Recent climate changes over the Tibetan Plateau and their impacts on energy and water cycle: A review

Arbuscular mycorrhiza (AM) fungi are considered as an important factor in predicting plants and ecosystem responses to climate changes on a global scale. The Tibetan Plateau is the highest region on Earth with abundant natural resources and one of the most sensitive region to climate changes. To evaluate the complex response of arbuscular mycorrhizal fungi colonization and spore density to climate changes, a reciprocal translocation experiment was employed in Tibetan Plateau. The reciprocal translocation of quadrats to AM colonization and spore density were dynamic. Mycorrhizal colonization frequency presented contrary changed trend with elevations of quadrat translocation. Colonization frequency reduced or increased in majority quadrats translocated from low to high or from high to low elevation. Responses of colonization intensity to translocation of quadrats were more sensitive than colonization frequency. Arbuscular colonization showed inconsistent trend in increased or decreased quadrat. Vesicle colonization decreased with changed of quadrat from low to high elevations. However, no significant trend was observed. Although spore density was dynamic with signs of decreasing or increasing in translocated quadrats, the majority enhanced and declined respectively in descent and ascent quadrat treatments. It is crucial to understand the interactions between AM fungi and prairie grasses to accurately predict effects of climate change on these diverse and sensitive ecosystems. This study provided an opportunity for understanding the effect of climate changes on AM fungi.

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Comparison of satellite-based evapotranspiration estimates over the Tibetan Plateau

Hydrology and Earth System Sciences ◽

10.5194/hess-20-3167-2016 ◽

2016 ◽

Vol 20 (8) ◽

pp. 3167-3182 ◽

Cited By ~ 17

Author(s):

Jian Peng ◽

Alexander Loew ◽

Xuelong Chen ◽

Yaoming Ma ◽

Zhongbo Su

Keyword(s):

Tibetan Plateau ◽

Vegetation Index ◽

Water Cycle ◽

Global Climate ◽

Spatial Scales ◽

Accurate Estimation ◽

The Tibetan Plateau ◽

North West ◽

Comparison Results ◽

Normalised Difference Vegetation Index

Abstract. The Tibetan Plateau (TP) plays a major role in regional and global climate. The understanding of latent heat (LE) flux can help to better describe the complex mechanisms and interactions between land and atmosphere. Despite its importance, accurate estimation of evapotranspiration (ET) over the TP remains challenging. Satellite observations allow for ET estimation at high temporal and spatial scales. The purpose of this paper is to provide a detailed cross-comparison of existing ET products over the TP. Six available ET products based on different approaches are included for comparison. Results show that all products capture the seasonal variability well with minimum ET in the winter and maximum ET in the summer. Regarding the spatial pattern, the High resOlution Land Atmosphere surface Parameters from Space (HOLAPS) ET demonstrator dataset is very similar to the LandFlux-EVAL dataset (a benchmark ET product from the Global Energy and Water Cycle Experiment), with decreasing ET from the south-east to north-west over the TP. Further comparison against the LandFlux-EVAL over different sub-regions that are decided by different intervals of normalised difference vegetation index (NDVI), precipitation, and elevation reveals that HOLAPS agrees best with LandFlux-EVAL having the highest correlation coefficient (R) and the lowest root mean square difference (RMSD). These results indicate the potential for the application of the HOLAPS demonstrator dataset in understanding the land–atmosphere–biosphere interactions over the TP. In order to provide more accurate ET over the TP, model calibration, high accuracy forcing dataset, appropriate in situ measurements as well as other hydrological data such as runoff measurements are still needed.

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Grazing alters environmental control mechanisms of evapotranspiration in an alpine meadow of the Tibetan Plateau

Journal of Plant Ecology ◽

10.1093/jpe/rtz021 ◽

2019 ◽

Vol 12 (5) ◽

pp. 834-845

Author(s):

Tingting An ◽

Mingjie Xu ◽

Tao Zhang ◽

Chengqun Yu ◽

Yingge Li ◽

...

Keyword(s):

Community Structure ◽

Tibetan Plateau ◽

Alpine Meadow ◽

Environmental Control ◽

Water Cycle ◽

Limiting Factor ◽

Peak Time ◽

The Tibetan Plateau ◽

Control Mechanisms ◽

Water Conditions

Abstract Aims Evapotranspiration (ET) is an important component of the terrestrial water cycle and is easily affected by external disturbances, such as climate change and grazing. Identifying ET responses to grazing is instructive for determining grazing activity and informative for understanding the water cycle. Methods This study utilized 2 years (2014 and 2017) of eddy covariance data to test how grazing regulated ET for an alpine meadow ecosystem on the Tibetan Plateau (TP) by path analysis. Important Findings Radiation dominated ET with a decision coefficient of 64–74%. The soil water content (SWC) worked as the limiting factor in the fenced site. However, in the grazing site, the limiting factor was the vapor pressure deficit (VPD). Grazing had large effects on ET because it greatly affected the water conditions. The SWC and VPD were enhanced by 14.63% and 4.36% in the grazing site, respectively. Therefore, sufficient water was supplied to ET, especially during drought, and strengthened the transpiration pull. As a result, a favorable micrometeorological environment was created for ET. Grazing shifted the limiting factor of ET from the SWC to VPD, which weakened the limiting effect of the water conditions on ET and advanced the ET peak time. In addition, grazing altered the compositions of ET by changing the community structure, which directly resulted in an increased ET. In summary, grazing enhanced ET through altering the community structure and micrometeorological environments. The findings of this study further improve our understanding of the driving mechanisms of grazing on ET and will improve our predictions for the global water cycle.

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Varying responses of vegetation activity to climate changes on the Tibetan Plateau grassland

International Journal of Biometeorology ◽

10.1007/s00484-017-1321-5 ◽

2017 ◽

Vol 61 (8) ◽

pp. 1433-1444 ◽

Cited By ~ 40

Author(s):

Nan Cong ◽

Miaogen Shen ◽

Wei Yang ◽

Zhiyong Yang ◽

Gengxin Zhang ◽

...

Keyword(s):

Tibetan Plateau ◽

Climate Changes ◽

The Tibetan Plateau ◽

Vegetation Activity

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Comparison of Hydrological Patterns between Glacier-Fed and Non-Glacier-Fed Lakes on the Southeastern Tibetan Plateau

Remote Sensing ◽

10.3390/rs13204024 ◽

2021 ◽

Vol 13 (20) ◽

pp. 4024

Author(s):

Fangdi Sun ◽

Bin He ◽

Caixia Liu ◽

Yuchao Zeng

Keyword(s):

Tibetan Plateau ◽

Water Cycle ◽

Environmental Research ◽

Altimeter Data ◽

The Tibetan Plateau ◽

Volume Increase ◽

Southeastern Tibetan Plateau ◽

Lake Volume ◽

Changing Patterns ◽

Precipitation Variation

Lakes on the Tibetan Plateau have experienced variations over the last several decades, and the delineation of lake dynamics is favorable for the regional water cycle and can serve as important information for plateau environmental research. This study focused on 57 lakes near the Tanggula Mountains on the southeastern Tibetan Plateau. Yearly inundations of the lakes in 1989–2019 and altimeter data available for 2003–2020 were integrated to illustrate the changing patterns of glacier-fed and non-glacier-fed lakes. These two groups of lakes presented very similar evolution stages. They both increased in 1989–1992, decreased in 1992–1996, increased rapidly in 1998–2005, and had batch-wise fluctuations since 2005, with respective areas of around 5305.28 and 1636.79 km2 in the last decade. The non-glacier-fed lakes were more sensitive to precipitation variation, and glacier-fed lakes were more sensitive to temperature changes. Based on lakes with obvious changes in water level, the whole water storage variations of the studied lakes were 1.90 Gt/y in 2003–2009, including 1.80 Gt/y for glacier-fed lakes and 0.10 Gt/y for non-glacier-fed lakes. The contribution from glacier melting in 2003–2009 amounted to 16.11% of the whole lake volume increase. In 2010–2020, water mass changes were 0.42 Gt/y for glacier-fed lakes and –0.14 Gt/y for non-glacier-fed lakes, respectively. The volume increase of glacier-fed lakes in 2010–2020 was mainly due to the expansion of Selin Co. Selin Co experienced a water increase of about 0.46 Gt/y, and the other glacier-fed lakes experienced a decreasing volume of –0.04 Gt/y. In 2010–2020, 99.43% of the glacier contribution supplied Selin Co.

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Changing Pattern of Water Level Trends in Eurasian Endorheic Lakes as a Response to the Recent Climate Variability

Remote Sensing ◽

10.3390/rs13183705 ◽

2021 ◽

Vol 13 (18) ◽

pp. 3705

Author(s):

Xin Zhang ◽

Abilgazi Kurbaniyazov ◽

Georgiy Kirillin

Keyword(s):

Climate Change ◽

Tibetan Plateau ◽

Central Asia ◽

Climatic Factors ◽

Hydrological Regime ◽

Water Levels ◽

The Tibetan Plateau ◽

Lake Levels ◽

Mongolian Plateau ◽

Recent Climate

Lake level is a sensitive integral indicator of climate change on regional scales, especially in enclosed endorheic basins. Eurasia contains the largest endorheic zone with several large terminal lakes, whose water levels recently underwent remarkable variations. To address the patterns of these variations and their links to the climate change, we investigated the variability of levels in 15 lakes of three neighboring endorheic regions—Central Asia, Tibetan Plateau, and Mongolian Plateau. Satellite altimetry revealed a heterogeneous pattern among the regions during 1992–2018: lake levels increased significantly in Central Asia and the Tibetan Plateau but decreased on the Mongolian Plateau. The shifts to the increasing trend were detected since 1997 in Central Asia, since 1998 in the southern part of the Tibetan Plateau, and since 2005 in its northern part. The shift in air temperatures around 1997 and the precipitation shifts around 1998 and 2004 contributed to the trend’s turning points, with precipitation being the major contributor to the heterogeneous pattern of lake levels. Our findings reveal the linkage of the heterogeneous pattern of lake levels to climatic factors in the endorheic basins, providing a further understanding of the hydrological regime in the Eurasian endorheic zone and its sensitivity to climate change.

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Missing water from the Qiangtang Basin on the Tibetan Plateau

Geology ◽

10.1130/g48561.1 ◽

2021 ◽

Author(s):

Bin Yong ◽

Chi-Yuen Wang ◽

Jiansheng Chen ◽

Jiaqi Chen ◽

D.A. Barry ◽

...

Keyword(s):

Tibetan Plateau ◽

Water Cycle ◽

Yellow River ◽

Outer Region ◽

Normal Faults ◽

The Tibetan Plateau ◽

Satellite Mission ◽

Qiangtang Basin ◽

Basin Scale ◽

Terrestrial Water

The Qiangtang Basin is a large endorheic basin in the inner part of the Tibetan Plateau, and has been thought to be a dry region in contrast with the surrounding wet outer region that feeds all the major Asian rivers. Combining surface hydrological data with modeling and satellite data from 2002 to 2016 CE, our study reveals that an enormous amount of water, ~54 ± 4 km3, is unaccounted for annually in the Qiangtang Basin. The amount of missing water is comparable to the total annual discharge of the Yellow River. Data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission show little increase of local terrestrial water storage. Thus, the missing water must have flowed out of the basin through underground passages. Interpreting this result in the context of recent seismic and geological studies of Tibet, we suggest that a significant amount of meteoric water in the Qiangtang Basin leaks out by way of groundwater flow through deep normal faults and tensional fractures along the nearly north-south rift valleys that are oriented subnormal to and cross the surficial hydrological divide on the southern margin of the basin. Cross-basin groundwater outflow of such a magnitude defies the traditional view of a basin-scale water cycle and leads to a very different picture from the previous hydrological view of the Qiangtang Basin. This finding calls for major rethinking of the regional water balance.

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Seasonality and spatial variability of dynamic precipitation controls on the Tibetan Plateau

10.5194/esd-2016-1 ◽

2016 ◽

Author(s):

Julia Curio ◽

Dieter Scherer

Keyword(s):

Tibetan Plateau ◽

Spatial Variability ◽

Water Cycle ◽

High Mountain ◽

The Tibetan Plateau ◽

Precipitation Distribution ◽

Mountain Ranges ◽

Boundary Layer Height ◽

Dynamic Factors ◽

Vertical Wind Speed

Abstract. The Tibetan Plateau (TP) is the origin of many large Asian rivers, which provide moisture for large regions in South and East Asia. Therefore, the water cycle on the TP and adjacent high mountain ranges and especially the precipitation distribution plays an important role for the water availability for billions of people in the regions downstream of the TP. Based on the High Asia Refined analysis (HAR) we analyse the influence of dynamic factors on precipitation, enhancing or suppressing precipitation development. We selected six precipitation controls, the horizontal and vertical wind speed at 300 hPa and in about two kilometres above ground, the atmospheric water transport, and the planetary boundary layer height. Focus of the study are the seasonality and the spatial variability of these precipitation controls and their dominant patterns. The results show that precipitation controls have different effects on precipitation in different regions and seasons. This depends mainly on the type of precipitation, convective or frontal/cyclonic precipitation. Additionally, the study reveals that the mid-latitude westerlies have a high impact on precipitation distribution on the TP and its surrounding year-round.

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