In this study, the relationship between land use and cover change (LUCC) and variation of groundwater level and quality in the Sangong Oasis Region was investigated using a spatial geostatistical approach. Specifically, interactions among groundwater, surface water, and LUCC were analyzed through the utilization of geographical information system (GIS), remote sensing (RS) Imagery processing, and geostatistics. Study outputs indicated that recharging into the groundwater did not change significantly during the period from 1978 to 1998. However, both LUCC and groundwater level changed substantially in the Sangong Oasis Region, and their variations were closely correlated to each other spatially and temporally over the past two decades. It confirmed that urbanization process and increased industrial activities were the direct reasons of groundwater table descending and the deterioration of water quality. The results of this research provided a scientific basis for understanding sustainability-related problems and solution options in the oasis areas of western China.

In response to limited availability of soil resources in basal root zone, plant extends its roots into nearby resource-rich zones to fulfill essential resource demands for survival and reproduction. This root proliferation into that enriched zones occupied by other plants constitutes interplant overlapping rooting zones and thereby the overlapping depletion zones, causing reduction in resource uptake by neighboring plants. By incorporating this mechanism into the classic resource competition model, we study interplant direct competition through their rooting system in an overlapping depletion zone. The model results indicate an extension of Tilman’s R* rule that has already been proved true when plants compete indirectly through their effect on shared resources. The results reveal that plant’s direct competitive ability (i.e., the ability to occupy an overlapping depletion zone by excluding others) can be characterized by its R*-value, where a best competitor having lowest R*-value excludes others from an overlapping zone and occupies the zone by depleting the resource level to the lowest as in its non-overlapping depletion zone. By analyzing the model, we find a suite of traits that confers R* variation among directly competing plants. This suite of traits would be a useful proxy measure for R* that do not necessarily require to establish equilibrium field monoculture—a requirement for R* measurement in the field.

This study seeks a routine to quantify spatial pattern of land cover changes in semiarid environment of China based on post-classification comparison method. The method consists of three major steps: (1) the image classification and unification of classified results based on two-level land cover classification themes, (2) the establishment of land cover change classes based on an unification land cover classification theme, (3) the reclassification and mapping of land cover change classes with three overall classes including no-change, gain and loss based on the unification land cover class. This method was applied to detect the spatial pattern of land cover changes in Yinchuan Plain, one of famous irrigation agricultural zones of the Yellow River, China. The results showed the land cover had undergone a remarkable change from 1991 to 2002 in the study area (the changed area was over 30%). Rapid increase of cropland (12.5%), built-up area (131.4%) and rapid decrease of bare ground (51.7%) were alarming. The spatial pattern of land cover changes showed clear regional difference in the study area and was clearly related to human activities or natural factors. Thus, it obtained a better understanding of the human impact on the fragile ecosystem of China’s semiarid environment.

The grain size composition, distribution characteristics and spatial variation of eolian sand soil on distinct positions across two longitudinal dunes and interdune areas were studied by means of conventional grain size analysis and geostatistical methods. In the study, 184 samples of eolian sand soil from the 0-30cm layer were systemically collected and measured from two longitudinal dunes and interdunes in the southern Gurbantunggut Desert. The results show that the dominant grain sizes are fine and very fine sands, and the differences of grain size compositions between the distinct geomorphologic positions are significant. The contents of clay and silt are highest on the interdune areas and lowest on the crests, and higher on the leeward slopes than on the windward slopes. The contents of very fine and fine sands are highest on the windward slopes and lowest on the crests. The contents of medium, coarse and very coarse sands are lowest on the interdune lands, and highest on the crests, and are identical on the two slopes. The coarser sizes (φ1) and mean sizes (Mz) for eolian sand soil all have a varying tendency from fine to coarse sizes with interdune area → leeward slope → windward slope → crest, and the sorting (σ) are poorly to well sorted. The results of geostatistical analysis reveal that φ1, Mz and σ values are moderately to strongly spatially autocorrelated. The values of the spatially correlated ranges are φ1＜σ＜Mz. The spatial variation for these grain size parameters is significant across the longitudinal dune landscape. From the crests towards the bottom of the slope, there is a varying gradient of zonal distribution, and the gradient values on the leeward slopes are larger than sites on the windward slopes.

Wheat growth in response to soil water deficit play an important role in yield stability. A field experiment was conducted for winter wheat (Triticum aestivum L.) during the period of 2002–2005 to evaluate the effects of limited irrigation on winter wheat growth. 80%, 70%, 60%, 50% and 40% of field capacity was applied at different stages of crop growth. Photosynthetic characteristics of winter wheat, such as photosynthesis rate, transpiration rate, stomatal conductance, photosynthetically active radiation, and soil water content, root and shoot dry mass accumulation were measured, and the root water uptake and water balance in different layer were calculated. Based on the theory of unsaturated dynamic, a one-dimensional numerical model was developed to simulate the effect of soil water movement on winter wheat growth using Hydrus-1 D. The soil water content of stratified soil in the experimental plot was calculated under deficit irrigation. The results showed that, in different growing periods, evapotranspiration, grain yield, biomass, root water uptake, water use efficiency, and photosynthetic characteristics depended on the controlled ranges of soil water content. Grain yield response to irrigation varied considerably due to differences in soil moisture contents and irrigation scheduling between seasons. Evapotranspiration was largest in the high soil moisture treatment, and so was the biomass, but this treatment did not produce the highest grain yield and root water uptake was relatively low. Maximum depth of root water uptake is from the upper 80 cm in soil profile in jointing stage and dropped rapidly upper 40 cm after heading stage, and the velocity of root water uptake in latter stage was less than that in middle stage. The effect of limited irrigation treatment on photosynthesis was complex owing to microclimate. But root water uptake increased linearly with harvest yield and improvement in the latter gave better root water uptake under limited irrigation conditions. Appropriately controlled soil water contents can improve the root water uptake and grain yield. Consistently high values of root water uptake and grain yield were produced under conditions of mild water deficit at the seedling and start of regrowth to stem-elongation stages, in addition to a further soil water depletion at the physiological maturity to harvest stage. We suggest that periods of mild soil water depletion in the early vegetative growth period together with severe soil water depletion in the maturity stage of winter wheat is an optimum for limited irrigation regime in this oasis. Considerable potential for further improvement in agricultural water use efficiency in the arid zone depends on effective conservation of moisture and efficient use of the limited water.

The biodiversity－productivity relationship is an important topic in the research of biodiversity and ecosystem function. The plant diversity－productivity pattern is commonly unimodal and positively correlated. This paper researches the characteristics of plant diversity-productivity patterns in the Bayanbuluk alpine steppe in the central Tianshan Mountains, Xinjiang, China, and analyzes the effects of environmental factors on the distribution of plant communities, species composition, plant diversity and productivity in the steppe. The results show a positive correlation between plant diversity and productivity. DCCA (detrended canonical correspondence analysis) ordination reveals a significant relationship between the effects of air temperature, soil moisture content, available soil nitrogen, relative humidity and pH value on the distribution and composition of plant communities. There are significant correlations between the soil moisture content, relative humidity, pH value, air temperature and species richness and the aboveground biomass of Gramineae and Cyperaceae, and also significant correlations between the relative humidity, pH values and the total aboveground biomass of plant communities.

This paper discusses oasis stability at regional scale with a case study in the northern slope areas of the Tianshan Mountains (NSTM). The results showed certain significant aspects. (1) As long as water resources in the oasis keep stable and their utilization efficiency can be maintained or gradually increased, the primary productivity could be continuously increased and the natural primary productivity keeped relatively stable. In this case, it is considered that the oasis is stable and its sustainable development can be achieved at regional scale. (2) Considering the availability of water resources in the oases, the oases on the alluvial-diluvial fans are highly stable. In the alluvial plain downstream of the groundwater overflowing zones the oases are moderately stable and in the lacustrine deltas or dry lacustrine deltas the oases are lowly stable. (3) Enlargement of oases and the increase of water resources and vegetation coverage in the oasis will certainly enhance the “cold-island effect” of the oasis and increase the stability of oases.

Samara is the reproductive organ (seed) for many tree species in arid land in northwestern China. It is ecologically important in population development due to its dispersal function. However, information on its photosynthesis and effect of environmental stresses on its photosynthesis is still very limited. In the present study, responses of photosystem II (PSII) activity in samara and leaf of Siberian maple to short-term chilling/freezing and subsequent recovery potential were comparatively investigated by using polyphasic fluorescence test. The samara had more efficient photosynthesis (Fv/Fm and PIABS) and more efficient electron transport (φEo) but lower energy dissipation (DIo/RC) than leaf. Generally, the PSII performance and the electron transport for both samara and leaf were inhibited under low temperature stress, accompanied by an increase of energy dissipation in PSII reaction centers (RCs). PSII of both samara and leaf was not markedly affected by chilling and could acclimate to chilling stress. Short-term freezing could completely inhibit PSII activity in both samara and leaf, indicated by the drop of values of Fv/Fm, PIABS, φEo to zero. PSII functional parameters of short-term dark frozen samara could be largely recovered whereas those of frozen leaf could not be recovered. The higher tolerance of samara to short-term low temperature stress than leaf is of great ecological significance for seed development, population establishment of Siberian maple.

The nrDNA internal transcribed spacer (ITS) and cpDNA trnL-F internal spacer (IGS) sequence data of Caragana eight species and one outgroup Halimodendron halodendron, was employed to reconstruct a phylogenetic tree, then the area relationship was analyzed by means of component analysis (CA), Brooks parsimony analysis (BPA), and dispersal-vicariance analysis (DIVA), six areas were selected from two divided distributions of East Asia and Tethys in Caragana. The phylogenetic tree indicated that there were three distinctive groups, which were attributed to some morphological characters, first with pinnate foliage and deciduous rachis, second with palmate foliage and persistent sclerotic stick rachis, and third with pinnate foliage and persistent sclerotic stick rachis. The results of CA and BPA illustrated general area relationships. An explicit area relationship should be Altai－Sayan, Far East－NE China and North China (Hengduan Mountains). DIVA recognized several explanatory vicariance and dispersal events. As the scenario of Caragana distribution pattern, it looks like the vicariance versus dispersal plays more important role. In vicaraince, there are not only the isolated far-distance vicariance, but also the adjacent vicariance especially a vicariance between Hengduan Mountains and North China.

The distribution and migration of houbara bustard in China was studied by range investigation and tracking through PTT satellite transmitter from 1997 to 2004. The houbara bustard occurs in the Junggar Basin, north part of Tacheng Basin and valley of Ulungur river in northern Xinjiang, southern part of Turpan Basin and Barkol in eastern Xinjiang. In Inner Mongolia, the houbara bustard occurs in Urathouqi, Alxahouqi and Ejinaqi. In Gansu province, the houbara bustard occurs in Wuwei, Minqin and Shandan. The whole range is not contiguous area. Houbara bastard started migration from Junggar Basin in northern Xinjiang, Turpan Basin and Barkol in eastern Xinjiang, Wuwei in western Gansu Province and Bayan Nur in western Inner Mongolia in the middle of September. Flying to the west and northwest, via Junggar Basin and area between Bole and Habahe in northern Xinjiang, entered Kazakhstan, they turned toward southwest, passed Uzbekistan and Turkmenistan, arrived in Arabia Bay of southern Iran or flied over Afghanistan, arrived in southern Pakistan for wintering. The whole migration usually took 35 ± 13 days covering a distance of 4 800-7 000 km. In the next year, houbara went back to the breeding grounds in China through the same routes at the beginning of March. However, it took the birds 64 ± 17 days to finish the spring migration. They arrived in breeding site between middle of April and late May. The sub-adults arrived later and did not breed.

Atmospheric nitrogen (N) deposition has been poorly documented in northern China, an intensive agricultural and industrial region with large emissions of NHx and NOy. To quantify N deposition, total airborne N deposition was determined at three agricultural sites using a manual integrated total nitrogen input (ITNI) system during growth of winter wheat (Triticum aestivum L.) and Italian ryegrass (Lolium multiflorum Lam.) from September 2005 to May 2006. Total estimated N deposition averaged 54.9 and 43.2 kg N/hm2 across the three sites when wheat was grown to flowering and maturing, respectively. The average value was 50.2 kg N/hm2 when ryegrass was the indicator plant. Both indicator species gave similar total airborne N input results. The intermediate level of N supplied resulted in the highest N deposition, and the ratio of N acquired from deposition to total N content of the whole system decreased with increasing N supply to the roots. The contribution of atmospheric N to the total N content of the wheat and ryegrass sand culture systems ranged from 10% to 24%.

Spatial organization of multiple plant species that appears as a non-random distribution of vegetative patches is one of the mostly observed spatial patterns in arid ecosystems. Yet understanding of ecological processes allowing this spatial pattern to emerge through interspecific interactions is still lacking. With a proposed conceptual model involving interspecific trade-offs between species competitive ability and colonization ability, we have argued that within patch abundance dynamics regulated by the mechanisms of competition are strongly influenced by the between patches colonization dynamics that are maintained via this trade-offs and it holds a positive, intraspecific occupancy-abundance relationship, in which increased patch occupancy increases species density within inhabiting patches. In a constant environment, while local abundance dynamics approach toward a stable equilibrium point, a fixed spatial arrangement of species can be retained through this coupled dynamics. However, in fluctuating environments where existence of such stable equilibriums is highly uncertain, it may involve continuous transitions from one community state to another as species re-organized themselves over space through the rapid changes in local species abundances. While some of the inhabiting patches are destroyed exogenously or endogenously, or species responses to increasing environmental fluctuations vary increasingly with time, discontinuous transitions into an abrupt, irreversible state of the community dynamics may occur, as with this effect the inherent positive relationship between occupancy and abundance of species is no longer maintained.

An experiment is made to detect the land-cover change in the area located to the south of Aksu in the northern Taklimakan desert through analyses of satellite data pixel by pixel basis. The analyzed data are those observed in the late summer and early autumn of 1973, 1977, 1993 and 1995. As a parameter of land-cover, SAVI (Soil Adjusted Vegetation Index) derived from the data of Landsat MSS and JERS-1 OPS (Optical Sensor) is used. The result indicates the increase of vegetation in the oasis areas, confluent area of the Yarkant and Kashgar Rivers and around reservoirs while little change occurs in the desert area. The 1973 satellite image shows the abundant flow in the Yarkant River while the river is almost dried up in the satellite images of later years. The trend of the decrease in the Hotan River flow is recognized although not so dramatic as that of the Yarkant River.

With the aid of analyses to landscape ecology in the highway region of the arid area in Xinjiang of China, vegetation type, soil type and land-use type were ascertained as environmental factors of highway landscape ecosystem fragility, and seasonal flood, blown-wind sand and alkali-salinization as disaster factors of highway engineering. All items of these factors constitute an objective hierarchy of evaluating landscape ecosystem risk of the highway region in the arid area. The weighted values of the items were determined according to the number of occupied area or length by them against each unit. The area or length was interpreted with the aids of GIS technology and gained by measuring in the highway reconnaissance. The results of the eco-environmental risk assessment of G315 Yitunbulake-Qiemo section in Xinjiang shows that eight units of landscape ecology can be sorted into four categories according to the differences of the fragility indices (Σxiwi) and the disaster indices (Σyiwj).

Eremosparton songoricum (Litv.) Vass. is a clonal shrub that reproduces both asexually by under-ground rhizomes and sexually by seeds. It is now a rare species with a narrow distribution in fragmented habitat patches in the Gurbantunggut Desert of Xinjiang, China. The objective of this study was to determine the spatial pattern or structure of genetic variation within population. The within-populations genetic structure of E. songoricum in a plot (10 m×10 m) was analyzed using inter simple sequence repeats (ISSR) markers. Correlograms of Moran’s I showed significant positive value was about 7 m, but changed into a negative correlation with the increase of distance, indicating strong genetic structure. The natural character of clonal reproduction, restricted seed and pollen dispersal were the main factors of influencing the spatial pattern. The knowledge of clonal structures within populations was crucial for understanding evolutionary processes and ecological adaptation. This study provided basic data for the conservation and management of E. songoricum, especially for sampling strategies for ex situ conservation.

This paper analyzes the urban spatial structure of Tarim River Basin from the perspectives of urbanization, urban density, grading scales and spatial evolution patterns, using geographical theories and methods, such as fractal theory, principle component analysis, urbanization imbalance index, urban scale imbalance indicator, and urban spatial interaction. The results show that the urban spatial structure displays balanced distribution in the overall pattern, while an imbalanced distribution in each region. The development of town pattern tends to be gathering to the central towns in the oasis of Tarim River Basin and a development axis has begun to form along the southern Xinjiang railway. Based on the division of urban hinterland, and the development characteristics of oasis economy, this paper puts forward an urban spatial organization model. This model uses “breakpoint model” and divides Tarim River Basin into five urban clusters: Korla urban cluster, Kuqa urban cluster, Aksu urban cluster, Kashgar urban cluster and Hotan urban cluster. As a conclusion, this article puts forward an overall framework of urban spatial organization in Tarim River Basin: “one axis, double core, and five groups”.

Rapid population growth and artificial oasis enlargement did pose great threat to the natural riparian ecosystems of Tarim River and caused seriously ecological deterioration and greater desertification of the Tarim River Basin in the second half of 20 century. Restoration of the endangered riparian ecosystem requires that environmental flow should be restored through restricted and uncontrolled flow diversion irrigation in tributary areas. Implementation of such restriction needs further the basin-wide reallocation of water resources through a set of engineering and non-engineering measures taken to ensure the water requirement in the tributary and maintain effective flows in Tarim River. As one of evolving HELP (Hydrology for Environment, Life and Policy) basins, the article first presents an overview of hydrology, socio-economic development and ecosystem evolution of the Tarim River Basin. Then, those measures for restoring and maintaining environmental flow are reviewed and analyzed along with its applicability and validity. The issues emerging in implementing those measures are also explored, and then the conclusions were summarized. Lessons learned could provide a good example for other basins under similar conditions.

Microorganisms and its metabolic types are diverse in Xinjiang because of those extreme/special environments of drought, high or low temperature, saline and alkaline, oligotrophy. This article reviewed the research progress and achievements of various microbial resources (bacteria, fungi and actinomycete) in the special environments from the point of its ecology, development and application. Meanwhile, the development trend, protection and sustainable utilization of the microorganism resources were discussed.

A short visit to the Bayanbuluk Grassland in the Tianshan Mountains, Xinjiang, PRC, revealed a number of environmental and livestock production problems, including grassland degradation, loss of grassland biodiversity, soil erosion and flash flooding downstream, decreased pasture productivity, and poor livestock nutrition (especially in winter) leading to stock losses and flocks and herds of low productivity. This paper describes those problems and then suggests some solutions. Short duration, high intensity grazing could be one of the solutions to both improving grassland condition and improving livestock nutrition. Local production of fodder crops for feeding in winter and spring deserves testing, using adapted strains of Alfalfa (Medicago sativa) and trialling fodder root crop production. It is important to realise that the land management objectives of scientists, administrators, herders and farmers may be similar, and that there are opportunities for land improvement through working together.

In order to study convergence zones or discontinuous lines formed locally in the Taklimakan Desert, we analyzed available MODIS images onboad TERRA or AQUA satellite for ten cases: 29 March 2002, 14 April 2002; 2 January 2003; 21 April 2003; 26 March 2004; 28 April 2004; 30 January 2005; 25 June 2005; 3 December 2005; and 26 July 2006. We used weather maps published by the Japan Meteorological Agency for the Asia and Pacific region at 500 hPa, 700 hPa and 850 hPa, at 00Z and 12Z to analyze the meteorological conditions occurring in each case. We estimated the positions of air streams, convergence zones or discontinuous lines between them, and thermal conditions on the maps and confirmed the presence of cumulus and cumulonimbus clouds through satellite images in particular. After a review of previous studies, this paper introduced the results of the present study. Closed warm areas in the Taklimakan Desert and on the Tibetan Plateau and local convergence zones or discontinuous lines in the Taklimakan Desert were discussed together with their diurnal changes, using composite maps of the ten cases. Along the long axis of the desert the convergence zones or discontinuous lines normally extend 70–80 km in a west-east direction, but are suspected to exceed 100 km in extreme cases. On the other hand, the convergence zones or discontinuous lines extending in a north-south direction on the southern fringe of the desert have a length of 40–60 km. The closed warm areas show clear diurnal changes, but they were not detected at the 500 hPa level. An example of a clear convergence zone running in a north-south direction on 26 July 2006 was presented in detail with corresponding satellite images.

We analyzed the 1961–2006 mean surface air temperature data of 138 stations in China’s northwest arid and semi-arid areas (CNASA), to measure climate change in terms of annual mean air temperature changes. We used methods of linear regression analysis, multinomial fitting, Empirical Orthogonal Function (EOF), Rotated Empirical Orthogonal Function (REOF), Mann-Kendall, Glide T-examination, wavelet analysis and power spectrum analysis. The results show that (1) the warming rate of the annual mean air temperature in CNASA was 0.35oC/10a during the 1961–2006 study period. Some places in the west part of Xinjiang and east part of the Qinghai plateau, which is impacted by the terrain of leeward slope, exhibit smaller increasing trends. However, the majority of region has shown distinct warming in line with general global warming; (2) The standard deviation of the annual mean temperature distribution is non-uniform. The south Xinjiang and east Qinghai–south Gansu areas show relatively small standard deviations, but the inter-annual variation in annual mean air temperature in the greater part of the region is high; (3) Inner Mongolia, Shaanxi, Gansu, Ningxia and Tarim Basin are the areas where the temperature changes are most sensitive to the environment. The degree of uniformity in annual mean air temperature increase is higher in the arid and semi-arid area. From the early 1970s, the trend in temperature changed from a decrease to an increase, and there was a marked increase in mean temperature in 1986. After that mean temperature went through a period of rapid increase. The entire area’s 10 hottest years all occurred in or since the 1990s, and 90% of various sub-districts’ hottest years also occurred after 1990. The process of temperature change appears to have a roughly 5-year and a 10-year cycle; (4) Annual mean air temperature variation has regional differences. In Inner Mongolia–Xinjiang and Shaanxi– Gansu–Ningxia–Qinghai areas, the temperature variation in their northern areas was very different from that in their southern areas; (5) Using the REOF method we divided the region into 4 sub-regions: the Northern region, the Plateau region, the Southern Xinjiang region and the Eastern region. The region’s annual mean air temperature transition has regional differences. The Plateau and Southern Xinjiang regions got warmer steadily without any obvious acceleration in the rate of warming. The Northern region’s warming started about 5-years earlier than that of the low latitude Eastern region. The ‘Startup region’ of the Qinghai-Tibet Plateau, appears to undergo temperature changes 3 to 10 years earlier than the other regions, and exhibits inter-decadal variations 1 to 2 years ahead of the other regions.

Hydraulic resistance components and water relations were studied on Haloxyolon ammodendron, a small xeric tree, growing at sites significantly differed in soil texture. Soil water content, leaf water potential (ψl), xylem water potential (ψx), root water potential (ψroot), leaf transpiration rate (TR) and stomatal conductance (gs) were measured at the two sites during the growing season of 2005 and 2006. Leaf specific hydraulic resistance (Rplant) during the whole growing season, hydraulic resistance of plants (Rp), shoots (Rshoot) and roots (Rroot) in the August of both years were calculated and expressed on leaf area basis. The results showed the proportion of the hydraulic resistance of the aerial part (Rshoot) to the Rp was the same to the proportion of the hydraulic resistance of the soil part (Rroot) to the Rp, indicating that both parts were equivalent important to plant water hydraulic system from soil to leaf. Positive significant correlations were found between Rp and Rroot, suggesting that root hydraulics resistance was a major determinant of plant hydraulic resistance (Rp) and transpiration rate. The integrated effect of stomatal control, hydraulic regulation and morphology adjustment enabled plants at heavy soil site surviving the extreme water deficit period.

The study of soil microbial populations and diversity is an important way to understanding the soil energy process. In this study we analyzed the characteristics of soil microbial populations of the Tarim Desert Highway shelter-forest, by identifying microbial fatty acids and using methods of conventional cultivation. The results illustrated that the amount of soil microbial activity and the diversity of soil microbial fatty acid increased significantly with the plantation age of the shelter-forest; the soil microbial population was dominated by bacteria. The fatty acids of C14:0, C15:0, C16:0, C17:0, C18:1ω9, C18:0, C18:2ω6 and C21:0 were found to be dominant soil microbial fatty acids in the shelter-forest soil. Principal analysis and regression analysis showed that (1) concentrations of fatty acids of C14:0, C16:0 and C18:0 could be used as indicators of total soil microbial population; (2) soil bacteria and actinomycetes populations were closely correlated with the amount of fatty acids of C15:0 and C17:0; and (3) soil fungi were closely correlated with the amount of fatty acids of C18:1ω9 and C18:2ω6.

Based on a database of more than 40 years of second production process and energy flow records for Maduo, Qumalai and Yushu counties, a dynamic model of the stress within grassland ecosystems was established using a nonlinear regression method for this source regions of the Yangtze and Yellow Rivers. The results show that dynamic curves of stress within grassland ecosystems in the three counties were in the shape of an inverted “U” during the period 1965–2007. It also revealed that the variation in actual amount of livestock inventories reflected the general trends of the stress within the grassland ecosystems in the source regions, although there were many other factors for the increase or reduction in grassland ecosystem stress.

The middle and lower reaches of the Tarim River are currently one of the main regions of ecological restoration in the arid areas of western China. Using the principles and method of landscape ecology, this study has chosen the fluvial corridor landscape in the middle and lower reaches of the Tarim River, and discusses the region’s ecologically functional regionalization system and issues related to its practical classification. On this basis the corresponding regionalizing principles and standards were developed which were used to qualitatively divide the three main landscapes as the ecologically functional areas in the drainage basin. The paper has also analyzed the characteristic of the study areas, and has put forward the measures for its ecological restoration.

The organic carbon and humus content in oil polluted brown and grey-brown soils in Mangyshlak, Pre-Caspian Sea Region, was analyzed from 2000 to 2008. The results indicated that bitumen substances from crude oil pollution deteriorated the soil property, however, the organic carbon content increased significantly. The products of oil pollution changed the composition of carbonaceous substances which formed soil humus, and changed the ratios of the humus components. Residual insoluble carbon increased with the rise of oil organic carbon. The mobility of humus components was significantly increased because of the high oxidation-reduction process in the topsoil, and the humus content and microorganism activity increased. The organic carbon content increased significantly, while it decreased with the distance away from the oil well. The rearrangement of physical, physical-chemical and chemical properties of the polluted soils was significant.

As an example of atmospheric nitrogen (N) deposition, the paper summarizes the definition, form and amount of nutrient from the environment (NFE) and the relationship between NFE and anthropogenic reactive N emission. Based on our own study and published articles, we find that N wet and dry deposition has been an important nutrient resource in agricultural and natural ecosystems in China. The total amount of N deposition and other environment-derived N in China was up to 18 Tg N/a, equal to approximately 60% of the national N fertilizer consumption. Nitrogen deposition is expected to contribute substantially to nutrient cycling and net primary productivity in various ecosystems. Therefore, it is crucial to utilize this environment-derived nutrient resource by integrated nutrient resource management in order to realize the sustainable development of both agricultural and non-agricultural ecosystems.

In many arid and semiarid regions, saline playas represent a significant source of unconsolidated sediments available for aeolian transport, and severe saline dust storms occur frequently due to human disturbance. In this study, saline dust storms are reviewed systematically from the aspects of concept, general characteristics, conditions of occurrence, distribution and ecological impact. Our researches showed that saline dust storms are a kind of chemical dust storm originating in dry lake beds in arid and semiarid regions; large areas of unconsolidated saline playa sediments and frequent strong winds are the basic factors to saline dust storm occurrence; there are differentiation characteristics in deposition flux and chemical composition with wind-blown distance during saline dust storm diffusion; and saline dust storm diffusion to some extent increases glacier melt and results in soil salinization in arid regions. An understanding of saline dust storms is important to guide disaster prevention and ecological rehabilitation.

The Relict Gull (Larus relictus) is recognized as a vulnerable species, with a worldwide population of about 6,000 individuals. Always inhabiting the extreme arid regions of Central Asia, their migratory routes and winter grounds are unclear. This research focused on distribution sites, habitat, behavior, population size and seasonal changes of Relict Gull. Line transects and point counts in every month were used to investigate the gulls around the Ebinur Lake. The result showed Relict Gull was summer visitor to Xinjiang, Western China. Population curve with a single peak was obtained. This gull appeared in early April and was 63 individuals (1% of the global population). The number remained stable from May to July in 2009. The discovery of fledglings indicates that Relict Gull may breed here. They left Ebinur Lake in August. Relict Gull in Ebinur Lake should belong to the Central Asian subpopulation, which was the most westerly record in 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.

Owing to global climatic changes and human activities, the lakes have changed dramatically in the Junggar Basin of Xinjiang in recent 50 years. Based on the remote sensing images from Beijing Satellite No.1 in 2006 together with the measured topographical data in 1999 and other data since the 1950s, this paper analyzes mainly the features of landforms around the Manas Lake and the changes of feeding sources of the lake. The results are as follows: (1) Tectonic movement brought about the fundamental geomorphological basis for lacustrine evolution, and the Manas Lake is one of small lakes broken up from the Old Manas Lake due to tectonic movement and drought climate; the Manas Lake had existed before the Manas River flowed into it in 1915. The geomorphologic evidences for evolution of the Manas Lake include: (a) Diluvial fans and old channels at the north of the lake indicate that the rivers originating from the north mountains of the Junggar Basin had fed the Old Manas Lake and now still feed the lake as seasonal rivers; (b) The Old Manas Lake was fed by many rivers originating from the mountains, except for the Manas River, from the evidence of small lakes around the Manas Lake, old channels, alluvial fans, etc.; (c) The elevations of the alluvial and diluvial fans are near to the 280 m a.s.l. and all of the small lakes and lacustrine plains are within the range of the 280 m a.s.l., which may prove that the elevation of the Old Manas Lake was about 280 m a.s.l.; (d) Core analysis of the Manas Lake area also indicates that the Manas Lake has existed since Late Pleistocene epoch. (2) Analysis on the feeding relations between the lakes and the lacustrine evolution shows that human activities are one of main driving forces of the lacustrine evolution in recent 50 years, and it is the precondition of restoring and maintaining the lacutrine wetlands in the study area to satisfy the feeding of the Baiyang and Manas rivers to the Manas Lake.

In order to investigate the spatio-temporal variability of soil water content to rainfall under Caragana microphylla shrub in Horqin Sandy Land, a plot of 25 m × 25 m, where there were 6 shrub canopies of C. microphylla, was sited for measuring soil water content at two soil layers of 0-20 cm (top layer) and 20-40 cm (lower layer). Soil water content was measured on the 1st, 5th, 10th and 15th day after a 42 mm rainfall in Naiman of Inner Mongolia. The results showed that soil water contents at both layers under C. microphylla shrub were gradually decreased after the rain. Soil water content at the top layer outside the shrub canopy was higher than that inside the shrub canopy within 5 days, and became similar inside and outside the shrub canopy on the 10th day after the 42 mm rainfall, and it was lower outside than that inside the shrub canopy on the 15th day. The soil water content at lower layer in the area without shrubs was higher than that under shrub canopy all along. All the measured values of soil water content can be fitted to a variogram model. There was significant autocorrelation of the values of soil water content between top layer and lower layer, except for the fourth measured values of soil water content at top layer. The range and spatial dependence of soil water content at top layer were lower than that at lower layer.

As one of the most important biological factors that maintain the stability of the largest fixed and semi-fixed desert in China, the Gurbantunggut Desert, the biological soil crusts (BSCs) develop well and play critical ecological roles in the desert ecosystem. In this paper, we briefly summarize our research findings since 2002 including species composition, distribution pattern and ecological functions of BSCs in the desert. Our results indicate abundant species diversity of BSCs in the Gurbantunggut Desert in comparison to other deserts in China. At the scales of sand dune or whole desert, the distribution patterns of BSCs are location-specific. The existence of BSCs in this desert could: (1) accelerate the formation of desert soil and the weathering of minerals; (2) accumulate organic matter in surface soil through related species in soil crusts; (3) enhance the abilities of sand surface to resist wind erosion; (4) influence seed germination of vascular plants; and (5) enhance the production of dew deposition on sandy soil surface.

Na+ ions play an important role in the growth of halophyte. The effect of Na+ ions on nitrate uptake and osmotic adjustment in the euhalophyte Suaeda physophora was investigated under glasshouse conditions. Seedlings were exposed to 1 mmol/L NaCl (control), 300 mmol/L NaCl, 150 mmol/L NaCl plus 150 mmol/L KCl or 300 mmol/L KCl treatments for 24 d. Dry weight was not affected greatly by different salt treatments, but water content and succulence in leaves of S. physophora were significantly increased at 300 mmol/L NaCl and 150 mmol/L NaCl plus 150 mmol/L KCl treatments. The concentrations of Na+ and NO3- in leaves of S. physophora were the highest at 150 mmol/L NaCl plus 150 mmol/L KCl, but lowest at 300 mmol/L KCl treatment. Moreover, the increase of NO3- concentration did not result in the decrease of Cl- concentration at 150 mmol/L NaCl plus 150 mmol/L KCl treatments. The estimated contribution of NO3- to osmotic potential (CNO3) in leaves of S. physophora was 9.8% at 150 mmol/L NaCl plus 150 mmol/L KCl, and CNa and CCl were 31.0% and 23.3%, respectively. However, CNO3, CNa and CCl were respectively 1.6%, 7.9% and 11.9% at 300 mmol/L KCl treatment. It is concluded that Na+ stimulates NO3- absorption and the stimulation is independent on the internal or the external Cl- concentration in the euhalophyte S. physophora. These characteristics may explain the high levels of N in leaves of saline desert plants in arid ecosystem.

Kanas is a National Nature Reserve and National 5A Scenic Area, and it is also high on China’s National Natural Heritage List. In this paper, with an integrated analysis and comparative geographical approach, the genesis and current features of the Kanas landscape are analyzed systematically according to the criteria for outstanding universal values that must be met for designation by the United Nations as World Natural Heritage. It is concluded that Kanas has outstanding universal values in geosciences, biology and aesthetics. Through comparison with other World Natural Heritage sites of the same geological types, in the same biogeographic zone and in the same latitude, it is concluded that Kanas meets criteria vii, viii, ix and x for designation as World Natural Heritage. Thus, this work establishes a scientific foundation for nomination of Kanas for such a status.

Taking Gansu province as a model case, this study provides an integrated analysis on the eco-economic system of arid and semi-arid region based on emergy synthesis theory. Through calculating the values of renewable emergy flow, non-renewable resources, imported emergy, exported emergy, waste emergy, and total emergy during the period of 1978-2007, the performance of Gansu eco-economic system was analyzed. The results indicated that the renewable emergy flow within the province basically remained steady state which was estimated at 2.99×1022 solar emjoules (sej) from 1978 to 2007. The imported emergy and exported emergy were estimated at 3.75×1017 sej and 2.99×1020 sej in 1978 and increased to 1.07×1022 sej and 1.44×1022 sej respectively in 2007. The nonrenewable emergy flow was estimated at 1.62×1022 sej and increased to 1.85×1023 sej, with annual growth rate of 8.7%, while the estimated total emergy was 4.58×1022 sej in 1978 and increased to 2.11×1023 sej in 2007, with annual growth rate of 5.41%. Our results indicate a deteriorate situation between economic development and environmental protection in the region. The rapid economic growth in the past thirty years was based on a great consumption of nonrenewable resource and caused continuous decrease in the capacity of sustainable development. The environmental loading ratio was 0.53 in 1978, increased to 6.06 in 2007, indicating a rapid degradation of the regional environment quality. We calculated that the actual population was 1.53 times the renewable resource population in 1978, increased to 7.06 times in 2007. During the period of 1978-2007, the emergy rose from 2.45×1015 sej/(capita·a) to 8.07×1015 sej/(capita·a). Our analysis revealed that the emergy density presented a trend of gradual increase, and then the emergy currency ratio in Gansu decreased from 7.08×1013 sej/Chinese Yuan to 7.82×1012 sej/Chinese Yuan.

In this paper, the oasis cities in Kashgar Prefecture and Kizilsu Kirgiz Autonomous Prefecture are taken as an example, through the factor analysis, spatial attraction interaction model and location quotient methods, urban hierarchy system, the intensity of urban economic ties, economic subordination degree, and structure of city functions were analyzed. The results indicated: (1) The urban hierarchy system takes Kashgar city as the main center, Artux city, Yarkant county and Maralbexi county as the sub-centers; (2) The intensity of economic ties among Kashgar city and each county is much higher than others. The interaction of Kashgar city, Shufu county and Shule county are the strongest, and the economic ties of Yarkant, Kagilik, Poskam counties are relatively close; All cities in the study area are economically subordinate to Kashgar city. (3) Three cities of Kashgar city, Shufu county and Shule county should connect strongly, with Kashgar city as the core. The cities and towns along the Southern Xinjiang Railway and along National Road 315 should be regarded as two strips, and the two city strips along the border, and the city strip along Provincial Road 215 should be treated as three axes. The ring structure strategy of “core ring, closer ring and radiated ring” was proposed. (4) It was proposed to build Kashgar city group in the north, and Yarkant city group in the south, Maralbexi city group in the southeast, and Taxkorgan border city group with four inner groups’ development strategy.

Altai (also named Altay in China) Mountain Country (Mountain System) is a unique natural region, located on the border between different floristic regimes of the Boreal and ancient Mediterranean sub-kingdoms, where distribution of plant species is actually limited. It is known to have sufficient endemic floral biodiversity in the Northern Asia. Many plants of Altai Mountain System need effective care and proper conservation measures for their survival and longer-term protection. Important Plant Area identified as the IUCN (the International Union for Conservation of Nature), specified criteria attract global attention for protection of floral biodiversity across the world. The records of 71 plant species from the Chinese Altai Mountains attributed to the criterion A and the dark conifer forests of Chinese Altai Mountains satisfied the criterion C, which may help qualify to fulfill the national obligation of the Convention on Biological Diversity.

By examination of Calligonum pumilum A. Los. and Calligonum ruoqiangense Liou f., collected from natural habitats, and the analysis of their variance, this paper revealed that the morphological characters of these specimens are quite different from each other, especially in the twist direction of ribs on fruits, rows of bristles along each rib, rigidity, interweaving degree of bristles, and their geographical distribution. Therefore, it is suggested that C. pumilum and C. ruoqiangense should be considered as two independent species.

The paper analyzes the hypothesis that the distribution of dominant plant species and characteristics of plant communities are related to groundwater depth. The results showed that variations of groundwater depth impacted distributions and characteristics of dominant plant communities. However, besides groundwater depth, the community composition and species diversity were also influenced by physiognomy of the habitat. Based on the similarity coefficient, the differences between dominant plant communities were significant at different groundwater depths. Compared with other results relating to desert vegetation and groundwater depth, variations of community distribution were similar at the large spatial scale. However, in this extremely arid region, there were significant differences in community type and community succession when compared with other arid regions, especially in relationship to deep groundwater depth. With groundwater depth from deep to shallow, communities transformed with the sequence of Alhagi communities, Tamarix spp. communities, Populus communities, Phragmites communities, and Sophora communities. At groundwater depth of less than 6.0 m, the community type and composition changed, and the species diversity increased. Among these dominant species, Tamarix exhibited the biggest efficiency in resource utilization according to niche breadth, which means it possessed the best adaptability to environmental conditions at the oasis margins.