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| 1 | Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau显示文摘Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the per- mafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively serious degradation. Furthermore, from the angles of grassland coverage and biological production the variation characteristics of high-cold eco- systems in different representative regions and different geomorphologic units under different climatic conditions were quantitatively assessed. In the future, adopting effective measures to protect permafrost is of vital importance to maintaining the stability of permafrost engineering and alpine cold eco- systems in the plateau. | WANG Genxu1,3 , LI Yuanshou2 , WU Qingbai2 & WANG Yibo3 1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China 2. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 3. Resource and Environment School, Lanzhou University, Lanzhou 730000, China | 2006 | Science China Earth Sciences2006，49，11： | 41 |
| 2 | Characteristics of Karst Ecosystems of Vietnam and Their Vulnerability to Human Impact显示文摘Karst in Vietnam covers an area of about 60,000 km2, i.e. 18 % of the surface of the country. The country has an annual average temperature of 24 ℃, an annual average rainfall of 2300 mm and a relative humidity of about 90%. Karst in Vietnam is typified by peak cluster-depression landscapes ranging in elevation from 200 to over 2000 m. Tower and coastal karst landscapes also exit. Because of naturally favourable conditions, karst ecosystems are diverse and very rich.Higher plants (cormophytes) are abundant. They are represented by approximately 2000 species, 908 genera, 224 families,86 orders and 7 phyla. They form a thick vegetation cover of evergreen tropical rainforest. Knowledge about lower plants is limited. The fauna is rich and diverse. Phyla such as Protozoa, Vermes, Mollusca and Arthropoda are yet ill known.Preliminary results show that the phylum Chordata is represented by 541 species from 80 families, 40 orders and 5 classes.There exist many precious and rare mammals, in particular some endemic species such as Trachypithecuspoliocephalus, T.delacouri, Rhinopithecus avanculus, Rhinolophus rouxi, Seotoma dineties and Silurus cuephuongensis. The class Insecta has about 2000 species.``The fast population growth, particularly in the mountainous areas of the country, triggers an increasing demand for land and therefore threatens the ecosystem. To obtain land for farming, people have cut, burned and destroyed natural forest cover; resulting in occurrence of hazards such as soil-loss, water-loss, flash floods, mud-rock flows, rock-falls, severe drought, water logging and changes of karstic aquifers etc. Poaching precious animals and illegal logging are increasing. In contrast to other natural systems, karst ecosystems cannot be reestablished once damaged. Living karst landscapes will become rocky desert ones without life. Conservation of karstic environmental systems in general and karstic ecosystems in particular should not be the sole vocation of scientists but also a duty and responsibility of authorities and people from all levels. A good example of a multidisciplinary approach to karst-related problems is the implementation of the VietnameseBelgian Karst Project (VBEKAP): 'Rural development in the mountain karst area of NW Vietnam by sustainable water and land management and social learning: its conditions and facilitation'. The aim of this project is to improve living conditions of local people and sustained protection and management of the karst environment and ecosystem. | Do TUYET | 2001 | Acta Geologica Sinica(English Edition)2001，75，3： | 27 |
| 3 | Establishment of apparent quantum yield and maximum ecosystem assimilation on Tibetan Plateau alpine meadow ecosystem显示文摘The alpine meadow is widely distributed on the Tibetan Plateau with an area of about 1.2×106kn2. Damxung County, located in the hinterland of the Tibetan Plateau, is the place covered with this typical vegetation. An open-path eddy covariance system was set up in Damxung rangeland station to measure the carbon flux of alpine meadow from July to October,2003. The continuous carbon flux data were used to analyze the relationship between net ecosystem carbon dioxide exchange (NEE) and photosynthetically active radiation (PAR), as well as the seasonal patterns of apparent quantum yield (α) and maximum ecosystem assimilation (Pmax).Results showed that the daytime NEE fitted fairly well with the PAR in a rectangular hyperbola function, with α declining in the order of peak growth period (0.0244 μmolCO2 · μmol-1pAR) >early growth period > seed maturing period > withering period (0.0098 μmolCO2 · μmol-1pAR).The Pmax did not change greatly during the first three periods, with an average of 0.433mgCO2· m-2· s-1, i.e. 9.829 μmolCO2· m-2· s-1. However, during the withering period, Pmax was only 0.35 mgCO2 · m-2 · s-1, i.e. 7.945 μmolCO2 · m-2 · s-1. Compared with other grassland ecosystems, the α of the Tibetan Plateau alpine meadow ecosystem was much lower. | XU Lingling, ZHANG Xianzhou, SHI Peili & YU Guirui Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China Graduate School of the Chinese Acedemy of Sciences, Beijing 100039, China | 2005 | Science China Earth Sciences2005，48，z1： | 23 |
| 4 | Nutrients concentration and changes in decade-scale in the central Bohai Sea显示文摘The nutrients contents and distributions are discussed briefly, based on the data obtained in 1998~1999. Besides explanation of the results,a 20 a time series data of nutrients and biological parameters for central Bohai Sea are reviewed. It is found that both concentration and relative content of nutrients have been changed dramatically. The increase of nitrogen and decrease of phosphate and silicate led to the dramatically increase of N/P ratio and the decrease of Si/N ratio. The situation of nitrogen limiting in central Bohai Sea is gradually changing to that of relative lack of phosphate and silicate. The decrease of the Huanghe River input to the Bohai Sea may be responsible for this change. These in turn may limit the growth of diatom and thus promote the development of pyrrophyta if other conditions (e.g. temperature and hydrodynamics) are suitable. We conclude that this may be the major inducement factor of pyrrophyta red tide in the Bohai Sea. | Yu Zhigang 1,Mi Tiezhu 1,Yao Qingzhen 1,Xie Baodong 1,Zhang Jing 11 .CollegeofChemistryandChemicalEngineering ,OceanUniversityofQingdao ,Qingdao 2 6 6 0 0 3 ,China | 2001 | Acta Oceanologica Sinica2001，20，1： | 18 |
| 5 | Experimental study on soil CO_2 emission in the alpine grassland ecosystem on Tibetan Plateau显示文摘The Tibetan Plateau, the Roof of the World, is the highest plateau with a mean elevation of 4000 m. It is characterized by high levels of solar radiation, low air temperature and low air pressure compared to other regions around the world. The alpine grassland, a typical ecosystem in the Tibetan Plateau, is distributed across regions over the elevation of 4500 m. Few studies for carbon flux in alpine grassland on the Tibetan Plateau were conducted due to rigorous natural conditions. A study of soil respiration under alpine grassland ecosystem on the Tibetan Plateau from October 1999 to October 2001 was conducted at Pangkog County, Tibetan Plateau (31.23°N, 90.01°E, elevation 4800 m). The measurements were taken using a static closed chamber technique, usually every two weeks during the summer and at other times at monthly intervals. The obvious diurnal variation of CO2 emissions from soil with higher emission during daytime and lower emission during nighttime was discovered. Diurnal CO2 flux fluctuated from minimum at 05:00 to maximum at 14:00 in local time. Seasonal CO2 fluxes increased in summer and decreased in winter, representing a great variation of seasonal soil respiration. The mean soil CO2 fluxes in the alpine grassland ecosystem were 21.39 mgCO2 · m-2 · h-1, with an average annual amount of soil respiration of 187.46 gCO2 · m-2 · a-1. Net ecosystem productivity is also estimated, which indicated that the alpine grassland ecosystem is a carbon sink. | ZHANG Xianzhou SHI Peili LIU Yunfen OUYANG Hua | 2005 | Science China Earth Sciences2005，48，z1： | 18 |
| 6 | Advances in carbon flux observation and research in Asia显示文摘As an important component of FLUXNET, Asia is increasingly becoming the hotspot in global carbon research for its vast territory, complex climate type and vegetation diversity. The present three regional flux observation networks in Asia (i.e. AsiaFlux, KoFlux and ChinaFLUX)have 54 flux observation sites altogether, covering tropic rainforest, evergreen broad-leaved forest, broad-leaved and coniferous mixed forest, shrubland, grassland, alpine meadow and cropland ecosystems with a latitudinal distribution from 2°N to 63°N. Long-term and continuous fluxes of carbon dioxide, water vapor and energy between the biosphere and atmosphere are mainly measured with eddy covariance technique to (1) quantify and compare the carbon, water and energy budgets across diverse ecosystems; (2) quantify the environmental and biotic controlling mechanism on ecosystem carbon, water and energy fluxes; (3) validate the soil-vegetation-atmosphere model; and (4) serve the integrated study of terrestrial ecosystem carbon and water cycle. Over the last decades, great advancements have been made in the theory and technology of flux measurement, ecosystem flux patterns, simulation and scale conversion by Asian flux community. The establishment of ChinaFLUX has greatly filled the gap of flux observation and research in Eurasia. To further promote the flux measurement and research,accelerate data sharing and improve the data quality, it is necessary to present a methodological system of flux estimation and evaluation over complex terrain and to develop the integrated research that combines the flux measurement, stable isotope measurement, remote sensing observation and GIS technique. It also requires the establishment of the Joint Committee of Asian Flux Network in the Asia-Pacific region in order to promote the cooperation and communication of ideas and data by supporting project scientists, workshops and visiting scientists. | YU Guirui, ZHANG Leiming, SUN Xiaomin, FU Yuling & LI Zhengquan Synthesis Center of Chinese Ecosystem Research Network (CERN), Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China Graduate School of the Chinese Academy of Sciences, Beijing 100039, China | 2005 | Science China Earth Sciences2005，48，z1： | 16 |
| 7 | Measurement of ecological capital of Chinese terrestrial ecosystem based on remote sensing显示文摘The biosphere of the Earth is essential to human survival and development. The services of ecosystems are critical to the functioning of the Earth’s life-support system. They contribute to human welfare both directly and indirectly. Ecological capital refers to the sum of the direct biological resources value and the indirect ecosystem services value. It is necessary to estimate the ecological capital in order to bring it to the society and market economic system, and draw the social attention to ecological environment constructions. An estimation model for eco-logical capital based on remote sensing is presented in this paper. The parameters in the model are quantitatively measured using NOAA/AVHRR and other ancillary data, including the land cover types, the vegetation coverage, and the vegetation net primary productivity (NPP) of ter-restrial ecosystem. Based on the economic parameters in previously published studies and a few original calculations, the annual ecological capital of the entire terrestrial ecosystem of China is quantitatively estimated at 6.44 trillion (1012) yuan (RMB), and the spatial distribution of the eco-logical capital is also analyzed. Traditional ecological methods to ecological capital measurement are based on homogeneous plot scales, and the regional scaling is a key problem in their appli-cations. As the proposed remote sensing approach, it provides a new method to ecological capital measurement completely based on observation data. It can not only overcome the re-gional scaling problem easily, but also allows the ecological capital to be estimated objectively and spatial-explicitly. | PAN Yaozhong SHI Peijun ZHU Wenquan GU Xiaohe FAN Yida LI Jing | 2005 | Science China Earth Sciences2005，48，6： | 14 |
| 8 | Characterizing CO_2 fluxes for growing and non-growing seasons in a shrub ecosystem on the Qinghai-Tibet Plateau显示文摘To assess carbon budget for shrub ecosystems on the Qinghai-Tibet Plateau, CO2flux was measured with an open-path eddy covariance system for an alpine shrub ecosystem during growing and non-growing seasons. CO2 flux dynamics was distinct between the two seasons. During the growing season from May to September, the ecosystem exhibited net CO2uptake from 08:00 to 19:00 (Beijing Standard Time), but net CO2 emission from 19:00 to 08:00.Maximum CO2 uptake appeared around 12:00 with values of 0.71, 1.19, 1.46 and 0.67 g CO2m-2 h-1 for June, July, August and September, respectively. Diurnal fluctuation of CO2 flux showed higher correlation with photosynthetic photon flux density than temperature. The maximum net CO2 influx occurred in August with a value of 247 g CO2 m-2. The total CO2 uptake by the ecosystem was up to 583 g CO2 m-2 for the growing season. During the non-growing season from January to April and from October to December, CO2 flux showed small fluctuation with the largest net CO2 efflux of 0.30 g CO2 m-2 h-1 in April. The diurnal CO2 flux was close to zero during most time of the day, but showed a small net CO2 efflux from 11:00 to 18:00. Diurnal CO2 flux, is significantly correlated to diurnal temperature in the non-growing season. The maximum monthly net CO2 efflux appeared in April, with a value of 105 g CO2 m-2. The total net CO2 efflux for the whole non-growing season was 356 g CO2 m-2. | XU Shixiao, ZHAO Xinquan, FU Yuling, ZHAO Liang, LI Yingnian, CAO Guangmin, GU Song, WANG Qinxue & DU Mingyuan Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, China Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China Graduate School of the Chinese Academy of Sciences, Beijing 100136, China National Institute for Environmental Studies, Tsukuba 305-8569, Japan National Institute for Agro-Environmental Science, Tsukuba 305-8604, Japan | 2005 | Science China Earth Sciences2005，48，z1： | 12 |
| 9 | Distributions of fatty acids in a stalagmite related to paleoclimate change at Qingjiang in Hubei,southern China显示文摘Fatty acids extracted from a subtropical stalagmite at Qingjiang in Southern China’s Hubei Province were analysed using gas chromatography-mass spectrometry. These n-alkanoic acids range from C14 to C26 in carbon number, maximizing at C16, with a second dominance at C22. In contrast to the stalagmite analysed, the overlying soils are characterized by the dominance of heavy-molecular-weight homologues (>C20). The n-fatty acids in the stalagmite were proposed to be contributed by both the soil ecosystems and the microbes harboring in the percolating water and the cave. The ratios of unsaturated to saturated n-fatty acids (C16:1i/C16:0, C18:1/C18:0) appear to show trends comparable with the oxygen isotope records of the stalagmite carbonate, with enhanced values associated with the cold episode such as Heinrich event 1. This paleoclimate-dependent record of the n-fatty acids might reflect microbial changes in physiology and activity in response to the temperature. This record shows somewhat difference from the previous paleoclimate signal extracted from n-alkanols and n-alkan-2-ones of the same stalagmite. The acid record fails to document the well-known Younger Dryas event which was effectively shown by the latter two biomarkers derived from soil ecosystems. This discrepancy might result from the changing biogeochemical impact on different lipid fractions as well as the varied organism populations in different ecosystems. | XIE Shucheng1,HUANG Junhua1,WANG Hongmei2,YI Yi1,HU Chaoyong1, CAI Yanjun3 & CHENG Hai4 1. Faculty of Earth Science,China University of Geosciences,Wuhan 430074,China 2. School of Environmental Studies,China University of Geosciences,Wuhan 430074,China 3. SKLLQG,Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710075,China 4. Department of Geology and Geophysics,University of Minnesota,MN55455,USA | 2005 | Science China Earth Sciences2005，48，9： | 12 |
| 10 | Ecohydrological change mechanism of a rainfed revegetation ecosystem at southeastern edge of Tengger desert,Northwest China显示文摘Study is made on a 45 km-long artificial ecosystem without irrigation in Tengger desert on the basis of long-term ecological monitoring and ecohydrological fundamentals.Changes in water allocation, utilization, cycle and balance patterns in more than 40-year evolution of the soil-plant system are analyzed. The formation of a drought horizon in shrub rhizosphere and its effect, ecohydrological function of the crust and its effect on the soil-plant system change are discussed. Driven by water self-regulation and water stress, the soil-plant system is going to develop towards the steppe desert to ensure more effective use and optimum collocation of water resource. | XIAO Honglang CHENG Guodong LI Xinrong SONG Yaoxuan WANG Xinping | 2004 | Science China Earth Sciences2004，47，z1： | 9 |
| 11 | Water demand for ecosystem protection in rivers with hyper-concentrated sediment-laden flow显示文摘Sediment transport is one of the main concerns in a river system with hyper-concentrated flows. Therefore, the water use for sediment transport must be considered in study on the water demand for river ecosystem. The conventional methods for calculating the Minimum Water Demand for River Ecosystem (MWDRE) are not appropriate for rivers with high sediment concentration. This paper studied the MWDRE in wet season, dry season and the whole year under different water-and-sediment conditions in the Lower Yellow River, which is regarded as a typical river with sediment-laden flows. The characteristics of MWDRE in the river are analyzed. Firstly, the water demand for sediment transport (WDST) is much larger than the demands for other riverine functions, the WDST accounts for the absolute majority of the MWDRE. Secondly, in wet season when the WDST is satisfied, not only most of the annual incoming sediment can be transported downstream, but also the water demands for other river functions can be satisfied automatically, so that the MWDRE in wet season is identical to the WDST. Thirdly, in dry season, when the WDST is satisfied, the water demands for other river functions can also be satisfied, but the low sediment transport efficiency results in significant waste of water resources. According to these characteristics and aiming at decreasing sediment deposition in the riverbed and improving the utilization efficiency of water resources, hydrological engineering works can be used to regulate or control flow and sediment so that the sediment incoming in dry season can be accumulated and be transported downstream intensively and thus efficiently in wet season. | LUO Huaming, LI Tianhong, NI Jinren & WANG Yudong Department of Environmental Engineering, Peking University, Beijing 100871, China The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China | 2004 | Science China(Technological Sciences)2004，47，z1： | 8 |
| 12 | Pioneer organisms after F-F mass extinction in Dushan region,Guizhou Province,and their significance in establishing new ecosystem显示文摘After mass extinctions, most areas became “ecologically barren areas” lacking or even without ecosystem over an extensive region. Studying the pioneer organisms and the reconstruction process of a new ecosystem in the “ecologically barren area” is very important for revealing the evo- lution after bio-mass extinctions. In the Dushan region, Guizhou Province, China, the trace fossils appeared and flourished evidently earlier than body fossils after Frasnian-Famennian (F-F) mass extinction. The pioneer organisms and pathfinders in the “ecologically barren areas” are the trace-makers that are deposit-feeders with relatively simple structure and conformation on or near the deposit surface. The trace-makers have undergone an evolutionary process that their trace structures changed from simple to complex, and their living and moving areas and spaces enlarged from linear to planar and then to three-dimension spaces. Those characters show that the ability of the trace-makers to deposits and their efficiency of looking for food have been enhanced gradually and that those trace-makers constructed gradually a base for the new ecosystem. This process is similar to that of the trace fossils near the Precambrian-Cambrian boundary. In the Dushan area, only the recovery intervals have been identified for the Famennian body fossils, with no eminent radiation interval recognizable due to the Devonian-Carboniferous (C-D) mass ex- tinction. However, both the recovery and radiation intervals may be clearly recognized in the Famen- nian trace fossils based on their conformation and diversity. The evolution and diversification of the trace fossils in the “ecologically barren area” is considered to have played a role of necessary foun- dation for the recovery of body fossils in the ecological chain. With the gradual disappearance of the unfavourable environment factors resulting in the F-F mass extinction, a new ecosystem was reconstructed in the “ecologically barren area” through a three-step process from the “original ecosystem” to “elementary ecosystem” and finally to the “developed eco- system”. The establishment of the new ecosystem has laid a foundation for the recovery of the body fossils thereafter. | WANG Yue1, 2, WANG Xunlian1 & SHI Xiaoying1 1. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China 2. School of Resources and Environment, Guizhou University, Guiyang 550003, China | 2006 | Science China Earth Sciences2006，49，5： | 7 |
| 13 | Numerical analysis of the source-sink alternation of composite global warming potential of the paddy ecosystem in the Yangtze Delta显示文摘By coupling the biogeochemical model with plant ecological model, a model was established to reveal the principle of the composite global warming potential transformation in the paddy ecosystem. Validation of the model with the observed data indicated that the model can simulate both the crop growth processes and emissions of CH4 and N2O accurately. Some nu-merical analyses were made to identify the impacts of different fertilizer application on assimilation of CO2 and emissions of CH4 and N2O, and the transformation principle of the composite global warming potential. Based on the results of the numerical analysis, the source-sink alternation of composite global warming potential in the paddy ecosystem was discovered, and some new con-ceptions of fertilizer index such as maximum-sink fertilizer, zero-emission fertilizer are put forward in this paper. The fertilizer scheme for Yangtze Delta was proposed to provide the important scien-tific basis for a sustainable agriculture in this region. | 刘建栋 周秀骥 于强 | 2003 | Science China Earth Sciences2003，46，4： | 5 |
| 14 | A simulation analysis on pelagic-benthic coupling ecosystem of the northern Jiaozhou Bay, Qingdao, China显示文摘 | Wu Zengmao, Zhai Xuemei, Zhang Zhinan, Yu Guangyao, Zhang Xinling, Gao Shanhong 1. College of Physical and Environmental Oceanography, Ocean University of Qingdao, Qingdao 266003, China 2. College of Marine Biology Science, Ocean University of Qi | 2001 | Acta Oceanologica Sinica2001，20，3： | 2 |
| 15 | On the variation of water resource structure in the Lower Yellow River显示文摘In view of river functions and the Minimum Water Demand for River Ecosystem (MWDRE), the water resources in the Lower Yellow River is further divided into three portions, i.e. water available for ecosystem (WE), water exploitable for socioeconomic purposes (WS) and excess flood water (WF). Corresponding conceptions and practical significances are expounded in details. The annual amount of the three portions of water resources from 1950 to 2001 is worked out on the basis of the daily hydrologic data, and the division of different portions is discussed. The results indicate that although the essential water demand for river functions is considered preferentially, the amount of the WE has decreased dramatically while its proportion increased gradually since the 1950s, and the shortage to the MWDRE increased markedly; both the amount and the proportion of the WS decreased notably. Since the 1990s, the actual water consumption for socioeconomic purposes in the lower reaches of the river basin has already exceeded the maximum amount of the WS and has to take over the WE which is already insufficient, hence not only the normal river functions are further disturbed and the river course shrinks greatly, but also the proportion and potential danger of the WF show no decreasing tendency in spite of the sharp decrease of upstream runoff. | NI Jinren1, WANG Yudong1, QIAN Zhenghan1, LI Tianhong1 & ZHAO Yean2 1. Department of Environmental Engineering, Peking University The Key Laboratory of Water and Sedi- ment Sciences, Ministry of Education, Beijing 100871, China 2. Institute of Hydraulic Research, Yellow River Conservancy Commission, Zhengzhou 450003, China | 2004 | Science China(Technological Sciences)2004，47，z1： | 2 |
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