| 1. |
- Ma, Tao, et al.
(författare)
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Genomic insights into salt adaptation in a desert poplar
- 2013
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4, s. 2797-
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Tidskriftsartikel (refereegranskat)abstract
- Despite the high economic and ecological importance of forests, our knowledge of the genomic evolution of trees under salt stress remains very limited. Here we report the genome sequence of the desert poplar, Populus euphratica, which exhibits high tolerance to salt stress. Its genome is very similar and collinear to that of the closely related mesophytic congener, P. trichocarpa. However, we find that several gene families likely to be involved in tolerance to salt stress contain significantly more gene copies within the P. euphratica lineage. Furthermore, genes showing evidence of positive selection are significantly enriched in functional categories related to salt stress. Some of these genes, and others within the same categories, are significantly upregulated under salt stress relative to their expression in another salt-sensitive poplar. Our results provide an important background for understanding tree adaptation to salt stress and facilitating the genetic improvement of cultivated poplars for saline soils.
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| 2. |
- Biskaborn, Boris K., et al.
(författare)
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Permafrost is warming at a global scale
- 2019
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Permafrost warming has the potential to amplify global climate change, because when frozen sediments thaw it unlocks soil organic carbon. Yet to date, no globally consistent assessment of permafrost temperature change has been compiled. Here we use a global data set of permafrost temperature time series from the Global Terrestrial Network for Permafrost to evaluate temperature change across permafrost regions for the period since the International Polar Year (2007–2009). During the reference decade between 2007 and 2016, ground temperature near the depth of zero annual amplitude in the continuous permafrost zone increased by 0.39 ± 0.15 °C. Over the same period, discontinuous permafrost warmed by 0.20 ± 0.10 °C. Permafrost in mountains warmed by 0.19 ± 0.05 °C and in Antarctica by 0.37 ± 0.10 °C. Globally, permafrost temperature increased by 0.29 ± 0.12 °C. The observed trend follows the Arctic amplification of air temperature increase in the Northern Hemisphere. In the discontinuous zone, however, ground warming occurred due to increased snow thickness while air temperature remained statistically unchanged.
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| 3. |
- Chen, Peng, et al.
(författare)
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Holocene monsoon dynamics at Kunlun Pass on the northeastern Qinghai-Tibet Plateau
- 2021
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 771
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Tidskriftsartikel (refereegranskat)abstract
- Various proxy records have been used for the understanding of environmental and climate variations during the Holocene. Here, for the first time, we use meteoric Be-10 isotope measurements performed on sediments from a drill core collected at the Kunlun Pass (KP) on the northeastern Qinghai-Tibet Plateau (NETP) to investigate hydroclimate changes during the Holocene. The Be-10 flux suggests relative low levels in the Early Holocene, followed by a sharp increase to high values at around 4 ka BP (4 ka BP - 4000 years before present). Afterwards, the Be-10 flux remains on a high level during the Late Holocene, but decreases slightly towards today. These Be-10 deposition patterns are compared to moisture changes in regions dominated by the Indian Summer Monsoon (ISM), East Asian Summer Monsoon (EASM), and the Westerlies. Different from the gradual changes in monsoon patterns, the Be-10 data reveal low levels during the Early Holocene until similar to 4 ka BP when an obvious increase is indicated and a relative high level continues to this day, which is relatively more in agreement with patterns of the Westerlies. This finding provides a new evidence fora shift in the dominant pattern of atmospheric circulation the KP region from a more monsoonal one to one dominated by the Westerlies. Our results improve the understanding of non-stationary interactions and spatial relevance of the EASM, the ISM and the Westerlies on the Qinghai-Tibet Plateau.
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| 4. |
- Chen, Peng, et al.
(författare)
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Use of Be-10 isotope to predict landscape development in the source area of the Yellow River (SAYR), northeastern Qinghai-Tibet Plateau
- 2019
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Ingår i: Journal of Environmental Radioactivity. - : ELSEVIER SCI LTD. - 0265-931X .- 1879-1700. ; 203, s. 187-199
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Tidskriftsartikel (refereegranskat)abstract
- The magnitude of soil and sediment erosion and accumulation processes can profoundly affect landscape development and hamper efficient management of natural resources. Consequently, estimating the rates and causes of these processes is essential, particularly in remote regions, for prediction of changes in landform and river evolution and protection of local ecosystem. We here present the results of a soil and sediment erosion investigation in the Source Area of the Yellow River (SAYR), northeast Qinghai-Tibet Plateau based on a combined analysis of Be-10 cosmogenic isotope and Soil and Water Assessment Tool (SWAT) simulation modelling. The data reveal variable soil erosion trends that range between 103 and 830 t km(-2) a(-1). The low values occur in the western part of the basin that are associated with low sediment yield, while the high values appear in the dominant sediment export part of the basin along the main stream of the Yellow River in the east. Generally, soil and sediment accumulation is characterized by high Be-10 concentration in the western part and the northwest of Ngoring Lake. The style of landform development by the erosion/accumulation processes is closely linked to the distribution and degradation extent of the permafrost in the study region. Soil surface erosion increases with more permafrost degradation from the western to the eastern part of the basin, and surface soil particles are dominantly removed from the surface rather than deeper layers.
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| 5. |
- Liu, Lei, et al.
(författare)
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The structural determination of endohedral metallofullerene Gd@C-82 by XANES
- 2008
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Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; :4, s. 474-476
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Tidskriftsartikel (refereegranskat)abstract
- Although the Gd ion in Gd@C-82 has been shown to lie above the C-C bond on the C-2 axis as an anomalous structure from the MEM/Rietveld analysis, the present XANES study reveals that it lies above the hexagon on the C-2 axis as a normal structure, and Gd oscillates around its equilibrium position with an amplitude increasing with temperature increase.
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| 6. |
- Song, Lei, et al.
(författare)
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Assessing hydrothermal changes in the upper Yellow River Basin amidst permafrost degradation
- 2024
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Ingår i: NPJ CLIMATE AND ATMOSPHERIC SCIENCE. - 2397-3722. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Since the 20th century, the temperature on the Qinghai-Tibetan Plateau (QTP) has increased at a rate of 2-3 times that of global warming. Consequently, the soil temperature and active layer thickness have also increased, which have directly caused severe degradation of the frozen ground on the QTP. Using a hydrological model driven by climate and vegetation forcing, the spatial and temporal changes in the hydrothermal characteristics of the Upper Yellow River Basin (UYRB) from 1960 to 2019 were modeled and the mechanism of the changes was analyzed. During the past six decades, the soil temperature in the UYRB exhibited an increasing trend. The degradation of permafrost in the UYRB was accompanied by thickening of the active layer, a reduction of the maximum depth of the seasonal frost penetration, and continuous extension of the basin thawing time. This degradation was also associated with the increase in the soil moisture content and decrease in the soil ice content, resulting in degradation of the permafrost area by one-tenth of the total area in the UYRB. The reduction of the permafrost area and the thickening of the active layer can profoundly impact hydrological processes and ecosystems. These findings play a critical role in designing efficient strategies to manage and protect frozen ground and serve as a valuable reference for understanding the consequences of frozen ground degradation globally.
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| 7. |
- Yi, Peng, et al.
(författare)
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Hydrological insights from hydrogen and oxygen isotopes in Source Area of the Yellow River, east-northern part of Qinghai-Tibet Plateau
- 2018
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : SPRINGER. - 0236-5731 .- 1588-2780. ; 317:1, s. 131-144
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Tidskriftsartikel (refereegranskat)abstract
- Analyses of stable (D and O-18) and radioactive (T) isotopes of different waters were applied to obtain the hydrological information in watersheds with different frozen ground types in the Source Area of the Yellow River, northeastern of Qinghai-Tibet Plateau in 2014 and 2016. Variations of oxygen and hydrogen isotope ratios, statistically higher tritium concentrations and lower water yields in thaw lakes confirm disparate sources of recharges to thaw lakes and other lakes. Thaw lakes at various stages of evolution influence the surface and subsurface water systems differently.
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