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NPP vulnerability of the potential vegetation of China to climate change in the past and future

Journal of Geographical Sciences 2017年第2期27卷 131-142页

作者： YUAN Quanzhi WU Shaohong DAI Erfu ZHAO Dongsheng REN Ping ZHANG Xueru Key Lab of Land Resources Evaluation and Monitoring in Southwest Ministry of Education Sichuan NormalUniversity Chengdu 610068 China Institute of Geography and Resources Science Sichuan Normal University Chengdu 610101 China Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China Key Laboratory of Land Surface Pattern and Simulation CAS Beijing 100104 China Chongqing Jiaotong University Chongqing 400074 China

Using the Integrated Biosphere Simulator, a dynamic vegetation model, this study initially simulated the net primary productivity（NPP） dynamics of China＇s potential vegetation in the past 55 years（1961–2015） and in the future 35 years（2016–2050）. Then, taking the NPP of the potential vegetation in average climate conditions during 1986–2005 as the basis for evaluation, this study examined whether the potential vegetation adapts to climate change or not. Meanwhile, the degree of inadaptability was evaluated. Finally, the NPP vulnerability of the potential vegetation was evaluated by synthesizing the frequency and degrees of inadaptability to climate change. In the past 55 years, the NPP of desert ecosystems in the south of the Tianshan Mountains and grassland ecosystems in the north of China and in western Tibetan Plateau was prone to the effect of climate change. The NPP of most forest ecosystems was not prone to the influence of climate change. The low NPP vulnerability to climate change of the evergreen broad-leaved and coniferous forests was observed. Furthermore, the NPP of the desert ecosystems in the north of the Tianshan Mountains and grassland ecosystems in the central and eastern Tibetan Plateau also had low vulnerability to climate change. In the next 35 years, the NPP vulnerability to climate change would reduce the forest–steppe in the Songliao Plain, the deciduous broad-leaved forests in the warm temperate zone, and the alpine steppe in the central and western Tibetan Plateau. The NPP vulnerability would significantly increase of the temperate desert in the Junggar Basin and the alpine desert in the Kunlun Mountains. The NPP vulnerability of the subtropical evergreen broad-leaved forests would also increase. The area of the regions with increased vulnerability would account for 27.5% of China.

关键词： climate change vulnerability potential vegetation net primary productivity IBIS China

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Pedotransfer Functions for Estimating Soil Bulk Density:A Case Study in the Three-River Headwater Region of Qinghai Province,China

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Pedosphere 2016年第3期26卷 362-373页

作者： YI Xiangsheng LI Guosheng YIN Yanyu Agriculture Resource Monitoring Station Chinese Academy of Agricultural Engineering Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of Sciences Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Bulk density(BD) is an important soil physical property and has significant effect on soil water conservation function. Indirect methods, which are called pedotransfer functions(PTFs), have replaced direct measurement and can acquire the missing data of BD during routine soil surveys. In this study, multiple linear regression(MLR) and artificial neuron network(ANN) methods were used to develop PTFs for predicting BD from soil organic carbon(OC), texture and depth in the Three-River Headwater region of Qinghai Province, China. The performances of the developed PTFs were compared with 14 published PTFs using four indexes, the mean error(ME), standard deviation error(SDE), root mean squared error(RMSE) and coefficient of determination(R^2). Results showed that the performances of published PTFs developed using exponential regression were better than those developed using linear regression from OC. Alexander(1980)-B, Alexander(1980)-A and Manrique and Jones(1991)-B PTFs, which had good predictions, could be applied for the soils in the study area. The PTFs developed using MLR(MLR-PTFs) and ANN(ANN-PTFs) had better soil BD predictions than most of published PTFs. The ANN-PTFs had better performances than the MLR-PTFs and their performances could be improved when soil texture and depth were added as predictor variables. The idea of developing PTFs for predicting soil BD in the study area could provide reference for other areas and the results could lay foundation for the estimation of soil water retention and carbon pool.

关键词： alpine soil artificial neural network multiple linear regression organic carbon soil depth soil texture

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The climatic impacts of land use and land cover change compared among countries

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Journal of Geographical Sciences 2016年第7期26卷 889-903页

作者：刘纪远邵全琴延晓冬樊江文战金艳邓祥征匡文慧黄麟 Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS Beijing Normal University

Land use and land cover change(LULCC) strongly influence regional and global climate by combining both biochemical and biophysical processes. However, the biophysical process was often ignored, which may offset the biogeochemical effects, so measures to address climate change could not reach the target. Thus, the biophysical influence of LULCC is critical for understanding observed climate changes in the past and potential scenarios in the future. Therefore, it is necessary to identify the mechanisms and effects of large-scale LULCC on climate change through changing the underlying surface, and thus the energy balance. The key scientific issues on understanding the impacts of human activities on global climate that must be addressed including:(1) what are the basic scientific facts of spatial and temporal variations of LULCC in China and comparative countries?(2) How to understand the coupling driving mechanisms of human activities and climate change on the LULCC and then to forecasting the future scenarios?(3) What are the scientific mechanisms of LULCC impacts on biophysical processes of land surface, and then the climate?(4) How to estimate the contributions of LULCC to climate change by affecting biophysical processes of land surface? By international comparison, the impacts of LULCC on climate change at the local, regional and global scales were revealed and evaluated. It can provide theoretical basis for the global change, and have great significance to mitigate and adapt to global climate changes.

关键词： land use and land cover change climate change biophysical effects model simulation

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Recent advances on reconstruction of climate and extreme events in China for the past 2000 years

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Journal of Geographical Sciences 2016年第7期26卷 827-854页

作者：葛全胜郑景云郝志新刘洋李明启 Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS University of Chinese Academy of Sciences

China is distinguished by a prominent monsoonal climate in the east of the country, a continental arid climate in the northwest and a highland cold climate on the Qinghai-Tibet Plateau. Because of the long history of Chinese civilization, there are abundant and well-dated documentary records for climate variation over the whole of the country as well as many natural archives（e.g., tree-rings, ice cores, stalagmites, varved lake sediments and corals） that enable high-resolution paleoclimatic reconstruction. In this paper, we review recent advances in the reconstruction of climate and extreme events over the last 2000 years in China. In the last 10 years, many new reconstructions, based on multi-proxies with wide spatial coverage, have been published in China. These reconstructions enable us to understand the characteristics of climate change across the country as well as the uncertainties of regional reconstructions. Synthesized reconstructed temperature results show that warm intervals over the last 2000 years occurred in AD 1–200, AD 551–760, AD 951–1320, and after AD 1921, and also show that cold intervals were in AD 201–350, AD 441–530, AD 781–950, and AD 1321–1920. Extreme cold winters, seen between 1500 and 1900, were more frequent than those after 1950. The intensity of regional heat waves, in the context of recent global warming, may not in fact exceed natural climate variability seen over the last 2000 years. In the eastern monsoonal region of China, decadal, multi-decadal and centennial oscillations are seen in rainfall variability. While the ensemble mean for drought/flood spatial patterns across all cold periods shows a meridional distribution, there is a tri-pole pattern with respect to droughts south of 25°N, floods between 25° and 30°N, and droughts north of 30°N for all warm periods. Data show that extreme drought events were most frequent in the periods AD 301–400, AD 751–800, AD 1051–1150, AD 1501–1550, and AD 1601–1650, while extreme flood events w

关键词： high-resolution paleoclimatic reconstruction extreme events China 2000 years

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Ecological compensation for winter wheat abandonment in groundwater over-exploited areas in the North China Plain

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Journal of Geographical Sciences 2016年第10期26卷 1463-1476页

作者：王学李秀彬辛良杰谈明洪李升发王仁靖 Key laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS University of Chinese Academy of Sciences

The land fallow policy was adopted by central and local governments to encourage the abandonment of water-intensive crops, such as winter wheat, in groundwater over-exploited areas. At the same time, since the 1990s, many households in the North China Plain （NCP） have chosen to replace the winter wheat and summer maize double-cropping system with the spring maize single-cropping system. Therefore, it is crucial to identify target land parcels for winter wheat abandonment and to design reasonable and proper standards for ecological compensation prior to the implementation of the land fallow policy in the NCP. In this study, multi-level Iogit models were used with household survey data in order to detect determinants across land parcel, household and village levels on household cropping system decisions; the opportunity costs for winter wheat abandonment were also calculated using cost-benefit analysis. The results show that：（1） land quality and irrigation condition at parcel level are two essential elements influencing household cropping system decisions. Nearly 70% of the total area of poor land and more than 90% of the total area of unirrigated land has suffered winter wheat abandonment. Target land parcels for the land fallow policy should be those that are irrigated and of high quality. （2） There were no significant differences between net profits from spring maize and summer maize under similar farming conditions, and the opportunity cost for winter wheat abandonment should be equal to the net profit of winter wheat. （3） The primary purpose of the land fallow policy is to induce groundwater recovery and restoration as a preliminary stage. A higher level of 350 yuan/mu is recommended as subsidy for ecological compensation at this stage. Later, the primary purpose of the policy should be a transition to a balance between exploitation and supplementation of water resources, and a lower level of 280 yuan/mu is recommended as a subsidy at this stage.

关键词： land fallow ecological compensation multi-level Iogit model opportunity cost groundwaterover-exploited areas

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Advances in terrestrial system research in China

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Journal of Geographical Sciences 2016年第7期26卷 791-802页

作者：吴绍洪尹云鹤郑度杨勤业邓浩宇 Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS University of Chinese Academy of Sciences

Land surface is of spatial-temporal heterogeneity. Terrestrial system（TS） comprehensively studies on land surface and physical regionalization objectively describes geographical zonation of the system. China has a vast area with apparent spatial variations in resources and environmental conditions, which highly influence on socio-economic development. In this paper, progress of the TS studies in China is overviewed and research priorities in the near future are prospected. Since the 1950 s, China has paid great attention to the TS study as its socio-economic development, and conducted research on physical geographical regionalization, eco-geographical regionalization and comprehensive regionalization. Along with the deepening of global change research, dynamics of TS have been highly concerned. During the studies, methodology has been developed from qualitative research of integration of experts＇ brainpower gradually to quantitative research based on field observation and experiments of the natural processes, including physical, chemical and biological processes, as well as application of information technology and mathematical simulation. In the near future, TS would combine with the ideology, objectives and key researches of Future Earth program, to focus on the mechanism and regional effects of interaction among land surface elements, the response of TS to global change, the quantitative recognition on regional unit boundary, and the application to TS in sustainable socio-economic development.

关键词： terrestrial system differentiation rules global change sustainable development China

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Length of stay in urban areas of circular migrants from the mountainous areas in China

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Journal of Mountain Science 2016年第5期13卷 947-956页

作者： TAN Ming-hong LI Xiu-bin YAN Jian-zhong XIN Liang-jie SUN Lai-xiang Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China College of Resources and Environment Southwest UniversityChongqing 400715China Department of Geographical Sciences University of MarylandCollege ParkMD 20742USA

Currently, there is limited literature dealing with the length of stay of circular migrants in urban areas （LSCMU）, although many studies have discussed the phenomenon of migration and the determinants of migration. This study attempts to fill that gap using survey data from the mountainous areas of Chongqing, Southwest China. From a comparative perspective, this study divided workers into two groups （a young group aged between 16 and 35 years and an old group aged between 36 and 65 years）. The average LSCMU values for the young and old groups were 225 days and ~74 days, respectively. Two multi-regression models were used to estimate the determinants of LSCMU in the two groups. The results showed that LSCMU was closely related to individual factors in both groups, including gender, age and job training. Family and community factors, including household size, arable land per capita and the distance from market, had much weaker effects on the dependent variable, especially in the older group. It was noticeable that job training had significant positive effects on LSCMU in both groups; these findings have special implications for the urbanization process in China.

关键词： Circular migrants Urban Mountain areas China

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Progress on quantitative assessment of the impacts of climate change and human activities on cropland change

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Journal of Geographical Sciences 2016年第3期26卷 339-354页

作者：石晓丽王卫史文娇 College of Resources and Environment Sciences Hebei Normal University Key Laboratory of Environmental Evolvement and Ecological Construction of Hebei Province Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS

It is important to study the contributions of climate change and human activities to cropland changes in the fields of both climate change and land use change. Relationships between cropland changes and driving forces were qualitatively studied in most of the previous researches. However, the quantitative assessments of the contributions of climate change and human activities to cropland changes are needed to be explored for a better understanding of the dynamics of land use changes. We systematically reviewed the methods of identifying the contributions of climate change and human activities to cropland changes at quantitative aspects, including model analysis, mathematical statistical method, framework analysis, index assessment and difference comparison. Progress of the previous researches on quantitative evaluation of the contributions was introduced. Then we discussed four defects in the assessment of the contributions of climate change and human activities. For example, the methods were lack of comprehensiveness, and the data need to be more accurate and abundant. In addition, the scale was single and the explanations were biased. Moreover, we concluded a clue about quantitative approach to assess the contributions from synthetically aspect to specific driving forces. Finally, the solutions of the future researches on data, scale and explanation were proposed.

关键词： climate change human activities contributions quantitative cropland pattern

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Response to Hydrothermal Change of Tree Radial Growth since 1990s in the Southern Taihang Mountains in Hebei Province

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Agricultural Science & Technology 2016年第12期17卷 2826-2827,2833页

作者： Yajun WANG Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences

On the basis of the relationship between tree ring width of Pinus tabulaeformis in the southern Taihang Mountains in Hebei Province and climate factors, such as mean temperature, mean maximum temperature, mean minimum temperature and precipitation, we find that tree-ring width correlates positively and significantly with mean and maximum temperature in March and Spring, and with minimum temperature in March, April, Spring and Autumn. The sampling tree radial growth responds sensitively to spring temperature change.

关键词： Southern Taihang Mountains in Hebei Province Tree radial growth Hydrothermal condition

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Assessing changes in wind erosion climatic erosivity in China＇s dryland region during 1961-2012

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Journal of Geographical Sciences 2016年第9期26卷 1263-1276页

作者： YANG Fengbo LU Changhe Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

China＇s dryland region has serious wind erosion problem and is sensitive to climate change due to its fragile ecological condition. Wind erosion climatic erosivity is a measure of climatic factors influencing wind erosion, therefore, evaluation of its intensity and response to recent climate changes can contribute to the understanding of climate change effect on wind erosion risk. Using the FAO equation, GIS and statistical analysis tools, this study quantified the climatic erosivity, analyzed its spatiotemporal variations, and detected the trend and sen- sitivity to climate factors during 1961-2012. The results indicate that mean annual climatic erosivity was 2-166 at 292 stations and 237-471 at 6 stations, with the spatial distribution highly in accordance with wind speed （R^2 = 0.94）. The climatic erosivity varied greatly over time with the annual variation （CV） of 14.7%-108.9% and monthly variation （concentration degree） of 0.10-0.71 in the region. Meanwhile, annual erosivity showed a significant down- ward trend at an annual decreasing rate mostly above 1.0%. This significantly decreasing trend was mainly attributed to the obvious decline of wind speed during the period. The results suggest that the recent climate changes were highly possible to induce a decrease of wind erosion risk in China＇s dryland region.

关键词： wind erosion climatic erosivity trend climate change dryland region China

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