Table of Content

15 May 2014, Volume 31 Issue 3 Previous Issue    Next Issue

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Simulation of Carbon Trend in Forest Ecosystem in Northern Slope  of the Tianshan Mountains Based on Biome-BGC Model HAN Qi-fei, LUO Ge-ping, LI Chao-fan,YE Hui,FENG Yi-xing 2014, 31 (3):  375-382.  Abstract ( 2058 )   PDF (1865KB) ( 1810 )   Forest ecosystems attract a continuous attention because of their importance for mitigating environmental change. Policy making in the fields of sustainable forest management and agendas related to climate change drives the research on forest carbon budget and its interpretation. The recent adoption of the Kyoto Protocol further spurs the need of a sound understanding of carbonrelated processes. There is a big challenge to accurately estimate the contribution of forest ecosystems to the global carbon cycle, as it is difficult to directly measure carbon pools or fluxes over large area. Some models are available to address the issues of carbon budget, and they may be classified into several ways. In terms of their capability to include the causality, the models can be either empirical regression models, or socalled process models including ecophysiological processes describing ecosystem functioning in terms of key processes with their interactions. The adopted simulation system may include all kinds of combinations of approaches to fulfill the modeling goals and create the specific model hybrids. In any case, the models developed based on the generalized approach to simulate ecosystem development must be parameterized for the target ecosystems. Regarding the estimation of carbon dynamics, the use of processbased ecosystem models is of particular interest because this approach allows not only to estimate the carbon budget under various environmental conditions, but also to interpret and quantify the possible causes of carbon stock change along with the environmental change. The application of ecosystem models, however, encounters some specific difficulties in dryland environment, which is characterized by its climatic and humaninduced features. After identifying the proper ecophysiological parameters used in BiomeBGC model, in this study the NPP (net primary productivity) and NEP (net ecological productivity) in the Tianshan Mountains were estimated. Furthermore, the responses of NPP/NEP to interannual climate change during the period of 1959-2009 and climate change scenarios in the future were modeled. Results showed that the average annual total NPP and NEP were 547.97 g·m-2·a-1 and 61.24 g·m-2·a-1 respectively, which revealed that the forests in the Tianshan Mountains perform as the carbon sinks. NPP and NEP were sensitive to the change of precipitation and the increase of air temperature. Under a scenario of 4 ℃ temperature increase, NPP was slightly improved, but NEP was decreased as soil respiration was boosted up. Drought stress was not significant in the study area as derived from the results.   Related Articles | Metrics

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Spatiotemporal Change of Drought over the Songliao Plain Based on TVDI WANG Ting-ting, ZHANG Hong-yan, GUO Xiao-yi, ZHANG Zheng-xiang, ZHAO Jian-jun 2014, 31 (3):  383-389.  Abstract ( 1278 )   PDF (2624KB) ( 750 )   Drought is a kind of natural disaster occurring frequently and affecting agricultural production in China, and it is important to improve the ecological environment, optimize the land allocation and water resources redistribution, and relieve the shortage of ecological resources in arid zone. The MODIS sensor is significantly advantageous in monitoring land use change because of its high spectral resolution, high temporal resolution and appropriate spatial resolution. Temperature vegetation drought index [WTBX](TVDI)[WTBZ] is widely used, and there are many evidences to reveal that it is a reasonable and effective way in monitoring land use change related significantly to drought. [WTBX]TVDI[WTBZ] is of an important theoretical significance in drought monitoring, crop irrigation, agricultural production, pasture conservation, forest fire detection, etc. By using [WTBX]TVDI[WTBZ] method from MODIS product, the spatiotemporal distribution of drought can be derived to explore the relationship between different land use types and drought over the Songliao Plain based on ecogeographical regionalization. The ecogeographical regionalization system is based on the biological and nonbiological factors. This study revealed that [WTBX]TVDI[WTBZ] turns out to be an effective way to get drought conditions, and the result was consistent with Zheng D[JP8]u’[JP]s ecogeographical regionalization theory. Temporal and spatial variation of drought in the study area was quite different from different time and different subregions during the period from 2002 to 2009. The area of drought was the largest in 2009 but the smallest in 2004. Holistically, the study area was in a wetting trend, and the proportion of wetting area including mainly the cropland, woodland and grassland was as high as 84.95%. [WTBX]TVDI[WTBZ] could not be used to monitor waters. Related Articles | Metrics

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Reference Crop Evapotranspiration in Hinterland of the Taklimakan Desert WANG Yong-dong, QIU Yong-zhi, XU Bo,ZHANG Zhong-liang,LI Sheng-yu 2014, 31 (3):  390-396.  Abstract ( 1518 )   PDF (1443KB) ( 1017 )   As a measurement of soilplantationatmosphere transfer system model, the reference crop evapotranspiration ([WTBX]ET0[WTBZ]), which affects the application of models and the precision of prediction, has traditionally been used for understanding water use and water consumption of plant. In order to test the applicability of different methods for hinterland of the Taklimakan Desert, PenmanMonteith method was taken as the standard to calculate the values of [WTBX]ET0[WTBZ] with eight methods of reference crop evapotranspiration at Tazhong Meteorological Station in hinterland of the Taklimakan Desert during the period of 2005-2010. The results showed that the annual [WTBX]ET0[WTBZ] calculated with Penman1948, FAO24-Penman, IrmarkAllen, Makkink and PriestleyTaylar were lower than that calculated with PenmanMonteith method, and that calculated with the modified FAO Penman was slightly higher than that calculated with PenmanMonteith method, and there was no significant difference between the results calculated with the Kimberley Penman, Hargreave and PenmanMonteith methods. The deviation of [WTBX]ET0[WTBZ] calculated with Penman1948, FAO24-Penman, IrmarkAllen, Makkink, Modified FAO Penman and PriestleyTaylar was higher than that calculated with PenmanMonteith method. There was a high deviation because the different modified wind speed formula were used in the calculation with three Penman methods (Penman1948, FAO24-Penman and Modified FAO Penman), and the radioactive term was considered only in the calculation with other three methods (IrmarkAllen, Makkink and PriestleyTaylar), but the aerodynamic term was ignored. Therefore, these six methods (Penman1948, FAO24-Penman, Modified FAO Penman, IrmarkAllen, Makkink and PriestleyTaylar) of [WTBX]ET0[WTBZ] was inapplicable for the extremely arid Taklimakan Desert expect the Kimberley Penman and Hargreave methods. Related Articles | Metrics

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Albedo of Cropland Covered with Plastic Film in an Arid  Area in Northwest China CHEN Ji-wei, ZUO Hong-chao 2014, 31 (3):  397-403.  Abstract ( 1149 )   PDF (1506KB) ( 927 )   1. Key Laboratory of Semiarid Climate Change of Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China; 2. Unit 93811 of the Chinese People]’s Liberation Army, Lanzhou 034000, Gansu Province, China Related Articles | Metrics

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Tourism Climate and Its Comfort Degree in Urumqi LI Dong, YANG Zhao-ping, SHI Hui, LUAN Fu-ming,WANG Zhao-guo 2014, 31 (3):  404-409.  Abstract ( 1393 )   PDF (1173KB) ( 1187 )   Climate is consisted of temperature, air relative humidity, wind speed, sunshine, precipitation and other factors, and the interaction among the factors affects the natural ecosystems and human activities. Studying the regional tourism climate could not only provide the meteorological evidences for the tourism development, but could also help the tourism operators to choose the appropriate activities, time and places for tourists. According to the meteorological data in Urumqi during the period from 1962 to 2011, in this paper the main tourism climatic factors, such as the air temperature, relative humidity, precipitation, wind speed and sunshine duration, were analyzed. Based on calculating and analyzing the hydrothermal index, windchill index and clothing index, a new integrated comfort index model was developed to analyze the integrated comfort degree of tourism climate in Urumqi, and the grades of tourist fitness and time distribution are divided. The results are as follows: ① The traveling period in Urumqi was from May to September, and April was the month turning from unsuitability to suitability, October was the month shifting from suitability to unsuitability, and the period from November to next March was not suitable for travel; ② During the study period, both the air temperature and precipitation were increased, wind speed was reduced, the change of relative humidity was slight, the climate was trended towards a warmingwetting pattern, and such climate would attract more and more visitors and increase their comfort degree during their trip; ③The suitable travel duration would be extended, and this change would promote the tourism development in Urumqi. Related Articles | Metrics

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Effect of Grain-for-Green Project on Evolution of Landscape Pattern in the Guanchuan River Basin, Dingxi LI Hai-fang, WEI Wei, CHEN Jin, LI Xu-chun, ZHANG Bai-lin 2014, 31 (3):  410-415.  Abstract ( 1135 )   PDF (1643KB) ( 1089 )   Based on the field investigation and the remote sensing images in 1995, 2000, 2005 and 2010, the land use change and landscape pattern change after implementing the Grain for Green project in the Guanchuan River Basin in Dingxi, Gansu Province were studied using remote sensing analysis and geographical information system (GIS). The results showed that the main types of land use were the farmland, forestland and grassland, and their proportions were changed from 56.86%, 9.01% and 31.92% to 28.50%, 20.01% and 48.30%, respectively during the period of 1995-2010. However, the area of building land was continuously enlarged, and that of waters was sharply reduced. Fragmentation of landscapes was enhanced, and the patch shape index was decreased to some extent. The landscape pattern revealed that the change of the indexes of dominance, diversity, evenness and connectivity was not so significant. The implementation of the Grain for Green project from 1999 was an important factor of enlarging the areas of forestland and grassland on the Loess Plateau. About 50.95% farmland was changed to grassland, but 46.24% forestland and grassland were converted to farmland, which revealed that there was still a big pressure for enlarging the areas of forestland and grassland due to the continuous population growth and urban expansion in the drainage basin. Furthermore, the sharp reduction of area of waters in the drainage basin revealed that the environment of water resources became worse. It was difficult to explain the relationship between the implementation of the Grain for Green project and the reduction of area of waters. Our study would provide a scientific basis for investigating the relationship between the Grain for Green project and the hydrological process and for controlling soil erosion on the Loess Plateau. Related Articles | Metrics

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Environmental Adaptability and Service Function of Chinese Jujube Forest Ecosystem in Jiaxian County, Shaanxi Province ZHANG Yong-xun, LIU Mou-cheng, MIN Qing-wen, LUN Fei, ZHANG Can-qiang 2014, 31 (3):  416-423.  Abstract ( 1110 )   PDF (1287KB) ( 815 )   As a long history of agriculture heritage system, Chinese jujube forest ecosystem is significantly affected by human activities and has its own environment conditions, ecosystem services and society requirements. A case study on Chinese jujube forest ecosystem in Jiaxian County, Shaanxi Province was carried out. The environmental adaptability and service function of Chinese jujube were comprehensively analyzed. The results showed that the physiological structure, growth cycle and tolerance of Chinese jujube adapted to the local environment in Jiaxian County, and Chinese jujube could also improve the local environment. Because of the high nutrient content and medical value, Chinese jujube has a huge market requirement, and also brings about the huge economic benefits. Furthermore, the local traditional myths and customs avoided the deforestation there, and Chinese jujube forest ecosystem services significantly the local economic development. The service value of Chinese jujube forest ecosystem in the county, as high as 1.72×109 yuan·a-1, was also evaluated. Moreover, the service function, direct economic value and soil conservation of Chinese jujube forest ecosystem were appraised. Apparently, the jujube forest ecosystem in the county has adapted the local natural and social environment, and such adaptability and ecosystem services promoted jointly the development of Chinese jujube forest ecosystem itself. Related Articles | Metrics

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Correlation between Industrial Carbon Emission and Its Affecting Factors—A Study Based on Empirical Analysis of Panel Data from the Five Provinces and Autonomous Regions in Northwest China   ZHANG Yan-fang, LI Xin-qiao 2014, 31 (3):  424-430.  Abstract ( 1069 )   PDF (1862KB) ( 992 )   The global environment problems caused by carbon emission attract more and more attention all over the world, the study on regional industrial carbon emission can provide the theoretical basis to the countries for saving energy, reducing carbon emission and exploring lowcarbon development path. In this paper, the relationships between the industrial carbon emission and its affecting factors were analyzed using the grey correlation model based on the panel data from the five provinces and autonomous regions in northwest China during the period of 19992010, which included the data of energy consumption, GDP, population, and calculated industrial carbon emission. The results are as follows: ① From the viewpoint of total energy consumption, the industrial carbon emission in the five provinces and autonomous regions in northwest China was in an increase trend in a fluctuation way. The carbon emissions in Shaanxi, Gansu, Qinghai, Ningxia and Xinjiang were increased from 3.22×107 t, 3.05×107 t, 7.80×106 t, 1.12×107 t and 3.02×107 t in 1999 to 1.24×108 t, 6.86×107 t, 2.15×107 t, 5.76×107 t and 9.29×107 t in 2010, respectively. The carbon emission in Shaanxi was higher than the national average from 2008. The per capita carbon emissions in Gansu in different years were higher than those of other four provinces; ② Spatially, the industrial carbon emission was in an order of Shaanxi>Xinjiang>Gansu>Ningxia>Qinghai; ③ There was a certain correlation between the industrial carbon emission and the affecting factors in the five provinces and autonomous regions in northwest China, and it was in an order of economic effect>population effect>structure effect>technical effect; ④ The correlation values between the industrial carbon emission and the affecting factors were different from different provinces and autonomous regions: the population effect was in an order of Ningxia>Gansu>Xinjiang>Qinghai>Shaanxi, the economic effect was in an order of Xinjiang>Ningxia>Qinghai>Shaanxi>Gansu, the structure effect was in an order of Gansu>Ningxia>Qinghai>Xinjiang>Shaanxi, and the technical effect was in an order of Ningxia>Qinghai>Xinjiang>Shaanxi>Gansu. Related Articles | Metrics

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Advance in the Study on Bioretention Technology for Low-impact Development LI Jia-ke, LIU Zeng-chao, HUANG Ning-jun, ZHANG Jia-yang, LI Huai-en1,SHEN Bing 2014, 31 (3):  431-439.  Abstract ( 1875 )   PDF (1557KB) ( 3300 )   With the acceleration of urbanization process in China, the environmental issues initiated by urban surface change and precipitation runoff is increasingly serious. Bioretention technology, as one of the lowimpact development measures, plays an important role on detaining, absorbing and purifying rainfall runoff. In this paper, the research trends of bioretention technology at home and abroad were comprehensively analyzed. The emphasis was to focus on the composition elements of bioretention system, runoff purification effect of bioretention system, hydrologic performance of bioretention system, and simulation models of water quality and water volume of bioretention system. The deficiency of present research on bioretention technology including purification mechanism, performance, affecting factors, simulation models, design and other aspects was discussed. The future research directions of bioretention technology, such as enhancing the removal efficiency of nitrogen and phosphorus, local application mechanism, design method, clogging mechanism and key antiblocking technology, were also prospected so as to provide the references for the ecocity construction and urban water environment improvement in China. Related Articles | Metrics

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Rapid-assessing Methods of Loss in Extremely Heavy Rainfall Disaster Chain in Semiarid Region — A Case Study on a Flash Flood Debris Flow in Minxian County, Gansu Province ZHOU Hong-jian, WANG Xi，YUAN Yi, WANG Dan-dan 2014, 31 (3):  440-445.  Abstract ( 1317 )   PDF (1266KB) ( 968 )   Less attention was paid to the extremely heavy rainfall disaster chain in semiarid regions in the previous researches. Under climate change, the frequency and intensity of extremely heavy rainfall in semiarid areas in China was in an obvious increase trend in recent decades. It is important to develop a methodology of rapid assessment of damage and loss (RADL) in an extremely heavy rainfall so as to enhance the capability of preventing the disasters in semiarid areas. In this paper, a method was developed to assess the damage and loss in an extremely heavy rainfall disaster chain, especially in flash flood and debris flow disaster chains based on multisource data and information, including the realtime precipitation, inundated area derived from remote sensing image interpretation results, social and economic information of the study area, etc. Three points should be emphasized in the framework of this method: ① The assessment unit of the RADL was the combination of watershed unit and GRID unit, in which the watershed unit included the secondlevel watersheds in the study area, and the spatial resolution of GRID unit was decided by the social and economic information (e.g. population density); ② The home vulnerability curve was an important factor to implement the RADL. In this paper, a home vulnerability matrix was established based on the realtime filed survey of disaster information collectors at village scale due to the lack of vulnerability curve at that time; ③ From the perspective of final damage and loss in the extremely heavy rainfall disaster chain (including flash flood and debris flow), the method was a comprehensive framework to implement the RADL. The study results could provide a scientific basis for the establishment of rapid assessment system of physical damage and loss induced by flood and debris flow disasters. Related Articles | Metrics

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Spatiotemporal Variation of Hail Weather in the Northeast  Qinghai-Tibetan Plateau ZHANG Li-yang, YANG Kun, ZHANG Zhi-xian 2014, 31 (3):  446-451.  Abstract ( 1484 )   PDF (2717KB) ( 803 )   Based on the data from 60 stations in the northeast Qinghai-Tibetan Plateau during the period of 1961-2010, the spatiotemporal and decadal variations of hail weather were analyzed statistically. The results are as follows: ① Hail disasters occurred generally from April to November, but the maximum frequency occurred in June. The daily variation of hail weather centralized from 12:00 to 20:00 (Beijing time), especially from 14:00 to 18:00, it was quite different from different months and decades, and the peakvalue time could be regarded as a reference indicator in forecasting hail weather; ② Geographically, hail weather decreased from the southwest to the northeast, more in central region, and less in the northwest and the southeast, and there was a significant positive correlation between hail frequency and altitude; ③ The occurring frequency of hail weather was the highest in the 1980s, and it was sharply decreased in recent dozen years. Such change trend revealed that there was a correlation between the changes of hail weather and temperature; ④ Viewing from the decadal variation, the occurring frequency of hail weather was continuously increased in the 1960s, but continuously decreased in the 1990s, especially in recent dozen years. Related Articles | Metrics

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Diagnostic Analysis on a Rainstorm in the Eastern Part of Northwest China WANG Fu-cun, XU Dong-bei,ZHANG De-yu, DAI De-bing, HAN Shu-pu, XIU Shao-yu 2014, 31 (3):  452-462.  Abstract ( 1231 )   PDF (2781KB) ( 720 )   In this study, a diagnostic analysis on a rainstorm occurred in the eastern part of northwest China on July 23, 2010 was carried out using the data from the sounding, a ground encryption automatic meteorological station, the satellite cloud images and reanalyzed data of NCEP 1°×1°. The results showed that a strong convergence formed at midlow level of the low vortex shear line, a strong divergence formed on the left of north jet on the eastern side of South Asia High in the upper troposphere, and an ascend movement formed over the rainstorm area in the eastern part of northwest China. Water vapor was continuously transported to the eastern part of northwest China under the interaction of the “Chanthu” typhoon and the subtropical high. During the rainstorm, precipitable water and rainfall intensity was consistent, and the precipitable water was over 50 mm during the period of strongest rainstorm. With the ascending and strengthening of southerly wind center, the rainstorm was enhanced, contrarily, it was weakened. The variation of the strength of secondary circulation excitated by divergence of nongeostrophic moisture [WTBX]Q[WTBZ]vector was in accordance with rainstorm intensity. The distribution of negative moisture helicity in midlow troposphere could give a good indicator to the distribution and center of rainfall. Related Articles | Metrics

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Change of Characteristic Index of Daily Snowfall in Winter  in Altay Prefecture, Xinjiang ZHUANG Xiao-cui, TIAN Zhong-feng, LI Bo-yuan 2014, 31 (3):  463-471.  Abstract ( 1469 )   PDF (2274KB) ( 923 )   After analyzing the data of daily snowfall at 7 observation stations in Altay Prefecture, Xinjiang in winter during the period of 1961-2011, in this paper the linear trend method, Cubic function, Morlet wavelet transform and R/S analysis were used to study climate change in the study area. The results are as follows: There was a significant positive correlation between winter snowfall and daily snowfall at the Altay and other stations, and also an obvious decadal change of daily snowfall and winter snowfall. Snowfall was in a linear increase trend in long term, in which the frequency and contribution rate of slight snowfall were the highest, and the frequency of slight snowfall was about 20 times of heavy snowfall. The effects of heavy snowfall on winter snowfall was significant at all the observation stations. Cubic function fitting revealed that slight snowfall frequency and its contribution rate were decreased from the 1990s, but the occurring frequency and contribution rate of heavy snowfall was in an increase trend. Morlet wavelet analysis revealed that there were the decadal and annual changes of daily snowfall. R/S analysis revealed that the daily snowfall in the study area will in a gradual decrease trend in the future, especially the snowfall frequency and its contribution rate. Related Articles | Metrics

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Spatiotemporal Variation of Heat Resources in the Ili River  Basin in Recent 51 Years XU Jiao-mei, XU Wen-xiu, LI Da-ping 2014, 31 (3):  472-480.  Abstract ( 1292 )   PDF (3660KB) ( 1045 )   Based on the data from 10 meteorological stations in the Ili River Basin during the period from 1960 to 2010, the spatiotemporal change of heat resources in this area in recent 51 years were analyzed using the methods of linear regression, Ttest and spatial interpolation. The results showed that, spatially, it was richer in heat resources in plain than in the mountainous regions. The mean annual temperature, accumulated temperatures ≥0 ℃ and ≥10 ℃ and their durations as well as the frost free period were increased by 0.43 ℃·（10a）-1, 89.9 ℃·d·(10a)-1, 88.0 ℃·d·(10a)-1, 4.0 d ·(10a)-1, 3.2 d·(10a)-1 and 5.4 d·(10a)-1, equally 2.2 ℃, 458.5 ℃·d, 448.8 ℃·d, 20.4 d, 16.3 d and 27.5 d, respectively. The variations occurred mostly from the late 1990s. After mutation, the change ranges of the mean annual temperature, duration of temperature ≥0 ℃ and frost free period were the highest in plain but the lowest in the mountainous regions. The change ranges of the accumulated temperature ≥0 ℃ and ≥10 ℃ were the most significant in the hilly area but the least in the mountainous regions. The change range of the duration of temperature ≥10 ℃ was the highest in the mountainous regions but the least in plain. Related Articles | Metrics

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Change of Pan Evaporation and Its Affecting Factors in Qinghai Province LIU Bei 2014, 31 (3):  481-488.  Abstract ( 1106 )   PDF (795KB) ( 840 )   The observation data of pan evaporation and other meteorological factors from 36 meteorological stations at different terrains (the river valleys, Qaidam Basin and Qingnan Plateau) in Qinghai Province during the period of 1961-2003 were applied in the study. Results showed that the pan evaporation at the most selected stations was in an obvious decrease trend, especially at the stations in the basin and valleys. The change trend of pan evaporation at the stations in the Qingnan Plateau was different, and the decrease was not so significant. In the river valleys, the pan evaporation was decreased due to the effects of mountains, emission of air pollutant, increase of aerosol particles, weakened direct solar radiation and mountain breeze circulation, and decrease of sunshine and daily temperature range. Under the global increase of greenhouse gases and aerosols, in the Qaidam Basin the pan evaporation was decreased due to the increase of cloud cover and precipitation, and decrease of wind speed, sunshine duration and daily temperature range, and the decrease of pan evaporation in the western part of the Qaidam Basin was more significant than that in the central and eastern parts. The Qingnan Plateau is located in the main part of the Qinghai-Tibet Plateau, where the change of pan evaporation was different from different stations.     Related Articles | Metrics

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Extraordinary Flood Events Recorded by Historical Documents in the Upper Reaches of the Hanjiang River  in the Eastern Han Dynasty LU Yue, ZHA Xiao-chun, HUANG Chun-chang, PANG Jiang-li, ZHAO Ying-jie 2014, 31 (3):  489-494.  Abstract ( 1312 )   PDF (1506KB) ( 970 )   The Hanjiang River is located in a region between the temperate and subtropical zones, and it is sensitive to environmental change. The river valleys are mostly Ushaped, deep and narrow, the stream is torrential, and the storage capacity is low. Therefore, flood disasters occur frequently in the Hanjiang River Basin. As a water source of the SouthtoNorth Water Transfer Project, the negative change of precipitation and meteorological conditions in the upper reaches of the Hanjiang River will endanger the security of peopl[JP8]e’[JP]s lives and impact the local economic development, thus more and more researches focused on this field. In this paper, the LWD, QFC and TJZ Holocene sedimentary profiles in the upper reaches of the Hanjiang River were analyzed, the SWDs were dated to 1 900-1 700 a B.P. in the Eastern Han Dynasty (from 25 A. D. to 220 A. D.). Based on the statistic results of the historical data and records in the upper reaches of the Hanjiang River, the flood disasters during the period from 221 B.C. to 618 A.D. were analyzed. The conclusion was that the flood frequency was the highest in the Eastern Han Dynasty. The flood occurrence was related to the unusual climate fluctuation and the unstable weather system. Related Articles | Metrics

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Water Conservation Services of Different Vegetation Types  in the Saihan Ulla National Nature Reserve JIA Xiao-yan, WANG Xiao-jiang,NIU Jian-ming,ZHANG Wen-jun, LIU Yu-jun 2014, 31 (3):  495-501.  Abstract ( 1296 )   PDF (743KB) ( 966 )   We measured the physical properties of soil and litters and soil retention under seven main plant communities-[WTBX]Filifolium sibirica[WTBZ] grassland, [WTBX]Betula platyphylla[WTBZ] forest, [WTBX]Quercus mongolica[WTBZ] forest, [WTBX]Larix pricepisruprechtii[WTBZ] forest, [WTBX]Ostryopsis davidiana[WTBZ] forest, [WTBX]Prunus sibirica[WTBZ] forest, and farming in the Saihan Ulla National Nature Reserve to assess water conservation efficiency of these communities. Our results were summarized as follows: ① Soil physical properties were significantly different among the communities, and the water conserving capability of land with natural vegetation was higher than that with artificial vegetation. The average bulk density of topsoil (0－60 cm) was the highest in cropland but the lowest in [WTBX]Betula platyphylla[WTBZ] forest. The maximum soil retention was the highest in [WTBX]Betula platyphylla[WTBZ] forest but the lowest in [WTBX]Filifolium sibirica[WTBZ] grassland. The noncapillary capacity of soil was also the highest in [WTBX]Betula platyphylla[WTBZ] forest but the lowest in cropland; ② Water conservation potential of soil litters under plant communities growing on shady slope was higher than that on sunny slope. It was consistently the highest in [WTBX]Larix princepisruprechtii[WTBZ] forest; ③ Water conservation efficiency of soil and litters was different among plant communities, and it was the highest in [WTBX]Betula platyphylla[WTBZ] forest.   Related Articles | Metrics

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Effects of Different Storage Conditions on Germination  of Leymus racemosus Seeds GULNAR Ablat, ZHOU Gui-ling, WANG Yi, HUANG Shi-you, ZHAO Wen-yan 2014, 31 (3):  502-507.  Abstract ( 1277 )   PDF (1523KB) ( 819 )   In this paper, the effects of different storage conditions on the germination of [WTBX]Leymus racemosus[WTBZ] seeds were studied manipulatively both in field and laboratory. The results showed that the seed germination was increased initially and then decreased slowly as the increase of dry storage time and the buried time in topsoil, which revealed that there was an afterripening in this species. The natural germination rates of the seeds buried in 5cm depth in topsoil for 2, 7 and 8 months were 5.15%, 7.52% and 94% respectively. The percentage of ungerminated seeds under natural conditions could be >95% in laboratory. There was no germination after the seeds were buried in natural habitat for 2 months, and the germination rate was as high as 90% after the seeds were buried for 8 months; thus, it could be considered that the seeds in soil formed a transient seed bank. Germination rate of [WTBX]L. racemosus[WTBZ] seeds was increased under darkness. Moisture content of seeds under different storage conditions was in an order of seeds buried at 5cm depth >seeds buried in topsoil >dry storage in laboratory, and the minimum moisture content of seeds was 19.5%. In the natural habitat, the proportion of seeds removed by animals varied in a range of 12%-90% (44.5% in average), as a result, the number of seeds in soil was sharply decreased. Seedlings of [WTBX]L. racemosus[WTBZ] in the natural habitat may die in short period under drought, so the renewal of sexual reproduction of [WTBX]L. racemosus[WTBZ] was low in the natural habitat.   Related Articles | Metrics

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Radial Growth of Populus euphratica and the Effect  of Runoff in the Tarim River Basin 涂文霞，叶茂，徐海量，白元 2014, 31 (3):  508-515.  Abstract ( 2502 )   PDF (1420KB) ( 1030 )   The data of treering of [WTBX]Populus euphratica[WTBZ] and monthly and annual runoff volumes of the Tarim River in Xinjiang during the period from 1957 to 2010 were analyzed using the methods of dendrohydrology and correlation analysis. The results are as follows: ① The radial growth of [WTBX]P.euphratica[WTBZ] changed significantly along the 4 profiles in the upper and middle reaches of the Tarim River. A peak value occurred during the period from the 1980s to the 1990s, and then it was in a gradual decrease trend. The change of annual radial growth of [WTBX]P.euphratica[WTBZ] along two profiles in the lower reaches of the Tarim River was not obvious before 2000, but the annual radial growth began to sharply increase after 2000; ② The MannKendall mutation analysis was used to analyze the change of radial growth of [WTBX]P.euphratica[WTBZ] along 6 profiles. The result showed that the mutation of radial growth of [WTBX]P.euphratica[WTBZ] along the profiles of Xoxak, Xinquman, Shazihekou, Archik, Yengisu and Yiganbjima occurred in 1996, 1999, 1991, 2000, 1998 and 1960 or 1968 or 1978 respectively; ③ There was a high correlation between the radial growth of [WTBX]P.euphratica[WTBZ] and the runoff volume in the upper and middle reaches of the Tarim River in January and February, but a high negative correlation between the radial growth of [WTBX]P.euphratica[WTBZ] and the runoff volume in the lower reaches. Related Articles | Metrics

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Seed Rain of Stipagrostis pennata in the Gurbantonggut Desert LONG Li-hong, WANG Hui, MA Xiao-li, XU Hong-bin, WANG Shao-ming 2014, 31 (3):  516-522.  Abstract ( 1376 )   PDF (1598KB) ( 900 )   In this study, some seed collectors were distributed to collect seeds of [WTBX]Stipagrostis pennata,[WTBZ] and the collected seeds were divided into several groups based on their temporal and spatial differences so as to analyze the characteristics of seed dispersal and seed rain of [WTBX]S. pennata[WTBZ] in the Gurbantonggut Desert. The results are as follows: ① The average accumulated density of seed rain of [WTBX]S. pennata[WTBZ] was as high as 3 766.30 seeds under each plant, in which the proportion of full seeds accounted for 19.56%; ② The peak of seed dispersal occurred from June 25 to July 15, the proportion of falling seeds during this period was 61.96% of the whole seed rain, and the seed rain density was decreased gradually with the time; ③ There was no significant difference of seed rain density among the different habitats; ④ There was a significant difference of seed rain amount among the different ages of [WTBX]S. pennata[WTBZ] plants; ⑤ Seeds fell intensively within a 4m extent downwind and 1m extent around the plants at the early stage of seed dispersal of seed rain. In the southern marginal zone of the Gurbantonggut Desert, the quality of seed rain was low, but the density was high and of a certain significance to the natural regeneration of the population.   Related Articles | Metrics

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Relationship between Grassland Plant Diversity and Foliar C∶N∶P Stoichiometry on the Western Slope of the Helan Mountain JIANG Shi-gao,SHANG Zhen-yan, NIU De-cao,ZHANG Bao-lin,ZHANG Si-lian, FU Hua 2014, 31 (3):  523-529.  Abstract ( 1474 )   PDF (2056KB) ( 1053 )   In recent years, the geographic variation in the plant stoichiometry has become as the center of studying the structure and function of ecosystems with global climate change. This resarch explored the relationship between the biodiversity and the foliar stoichiometry (C, N and P contents) in 7 different plant communities at different altitudes on the western slope of the Helan Mountain. The results showed that the species richness in plant community was decreased with the increase of elevation in lowaltitude areas in the Helan Mountain, and there was no significant correlation between the species richness in plant community and the foliar stoichiometry (C, N and P contents and stoichiometric ratios and coefficients of variation of these indicators) in the Helan Mountain, which did not surpport the viewpoint that the value of species richness was higher when the foliar N[JP20]∶[JP]P mass ratio varied in a range of 14-16 than that when the foliar N[JP20]∶[JP]P mass ratio was higher than 14 or lower than 16, and the hypothesis that there was a positive correlation between the species richness and the variance of foliar mass ratio was surpported neither. Such results may be caused by the slight change of plant species richness in our research (9-16 plant species).    Related Articles | Metrics

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Allelopathic Effect of Xanthium spinosum on Seeds of Triticum aestivum and Medicago sativa DONG Fang-hui, LIU Ying, JIANG Meng-jiao, LI Hai-bing, HU Yun-xia 2014, 31 (3):  530-535.  Abstract ( 1430 )   PDF (2103KB) ( 819 )   Xanthium spinosum [WTBZ] is an annual invasive species, and it was originated from South American. It has a wide adaptability to barren soil and saline or alkaline soil as well as flood and drought conditions. Just because of its transmission capability, [WTBX]X.spinosum[WTBZ] devastates the native biodiversity, plant distribution, community formation and intercrop evolution. In this paper, the aqueous extract from the roots, stems and leaves of [WTBX]X.spinosum[WTBZ], at concentrations of 0.012 5, 0.250, 0.050 g·mL-1 and 0.100 g·mL-1, was used as a treatment solution to study its allelopathic effect on seed germination of [WTBX]Triticum aestivum[WTBZ] and [WTBX]Medicago sativa[WTBZ]. The results revealed that the seed germination of [WTBX]T.aestivum[WTBZ] and [WTBX]M.sativa[WTBZ] was significantly inhibited by the aqueous extract at concentration ≥ 0.012 5 g·mL-1. All the aqueous extract of the roots, stems and leaves inhibited seed germination of [WTBX]T.aestivum[WTBZ] and [WTBX]M.sativa[WTBZ], which not only reduced the germination rate of seeds but also prolonged the period of ultimate germination. The allelopathic effect of the aqueous extract was in an order of stem > leaf > root, and the effect was intensified at higher extract concentration. The results are of the theoretical significance and practical value in conducting biological control of exotic species and developing new biological pesticide. Related Articles | Metrics

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Species Diversity and Geographical Distribution of Pedicularis  (Orobanchaceae) in Xinjiang LI Wen-jun, GUAN Kai-yun, DUAN Shi-min, FENG Ying,ZHUO Lu, BUHAILICHIRM Abudureheman 2014, 31 (3):  536-541.  Abstract ( 1376 )   PDF (663KB) ( 994 )   According to the system of Tsoong P C, there are 29 species in 14 series of 6 grexes in the genus of [WTBX]Pedicularis[WTBZ] distributed in Xinjiang, the area where the species of this genus were firstly explored in China. The characteristics of [WTBX]Pedicularis[WTBZ] in Xinjiang can be summarized as follows: ① The species richness is poor, constituting 8.24% species of the total in China with 3 endemic species; ② The species in this area are mainly in three grexes, i.e. the Sigmantha, Orthosiphonia and Apocladus, which account for 86.21% of the total species in Xinjiang, in which 10 species are in Ser. Comosae of Apocladus and account for a high proportion in the total; ③ The horizontal distribution forms a Eshaped pattern and fits to the main mountain systems in Xinjiang, and the vertical distribution is in a big range from 900 m to 5 180 m a. s. l.; ④ The species have a great community with the species distributed also in adjacent countries, especially in Russia and Kazakhstan, the common species account for 58.62% and 51.72% respectively, which implies their floristic relationship. However, the floristic links with the neighboring provinces of China are relatively weak. Related Articles | Metrics

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Gas Exchange of Haloxylon ammodendron and H. persicum TIAN Yuan,TAXIPLAT Teybay, XU Gui-qing 2014, 31 (3):  542-549.  Abstract ( 1404 )   PDF (1691KB) ( 1000 )   Haloxylon ammodendron[WTBZ] and [WTBX]H.persicum[WTBZ] are two main edificators in the Gurbantonggut Desert, Xinjiang. Based on the simultaneous observations of photosynthetic characteristics and related environmental factors affecting the growth of H.ammodendron and [WTBX]H.persicum[WTBZ], different photosynthetic responses of the two species to environmental factors were studied. Results showed that H.ammodendron was better in using lowlight than [WTBX]H.persicum[WTBZ], but it was contrary in using highlight. The curves of daily variation of net photosynthetic rate, stomatal conductance and transpiration rate were all unimodal, the time of occurring the peak values of net photosynthetic rate and stomatal conductance was slightly different, and the peak value of transpiration rate occurred always at 16:00. According to the variation of photosynthetic rate, intercellular CO2 concentration and stomatal limitation of H.ammodendron and [WTBX]H.persicum[WTBZ], it was considered that the “midday depression” of photosynthesis was mainly caused by stomatal factors. The daily averages of photosynthetic rate, transpiration rate and water use efficiency of [WTBX]H.persicum[WTBZ] were higher than those of H.ammodendron. Correlation analysis revealed that the photon flux density was the most significant environmental factor affecting the photosynthetic rate of H.ammodendron and [WTBX]H.persicum[WTBZ]. Related Articles | Metrics

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Parameter Difference of Chlorophyll Fluorescence in Leaves  of Different Cultivars of Lycium barbarum YANG Juan, WANG You-ke, LI Jie, CHEN Na, LI Xiao-gang, ZHANG Xiao-na 2014, 31 (3):  550-555.  Abstract ( 1368 )   PDF (1551KB) ( 1045 )   In this research, some cultivars of [WTBX]Lycium barbarum[WTBZ] were taken as the materials. In the field experiment, the chlorophyll fluorescence parameters and the chlorophyll contents in the cultivars of [WTBX]L. barbarum[WTBZ] were studied using the chlorophyll fluorescence measuring technique. The results revealed that the maximal photochemical efficiency of PSⅡ [WTBX](Fv/Fm)[WTBZ] and potential activity of PSⅡ [WTBX](Fv/Fo)[WTBZ] of Ningqi No.2 were remarkably higher than those of other three cultivars. The actual photosynthesis yield [WTBX](Y[WTBZ](Ⅱ)), activity photosynthesis yield [WTBX]（Fv′/Fm′）,[WTBZ] photochemical quenching [WTBX](qP)[WTBZ] and electron transport rate [WTBX](ETR)[WTBZ] were significantly different from different cultivars under a photo synthetically active radiation of 0-2 847 μmol·m-2·s-1, and they were the highest in Ningqi No.2, followed by Mengqi No.1 and Damaye, and the lowest in Ningqi No.1. The initial slope α of fitting parameter [WTBX]ETR[WTBZ] was similar to the change trend of [WTBX]ETR.[WTBZ] The content of Chlorophyll a, Chlorophyll b and Chlorophyll a+b in Ningqi No.2 were the highest. There was an extremely significant or a significant positive correlation between chlorophyll a+b and [WTBX]Y[WTBZ](Ⅱ), [WTBX]Fv′/Fm′, qP[WTBZ] and [WTBX]ETR,[WTBZ] but a negative correlation with [WTBX]NPQ.[WTBZ] So it could be concluded that Ningqi No.2 had a higher physiological activity of PS II and physiological basis of potential biomass, the photosynthesis capability of all the four cultivars was strong. The photochemical efficiency of Ningqi No.1 was weaker, and it was easy to suffer from photo inhibition at high light intensity. Related Articles | Metrics

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Morphological Features and Spatial Distribution Pattern of Tamarix  ramosissima Nebkhas in an Oasisdesert Ecotone YANG Fan, WANG Xue-qin, HE Qing, ZHENG Xin-qian, HAN Zhang-yong,HUO Wen 2014, 31 (3):  556-563.  Abstract ( 1569 )   PDF (2279KB) ( 830 )   The morphological features of [WTBX]Tamarix ramosissima[WTBZ] nebkhas in three different sample plots in the internal, central and peripheral areas of the oasisdesert ecotone in Qira, Xinjiang were investigated. The relationships among the morphological parameters, spatial distribution pattern and corresponding variation were quantitatively analyzed. The results are as follows: ① The [WTBX]Tamarix ramosissima[WTBZ] nebkhases were convex and semiellipticalshaped, and they were covered with thickets. The values of nebkhas height and volume and crown area of [WTBX]T. ramosissima[WTBZ] varied in ranges of 0.27-3.21 m, 0.30-291.63 m3 and 2.39-128.76 m2 respectively. From the internal area to the peripheral area of the oasisdesert ecotone, the scale of nebkhas became larger, and the thickets grew luxuriantly;② There were the significant correlations among the morphological parameters of nebkhas. Among them the significant regression relationships between nebkhas length and width, nebkhas area and height changed gradually from linear relation to quadratic function for the nebkhases from the internal area to the peripheral area of the ecotone. There was a significant linear relationship between the crown area of [WTBX]T.ramosissima[WTBZ] and the nebkhas; ③ From the internal area to the peripheral area of the oasisdesert ecotone, the nebkhas density reduced, the spatial distribution pattern of nebkhas changed from aggregation to random pattern at spatial scale of 100-250 m, and the aggregation degree decreased. The nebkhases are currently still at growing stage, and it was considered that the formation and development of nebkhas is caused by land degradation. Related Articles | Metrics

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Near-surface Horizontal Sanddust Flux over  Different Underlying Surfaces in a Desert YANG Xing-hua, HE Qing,HUO Wen, ALI Mamtimin, LIU Xin-chun 2014, 31 (3):  564-569.  Abstract ( 1160 )   PDF (1499KB) ( 912 )   Aeolian sanddust transport is a serious problem in many arid regions in the world, and it is considered to be the significant part of global biogeochemical cycles. Deserts are the main sources of aeolian sanddust transport in the nearsurface air layer, and aeolian sanddust transport process is closely related to the variation of horizontal sanddust flux near ground surface with the height. In this study, the samples were collected with BSNE samplers, the data of horizontal sanddust flux over sand dune top and level sandland in hinterland of the Taklimakan Desert were analyzed, and the variation of horizontal sanddust flux within 200 cm above the ground surface with the height was researched. The results indicated that, in the nearsurface air layer in a range of 0-200 cm, the intensity of horizontal flux of aeolian sanddust decreased significantly with the increase of the height over sand dune top and level sandland. Over the two different underlying surfaces, the change of horizontal sanddust flux with the height obeyed the power function well. The total flux of aeolian sanddust passing through a section of 100 cm×200 cm was 3 721.0 kg over sand dune top, but 2 252.9 kg over level sandland and reduced by 39.5% compared with that over sand dune top. The horizontal fluxes of aeolian sanddust of PM80 over sand dune top and level sandland were 996.8 kg and 678.9 kg respectively.   Related Articles | Metrics

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Restriction of Nd-Sr Isotopes to Sediment Source —A Case Study at the Dishaogouwan Profile WANG Xiao, RAO Wen-bo, PAN Yao-dong 2014, 31 (3):  570-577.  Abstract ( 1378 )   PDF (1386KB) ( 1057 )   The Salawusu Valley is located in a zone between the Loess Plateau and the Ordos Desert, and it is an important part of the desertloess ecotone in north China and is very sensitive to climatic and environmental changes. In this study, the Dishaogouwan profile, a typical sedimentary sequence in the Salawusu Valley, was chosen as the study area to investigate the isotopic profiles and try to reveal the variation of sediment sources in the desertloess ecotone. The results are as follows: ① Coarse eolian deposits (>75 μm) came from wind erosion of the highlands in the centralwestern Ordos, and coarse fluviallacustrine deposits originated mainly from water erosion of underlying eolian deposits; ② Fine eolian deposits (<75 μm) with absolute  [WTBX]ΔεNd(0)[WTBZ] values ≤1 originated basically from the wind erosion of the highlands in centralwestern Ordos and the refining of coarse particles in situ, but fine eolian deposits with absolute   [WTBX]ΔεNd(0)[WTBZ] values ＞1 came from more complex sources; ③ Fluviallacustrine fine deposits of the Chengchuan and middlelower Salawusu formations came from water erosion in the central Loess Plateau, but the deposits of the upper Salawusu formation were significantly disturbed by eolian fine particles from the centraleastern Ordos Desert. This study is very helpful for understanding the evolution of the desertloess ecotone in north China. Related Articles | Metrics

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Features and Formation Causes of Granitic Stone  Forest in Bayan Nur, Inner Mongolia WANG Lu-lin, WU Fa-dong 2014, 31 (3):  578-584.  Abstract ( 1829 )   PDF (1755KB) ( 986 )   Based on the field investigation on the granitic stone forest in Bayan Nur, Inner Mongolia, in this paper the features and formation causes of the granitic stone forest were discussed in detail. The granitic stone forest was divided into five types, i.e. the stalagnate, talus cone, stone egg, mushroom stone and stone row. According to the morphologic features of the granitic stone forest, it was considered that the stone forest is a kind of special landform and formed from the Late Paleozoic granodioritebiotite monzonitic granite under the effect of external forces, such as gravitational collapse, weathering, water erosion and wind erosion. The formation and development of the stone forest are affected by lithology, geological structure, climate conditions, etc. Related Articles | Metrics