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Effects of Irrigation Schedules on Photosynthetic Carbon Assimilation of Winter Wheat (Triticum aestivum L.) in North China Plain:from Leaf to Population

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Journal of Northeast Agricultural University(English Edition) 2012年第4期19卷 20-29页

作者： Liu Li-Ping Ouyang Zhu Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographical Sciences and Natural Resources ResearchChineseAcademy of Sciences Graduate University of Chinese Academy of Sciences

A field experiment was conducted to elucidate the regulation mechanism of different irrigation schedules on population photosynthetic of winter wheat. The experiment included five irrigation schedules, such as no irrigation （W0）, irrigation once at jointing （W1j） or at booting （W1b）, irrigation twice at jointing and booting （W2）, and irrigation three times at jointing, booting and grain-filling （W3） and three planting densities, such as 180 （D1）, 300 （D2） and 450 （D3） seedlings per square meter. The results indicated that irrigation significantly improved population photosynthesis. The relationship between population photosynthesis and irrigation time/volume was to some extent parabolic. Improvements in population photosynthesis （resulting from more irrigation time/volume） were mainly related to increase in leaf area index and population light interception. Population photosynthesis exhibited a significantly negative correlation with canopy light transmittance. Population photosynthesis at grain filling stage was significantly positively correlated with dry matter accumulation at post-anthesis and grain yield. Main effects and partial correlation analysis showed that population photosynthesis of W0, W1j, W1b and W3 were regulated by canopy light transmittance and leaf area. On the other hand, population photosynthesis of W2 was mainly influenced by flag leaf photosynthetic rate. On this basis, planting 300 seedlings per square meter was the optimum combination. The combination of W2D2 increased population photosynthesis during mid-late growth stages and extended high population photosynthesis duration, which ultimately increased grain yield.

关键词： population photosynthesis leaf photosynthesis leaf area index canopy light transmittance dry matter accumulation at post-anthesis grain yield irrigating schedule

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Effects of Permafrost Degradation on Soil Hydrological Processes in Alpine Steppe on the Qinghai-Tibet Plateau

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Chinese Journal of Population,Resources and Environment 2012年第3期10卷 54-61页

作者： Yin Zhifang Ouyang Hua Yang Zhaoping Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100049China Graduate University of the Chinese Academy of Sciences Beijing 100049China Integrated Water and Hazards Management International Centre for Integrated Mountain Development(ICIMOD)Kathmandu Nepal

Permafrost degradation is prevalent on the Qinghai-Tibet *** may lead to changes in water and heat transition in soils and thus affect the structure and function of *** this paper,using the measured data of alpine steppe in Wudaoliang assessed the model performance in simulating soil freezing and thawing *** of the simulated results by simultaneous heat and water(SHAW) model to the measured data showed that SHAW model performed *** on analyzing the simulated and predicted results,two points were obtained:(1) freezing and thawing of the active layer proceeded both from the soil surface *** with the freezing process,the thawing process was *** freezing period persisted in the surface layer(4 cm depth) for about 5 months;(2) in the next 50 years,frozen period would be shorten about 20 days in the top 100 cm depth while the thawing would start earlier 40 days than *** water storage in the 0-60 cm would decrease by 22% averagely,especially from June to August when the vegetation is at the dominating water consumed ***,this kind of permafrost degradation as active layer freezing and thawing processes changes will reduce soil water content and thus influence those ecosystems above it.

关键词： Qinghai-Tibet Plateau permafrost degradation SHAW model soil water content

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Land-use impact on soil carbon and nitrogen sequestration in typical steppe ecosystems, Inner Mongolia

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Journal of Geographical Sciences 2012年第5期22卷 859-873页

作者： HE Nianpeng ZHANG Yunhai DAI Jingzhong HAN Xingguo BAOYIN Taogetao YU Guirui Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic: Sciences and Natural Resources Research CAS Beijing 100101 China State Key Laboratory of Vegetation and Environmental Change Institute of Botany CASBeijing 100093 China Inner Mongolia Agricultural University Hohhot 010018 China Institute of Natural Resources Inner Mongolia University Huhhot 010021 China

To explore the optimal land-use for soil carbon （C） sequestration in Inner Mongolian grasslands, we investigated C and nitrogen （N） storage in soil and soil fractions in 8 floristi- cally and topographically similar sites which subjected to different lancl-use types （free-grazing, grazing exclusion, mowing, winter grazing, and reclamation）. Compared with free-grazing grasslands, C and N storage in the 0-50 cm layer increased by 18.3% （15.5 Mg C ha-1） and 9.3% （0.8 Mg N ha-1） after 10-yr of grazing exclusion, respectively, and 21.9% （18.5 Mg C ha-1） and 11.5% （0.9 Mg N ha-1） after 30-yr grazing exclusion, respectively. Similarly, soil C and N storage increased by 15.3% （12.9 Mg C ha-1） and 10.2% （0.8 Mg N ha-1） after 10-yr mowing, respectively, and 19.2% （16.2 Mg C ha-1） and 7.1% （0.6 Mg N ha-1） after 26-yr mowing, respectively. In contrast, soil C and N storage declined by 10.6% （9.0 Mg C ha-1） and 11.4% （0.9 Mg N ha-1） after 49-yr reclamation, respectively. Moreover, increases in C and N storage mainly occurred in sand and silt fractions in the 0-10 cm soil layer with grazing exclusion and mowing. Our findings provided evidence that Inner Mongolian grassslands have the capacity to sequester C and N in soil with improved management practices, which were in the order： grazing exclusion 〉 mowing 〉 winter grazing 〉 reclamation.

关键词： carbon grazing land-use nitrogen reclamation soil fractions

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Spatial simulation of soil total potassium in regional scale for Loess Plateau Region

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Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering 2012年第22期28卷 132-140页

作者： Liu, Zhipeng Shao, Ming'an Wang, Yunqiang State Key Laboratory of Soil Erosion and Dry-Land Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources Yangling 712100 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

To understand the spatial heterogeneity of soil total potassium in regional scale for Loess Plateau Region and its influencing factors, In the study, a total of 283 sampling sites were investigated in order to estimate the spatial variation of soil total potassium (STK) across the entire Loess Plateau (620, 000 km2). Spatial simulation and classical linear regression were used to quantify the relationships between STK and bulk density, clay and silt content, soil pH, precipitation, temperature, and elevation. The best state-space models explained more than 97% of the STK variation, while the best linear regression model explained less than 26% of the STK variation. The results showed that all the state-space models described the spatial variation of STK much better than that of the corresponding linear regression models. Spatial simulation is recommended as a useful tool for quantifying spatial relationships between soil properties and the other environmental factors in large-scale regions.

关键词： Linear regression

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Erratum to “Seasonal change of non-point source pollution-induced bioavailable phosphorus loss: A case study of Southwestern China”

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Journal of Hydrology 2012年 438-439卷 234-235页

作者： Yang Gao Bo Zhu Tao Wang Yafeng Wang Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China Institute of Mountain Hazards and Environment CAS Chengdu 610041 China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences CAS Beijing 100085 China

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Dynamics of soil organic carbon in alpine meadow of Tibetan Plateau with CENTURY model

Dynamics of soil organic carbon in alpine meadow of Tibetan ...

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International Conference on Business Management and Electronic Information (BMEI)

作者： Li, Xiaojia Zhang, Xianzhou Zhao, Yuping Zhang, Yangjian Shen, Zhenxi Wang, Jingsheng Wu, Jianshuang Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Graduate University Chinese Academy of Science Beijing China

ISBN: (纸本)9781612841069

The estimation of soil organic carbon(SOC) densities and dynamics is necessary to understand terrestrial carbon cycle and carbon budget. The relative research on the Tibetan Plateau was few and uncertainty of the SOC densities and dynamics. The dynamics of soil organic carbon and its fractions, including active, slow and passive pools, were simulated using CENTURY model in alpine meadow at Damxung on Tibetan Plateau. Results showed that the SOC density in surface soil (0-20cm) was approximately 3292.2015.78g/m2 in alpine meadow. The study simulated the change process of soil organic carbon and its components. Active, slow and passive soil organic carbon were respectively stable in 76.07-100.55g/m2, 1913.05-2008.05g/m2, 1312.47-1320.76g/m2 in equilibrium state. Soil organic carbon decreased in the past 30 years and slightly decreased in the future 100 years using CENTURY model. Results of this study indicated that CENTURY model was applied to alpine meadow ecosystem. This suggest that CENTURY model is a uesful tool for alpine meadow ecosystem study. While our study represents a case study, the results suggest that CENTURY model studies in alpine meadow can help to evaluate the dynamics of SOC and the grassland management. © 2011 IEEE.

关键词： ecosystems

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Effect of solar radiation on net ecosystem CO_2 exchange of alpine meadow on the Tibetan Plateau

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Journal of Geographical Sciences 2011年第4期21卷 666-676页

作者： FAN Yuzhi ZHANG Xianzhou WANG Jingsheng SHI Peili Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

On the Tibetan Plateau, the alpine meadow is the most widespread vegetation type. The alpine meadow has a low biological productivity and low vegetation coverage in the growing season. The daytime NEE between the atmosphere and the alpine meadow ecosystem was influenced by solar radiation. To analyze the characteristics of change in NEE and to calculate the parameters related to photosynthesis and respiration in different solar radiation environments, the NEE measurements were taken in Damxung from July to August in 2003, 2004, 2005 and 2006 using the eddy covariance technique. Solar radiation was grouped into three levels according to the net radiation, which was more than 155 W m-2 d-1 on clear days, 144±5 W m-2 d-1 on partly cloudy days and less than 134 W m-2 d-1 on cloudy days. The diurnal relationships between NEE and PAR varied with differences in solar radiation, which was a rectangular hyperbola form on clear days, two different concave curves on partly cloudy days and an irregular triangle form on cloudy days. The mean CO2 absorption rate showed a decreasing trend with increasing solar radiation. The daytime absorption maximum occurred around 10：00 on clear days with an average of slightly less –0.2 mg m-2 d-1, around 11：00 on partly cloudy days with an average of about –0.2 mg m-2 d-1, and around 12：00 on cloudy days with an average of about –0.25 mg m-2 d-1. As solar radiation increased, the Amax and the Q10 decreased. However, the R10 increased and the maximum of the α occurred on partly cloudy days. The optimum net solar radiation was about 134–155 W m-2 d-1, which induced a PAR of about 1800-2000 μmol m-2 s-1 and soil temperature at a depth of 5 cm of about 14℃. Therefore, on the Tibetan Plateau, the alpine meadow ecosystem will have a higher carbon absorption potential while solar radiation decreases in the future.

关键词： Tibetan Plateau alpine meadow net ecosystem CO2 exchange solar radiation

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Patterns and driving factors of WUE and NUE in natural forest ecosystems along the North-South Transect of Eastern China

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Journal of Geographical Sciences 2011年第4期21卷 651-665页

作者： SHENG Wenping REN Shujie YU Guirui FANG Huajun JIANG Chunming ZHANG Mi Key Laboratory of Ecosystem Network Observation and Modeling Synthesis Research Center of Chinese Ecosystem Research Network Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100094 China Institute of Applied Ecology CAS Shenyang 110016 China

From July 2008 to August 2008, 72 leaf samples from 22 species and 81 soil samples in the nine natural forest ecosystems were collected, from north to south along the North-South Transect of Eastern China （NSTEC）. Based on these samples, we studied the geographical distribution patterns of vegetable water use efficiency （WUE） and nitrogen use efficiency （NUE）, and analyzed their relationship with environmental factors. The vegetable WUE and NUE were calculated through the measurement of foliar δ 13C and C/N of predominant species, respectively. The results showed：（1） vegetable WUE, ranging from 2.13 to 28.67 mg C g-1 H2O, increased linearly from south to north in the representative forest ecosystems along the NSTEC, while vegetable NUE showed an opposite trend, increasing from north to south, ranging from 12.92 to 29.60 g C g-1 N. （2） Vegetable WUE and NUE were dominantly driven by climate and significantly affected by soil nutrient factors. Based on multiple stepwise regression analysis, mean annual temperature, soil phosphorus concentration, and soil nitrogen concentration were responding for 75.5% of the variations of WUE （p0.001）. While, mean annual precipitation and soil phosphorus concentration could explain 65.7% of the change in vegetable NUE （p0.001）. Moreover, vegetable WUE and NUE would also be seriously influenced by atmospheric nitrogen deposition in nitrogen saturated ecosystems. （3） There was a significant trade-off relationship between vegetable WUE and NUE in the typical forest ecosystems along the NSTEC （p0.001）, indicating a balanced strategy for vegetation in resource utilization in natural forest ecosystems along the NSTEC. This study suggests that global change would impact the resource use efficiency of forest ecosystems. However, vegetation could adapt to those changes by increasing the use efficiency of shortage resource while decreasing the relatively ample one. But extreme impacts, such as heavy nitrogen deposition, would break this trade

关键词： water use efficiency （WUE） nitrogen use efficiency （NUE） δ 13C C/N North-South Transect of Eastern China （NSTEC）

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Responses of grassland vegetation to climatic variations on different temporal scales in Hulun Buir Grassland in the past 30 years

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Journal of Geographical Sciences 2011年第4期21卷 634-650页

作者： ZHANG Geli XU Xingliang ZHOU Caiping ZHANG Hongbin OUYANG Hua Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Hulun Buir Grassland Ecosystem Observation and Research Station Beijing 100081 China Ministry of Agriculture Key Laboratory of Resource Remote Sensing and Digital Agriculture Beijing 100081 China

Global warming has led to significant vegetation changes especially in the past 20 years. Hulun Buir Grassland in Inner Mongolia, one of the world’s three prairies, is undergoing a process of prominent warming and drying. It is essential to investigate the effects of climatic change （temperature and precipitation） on vegetation dynamics for a better understanding of climatic change. NDVI （Normalized Difference Vegetation Index）, reflecting characteristics of plant growth, vegetation coverage and biomass, is used as an indicator to monitor vegetation changes. GIMMS NDVI from 1981 to 2006 and MODIS NDVI from 2000 to 2009 were adopted and integrated in this study to extract the time series characteristics of vegetation changes in Hulun Buir Grassland. The responses of vegetation coverage to climatic change on the yearly, seasonal and monthly scales were analyzed combined with temperature and precipitation data of seven meteorological sites. In the past 30 years, vegetation coverage was more correlated with climatic factors, and the correlations were dependent on the time scales. On an inter-annual scale, vegetation change was better correlated with precipitation, suggesting that rainfall was the main factor for driving vegetation changes. On a seasonal-interannual scale, correlations between vegetation coverage change and climatic factors showed that the sensitivity of vegetation growth to the aqueous and thermal condition changes was different in different seasons. The sensitivity of vegetation growth to temperature in summers was higher than in the other seasons, while its sensitivity to rainfall in both summers and autumns was higher, especially in summers. On a monthly-interannual scale, correlations between vegetation coverage change and climatic factors during growth seasons showed that the response of vegetation changes to temperature in both April and May was stronger. This indicates that the temperature effect occurs in the early stage of vegetation growth. Co

关键词： climatic variation vegetation change NDVI temperature precipitation Hulun Buir Grasssland Inner Mongolia

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Ecological and environmental evaluation for water and soil losscomprehensive harness in Loess hilly region

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Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering 2012年第20期28卷 150-161页

作者： Wang, Bing Zhang, Guanghui Liu, Guobin Yang, Qinke Yang, Yanfen School of Geography Beijing Normal University Beijing 100875 China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Water and Soil Conservation Chinese Academy of Sciences and Ministry of Water Resources Yangling 712100 China College of Urbun and Environmental Science Northwest University Xi'an 710127 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

Hierarchy,complexity and polytropy of eco-environment determine the difficulty in accessing its quality. It is a key issue that many scholars concern for a long time in establishing a set of index system and evaluation method, which is reasonable, scientific and representative in solving the same kind of problem. Methods of Grey relation degree,comprehensive evaluation and DPSIR-mDSS model (driving force, pressure, state, impact, response framework-multiple decision support system) were adopted tocompare their difference in accessing eco-environmental effects. Meanwhile, demonstration area of soil conservation and eco-environment construction in Yan'an was taken as a study object to access environmental effects of ecological restoration of water and soil losscomprehensive harness from 1999 to 2009. The results showed thatcomplicated relationship between human social and economic behavior and environmental system could be simplified to "one to one" causal chain by DPSIR model in constructing index system for accessing environmental effect of ecological restoration of water and soil losscomprehensive harness, accessing process could be decomposed and simplified. Also, the evaluation results of DPSIR-mDSS model was consistent with the actual situation of ecological restoration effects of study area, and would be better explained the variation of ecological restoration effects of water and soil losscomprehensive harness with time, which also provide a new method for ecological restoration effects assessment. In general, the eco-environmental status improved greatly due to the implement of "grain for green"project. However, more attention should be paid to problems in the future, such as pressure on cropland and ecological water storage deficit.

关键词： Decision support systems

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