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Seasonal patterns and environmental control of ecosystem respiration in subtropical and temperate forests in china

Science china Earth sciences 2005年第Z1期48卷 93-105页

作者： YU Guirui, WEN Xuefa, LI Qingkang, ZHANG Leiming, REN Chuanyou, LIU Yunfen & GUAN Dexin chinese Ecosystem Research Network Synthesis Research Center, institute of Geographic sciences and Natural Resources Research, chinese academy of sciences, Beijing 100101, china institute of applied ecology, chinese academy of sciences, shenyang 110016, china Graduate School of the chinese academy of sciences, Beijing 100039, china chinese Ecosystem Research Network Synthesis Research Center Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China chinese Ecosystem Research Network Synthesis Research Center 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 applied ecology Chinese Academy of Sciences Shenyang 110016 China

Continuous measurement of carbon dioxide exchange using the eddy covariance (EC) technique was made at two chinaFLUX forest sites including the young subtropical Pinus plantation (Qianyanzhou) and old temperate broad-leaved Korean pine mixed forest (Changbai Mountains) as part of the chinaFLUX network. Seasonal patterns and environmental control of ecosystem respiration in the subtropical and temperate forests were evaluated by the often-used multiplicative model and do model as a function of temperature and soil water content. The results suggested that (i) temperature was found to be a dominant factor in the ecosystem respiration, and most of the temporal variability of ecosystem respiration was explained by temperature. However, in the drought-stressed ecosystem, soil water content controlled the temporal variability of ecosystem respiration other than temperature effects, and soil water content became a dominat factor when severe drought affected the ecosystem respiration; (ii) the regression models analysis revealed that in the drier soil, ecosystem respiration was more sensitive to soil moisture than was expressed by the often-used multiplicative model. It was possible to accurately estimate the seasonal variation of ecosystem respiration based on the Q10 model; and (iii) annual ecosystem respiration derived from the often-used multiplicative model was 1209 g C m-2 and 1303 g Cm-2, and was consistently a little higher than the Q10 model estimates of 1197 g C m-2 and 1268 g Cm-2 for Qianyanzhou and Changbai Mountains, respectively.

关键词： chinaFLUX, eddy covariance, Q10, drought effects, temperature effects.

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Photosynthesis-transpiration coupling model at canopy scale in terrestrial ecosystem

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Science china Earth sciences 2005年第Z1期48卷 160-171页

作者： REN Chuanyou, YU Guirui, WANG Qiufeng & GUAN Dexin institute of Geographic sciences and Natural Resources Research, chinese academy of sciences, Beijing 100101, china shenyang Agricultural University, shenyang 110161, china institute of applied ecology, chinese academy of sciences, shenyang 110016, 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 shenyang Agricultural University Shenyang 110161 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 institute of applied ecology Chinese Academy of Sciences Shenyang 110016 China

At the hypothesis of big leaf, an ecosystem photosynthesis-transpiration coupling cycle model was established by the scaled SMPT-SB model from single leaf to canopy, and model parameterization methods were discussed. Through simulating the canopy light distribution, canopy internal conductance to CO2 can be scaled from single leaf to canopy by integrating to canopy using the relationship between single internal conductance and photosynthetic photon flux density. Using the data observed by eddy covariance method from the Changbai Mountains site of chinaFLUX, the application of the model at the canopy scale was examined. Under no water stress, the simulated net ecosystem photosynthesis rate fitted with the observed data very well, the slope and R2 of the line regression equation of the observed and simulated values were 0.7977 and 0.8892, respectively (n = 752), and average absolute error was 3.78 μmol CO2 m-2s-1; the slope, R2 and average absolute error of transpiration rate were 0.7314, 0.4355 and 1.60mmol H2O m-2 s-1, respectively (n = 752). The relationship between canopy photosynthesis,transpiration and external environmental conditions was discussed by treating the canopy as a whole and neglecting the comprehensive feedback mechanism within canopy, and it was noted that the precipitation course affected the transpiration rate simulation badly. Compared to the models based on eco-physiological processes, the SMPT-SB model was simple and easy to be used. And it can be used as a basic carbon and water coupling model of soil-plant-atmosphere continuum.

关键词： photosynthesis rate, transpiration rate, SMPT-SB model, internal conductance, canopy scale.

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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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Biore mediation: A review of applications and problems to be resolved

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Progress in Natural Science:Materials International 2004年第11期 1-8页

作者： ZHOU Qixing* and HUA Tao(Key Laboratory of Terrestrial Ecological Process, institute of applied ecology, chinese academy of sciences, shenyang 110016, china) KeyLaboratoryofTerrestrialEcologicalProcess InstituteofAppliedEcologyChineseAcademyofSciencesShenyang110016China

This review article describes the factors affecting bioremediation processes including: goals of bioremediation and the optimal ecological conditions required; inoculation of microorganisms; co-metabolism; bioavailability and its improvement; biological evolution and its utilization; monitoring and control of bioremediation processes; identification of bioremediation effectiveness and ecological remediation and its key elements. The current progress in bioremediation techniques is summarized. The direction of future development, research and applications is also examined.

关键词： polluted environment bioremediation ecological process new research progress.

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Greenhouse Gas Emissions from Northeast china Rice Fields in Fallow Season

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Pedosphere 2007年第5期17卷 630-638页

作者： LIANG Wei SHI Yi ZHANG Hua YUE Jin HUANG Guo-Hong institute of applied ecology Chinese Academy of Sciences Shenyang 110016 （China） Graduate School of the chinese academy of sciences Beijing 10005g （China） College of Resources and Environment Huazhong Agricultural University Wuhan 430070 （China）

CH4, N2O and CO2 emissions from northeast chinese rice fields were measured in the fallow season （November to March） to investigate the effects of freezing-thawing on the emissions. Both CH4 emission from and atmospheric CH4 oxidation by the soil occurred, but the flux was small. During the fallow season, rice fields acted as a minor source of atmospheric CH4, which accounted for about 1% of the CH4 emission during the rice growing period. The field was also a substantial source of atmospheric N20, which ranged between 40 to 77 mg m-2 and eu=counted for 40%-50% of the annual N20 emission. The largest N20 flux was observed in the thawing period during the fallow season. Laboratory incubation tests showed that the largest N20 flux came from the release of N20 trapped in frozen soil. Tillage and rice straw application （either mulched on the soil surface or incorporated in the soil） stimulated the CH4 and CO2 emissions during the fallow season, but only straw application stimulated N2O emission substantially.

关键词： CH4 CO2 freezing-thawing N2O rice field

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Landscape Changes from 1974 to 1995 in the Upper Minjiang River Basin, china

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Pedosphere 2006年第3期16卷 398-405页

作者： HE Xing-Yuan ZHAO Yong-Hua HU Yuan-Man CHANG Yu ZHOU Qi-Xing institute of applied ecology the Chinese Academy of Sciences Shenyang 110016 （China） College of Earth Science ＆ Land Resources Management Chang＇an University Xi＇an 710054 （China） Graduate School of the chinese academy of sciences Beijing 100039 （China）

Landscape changes were traced over the 20 years from 1974 to 1995 in the upper Minjiang River basin, one of the most important forest regions in china, based on satellite image interpretation to provide basic data for local decision-making as well as sustainable landscape use and management. Results revealed that landscape from 1974 to 1995 changed at the regional scale as the area of forestland decreased, while cropland, shrubland, economic forest, grassland, and built-up land increased. Landscape changes mainly occurred in forestland, shrubland, grassland, economic forest, and built-up land. Moreover, the changes among forestland, shrubland, and grassland were the largest, influencing the whole characteristics of the changes in the basin. Analysis of the changes between 1974 and 1995 in the study area indicated that landscape heterogeneity and fragmentation increased, whereas landscape connectivity decreased. There were multiple reasons for landscape changes. A principal component analysis (PCA) was used to quantitatively study driving forces of landscape changes. The PCA results showed that economic and population factors were the principal driving forces of landscape changes from 1974 to 1995 in the upper Minjiang River basin, and that PCA was a suitable method for investigating driving forces of landscape changes.

关键词： driving forces landscape change satellite image quantification principal component analysis

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Surface roughness length dynamic over several different surfaces and its effects on modeling fluxes

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Science china Earth sciences 2006年第S2期49卷 262-272页

作者： ZHOU Yanlian, SUN Xiaomin, ZHU Zhilin, ZHANG Renhua, TIAN Jing, LIU Yunfen, GUAN Dexin & YUAN Guofu Key Laboratory of Ecosystem Network Observation and Modeling, 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 institute of applied ecology, chinese academy of sciences, shenyang 110016, china 1. Key Laboratory of Ecosystem Network Observation and Modeling 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 3. institute of applied ecology Chinese Academy of Sciences Shenyang 110016 China

Roughness length and zero-plane displacement over three typical surfaces were calculated iteratively by least-square method, which are Yucheng Experimental Station for agriculture surfaces, Qianyanzhou Experimental Station for complex and undulant surfaces, and Changbai Mountains Experimental Station for forest surfaces. On the basis of roughness length dynamic, the effects of roughness length dynamic on fluxes were analyzed with SEBS model. The results indicate that, aerodynamic roughness length changes with vegetation conditions (such as vegetation height, LAI), wind speed, friction velocity and some other factors. In Yucheng and Changbai Mountains Experimental Station, aerodynamic roughness length over the fetch of flux tower changes with vegetation height and LAI obviously, that is, with the increase of LAI, roughness length increases to the peak value firstly, and then decreases. In Qianyanzhou Experimental Station, LAI changes slightly, so the relationship between roughness length and LAI is not obvious. The aerodynamic roughness length of Yucheng and Changbai Mountains Experimental Station changes slightly with wind direction, while aerodynamic roughness length of Qianyanzhou Experimental Station changes obviously with wind direction. The reason for that is the terrain in Yucheng and Changbai Mountains Experimental Station is relatively flat, while in Qianyanzhou Experimental Station the terrain is very undulant and heterogeneous. With the increase of wind speed, aerodynamic roughness length of Yucheng Experimental Station changes slightly, while it decreases obviously in Qianyanzhou Experimental Station and Changbai Mountains Experimental Station. Roughness length dynamic takes great effects on fluxes calculation, and the effects are analyzed by SEBS model. By comparing 1 day averaged roughness length in Yucheng Experimental Station and 5 day averaged roughness length of Qianyanzhou and Changbai Mountains Experimental Station with roughness length parameter

关键词： chinaFLUX surface roughness length dynamic spatial heterogeneity Yucheng Experimental Station Qianyanzhou Experimental Station Changbai Mountains Experimental Station.

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UU_* filtering of nighttime net ecosystem CO_2 exchange flux over forest canopy under strong wind in wintertime

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Science china Earth sciences 2005年第Z1期48卷 85-92页

作者： ZHANG Junhui, HAN Shijie, SUN Xiaomin & TANG Fengde 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 Department of Environment and Life sciences, Liaoning University, shenyang 110036, china 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 institute of applied ecology Chinese Academy of Sciences Shenyang 110016 China Department of Environment and Life sciences Liaoning University Shenyang 110036 China

The mechanism of the negative nighttime net CO2 flux in wintertime and reasonable treatment with it is of great importance in evaluating the carbon metabolism of boreal forest. Results, based on the data obtained with open-path eddy covariance system and CO2 profile measurement system from Nov. 2002 to Apr. 2003 and that obtained with five sonic anemometers in Nov. 1999, show that (1) the negative net ecosystem CO2 exchange flux (NEE) always appeared under conditions of strong wind; (2) the pressure fluctuation and horizontal advection flow are dominantly responsible for the negative NEE. Operable upper bound u* filtering method (UU* filtering) was introduced since the difficulties in real-time measuring of pressure fluctuation and horizontal advection fluxes under conditions of strong wind. Nighttime upper u*. threshold for the broad-leaved Korean pine mixed forest of the Changbai Mountains is 0.4 ms-1 and can be applied to the daytime filtering; and (3) the UU* filtering corrected the nighttime 'problem' of negative NEE under strong wind and made the estimates more ecologically reasonable.

关键词： night in wintertime negative NEE eddy-covariance pressure fluctuation UU. filtering

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Spatial Variability of Nutrient Properties in Black Soil of Northeast china

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Pedosphere 2007年第1期17卷 19-29页

作者： ZHANG Xing-Yi SUI Yue-Yu ZHANG Xu-Dong MENG Kai S. J. HERBERT Northeast institute of Geography and Agroecology Chinese Academy of Sciences Harbin 150081 （China） institute of applied ecology Chinese Academy of Sciences Shenyang 110016 （China） Heilongjiang University Harbin 150080 （China） Department of Plant Soil and Insect Sciences University of Massachusetts Amherst MA 01003 （USA）

A total of 1400 soil samples from the plow layer （0-20 cm） at an approximate interval of 5 km were collected in the autumn of 2002 over the entire black soil arable crops region to determine the spatial variability of seven variables, such as total organic matter content （OMC）, total N, total P, total K, alkali-dissolvable N （AN）, available P （AP） and available K （AK）, with classical statistics and geostatistical analysis across the entire black soil area in Northeast china. In nonsampled areas ordinary kriging was utilized for interpolation of estimated nutrient determinations. Classical statistics revealed highly significant （P ≤ 0.01） correlations with all seven of the soil properties, except for OMC with AP and total K with AK. In addition, using coefficients of variation, all soil properties, except for total K, were moderately variable. A geostatistical analysis indicated that structural factors, such as parent material, terrain, and water table, were the main causes of the spatial correlations. Strong spatial correlations were noted with OMC, total N, total P, AN, and AP, while they were moderate for total K and AK. The effective spatial autocorrelation of OMC, total N, total P, and AN ranged from 1 037 to 1353 km, whereas the ranges of total K, AP, and AK were only from 6 to 138 km. The fit of the experimental scmi-variograms to the theoretical models indicated that except for AN, kriging could successfully interpolate other six variables. Thns, the geostatistical method used on a large scale could accurately evaluate the spatial variability of most black soil nutrient properties in Northeast china.

关键词： black soil china geostatistics analysis soil survey spatial variability

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Meteorological control on CO_2 flux above broad-leaved Korean pine mixed forest in Changbai Mountains

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Science china Earth sciences 2005年第Z1期48卷 116-122页

作者： GUAN Dexin, WU Jiabing, YU Guirui, SUN Xiaomin, ZHAO Xiaosong, HAN Shijie & JIN Changjie 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 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

The impacts of temperature, photosynthetic active radiation (PAR) and vapor pressure deficit (VPD) on CO2 flux above broad-leaved Korean pine mixed forest in the Changbai Mountains were studied based on eddy covariance and meteorological factors *** results showed that, daytime CO2 flux was mainly controlled by PAR and they fit Michaelis-Menten equation. Meanwhile VPD also had an influence on the daytime flux. Drier air reduced the CO2 assimilation of the ecosystem, the drier the air, the more the reduction of the assimilation. And the forest was more sensitive to VPD in June than that in July and August. The respiration of the ecosystem was mainly controlled by soil temperature and they fit exponential equation. It was found that this relationship was also correlated with seasons; respiration from April to July was higher than that from August to November under the same temperature. Daily net carbon exchange of the ecosystem and the daily mean air temperature fit exponential equation. It was also found that seasonal trend of net carbon exchange was the result of comprehensive impacts of temperature and PAR and so on. These resulted in the biggest CO2 uptake in June and those in July and August were next. Annual carbon uptake of the forest ecosystem in 2003 was -184 gC. m-2.

关键词： CO2 flux, soil temperature, PAR, broad-leaved Korean pine mixed forest.

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