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Reconstruction of precipitation variation from tree rings in recent 1000 years in Delingha, Qinghai

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Science china Earth sciences 2005年第7期48卷 939-949页

作者： SHAO Xuemei1, HUANG lei1, LIU Hongbin2. LIANG Eryuan1, FANG Xiuqi3.& WANG Lili1 1. institute of {2. sciences and Natural Resources research, chinese academy of sciences, beijing 100101, china 2. National Climate Center, beijing 100081, china 3. beijing Normal University, beijing 100875, china institute of geographic {2. Natural Resources Research Chinese Academy of Sciences Beijing 100101 China National Climate Center Beijing 100081 China beijing Normal University Beijing 100875 China

Using seven well-replicated Qilian juniper (Sabina przewalskii Kom.) ring-width chronologies developed at Zongwulong and Shalike Mts. in the northeastern part of the Qaidam Basin annual precipitation from previous July to current June in the recent 1000 years was re- constructed for Delingha. The reconstruction can capture 63.1% of precipitation variance and the equation was stable over time. For the reconstructed precipitation, wet periods occurred in AD152.—163. and 193.—2.01, whereas dry intervals in 142.—1519 and 163.—1741. In ad- dition, the magnitude in precipitation variation was lower before 143. with about 15 mm, but it increased to 3. mm during the period of 143. to 1850. After 1850, the precipitation variance de- creased again. In contrast to the increase in temperature, a decrease in annual precipitation was evident since the 1990s. The agreement in low-frequency variation between the reconstruction and the glacier accumulation and particulate content in Dunde ice cores during the recent several hundred years suggested that the precipitation reconstructed in this study was rather reliable, and represented a regional signal. This 1000-year reconstruction could benefit our understanding of climatic variation in decadal to century-scale in this region, and provide basic data to climate models and to prediction of future climate in the 2.st century.

关键词： northeastern part of the Qaidam Basin tree-ring width series of Qilian juniper precipitation reconstruction in 1000 years.

Comparative analysis of temperature and CO2.fluxes for winter wheat in Tibetan Plain and North china Plain using the EMD method

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Progress in Natural Science:Materials International 2006年第10期16卷 1066-1071页

作者： JIANG Zhaoyang, YU Qiang, lei Shuhe, WANG Tianduo, SUN Xiaomin and ZHANG Renhua ( chinese {2. of Meteorological Science, {3. 100081, china institute of geographic sciences and Natural Resources research, chinese academy of sciences, beijing 100101, china Mathematics Department, Ocean University of china, Qingdao 2.6071, china Shanghai institute of Plant Physiology and Ecology, chinese academy of sciences, Shanghai 2.003.2} china) chinese academy of Meteorological Science Beijing 100081 China institute of geographic {2. and Natural Resources {3. Chinese Academy of Sciences Beijing 100101 China Mathematics Department Ocean University of China Qingdao 266071 China Shanghai institute of Plant Physiology and Ecology Chinese Academy of Sciences Shanghai 200032 China

Comparative study of spectral properties of temperature and CO2.fluxes measured by eddy covariance method at Yucheng (3.°57'N, 116°3.'E, 2. m a.s.l., in the North china Plain) and at Lhasa (2.°41'N, 91°2.'E, 3.88 m a.s. 1., on the Tibetan Plateau) is described using the empirical mode decomposition (EMD) method. The main results are: (1) The intrinsic oscillation modes or intrinsic mode functions (IMFs) were extracted from data of temperature ( T) and CO2.fluxes (F) measured at Yucheng ( T1 and F1) and Lhasa ( T2.and F2. . (2. Hilbert transform was applied to these IMF components, then the Hubert-Huang spectra and the marginal spectra of these data were obtained. (3. Comparison of temperature and CO2.fluxes in North china Plain and on Tibetan Plain illustrated that the characteristic frequencies corresponding to T1, F1, T2.and F2.are 0.05 Hz, 0.03.Hz, 0.014 Hz and 0.005 Hz, respectively.

关键词： empirical mode decomposition (EMD) intrinsic mode function (IMF) flux Hilbert transform wheat Tibet.

Indoor imitation experimental study on driving factors of rainfall-runoff process

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Science china Earth sciences 2005年第3期48卷 417-428页

作者： ZHANG Shifeng1, LIU Changming 1, XIA Jun1, TAN Ge 1, LI Lin1, LIU Caitang1, ZHOU Changqing 1 & GUO lei2.1. institute of {2. sciences and Natural Resources research, chinese academy of sciences, beijing 100101, china 2. College of Water Resources and Hydropower Engineering, Wuhan University, Wuhan 43.072. china institute of geographic {2. and Natural Resources {3. Chinese Academy of Sciences Beijing China College of Water Resources and Hydropower Engineering Wuhan University Wuhan China

The driving actions of rainfall-runoff process can be attributed to two aspects. The first is the influence of precipitation process, and the second is that of the ground pad. The re- search results of 179 indoor experiments conducted to imitate rainfall-runoff process indicate that both precipitation duration and intensity play important roles in affecting confluence lag time, which is obviously inconsistent with the traditional hypotheses. The nonlinear relationship is of great significance to the confluence curve especially when the precipitation duration is less than the total confluence time or the precipitation intensity is small. Therefore it can be concluded that the unit hydrograph (UH) can be applied to rainfall-runoff process imitation in the humid areas in the south china region. However, the UH application should be strictly modified in accordance with precipitation conditions in the arid and semiarid region of north china where the precipitation duration is short and the intensity is unstable. It will be hard to get ideal imitation results if the UH is applied blindly without considering specific conditions in the north china region. This also explains the unsatisfactory imitation results caused by using various hydrological models in the north china region. When the precipitation duration is short, and the watershed has not reached total watershed concentration, the characteristics of confluence change greatly, which reflects the actual situation in the north china region. Therefore necessary nonlinear corrections should be made when UH is applied. If the duration is longer than the total confluence time and the balance between pondage and discharge is stricken, the imitation research results will be applicable to both rainfall-runoff relation with longer duration in the south china region and the basic theoreti- cal research on runoff generation and concentration. On conditions of adequate rainfall, peak discharge is in linear relationship with inten

关键词： rainfall-runoff, driving factors, indoor imitation, experiment.

Annual variation of carbon flux and impact factors in the tropical seasonal rain forest of Xishuangbanna, SW china

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Science china Earth sciences 2006年第S2期49卷 150-162页

作者： ZHANG Yiping, SHA liqing, YU Guirui, SONG Qinghai, TANG Jianwei, YANG Xiaodong, WANG Yuesi, ZHENG Zheng, ZHAO Shuangju, YANG Zhen & SUN Xiaomin Xishuangbanna Tropical Botanical Garden, chinese academy of sciences, Kunming 6502.3.{2. institute of geographic sciences and National Resources research, chinese academy of sciences, beijing 100101,{2. institute of Atmospheric Physics, chinese academy of sciences, {12. 10002.,{2. Graduate University of chinese academy of sciences, {12. 100049,{2. 1. Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Kunming 650223 China 2. institute of geographic {2. and National Resources research Chinese Academy of Sciences Beijing 100101 China 4. Graduate University of chinese academy of sciences Beijing 100049 China 3. institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

Two years of eddy covariance measurements of above- and below-canopy carbon fluxes and static opaque chamber and gas chromatography technique measurements of soil respiration for three treatments (bare soil, soil+litterfall, soil+litterfall+seedling) were carried out in a tropical seasonal rain forest. In addition, data of photosynthesis of dominant tree species and seedlings, leaf area index, litter production and decomposing speed, soil moisture, soil temperature and photosynthetic photon flux density within the forest were all measured concurrently. Data from January 2.03.to December 2.04 are used to present annual variability of carbon flux and relationships between carbon flux and impact factors. The results show that carbon flux of this forest presented unusual tendency of annual variation; above-canopy carbon fluxes were negative in the dry season (November-April) and mainly positive in the rainy season, but overall the forest is a carbon sink. Carbon flux has obviously diurnal variation in this tropical seasonal rain forest. Above-canopy carbon fluxes were negative in the daytime and absolute values were larger in the dry season than that in the rainy season, causing the forest to act as a carbon sink; at night, carbon fluxes were mainly positive, causing the forest to act as a carbon source. Dominant tree species have greater photosynthesis capability than that of seedlings, which have a great effect on above-canopy carbon flux. There was a significant correlation between above-canopy carbon flux and rate of photosynthesis of tree species. There was also a significant correlation between above-canopy carbon flux and rate of photosynthesis of seedlings; however, the below-canopy carbon flux was only significantly correlated with rate of photosynthesis of seedlings during the hot-dry season. Soil respiration of the three treatments displayed a markedly seasonal dynamic; in addition, above-canopy carbon fluxes correlated well with soil respiration, litterfall

关键词： carbon flux annual variation impact factors tropical seasonal rain forest Xishuangbanna.

A preliminary study on the heat storage fluxes of a tropical seasonal rain forest in Xishuangbanna

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Science china Earth sciences 2006年第S2期49卷 163-173页

作者： DOU Junxia, ZHANG Yiping, YU Guirui, ZHAO Shuangju, WANG Xin & SONG Qinghai Xishuangbanna Tropical Botanical Garden, chinese academy of sciences, Kunming 6502.3. china {2. of geographic sciences and National Resources research, chinese academy of sciences, beijing 100101, china research Centre for Eco-environmental sciences, chinese academy of sciences, {12. 100085, china Graduate University of the chinese academy of sciences, {12. 100049, china 1. Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Kunming 650223 China 3. research Centre for Eco-environmental sciences Chinese Academy of Sciences Beijing 100085 China 4. Graduate University of the chinese academy of sciences Beijing 100049 China 2. institute of geographic {2. and National Resources research Chinese Academy of Sciences Beijing 100101 China

In order to discuss the values and daily variation characteristics of heat storage fluxes in a tropical seasonal rain forest in Xishuangbanna, the sensible and latent heat storage flux within air column, canopy heat storage flux, energy storage by photosynthesis and ground heat storage above the soil heat flux plate, as well as the ratios of these heat storage fluxes to the net radiation in the cool-dry, hot-dry and rainy season were compared and analyzed based on the observation data of carbon fluxes, meteorological factors and biomass within this tropical seasonal rain forest from January 2.03.to December 2.04. The findings showed that heat storage terms ranged significantly in the daytime and weakly in the nighttime, and the absolute values of sensible and latent heat storage fluxes were obviously greater than other heat storage terms in all seasons. In addition, the absolute values of total heat storage fluxes reached the peak in the hot-dry season, then were higher in the rainy season, and reached the minimum in the cool-dry season. The ratios of heat storage fluxes to net radiation generally decreased with time in the daytime, moreover, the sensible and latent heat storage dominated a considerable fraction of net radiation, while other heat storage contents occupied a smaller fraction of the net radiation and the peak value was not above 3.5%. In the daytime, the ratios of the total heat storage to net radiation were greater and differences in these ratios were distinct among seasons before 12.00, and then they became lower and differences were small among seasons after 12.00. The energy closure was improved when the storage terms were considered in the energy balance, which indicated that heat storage terms should not been neglected. The energy closure of tropical seasonal rain forest was not very well due to effects of many factors. The results would help us to further understand energy transfer and mass exchange between tropical forest and atmosphere. Moreo

关键词： heat storage flux energy closure tropical seasonal rain forest Xlshuangbanna.

Mapping forest fire risk zones with spatial data and principal component analysis

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Science china(Technological sciences) 2006年第Z1期49卷 140-149页

作者： XU Dong, Guofan Shao, DAI Limin, HAO Zhanqing, TANG lei & WANG Hui institute of Applied Ecology,{2., Shenyang 110016,{3. Graduate University of{2., beijing 10003.,{3. Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA Department of Management, Shenyang institute of Aeronautical Engineering, Shenyang 11003.,{3. Department of City Development, Jinan University, Jinan 2.0002.{3. institute of Applied Ecology Chinese Academy of Sciences Shenyang China Graduate University of chinese academy of sciences Beijing China Department of Forestry and Natural Resources Purdue University West Lafayette USA Department of Management Shenyang Institute of Aeronautical Engineering Shenyang China Department of City Development Jinan University Jinan China

By integrating forest inventory data with remotely sensed data, new data layers for factors that affect forest fire potentials were generated for Baihe Forestry Bureau in Jilin Province of china. The principle component analysis was used to sort out the relationships between forest fire potentials and environmental factors. The classifications of these factors were performed with GIS, generating three maps: a fuel-based fire risk map, a topography-based fire risk map, and an anthropogenic-factor fire risk map. These three maps were then synthesized to generate the final fire risk map. The linear regression method was used to analyze the relationship between an area-weighted value of forest fire risks and the frequency of historical forest fires at each forest farm. The results showed that the most important factor contributing to forest fire ignition was topography, followed by anthropogenic factors.

关键词： wildfire risk, regression analysis, geographic information system, remote sensing, Baihe Forestry Bureau.

Distributions of arsenic and essential elements in pinna of arsenic hyperaccumulator Pteris vittata L.

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Science china(Life sciences) 2005年第1期48卷 18-24页

作者： CHEN Tongbin, HUANG Zechun, HUANG Yuying & lei Mei Laboratory of Environmental Remediation, institute of {2. {3. and Natural Resources research, chinese academy of sciences, beijing 100101, china Laboratory of Synchrotron Radiation, institute of High Energy Physics, chinese academy of sciences, beijing 10003., china Laboratory of Environmental Remediation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China Laboratory of Synchrotron Radiation Institute of High Energy Physics Chinese Academy of Sciences Beijing100039 China

The distributions of arsenic and 6 essential elements in the pinna of As hyperaccumulator, Pteris vittata L., were studied using synchrotron radiation X-ray fluorescence (SRXRF). Significant correlation between the distribution and mobility of the elements revealed that SRXRF study on the elemental distribution was feasible to inspect the transportations of elements in plants. The distribution of As in the pinna showed that As had great abilities to be transported in xylem vessels and from xylem to mesophyll. The distribution of K, one of the most mobile elements in plants, was similar to that of As, whereas the distributions of Fe and Ca with less mobility in plants were almost opposite to that of As in the pinna.

关键词： hyperaccumulator, chinese brake (Pteris vittata L.), arsenic, element, distribution, SRXRF.

Run off-on-out method and models for soil infiltrability on hill-slope under rainfall conditions

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Science china Earth sciences 2006年第2期49卷 193-201页

作者： lei Tingwu1,2. LIU Han1, PAN Yinghua3. ZHAO Jun2. ZHAO Shiwei2.& YANG Yonghui2.1. The Key Laboratory of Modern Precision Agriculture System Integration research, College of Hydraulic and Civil Engineer-ing,{2. Agricultural University, beijing 100083.{2. 2. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, institute of Soil and Water Conservation, Yangling 712.00,{2. 3. {13. and Resources Management College, Yantai Normal University, Yantai 2.402.,{2. The Key Laboratory of Modern Precision Agriculture System Integration research College of Hydraulic and Civil Engineering China Agricultural University Beijing China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Yangling China geographic and Resources Management College Yantai Normal University Yantai China

The soil infiltrability of hill-slope is important to such studies andpractices as hydrological process, crop water supply, irrigation practices, and soil erosion. A newmethod for measuring soil infiltrability on hill-slope under rainfall condition with run off-on-outwas advanced. Based on water (mass) balance, the mathematic models for soil infiltrability estimatedfrom the advances of runoff on soil surface and the water running out of the slope were *** of 2.cases were conducted. Case Ⅰ was done under a rainfall intensity of 2. mm/h, at aslope gradient of about 0° with a runoff/on length (area) ratio of 1 : 1. Case Ⅱ was under arainfall intensity of 60 mm/h and a slope of 2.° with a runoff/on length (area) ratio of 1 : *** ring method was also used to measure the infiltrability for comparison purposes. Theexperiments were done with soil moisture of 10%. Required data were collected from laboratoryexperiments. The infiltrability curves were computed from the experimental data. The resultsindicate that the method can well conceptually represent the transient infiltrability process, withcapability to simulate the very high initial soil infiltrability. The rationalities of the methodand the models were validated. The errors of the method for the two cases were 1.82./1.3.% and4.49%/3.52.% (Experimental/Model) respectively, as estimated by comparing the rainfall amount withthe infiltrated volume, to demonstrate the accuracy of the method. The transient and steadyinfiltrability measured with double ring was much lower than those with this new method, due towater supply limit and soil aggregates breaking down at initial infiltration stage. The method canovercome the short backs of the traditional sprinkler method and double ring method for soilinfil-traility. It can be used to measure the infiltrability of sloped surface underrainfall-runoff-erosion conditions, in the related studies.

关键词： Infiltrability, runoff-on-out, rainfall, sloped surface, model.

Phylogeography of regional fauna on the Tibetan Plateau: A review

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Progress in Natural Science:Materials International 2009年第7期19卷 789-799页

作者： Shujuan Yanga, Hailiang Dongb,c, Fumin lei d a State Key Laboratory of Geological Processes and Mineral Resources, china University of Geo{2., {3. 100083. china b Geomicrobiology Laboratory, china University of Geo{2., {3. 100083. china c Department of Geology, Miami University, Oxford, OH 45056, USA d institute of Zoology, chinese academy of sciences, beijing 100101, china State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China Geomicrobiology Laboratory China University of Geosciences Beijing 100083 China Department of Geology Miami University Oxford OH 45056 USA institute of Zoology Chinese Academy of Sciences Beijing 100101 China

The studies of uplift and glaciations of the Tibetan Plateau are summarized, and a series of recent case studies of the endemic species based on DNA sequences are detailed. In general, these molecular data show that all the organisms originated from Early Pliocene to Late Miocene, and then multi-stages of divergence/speciation occurred within each taxa following their original occupation on the plateau, mainly as a result of periodic glacial cycles and geographic isolation. The regional fauna may have undergone several range contractions and expansions during the Pleistocene glaciations. However, the population expansion and refugia may vary in space, time, and extent. The regional fauna of the Tibetan Plateau may be combinations of ancient movement from adjacent zoogeographical regions, speciation in situ, and postglacial colonization from adjacent areas. Geomorphic and climatic changes on the plateau definitely have a remarkable influence on the regional and adjacent biogeographic patterns, and the mechanism is very complex.

关键词： Divergence Refugia Postglacial colonization Phylogeography Regional fauna Tibetan Plateau