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Oasis System and Its Reasonable Development in Sangong River Watershed in North of the Tianshan Mountains,Xinjiang,China

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Chinese Geographical Science 2006年第3期16卷 236-242页

作者： LEI Jun luo geping ZHANG Xiaolei LU Qi Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Under the guide of system theory, taking the oasis in the Sangong River watershed as a case study, this paper analyzes the oasis structure and function from 4 aspects including oasis spatial structure, water resources structure, vegetation structure, economic structure and their corresponding functions. The results indicate that as a typical small-scale watershed, Sangong River watershed has the relatively complete mountain-basin structure, and ecological and productive function. Because of human drastic activity the utilization rate of water resources was as high as 98.7%, and the utilization of groundwater was not reasonable, which resulted in an average annual decline of 0.353m in the water table of alluvial-diluvial-fan oasis, and an average annual increase of 0.047m in the alluvial-plain. The layout of crop and shelter forest benefits to the utilization of water and land resources. The development of oasis economy is at low level, and its eco-economic function is weak.

关键词： oasis structure oasis function oasis economy Sangong River watershed

Modeling the contribution of abiotic exchange to CO_2 flux in alkaline soils of arid areas

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Journal of Arid Land 2014年第1期6卷 27-36页

作者： WenFeng WANG Xi CHEN geping luo LongHui LI State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences University of Chinese Academy of Sciences

Recent studies on alkaline soils of arid areas suggest a possible contribution of abiotic exchange to soil CO2 flux(Fc).However,both the overall contribution of abiotic CO2 exchange and its drivers remain *** we analyzed the environmental variables suggested as possible drivers by previous studies and constructed a function of these variables to model the contribution of abiotic exchange to Fc in alkaline soils of arid *** automated flux system was employed to measure Fc in the Manas River Basin of Xinjiang Uygur autonomous region,*** pH,soil temperature at 0–5 cm(Ts),soil volumetric water content at 0–5 cm(θs)and air temperature at10 cm above the soil surface(Tas)were simultaneously *** highlight reduced sensitivity of Fc to Ts and good prediction of Fc by the model Fc=R10Q10(Tas–10)/10+r7q7(pH–7)+λTas+μθs+e which represents Fc as a sum of biotic and abiotic *** presents an approximate method to quantify the contribution of soil abiotic CO2 exchange to Fc in alkaline soils of arid areas.

关键词： soil respiration temperature sensitivity Q10 model soil abiotic CO2 exchange soil alkalinity

Effects of grazing on net primary productivity,evapotranspiration and water use efficiency in the grasslands of Xinjiang,China

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Journal of Arid Land 2018年第4期10卷 588-600页

作者： HUANG Xiaotao luo geping YE Feipeng HAN Qifei State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China College of Resource and Environment Sciences Xinjiang UniversityUrumqi 830046China Nanjing University of Information Science&Technology Nanjing 210044China

Grazing is a main human activity in the grasslands of Xinjiang, China. It is vital to identify the effects of grazing on the sustainable utilization of local grasslands. However, the effects of grazing on net primary productivity （NPP）, evapotranspiration （ET） and water use efficiency （WUE） in this region remain unclear. Using the spatial Biome-BGC grazing model, we explored the effects of grazing on NPP, ET and WUE across the different regions and grassland types in Xinjiang during 1979-2012. NPP, ET and WUE under the grazed scenario were generally lower than those under the ungrazed scenario, and the differences showed increasing trends over time. The decreases in NPP, ET and WUE varied significantly among the regions and grassland types. NPP decreased as follows： among the regions, Northern Xinjiang （16.60 g C/（m2·a））, Tianshan Mountains （15.94 g C/（m2·a）） and Southern Xinjiang （-3.54 g C/（m2·a））; and among the grassland types, typical grasslands （25.70 g C/（m2·a））, swamp meadows （25.26 g C/（m2·a））, mid-mountain meadows （23.39 g C/（m2·a））, alpine meadows （6.33 g C/（m2·a））, desert grasslands （5.82 g C/（m2·a）） and saline meadows （2.90 g C/（me.a））. ET decreased as follows： among the regions, Tianshan Mountains （28.95 mm/a）, Northern Xinjiang （8.11 mm/a） and Southern Xinjiang （7.57 mm/a）; and among the grassland types, mid-mountain meadows （29.30 mm/a）, swamp meadows （25.07 mm·a）, typical grasslands （24.56 mm/a）, alpine meadows （20.69 mm/a）, desert grasslands （11.06 mm/a） and saline meadows （3.44 mm/a）. WUE decreased as follows： among the regions, Northern Xinjiang （0.053 g C/kg H2O）, Tianshan Mountains （0.034 g C/kg H2O） and Southern Xinjiang （0.012 g C/kg H2O）; and among the grassland types, typical grasslands （0.0609 g C/kg H2O）, swamp meadows （0.0548 g C/kg H2O）, mid-mountain meadows （0.0501 g C/kg H2O）, desert grasslands （0.0172 g C/kg H2O）, alpine meadows （0.0121 g C/kg H2O） and saline meadows （0.0067 g C/kg H2O）. In general, the decreases in NPP and WUE were m

关键词： grazing effect grassland type net primary productivity evapotranspiration water use efficiency BiomeBGC grazing model

Stability of patches of oasis landscape in arid areas:A case study of Sangong River Watershed,Xinjiang,China

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Chinese Science Bulletin 2006年第A01期51卷 92-100页

作者： luo geping ZHOU Chenghu CHEN Xi Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China Institute of Geographical Science and Resources Research Chinese Academy of Sciences Beijing 100101 China

绿洲的稳定性是在进化的过程和在干旱区域的绿洲的管理的关键科学问题之一。绿洲和它的表示的稳定性在不同规模也是不同的。这篇论文在 Tianshan 山的 Sangong 河分水岭与案例研究在风景补丁规模处理绿洲的稳定性。我们采用了 ther 激... 详细信息

绿洲的稳定性是在进化的过程和在干旱区域的绿洲的管理的关键科学问题之一。绿洲和它的表示的稳定性在不同规模也是不同的。这篇论文在 Tianshan 山的 Sangong 河分水岭与案例研究在风景补丁规模处理绿洲的稳定性。我们采用了 ther 激动地表达感情到进程 ther 的察觉到的、地理信息系统和数学统计方法激动地表达感情在 1978， 1987 和 1998 察觉到三个时期的图象，并且为在风景补丁规模代表绿洲稳定性提出途径。绿洲补丁的风景控制能力是动态风景变化的一种自然驱动力。在有它在它和另外的补丁之间的区域和形状复杂性和对比的风景变化增加以后的某个补丁类型的控制能力，和有它在它和另外的补丁之间的空间距离的还原剂。有最强壮的控制能力的补丁类型应该是风景的矩阵。绿洲风景补丁的变换源于自然、人为的驱动力，特别地人为的驱动力。变换比例越高，越多降低补丁类型的稳定性并且人为的骚乱越更强壮。有在在 1987 的 Sangong 河分水岭的最强壮的网控制能力的补丁类型是荒芜的草地，它是风景的矩阵；但是风景的矩阵在 1987 和 1998 被变成了灌溉陆地。绿洲风景进化上的风景补丁的控制能力逐渐地在程度也逐渐地减少了的 Sangong 河分水岭，和变化与时间减少了。这表明在风景补丁类型之中的相互作用通常通常趋于到还原剂，和绿洲风景补丁的自然稳定性趋于增加。然而，在风景补丁之中的变换由于集中的人的活动的增加更经常发生，它可能在绿洲风景引起环境资源补丁的更低的稳定性和介绍补丁的更高的稳定性。

关键词：稳定性景观保护绿洲 GIS 遥感 NDVI

Can soil respiration estimate neglect the contribution of abiotic exchange?

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Journal of Arid Land 2014年第2期6卷 129-135页

作者： Xi CHEN WenFeng WANG geping luo Hui YE State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences University of Chinese Academy of Sciences

This study examines the hypothesis that soil respiration can always be interpreted purely in terms of biotic processes, neglecting the contribution of abiotic exchange to COg fluxes in alkaline soils of arid areas that characterize 5% of the Earth＇s total land surface. Analyses on flux data collected from previous studies suggested reconciling soil respiration as organic （root/microbial respiration） and inorganic （abiotic CO2 exchange） respiration, whose contributions in the total CO2 flux were determined by soil alkaline content. On the basis of utilizing mete- orological and soil data collected from the Xinjiang and Central Asia Scientific Data Sharing Platform, an incorpo- rated model indicated that inorganic respiration represents almost half of the total CO2 flux. Neglecting the abiotic module may result in overestimates of soil respiration in arid alkaline lands, which partly explains the long-sought ＂missing carbon sink＂.

关键词： soil respiration abiotic exchange hypothetical system incorporated model missing carbon sink

Processes and trends of the land use change in Aksu watershed in the central Asia from 1960 to 2008

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Journal of Arid Land 2010年第3期2卷 157-166页

作者： Zhou, DeCheng luo, geping Lu, Lei Chinese Acad Sci Xinjiang Inst Ecol & Geog Urumqi 830011 Peoples R China Chinese Acad Sci Grad Univ Beijing 100049 Peoples R China

Land use change (LUC) in trans-boundary watersheds is of great importance to environmental assessment. The Aksu River is the largest trans-boundary river crossing Kyrgyzstan and China,but there was little information on the LUC of the watershed. We quantitatively investigated the processes and trends of its LUC by using analytic models based on the land use data derived from the remote sensing images and topographic maps. The LUC was in the quasi-balanced status with a slight difference between the loss and the gain of the area for most land use types during the period of 1960-1990,whereas transferred to the unbalanced status with significant difference between the loss and gain of the area during the period of 1990-2008. At the same time,land conversion direction changed from two-way transition to one-way transition for the most land use types. The integrated rate of net change of land use during the period of 1990-2008 is 2.1 times of that during the period of 1960-1990. Information on the processes and trends of LUC is valuable for better understanding the environmental changes across the whole trans-boundary watershed,and helpful to decision-making management for Kyrgyzstan and China.

关键词： land use change (LUC) trans-boundary river Aksu River remote sensing

Detecting soil salinity with arid fraction integrated index and salinity index in feature space using Landsat TM imagery

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Journal of Arid Land 2013年第3期5卷 340-353页

作者： Fei WANG Xi CHEN geping luo JianLi DING XianFeng CHEN State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences University of Chinese Academy of Sciences College of Resources and Environmental Science Xinjiang University Slippery Rock University of Pennsylvania Slippery RockPA16057USA

Modeling soil salinity in an arid salt-affected ecosystem is a difficult task when using remote sensing data because of the complicated soil context （vegetation cover, moisture, surface roughness, and organic matter） and the weak spectral features of salinized soil. Therefore, an index such as the salinity index （SI） that only uses soil spectra may not detect soil salinity effectively and quantitatively. The use of vegetation reflectance as an indirect indicator can avoid limitations associated with the direct use of soil reflectance. The normalized difference vegetation index （NDVI）, as the most common vegetation index, was found to be responsive to salinity but may not be available for retrieving sparse vegetation due to its sensitivity to background soil in arid areas. Therefore, the arid fraction integrated index （AFⅡ） was created as supported by the spectral mixture analysis （SMA）, which is more appropriate for analyzing variations in vegetation cover （particularly halophytes） than NDVI in the study area. Using soil and vegetation separately for detecting salinity perhaps is not feasible. Then, we developed a new and operational model, the soil salinity detecting model （SDM） that combines AFⅡ and SI to quantitatively estimate the salt content in the surface soil. SDMs, including SDM1 and SDM2, were constructed through analyzing the spatial characteristics of soils with different salinization degree by integrating AFⅡ and SI using a scatterplot. The SDMs were then compared to the combined spectral response index （COSRI） from field measurements with respect to the soil salt content. The results indicate that the SDM values are highly correlated with soil salinity, in contrast to the performance of COSRI. Strong exponential relationships were observed between soil salinity and SDMs （R2〉0.86, RMSE〈6.86） compared to COSRI （R2=0.71, RMSE=16.21）. These results suggest that the feature space related to biophysical properties combined with AFII and SI can effectively pr

关键词： soil salinity spectrum halophytes Landsat TM spectral mixture analysis feature space model

Modeling grassland net primary productivity and water-use efficiency along an elevational gradient of the Northern Tianshan Mountains

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Journal of Arid Land 2013年第3期5卷 354-365页

作者： QiFei HAN geping luo ChaoFan LI Hui YE YaoLiang CHEN State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences University of Chinese Academy of Sciences

Mountainous ecosystems are considered highly sensitive and vulnerable to natural disasters and cli- rnatic changes. Therefore, quantifying the effects of elevation on grassland productivity to understand ecosys- tem-climate interactions is vital for mountainous ecosystems. Water-use efficiency （WUE） provides a useful index for understanding the metabolism of terrestrial ecosystems as well as for evaluating the degradation of grasslands. This paper explored net primary productivity （NPP） and WUE in grasslands along an elevational gradient ranging from 400 to 3,400 m asl in the northern Tianshan Mountains-southern Junggar Basin （TMJB）, Xinjiang of China, using the Biome-BGC model. The results showed that： 1 ） the NPP increased by 0.05 g C/（m2-a） with every increase of 1-m elevation, reached the maximum at the mid-high elevation （1,600 m asl）, and then decreased by 0.06 g C/（m2.a） per 1-m increase in elevation; 2） the grassland NPP was positively correlated with temperature in alpine meadow （AM, 2,700-3,500 m asl）, mid-mountain forest meadow （MMFM, 1,650-2,700 m asl） and low-mountain dry grassland （LMDG, 650-1,650 m asl）, while positive correlations were found between NPP and annual precipitation in plain desert grassland （PDG, lower than 650 m asl）; 3） an increase （from 0.08 to 1.09 g C/（m2.a）） in mean NPP for the grassland in TMJB under a real climate change scenario was observed from 1959 to 2009; and 4） remarkable differences in WUE were found among different elevations, in general, WUE increased with decreasing elevation, because water availability is lower at lower elevations; however, at elevations lower than 540 m asl, we did observe a decreasing trend of WUE with decreasing elevation, which may be due to the sharp changes in canopy cover over this gradient. Our research suggests that the NPP simulated by Biome-BGC is consistent with field data, and the modeling provides an opportunity to further evaluate interactions between environmental factors and ecosystem

关键词： elevational gradient net primary production water-use efficiency climate

The relationship between soil,climate and forest development in the mid-mountain zone of the Sangong River watershed in the northern Tianshan Mountains,China

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Journal of Arid Land 2015年第1期7卷 63-72页

作者： Li DAI YiXing FENG geping luo YanZhong LI WenQiang XU School of Geographic and Environmental Sciences Guizhou Normal University State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences

The mountainous forests in arid regions, being sensitive to climate change, are one of the key research topics related to the mechanism of interaction between climate and the terrestrial ecosystem. In this study, the spatial distribution of a mid-mountain forest and its environmental factors were investigated by using a combination of remote sensing technology, field survey, climate indices and soil nutrient analysis in the Sangong River watershed of the northern Tianshan Mountains. The forest （Picea schrenkiana） was distributed between 1,510 and 2,720 m asl. Tree height and diameter at breast height （DBH） exhibited a bi-modal pattern with increasing elevation, and rested at 2,450 and 2,250 m asl, respectively. The two maxima of DBH appeared at 2,000 and 2,550 m asl, and the taller trees were observed at 2,100 and 2,600 m asl. For the annual mean temperature, the difference was approximately 5.8℃ between the lowest and the highest limits of the forest, and the average decreasing rates per hundred meters were 0.4g℃ and 0.55℃ with increasing altitude between 1,500 and 2,000 m asl and above 2,000 m asl, respec- tively. The annual precipitation in the forest zone first increased and then decreased with the increase of altitude, and the maximum value was at 2,000 m asl. For per hundred meters, the annual precipitation increased with the rate of 31 mm between 1,500 and 2,000 m asl and decreased by 7.8 mm above 2,000 m asl. The SOM, TN and TP were high between 2,000 and 2,700 m asl and low at the lower and upper forest limits. The minimum CaCO3 con- centration, pH value and EC coincided with the maximum precipitation belt at 2,000 m asl. The SOM, TN and TP were high in the topsoil （0-10 cm） and differed significantly from the values observed in the deep soil layers （〉10 cm）. The soil nutrients exhibited spatial heterogeneity and higher aggregation in the topsoil. In conclusion, soil and climate are closely related to each other, working synergistically to determine the dev

关键词： mid-mountain forest climatic conditions soil properties Picea schrenkiana arid region central Asia