chinese Academy of Sciences, beijing 100101, China 2. institute of Forestry, Chinese Academy of Forestry Sciences, beijing 100091, China 3. Department of Civil Engineering, University of Hong Kong, Hong Kong, China 4. Eco-environmental Research Center, Chinese Academy of Sciences, beijing 100085, China 5. College of Resources and Environment, Southwest Agricultural University, Chongqing 400716, China Correspondence should be addressed to Chen Hao Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China institute of Forestry Chinese Academy of Forestry Sciences Beijing China Department of Civil Engineering University of Hong Kong Hong Kong China Eco-environmental Research Center Chinese Academy of Sciences Beijing China College of Resources and Environment Southwest Agricultural University Chongqing China

According to the characteristics of water and erosion environments of different natural zones on the Loess Plateau, this paper studies changes of vegetation types, distribution boundaries of forest and grass as well as restoration capacity of vegetation in different natural zones in the middle Yellow River. The annual precipitation of 53. mm is the critical annual pre-cipitation for forest and grass distribution in the middle Yellow River. Among the zonal and azonal environmental factors affecting watershed sediment yield, the intermediate diameter D50 (mm) of suspended load and forest coverage (V, %) play the leading role. Of them the effect weight of forest coverage (V, %) on catchments sediment yield is only 3.4% less than the role of the intermediate diameter (D50, mm), they are almost the same. To effectively control soil erosion in semiarid, especially in hilly-gullied areas and make sediment transport modulus reduce to less than 6000 t/km2. it is rather difficult by merely relying on natural restoration of forest. In the process of cultivated land conversion into forest land and grassland, measures suiting local conditions should be adopted in tree species selection and artificial afforestation (grass planting) based on management with biological measures for slopeland and engineering measures for hilly-gullied areas, so that watershed forest coverage in key counties can reach at least over 3.%.Compared with the standard period of precipitation prior to the 1960s, with the decrease of an-nual precipitation at various periods, plant productivities decline to different degrees under natural conditions. The main reason accountable for the low survival rate of new seedlings and grass over years is due to precipitation decrease. In light with regression models of annual pre-cipitation and natural vegetation productivities, it is possible to obtain estimated values of wa-tershed natural vegetation productivity and eco-water consumption needed for the restoration to

关键词： vegetation restoration, eco-water requirement, watershed sediment yield, the middle Yellow River.

Buckling of shear zone under generalized boundary forces and its tectonic significance

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Chinese Science Bulletin 1997年第13期42卷 1119-1122页

作者： XIE Xinshenginstitute of Crustal Dynamics, State seismological {2.,{3., China institute of Crustal Dynamics State Seismological Bureau Beijing 100085 China

EN echelon fold tectonics of the crust is the result of buckling of a shear zone with long bound-aries under the action of pure shear, and also of a rectangular plate with simple supportedboundaries under pure shear a... 详细信息

关键词： echelon fold echelon angle echelon pitch interval critical stress strain energy of bending.

Research on the multi-level intake water temperature effect of the Yalong River Jinping-I hydropower project

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Science China(Technological Sciences) 2011年第S1期54卷 125-132页

作者： WU ShiYong 1,CAO Wei 1,WANG HongMei 1,SUN ShuangKe 2.&CHEN QiuWen 3.1 Ertan Hydropower Development Company,Ltd.,Chengdu 610051,China 2.China institute of Water Resources and Hydropower Research,{3. 10003.,China 3.Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,{3. {3.,China Ertan Hydropower Development Company Ltd. Chengdu China China institute of Water Resources and Hydropower Research Beijing China Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing China

Based on the discussion of the multi-level intake application status of high dam reservoir,this paper takes the Jinping-I hydropower project reservoir in the Yalong River as an example,which is shaped by the highest 3.5 m high arch dam,and carries out the forecasting research on the reservoir temperature by numerical simulation and physical model *** paper studies the intake effect of withdrawing the surface warm water by the stoplog gates inlets and verifies the reliability of the mathematical model by comparative *** results show that for a high dam hydropower station,taking the appropriate multi-level intake measure can withdraw the surface warm water in the spawning season and provide a favorable environment for the fish *** technical ideas and implementation scheme are adopted in this *** can provide technical reference for the solutions of similar problems in the future and it also has important engineering significance on the research of water temperature in large deep reservoirs.

关键词： water temperature multi-level intake Jinping-I hydropower project

Geophysical and Geological Features of the Meso-Cenozoic Lower Yangtze Rift Zone

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Acta Geologica Sinica(English Edition) 1990年第4期64卷 363-378页

作者： Chen Shengzao institute of Geophysics, State seismological {2., {3. Zhu Lupei institute of Geophysics State Seismological Bureau Beijing

It is clarified in this paper that the Lower Yangtze depression is a Meso-Cenozoic rift zone formed on thebasement of the Hercynian-Indosinian foreland basins. The rift zone is divided into eastern and western sectorsand is different in northern and southern parts. The rift zone in plane combination comprises *** or splitting rifts. The North Jiangsu-South Yellow Sea region represents a 'drift-type' rift basinwhose deposition center migrates gradually castward. The formation mechanism and dynamic evolution of therift basin are discussed from a viewpoint of the crustal fine-structure, with evidence in geology and geophysicsand analysis results of dynamic forces given.

关键词： Geophysical and Geological Features of the Meso-Cenozoic Lower Yangtze Rift Zone

Temporal variations of δ^(18)O of atmospheric water vapor at Delingha

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Science China Earth Sciences 2008年第7期51卷 966-975页

作者： YIN ChangLiang1, YAO TanDong2. TIAN LiDe2. LIU DongNian3. YU WuSheng2.& QU DongMei2.1 State Key Laboratory of Cryoshperic Science, Cold and Arid Regions Environmental and Engineering Research institute, Chinese Academy of Sciences, Lanzhou 73.000, China 2.Laboratory of Environment and Processes, institute of Tibetan Plateau Research, Chinese Academy of Sciences,{2., China 3.Meteorological Observatory of Haixi Prefecture of Qinghai Province, Delingha 817000, China State Key Laboratory of Cryoshperic Science Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China Laboratory of Environment and Processes Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China Meteorological Observatory of Haixi Prefecture of Qinghai Province Delingha China

Oxygen stable isotope of atmospheric water vapor is widely used to study the modern process of cli- mate. Atmospheric water vapor samples were collected at Dlingha, northeast of Tibetan Plateau during the period from July 2.05 to February 2.06. The variation of δ18O and the relationships between δ18O and both the temperature and specific humidity are analyzed in this paper. Results show that the sea- sonal variation of δ18O of atmospheric water vapor at Delingha is remarkable with higher δ18O in summer and lower δ18O in winter. The temporal variation of vapor δ18O shows obvious fluctuations, with magnitude of over 3.‰. The daily variation of the δ18O is highly correlated with air temperature. The relationship between δ18O and atmospheric water vapor content is complex. Study shows that δ18O of atmospheric water vapor is positively correlated with specific humidity in winter in seasonal scale and inversely correlated with specific humidity in summer rainy period. The δ18O values of at- mospheric water vapor are lower than those of precipitation at Delingha, and the average difference is 10.7‰. Variations of δ18O of atmospheric water vapor is also found to be affected by precipitation events, The model results show that the precipitation effect could have caused the vapor δ18O in the raining season to lower by 7% in average in July and August.

关键词： Delingha δ18O atmospheric water vapor

Variations of δ^(18)O in precipitation from the Muztagata Glacier, East Pamirs

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Science China Earth Sciences 2006年第1期49卷 36-42页

作者： LI Zhen1, YAO Tandong1,2. TIAN Lide1,2. XU Baiqing1,2.& Wu Guangjian2.1. Key Laboratory of Cryosphere and Environment, Jointly Established by Cold and Arid Regions Environmental and Engi-neering Research institute and institute of Tibetan Plateau Research, Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences, China Meteorological Administration, CAS, Lanzhou 73.000, China 2. Laboratory of Environment and Process on Tibetan Plateau, institute of Tibetan Plateau Research, Chinese Academy of Sciences,{3., China Key Laboratory of Cryosphere and Environment Jointly Established by Cold and Arid Regions Environmental and Engineering Research Institute and Institute of Tibetan Plateau Research Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences China Meteorological Administration Lanzhou China Laboratory of Environment and Process on Tibetan Plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China

Expeditions to Muztagata (in the eastern Pamirs) during the summer seasons of2.02.and 2.03.collected precipitation samples and measured their oxygen isotopes. The δ^(18)O inprecipitation displays a wide range, varying from -17.40per thousand to +1.3.per thousand inJune—September 2.02.and from -2..3.per thousand to +4.59per thousand in May—August 2.03. Theδ^(18)O in precipitation correlates with the initial temperature of precipitation during theobserving periods. The positive correlation between δ^(18)O and temperature suggests that δ^(18)Ocan be used as an indicator of temperature in this region. The δ^(18)O values in fresh-snow samplescollected from two snow events at different elevations on the Muztagata Glacier show a strong''altitude effect'', with a ratio of nearly -0.40per thousand per 100 m from 5500 m to 7450 m.

关键词： Muztagata, δ18O, temperature, altitude effect.

Dynamic mechanisms of the post-seismic deformation following large events:Case study of the 1999 Chi-Chi earthquake in Taiwan of China

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Science China Earth Sciences 2009年第11期52卷 1813-1824页

作者： ZHU ShouBiao1,2.& CAI YongEn2.1 institute of Crustal Dynamics, China Earthquake Administration,{3., China 2.Department of Geophysics, Peking University, {2. 100871, China institute of Crustal Dynamics China Earthquake Administration Beijing China Department of Geophysics Peking University Beijing China

The mechanism of postseismic deformation related to strong earthquakes is important in geodynamics, and presumably afterslip or viscoelastic relaxation is responsible for the postsesimic deformation. The 1999 Chi-Chi, Taiwan of China, earthquake occurred in the region where GPS observation station is most densely deployed in the world. The unprecedented GPS data provides a unique opportunity to study the physical processes of postseismic deformation. Here we assume that the interactions of viscoelastic relaxation, afterslip, fault zone collapse, poroelastic rebound, flow of underground fluids, and all these combined contribute to the surface displacements following the main shock. In order to know the essence of the postseismic deformation after the strong event, fault zone collapse, poroelastic rebound, flow of underground fluids, and so on, are represented equivalently by the variations of the focal medium properties. Therefore, the viscoelastic relaxation, afterslip, and the variations of the equivalent focal medium properties are inverted by applying the GPS temporal series measurement data with viscoelastic finite element method. Both the afterslip rate distribution along the fault and the afterslip evolution with time are obtained by means of inversion. Also, the preliminary result suggests that viscosities of the lower crust and the upper mantle in Taiwan region is 2.7×1018 and 4.2.102. Pa·s, respectively. Moreover, the inversion results indicate that the afterslip contributing to postseismic deformation of 44.6% in 450 days after the Chi-Chi earthquake, with 3..7% caused by the viscous relaxation and 2..7% by other factors such as fault zone collapse, poroelastic rebound, and the flow of liquids.

关键词： mechanism of postseismic deformation viscoelastic finite element method GPS temporal series data Chi-Chi earthquake

Asymptotic behavior of the shock solution for a class of nonlinear equations

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Progress in Natural Science:Materials International 2003年第10期 48-50页

作者： MO Jiaqi 1*, ZHU Jiang 2.and WANG Hui 3.1. Department of Mathemtics, Anhui Normal University, Wuhu 2.1000, China 2. ICEES, {3. of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., China 3. National Natural Science Foundation of China,{2., China) Department of Mathemtics Anhui Normal University Wuhu 241000 China ICEES Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China National Natural Science Foundation of China Beijing 100085 China

The high precision approximation of the shock solution for a class of nonlinear problems is obtained using a simple method.

关键词： nonlinear equation shock boundary layer.