Key Laboratory of Oasis Ecology of Ministry of Education

Urunchi, China

Key Laboratory of Oasis Ecology of Ministry of Education

Urunchi, China
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Gong X.,Key Laboratory of Oasis Ecology of Ministry of Education | Gong X.,Xinjiang University | Lu G.,Key Laboratory of Oasis Ecology of Ministry of Education | Lu G.,Xinjiang University | And 8 more authors.
Linye Kexue/Scientia Silvae Sinicae | Year: 2017

Objective: This study aimed to investigate the variation of stoichiometry in soil under crown and in leaves of desert halophytes along soil salinity gradients, and the major soil factors that affect leaf stoichiometry of desert halophytes, which is of great significance to ecological conservation in drought and salinization zone. Method: This study was conducted at the Ebinur Lake Wetland National Nature Reserve in Xinjiang Uygur Autonomous Region of China. Three plots with 10 m×10 m for each desert halophyte (Alhagi sparsifolia and Nitraria tangutorum) were set along soil salinity gradients. Based on the 216 samples of soil under crown and plant, the concentration of carbon (C), nitrogen (N) and phosphorus (P) and the ratios of C:N, C:P, and N:P in soil under crown and leaves of two desert halophytes in different soil salinity gradients were studied. Besides, the main soil properties that affect the leaf stoichiometry of the two halophytes were determined with redundancy analysis. Result: The results showed that a modest increase in the soil salinity obviously improved C, N and P concentration in soil under crown of desert halophytes, while heavy salinity reduced C, N and P concentration in soil under crown of A. sparsifolia. The C:N, and C:P in soil under the crown of A. sparsifolia in medium salinity were the highest, while the largest values of N:P of A. sparsifolia and C:N, C:P, N:P of N. tangutorum appeared in light salinity plot, and, without striking difference with soil salinity gradient (P>0.05). The concentration of C, N and P in leaves of N. tangutorum increased significantly with the increase of soil salinity (P<0.05). The C:N, and C:P ratios under medium salinity treatment were greater than that under heavy salinity treatment. Light salinity increased the content of C and P in leaves of A. sparsifolia, but reduced N content. Medium salinity caused increases in C:N, and C:P in A. sparsifolia leaves. The leaf N:P of the two desert halophytes did not show a marked difference (P>0.05) along with salinity gradient, and the average value was 15.41±2.16 and 8.01±0.83, respectively. Redundancy analysis showed that the P content in soil under crown, and salinity were the main factors that affect C, N and P stoichiometry in A. sparsifolia and N. tangutorum leaves, respectively. Conclusion: A modest increase in soil salinity improved the content of C, N, P in the soil under crown, and changed the content of C, N, P and the C:P ratio in leaves of the two desert halophytes. Leaf stoichiometry of halophytes was influenced by salinity and sodicity as well as element content in soil, and the interspecific difference resulted in the difference in main soil factor that affected leaf stoichiometry of the two desert halophytes. © 2017, Editorial Department of Scientia Silvae Sinicae. All right reserved.


Tan J.,Xinjiang University | Tan J.,Key Laboratory of Oasis Ecology of Ministry of Education | Ding J.,Xinjiang University | Ding J.,Key Laboratory of Oasis Ecology of Ministry of Education | And 5 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2017

Evapotranspiration is one of the important parameters in hydrological and meteorological studies. Under the background of global warming, it is essential to accurately estimate the potential evapotranspiration (ET0) in arid and semiarid areas where the water resources are limited and excessively explored. In this study, we used the data of main daily meteorological factors such as temperature, relative humidity, wind speed and sunshine duration from 4 meteorological stations to calculate the ET0 based on Penmen-Monteith equation for analyzing the spatial distribution and temporal change in the ET0 in Xinjiang Ebinur Lake oasis during 1961-2013. The Cramer mutation analysis was used for determination of the mutation point of ET0, the partial correlation analysis was conducted, and the contribution of the main climatic factors to ET0 was calculated. The results showed that: 1) the accumulative anomaly of ET0 was positive in 1960-1989 and negative in 1990-1999. The ET0 was the lowest in the 1990s and then increased since 2000. As a whole, the ET0 in the study area decreased from 1960 to 2013. The change of ET0 in the spring, summer and autumn was consistent with that of the whole year, and the change of ET0 in the winter was not obvious. The average ET0 calculated based on the whole year from 1960-2013 was 1 064 mm. The ET0 in the spring, summer, autumn and winter accounted for 29%, 52%, 16% and 3% of the total, respectively, indicating that ET0 in the spring and summer had the largest contribution to ET0; 2) the ET0 mutation was in the year of 1997 based on the whole year data, in 1999 based on the spring data, in 1996 in the summer and in 1999 in the autumn. ET0 was decreased at a rate of -2.81 mm/a from 1960 to 1996 and then increased at a rate of 3.43 mm/a since 1997 to 2013. There was no mutation in the winter; 3) the mean temperature, daily range of temperature, sunshine duration, wind speed, relative humidity and annual precipitation had different influence on the ET0. In the spring of 1960-1998, there was a high correlation between ET0 and wind speed and relative humidity. In the spring of 1999-2013, ET0 had a high correlation with mean temperature, wind speed and sunshine duration. In the summer of 1960-1995 and 1996-2013, ET0 had a high correlation with the mean temperature, relative humidity, wind speed and sunshine duration. In the autumn of 1960 to 1998, ET0 had a high correlation with the mean temperature, relative humidity and wind speed. However, after 1998, ET0 only had a high correlation with wind speed. There was a high correlation between ET0 and mean temperature, relative humidity and wind speed in the winter. According to the relative contribution of each factor to ET0, the wind speed was the main factor affecting ET0 in the study area. In the spring, ET0 was also affected by the daily range of temperature, and in the summer, autumn and winter it was also affected by the mean temperature. The results would provide valuable information for restoration of fragile ecological environment water resources allocation, agricultural irrigation and management science. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.


Gong X.,Key Laboratory of Oasis Ecology of Ministry of Education | Gong X.,Xinjiang University | Lu G.,Key Laboratory of Oasis Ecology of Ministry of Education | Lu G.,Xinjiang University
Biodiversity Science | Year: 2017

Patterns of species diversity are determined by both species interactions and environmental adaptations. The species composition and environmental factors of the Tugai forest on the north shore of the Aqikesu River was investigated to determine species diversity and the ecological niche of dominant species in the Ebinur basin. Using a multivariate regression tree based on the content of soil water and salinity, our results showed that the plant communities were divided into three associations. The three associations are the Ass. Populus euphratica – Apocynum venetum – Phragmites australis (type I), the Ass. Populus euphratica – Reaumuria songonica (type II), and the Ass. Kalidium foliatum ǁ Populus euphratica – Apocynum venetum + Alhagi sparsifolia (type III). Association I had a weak ability to tolerate extreme environments, including 5 quadrats, while Association II could tolerate mild salt and drought stress, including 3 quadrats, and Association III had a certain degree of adaptability to salty and dry habitats, including 22 quadrats. With succession of typical associations from type I to III, psammophytes and halophytes gradually occupied the habitats and become the dominant species. The Shannon-Wiener biodiversity index and Margalef richness index initially decreased and then increased along with environmental degradation, while the Simpson dominance index and Pielou evenness index showed the opposite trend. The variation of associations and species diversity along the environmental gradient reflects the succession of plant communities. The Bray-Curtis similarity analysis of niche breadth clustered 13 dominant species into two groups, with an average similarity of 96.89% and 97.66%, respectively, reflecting that the niche breadth of species has a high similarity. The pressure coefficient of non-metric multidimensional scaling (NMDS) ordination was 0.04 and except for Halimodendron halodendron and Glycyrrhiza uralensis, and species distribution also had a high similarity. In summary, soil water and salt contents are the main environmental factors that are responsible for plant structure and diversity, and determine the direction of succession. The niche and distribution of dominant species show high similarity, indicating obvious competitive relationship between them. © 2017, Chinese Academy of Sciences. All rights reserved.


Lei L.,Xinjiang University | Lei L.,Key Laboratory of Oasis Ecology of Ministry of Education | Tiyip T.,Xinjiang University | Tiyip T.,Key Laboratory of Oasis Ecology of Ministry of Education | And 6 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2014

The present paper selects the Kuqa Oasis as the study area, studies spectrum characteristics of soil salinity, and establishes soil spectrum library. Through transforming and analyzing varying degrees of soil salinization reflectance spectra data in the typical study area, and selecting the most sensitive spectral bands in response to salinization, we established the measured hyperspectral soil salinity monitoring model, and by correcting the soil salinity monitoring model established by HIS image through scale effect conversion improved the model accuracy under the conditions of a regional-scale monitoring of soil salinization. The results show that both measured hyperspectral soil salinity monitoring model and HSI image soil salinity inversion model have good accuracy, model determination coefficient (R2) is higher than 0.57 and the model stability is better. Compared with the corrected HSI image soil salinity inversion model and uncorrected HSI image soil salinity inversion model, the coefficient of determination has been greatly improved, which increased from 0.571 to 0.681, and through the 0.01 significance level, the root mean square error (RMSE) value is 0.277. The correction HIS image soil salinization monitoring model can better improve the model accuracy under the condition of regional scale soil salinization monitoring, and using this method to carry out the soil salinization quantitative remote sensing monitoring is feasible, and also can provide scientific reference for future research.


Yao J.,Xinjiang University | Yao J.,Key Laboratory of Oasis Ecology of Ministry of Education | Yang Q.,Institute of Desert Meteorology | Liu Z.,Xinjiang University | And 2 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2015

Using monthly precipitation records from 122 meteorological stations in the arid region of Northwest China, the spatial and temporal distribution of precipitation were analyzed for the period 1961—2011. The Mann-Kendall trend test and Morlet wavelet analysis were utilized to detect the spatio-temporal distribution of the mean annual and seasonal precipitation. In the present paper, the Northwest arid area was divided into the northern Xinjiang region, the southern Xinjiang region, Qilian Mountains, Tianshan Mountains, Hexi Corridor region, and the Inner Mongolia Plateau region. The results obtained indicate that the mean annual precipitation (MAP) in the northwest arid region had a significant rising trend (P < 0.01), at a rate of 9.31 mm/ decade. The mean annual precipitation in the Qilian Mountains area rose the fastest, increasing by 38.67 mm/ decade; the second fastest was on the Tianshan Mountains, increasing by 16. 79 mm/ decade; the slowest increase was in the Hexi Corridor, southern Xinjiang, and western Inner Mongolia, increasing by 8.49 mm/ decade, 5.44 mm/ decade, and 5.09 mm/ decade, respectively. The Mann-Kendall test showed that the increasing trend of the mean annual precipitation in each area was statistically significant at P<0.05 level, except in western Inner Mongolia. A rising tendency of the mean annual precipitation was observed in 95.9% of the stations in the study region, but the amplitude shows regional differences. The Tianshan Mountains, Qilian Mountains, and northern Xinjiang show a rising tendency in all stations, followed by those in southern Xinjiang and the Hexi Corridor, whereas the lowest increase is in western Inner Mongolia, accounting for 77. 78% of the stations. Centers of the highest increase in mean annual precipitation were identified. for example, Yeniugou (52.5 mm/ decade) in the Qilian Mountains, Tianchi (22.8 mm/ decade) in the middle of the Tianshan Mountains, and Xinyuan (28. 3 mm/ decade) west of the Tianshan Mountains. There are seasonal differences in the rising trend of the mean annual precipitation. The rate of precipitation increased the fastest in spring, by 3.32 mm/ decade, followed by the rate in summer and winter, by 5.44 mm/ decade and 5.09 mm/ decade, respectively, whereas it is the slowest in fall (only 2.07 mm/ decade). The precipitation rate in winter was universal across the studied region, it was 98.36% in all stations. Summer precipitation rate presented regional differences; the precipitation rate was 79.51%. Abrupt changes in mean precipitation in the arid region and sub-region of northwest China are evident. The changes occurred in northern and southern Xinjiang and western Inner Mongolia in the middle of the 1980s, in the Hexi Corridor and the Qilian Mountains changes occurred in the middle of the 1970s, and in the Tianshan Mountains the changes occurred in 1991. The abrupt changes in the mean precipitation in each area were statistically significant at P < 0.05 level. The Morlet wavelet analysis showed that the precipitation has an approximate 4-year, 8-year, 12-year, and 22-year cycle in the studied region. According to the level of wet and dry, the rates for normal, abnormally dry, dry, wet, and extremely wet mean precipitation series were 32%, 12%, 24%, 16%, and 16%, respectively. Since the 1980s, precipitation has increased significantly; the rate of positive anomalous years has increased from 10% in the 1970s to 80% nowadays. Today, it is relatively wetter in the arid region of northwest China, with an obvious ongoing increasing trend. © 2015 Ecological Society of China. All Rights Reserved.


Long T.,Xinjiang University | Long T.,Key Laboratory of Oasis Ecology of Ministry of Education | Xiong H.,Beijing Union University | Xiong H.,Key Laboratory of Oasis Ecology of Ministry of Education | And 4 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2010

In order to optimize the micro-lysimeters (MLS) and improve its measurement accuracy, influential elements of accuracy was studied by the field testing without changing soil in 15 days. Result showed that the accuracy of all test treatments was high. The highest point was up to 97.40%. Whether the inner cylinder was drilled or not did not affect obviously the measurement accuracy. The accuracy of the drilled outside cylinder was higher than the undrilled ones, and the drilled holes were better to be equally distributed. Further more, the holes number was less than 36 when the diameter was 3 mm. The sealed outside cylinder could lower the measurement accuracy. The thinner material of sealed inside cylinder was and the more ventilative function was, the higher accuracy could be achieved. Moreover, when the space between inside and outside cylinder was smaller, the measurement accuracy also became higher. Dew studying results indicated that dew at night could markedly lower measurement accuracy of MLS. When the condensed quantum was above soil evaporation, MLS could not accurately measure out soil evaporation. Meanwhile, the measurement accuracy varied from time to time. The soil water content in the first 3 days was more, but the accuracy of MLS was lower than the later days. If there was available water supply, it was practicable without changing the MLS soil in 15 days.


Luo Y.,Xinjiang University | Luo Y.,Key Laboratory of Oasis Ecology of Ministry of Education | Gong L.,Xinjiang University | Gong L.,Key Laboratory of Oasis Ecology of Ministry of Education
Chinese Journal of Ecology | Year: 2016

The ecological stoichiometry of root, stem and leaf of Phragmites australis in different habitats of Keriya River of the southern marginal zone of Tarim Basin, Xinjiang was studied, to explore the effects of habitats and organs on stoichiometry. The results showed that the mean concentrations of C, N and P in P. australis organs were in order of leaves > stems > roots, the C: N and C: P ratios were in order of roots > stems > leaves, whereas the N: P ratio was in order of leaves > stems > roots. The concentrations of C, N, P and their stoichiometric ratios in roots, stems and leaves differed with habitat. The concentrations of C in root, stem and leaf were significantly higher in riverbank than in oasis and desert. Stem N concentration was significantly lower in desert than in riverbank and oasis, while the concentrations of N in leaf and root were not significantly different among the three habitats. Leaf P concentration in oasis was significantly higher than in desert, and the concentrations of P in stem and root were significantly higher in ri-verbank than in oasis and desert. There was no significant difference in C: N ratio among root, stem and leaf. The C: P ratios in stem and root differed between riverbank and desert, while the ratio of N: P did not differ among the three habitats and was less than 14, which indicated that the growth of P. australis was mainly limited by N. The N concentration was positively correlated with the P concentration, indicating a consistent demand of N and P during P. australis growth. According to the factorial analysis of GLM, we concluded that the C and N concentrations and C: N and N: P ratios were mainly affected by the organs, while the P concentration and C: P ratio were mainly determined by the habitats. © 2016, Editorial Board of Chinese Journal of Ecology. All rights reserved.

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