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On the major proposals for carbon emission reduction and some related issues

Science china Earth sciences 2010年第12期53卷 159-172页

作者： DING ZhongLi1,DUAN XiaoNan2,GE QuanSheng3 & ZHANG ZhiQiang4 1 CAS Key Lab of Cenozoic Geology and Environment,institute of Geology and Geophysics,chinese academy of sciences,beijing 100029,china 2 The General Office of chinese academy of sciences,beijing 100864,china 3 institute of geographic sciences and natural resources research,chinese academy of sciences,beijing 100101,china 4 The Lanzhou Branch of the National Science Library,Scientific Information Center for resources and Environment of CAS,Lanzhou 730000,china 1. CAS Key Lab of Cenozoic Geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China2. The General Office of Chinese Academy of Sciences Beijing 100864 China3. Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China4. The Lanzhou Branch of the National Science Library Scientific Information Center for Resources and Environment of CAS Lanzhou 730000 China

We evaluated and ran simulations for seven proposals for the reduction of global CO2 emissions (e.g.,those of the Intergovernmental Panel on Climate Change (IPCC),United Nations Development Program,and Organization for Economic Cooperation and Development).All the proposals ignored the fact that the cumulative CO2 emissions per capita for developed countries were 7.54 times those for developing countries in the historical period of *** proposals further deliberately allocate 2006-2050 emission quotas to developed countries that are 2.3-6.7 times those to developing *** will seriously violate the development rights of developing *** paper clearly states that proposals such as that of the IPCC are not suitable references for future international climate change negotiations as they violate the fundamentals of fairness and equity in international relationships and the UNFCCC principle of "common but differentiated responsibilities".Comparing estimates of emissions in china in the scenario of rapid development with low-CO2-emission technology in the period 2006-2050 with estimates for other countries and groups,we find that china can logically and morally argue for equivalent emission rights even in the case of the strict CO2 concentration target of 450-470 ppmv.

关键词： CO2 emission reduction cumulative CO2 emission per capita emission rights

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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 geographic sciences and natural resources research, chinese academy of sciences, beijing 100101, china 2. College of Water resources and Hydropower Engineering, Wuhan University, Wuhan 430072, china 1. institute of geographic sciences and natural resources research Chinese Academy of Sciences 100101 Beijing China 2. College of Water resources and Hydropower Engineering Wuhan University 430072 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.

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Establishment of apparent quantum yield and maximum ecosystem assimilation on Tibetan Plateau alpine meadow ecosystem

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Science china Earth sciences 2005年第Z1期48卷 141-147页

作者： 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 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 institute of geographic sciences and natural resources research Chinese Academy of Sciences Beijing 100101 China

The alpine meadow is widely distributed on the Tibetan Plateau with an area of about 1.2×106km2. 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 0.433 mgCO2 · 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.

关键词： Tibetan Plateau, alpine meadow ecosystem, eddy covariance, apparent quantum yield, maximum ecosystem assimilation.

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Effect of water stress on ecosystem photosynthesis and respiration of a Leymus chinensis steppe in Inner Mongolia

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Science china Earth sciences 2006年第S2期49卷 196-206页

作者： FU Yuling , YU Guirui , WANG Yanfen, LI Zhengquan & HAO Yanbin institute of geographic sciences and natural resources research, chinese academy of sciences, beijing 100101, china The Graduate University of chinese academy of sciences, beijing 100049, china institute of Botany, chinese academy of sciences, beijing 100093, china 1. institute of geographic sciences and natural resources research Chinese Academy of Sciences Beijing 100101 China 2. The Graduate University of chinese academy of sciences Beijing 100049 China 3. institute of Botany Chinese Academy of Sciences Beijing 100093 China

Many studies on global climate have forecast major changes in the amounts and spatial patterns of precipitation that may significantly affect temperate grasslands in arid and semi-arid regions. As a part of chinaFLUX, eddy covariance flux measurements were made at a semi-arid Leymus chinensis steppe in Inner Mongolia, china during 2003-2004 to quantify the response of carbon exchange to environmental changes. Results showed that gross ecosystem production (FGEP) and ecosystem respiration (Reco) of the steppe were significantly depressed by water stress due to lack of precipitation during the growing season. Temperature was the dominant factor affecting FGEP and Reco in 2003, whereas soil moisture imposed a significant influence on both Reco and FGEP in 2004. Under wet conditions, Reco showed an exponentially increasing trend with temperature (Q10 = 2.0), but an apparent reduction in the value of Reco and its temperature sensitivity were observed during the periods of water stress (Q10=1.6). Both heat and water stress can cause decrease in FGEP. The sea-sonality of ecosystem carbon exchange was strongly correlated with the variation of precipitation. With less precipitation in 2003, the steppe sequestrated carbon in June and July, and went into a senescence in early August due to water stress. As compared to 2003, the severe drought during the spring of 2004 delayed the growth of the steppe until late June, and the steppe became a CO2 sink from early July until mid-September, with ample precipitation in August. The semi-arid steppe released a total of 9.7 g C·m-2 from May 16 to the end of September 2003, whereas the net carbon budget during the same period in 2004 was close to zero. Long-term measurements over various grasslands are needed to quantify carbon balance in temperate grasslands.

关键词： Leymus chinensis steppe water stress ecosystem respiration gross ecosystem production net ecosystem CO2 exchange.

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A comparison between simulated and measured CO_2 and water flux in a subtropical coniferous forest

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Science china Earth sciences 2006年第S2期49卷 241-251页

作者： GU Fengxue, CAO Mingkui, WEN Xuefa, LIU Yunfen & TAO Bo institute of geographic sciences and natural resources research, chinese academy of sciences, beijing 100101, china Graduate University of the chinese academy of sciences, beijing 100049, china 1. institute of geographic sciences and natural resources research Chinese Academy of Sciences Beijing 100101 China 2. Graduate University of the chinese academy of sciences Beijing 100049 China

Using data from eddy covariance measurements in a subtropical coniferous forest, a test and evaluation have been made for the model of Carbon Exchange in the Vegetation-Soil-Atmosphere (CEVSA) that simulates energy transfers and water, carbon and nitrogen cycles based on ecophysiological processes. In the present study, improvement was made in the model in calculating LAI, carbon allocation among plant organs, litter fall, decomposition and evapotranspiration. The simulated seasonal variations in carbon and water vapor flux were consistent with the measurements. The model explained 90% and 86% of the measured variations in evapotranspiration and soil water content. However, the modeled evapotranspiration and soil water content were lower than the measured systematically, because the model assumed that water was lost as runoff if it was beyond the soil saturation water content, but the soil at the flux site with abundant rainfall is often above water saturated. The improved model reproduced 79% and 88% of the measured variations in gross primary production (GPP) and ecosystem respiration (Re), but only 31% of the variations in measured net ecosystem exchange (NEP) despite the fact that the modeled annual NEP was close to the observation. The modeled NEP was generally lower in winter and higher in summer than the observations. The simulated responses of photosynthesis and respiration to water vapor deficit at high temperatures were different from measurements. The results suggested that the improved model underestimated ecosystem photosynthesis and respiration in extremely condition. The present study shows that CEVSA can simulate the seasonal pattern and magnitude of CO2 and water vapor fluxes, but further improvement in simulating photosynthesis and respiration at extreme temperatures and water deficit is required.

关键词： ecosystem CO2 and water flux CEVSA eddy covariance subtropical coniferous forest.

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Seasonal and annual variation of CO_2 flux above a broad-leaved Korean pine mixed forest

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Science china Earth sciences 2006年第S2期49卷 63-73页

作者： ZHANG Junhui, YU Guirui, HAN Shijie, GUAN Dexin & SUN Xiaomin institute of Applied Ecology, chinese academy of sciences, Shenyang 110016, china institute of geographic sciences and natural resources research, chinese academy of sciences, beijing 100101, china 1. institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China 2. institute of geographic sciences and natural resources research Chinese Academy of Sciences Beijing 100101 China

Long-term measurement of carbon metabolism of old-growth forests is critical to predict their behaviors and to reduce the uncertainties of carbon accounting under changing climate. Eddy covariance technology was applied to investigate the long-term carbon exchange over a 200 year-old chinese broad-leaved Korean pine mixed forest in the Changbai Mountains (128°28’E and 42°24’N, Jilin Province, P. R. china) since August 2002. On the data obtained with open-path eddy covariance system and CO2 profile measurement system from Jan. 2003 to Dec. 2004, this paper reports (i) annual and seasonal variation of FNEE, FGPP and Re; (ii) regulation of environmental factors on phase and amplitude of ecosystem CO2 uptake and release Corrections due to storage and friction velocity were applied to the eddy carbon flux. Lal and soil temperature determined the seasonal and annual dynamics of FGPP and RE separately. VPD and air temperature regulated ecosystem photosynthesis at finer scales in growing seasons. Water condition at the root zone exerted a significant influence on ecosystem maintenance carbon metabolism of this forest in winter. The forest was a net sink of atmospheric CO2 and sequestered -449 g C·m-2 during the study period; -278 and -171 gC·m-2 for 2003 and 2004 respectively. FGPP and FRE over 2003 and 2004 were -1332, -1294 g C·m-2. and 1054, 1124 g C·m-2 respectively. This study shows that old-growth forest can be a strong net carbon sink of atmospheric CO2. There was significant seasonal and annual variation in carbon metabolism. In winter, there was weak photosynthesis while the ecosystem emitted CO2. Carbon exchanges were active in spring and fall but contributed little to carbon sequestration on an annual scale. The summer is the most significant season as far as ecosystem carbon balance is concerned. The 90 days of summer contributed 66.9, 68.9% of FGPp, and 60.4, 62.1% of RE of the entire year.

关键词： old-growth forest eddy-covariance carbon metabolism seasonal and annual dynamics

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Impacts of land-use and climate changes on ecosystem productivity and carbon cycle in the cropping-grazing transitional zone in china

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Science china Earth sciences 2005年第9期 153-165页

作者： GAO Zhiqiang, LIU Jiyuan, CAO Mingkui, LI Kerang & TAO Bo institute of geographic sciences and natural resources research, chinese academy of sciences, beijing 100101 , china

The impact of land-use/land-cover and climate changes on ecosystem productivity and carbon cycle is one of the most important issues in global change studies. In the past 20 years, the climate and land-use in china have changed significantly and have had important ecological consequences, especially in ecologically sensitive regions, e.g. the cropping-grazing transition zone (CGTZ). Here we present a study that used a process-based ecosystem model and data of land-use changes based on remote sensing and of climate change at high spatial and temporal resolution to estimate the impacts of land-use and climate changes on net primary productivity (NPP), vegetation carbon storage, soil heterotrophic respiration (HR), carbon storage and net ecosystem productivity (NEP) in the CGTZ of china. The results show that the warming and decreases in precipitation in CGTZ reduced NPP by 3.4%, increased HR by 4.3%, and re- duced annual mean total NEP by 33.7Tg from the 1980s to the 1990s. Although carbon storage in vegetation and soil was increasing because the mean NPP for the period was higher than HR, the decreasing NEP indicate that climate change reduced the carbon uptake rate. However, land-use changes in this zone caused increases in NPP by 3.8%, vegetation carbon storage by 2.4%, and annual total NEP by 0.59Tg. The land-use changes enhanced ecosystem carbon up- take, but not enough to offset the negative effect of the climate change. The climate change had greater impacts than the land-use change for the whole CGTZ zone, but had smaller impacts than the land-use change in the regions where it occurred.

关键词： cropping-grazing transitional zone ecosystem carbon cycle climate change land-use china.

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Effects of Temperature and Water Saturation on CO_2 Production and Nitrogen Mineralization in Alpine Wetland Soils

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Pedosphere 2009年第1期19卷 71-77页

作者： GAO Jun-Qin OUYANG Hua XU Xing-Liang ZHOU Cai-Ping ZHANG Feng beijing Forestry University Beijing 100083 （China） institute of geographic sciences and natural resources research Chinese Academy of Sciences Beijing 100101 （China） Graduate University of the chinese academy of sciences Beijing 100049 （China）

Relationships between carbon (C) production and nitrogen (N) mineralization were investigated in two alpine wetland soils of the Tibetan Plateau using laboratory incubation under different temperatures (5, 15, 25, and 35 ℃) and water saturation (noninundation and inundation). A significant positive relationship was found between CO2 production and N mineralization under increasing temperatures from 5 to 35 ℃ with the same water saturation condition in the marsh soil (r2 > 0.49, P 0.38, P 0.70, P 0.61, P < 0.013). In conclusion, temperatures and water saturation could regulate the relationship between CO2 production and net N mineralization in the Tibetan alpine marsh and peat soils.

关键词： CO2 production N mineralization temperature water saturation wetland

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Correcting method of eddy covariance fluxes over non-flat surfaces and its application in chinaFLUX

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Science china Earth sciences 2005年第Z1期48卷 42-50页

作者： ZHU Zhilin, SUN Xiaomin, ZHOU Yanlian, XU Jinping, YUAN Guofu & ZHANG Renhua 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 institute of geographic sciences and natural resources research Chinese Academy of Sciences Beijing 100101 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 100039 China

Although Eddy Covariance (EC) technique is one of the best methods for estimating the energy and mass exchanges between underlying surface and atmosphere in micrometeorology, errors and uncertainties still exist without necessary corrections. In this paper, we will focus on the effect of coordinate system on the eddy fluxes. Based on the data observed over four sites (one farmland site, one grassland site and two forest sites), the effects of three coordinate system transforming methods (Double Rotation-DR, Triple Rotation-TR and Planar Fit-PF)on the turbulent fluxes are analyzed. It shows that (i) the corrected fluxes are more or less than the uncorrected fluxes, which is related mainly to the sloping degree of surface, wind speed and wind direction; and (ii) pitch angle has a sinusoidal dependence on wind direction, especially in the regular sloping terrain; and (iii) PF method is something like the simplification of TR or DR,and there are not obvious distinctions in correction in sloping grassland and flat farmland, but PF method is not suitable for uneven and irregular forest sites.

关键词： eddy covariance fluxes, unhomogeneous surfaces, coordinate transform, correction, chinaFLUX.

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Determination of averaging period parameter and its effects analysis for eddy covariance measurements

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Science china Earth sciences 2005年第Z1期48卷 33-41页

作者： SUN Xiaomin, ZHU Zhilin, XU Jinping, YUAN Guofu , ZHOU Yanlian & ZHANG Renhua 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 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 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

It is more and more popular to estimate the exchange of water vapor, heat and CO2fluxes between the land surface and the atmosphere using the eddy covariance technique. To get believable fluxes, it is necessary to correct the observations based on the different surface conditions and to determine relevant techinical parameters. The raw 10 Hz eddy covariance data observed in the Yucheng and Changbai Mountains stations were recalculated by various averaging periods (from 1 to 720 min) respectively, and the recalculated results were compared with the results calculated by the averaging period of 30 mins. Meanwhile, the distinctions of fluxes calculated by different averaging periods were analyzed. The continuous 15 days observations over wheat fields in the Yucheng station were mainly analyzed. The results are shown that: (i) In the Yucheng station, compared with the observations by 30 min, when the averaging period changes from 10 to 60 min, the variations of the eddy-covariance estimates of fluxes were less than 2%; when the averaging period changes less than 10 min, the estimate of fluxes reduced obviously with the reduction of the averaging period (the max relative error was -12%); and when the averaging period exceeds 120 min, the eddy covariance estimates of fluxes will be increased and become unsteady (the max relative error is over 10%); (ii) the eddy covariance estimates of fluxes over wheat field in the Yucheng station suggusted that it is much better to take 10 min as an averaging period in studying diurnal change of fluxes, and take 30min for a long-term flux observation; and (iii) normalized ratio was put forward to determine the range of averaging period of eddy covariance measurements. By comparing the observations over farmlands and those over forests, it is indicated that the increase of eddy covariance estimates over tall forest was more than that over short vegetation when the averaging period increased.

关键词： eddy covariance, various surface conditions, averaging period, parameter, chinaFLUX.

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