scholarly journals Prokaryotic Community Structure Driven by Salinity and Ionic Concentrations in Plateau Lakes of the Tibetan Plateau

2016 ◽  
Vol 82 (6) ◽  
pp. 1846-1858 ◽  
Author(s):  
Zhi-Ping Zhong ◽  
Ying Liu ◽  
Li-Li Miao ◽  
Fang Wang ◽  
Li-Min Chu ◽  
...  
Keyword(s):  
Community Structure ◽  
Tibetan Plateau ◽  
Community Composition ◽  
Qaidam Basin ◽  
Nitrogen Concentration ◽  
Distribution Patterns ◽  
The Tibetan Plateau ◽  
Prokaryotic Community ◽  
Content Type ◽  
Ionic Concentrations

ABSTRACTThe prokaryotic community composition and diversity and the distribution patterns at various taxonomic levels across gradients of salinity and physiochemical properties in the surface waters of seven plateau lakes in the Qaidam Basin, Tibetan Plateau, were evaluated using Illumina MiSeq sequencing. These lakes included Lakes Keluke (salinity, <1 g/liter), Qing (salinity, 5.5 to 6.6 g/liter), Tuosu (salinity, 24 to 35 g/liter), Dasugan (salinity, 30 to 33 g/liter), Gahai (salinity, 92 to 96 g/liter), Xiaochaidan (salinity, 94 to 99 g/liter), and Gasikule (salinity, 317 to 344 g/liter). The communities were dominated byBacteriain lakes with salinities of <100 g/liter and byArchaeain Lake Gasikule. The clades At12OctB3 andSalinibacter, previously reported only in hypersaline environments, were found in a hyposaline lake (salinity, 5.5 to 6.6 g/liter) at an abundance of ∼1.0%, indicating their ecological plasticity. Salinity and the concentrations of the chemical ions whose concentrations covary with salinity (Mg2+, K+, Cl−, Na+, SO42−, and Ca2+) were found to be the primary environmental factors that directly or indirectly determined the composition and diversity at the level of individual clades as well as entire prokaryotic communities. The distribution patterns of two phyla, five classes, five orders, five families, and three genera were well predicted by salinity. The variation of the prokaryotic community structure also significantly correlated with the dissolved oxygen concentration, pH, the total nitrogen concentration, and the PO43−concentration. Such correlations varied depending on the taxonomic level, demonstrating the importance of comprehensive correlation analyses at various taxonomic levels in evaluating the effects of environmental variable factors on prokaryotic community structures. Our findings clarify the distribution patterns of the prokaryotic community composition in plateau lakes at the levels of individual clades as well as whole communities along gradients of salinity and ionic concentrations.

Paleolake salinity evolution in the Qaidam Basin (NE Tibetan Plateau) between ~42 and 29 Ma: Links to global cooling and Paratethys sea incursions

2021 ◽  
Author(s):  
Chengcheng Ye ◽  
Yibo Yang ◽  
Xiaomin Fang ◽  
Weilin Zhang ◽  
Chunhui Song ◽  
...  
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Middle Eocene ◽  
Qaidam Basin ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Driving Mechanism ◽  
The Tibetan Plateau ◽  
Early Oligocene ◽  
Global Cooling

&lt;p&gt;Global cooling, the early uplift of the Tibetan Plateau, and the retreat of the Paratethys are three main factors that regulate long-term climate change in the Asian interior during the Cenozoic. However, the debated elevation history of the Tibetan Plateau and the overlapping climate effects of the Tibetan Plateau uplift and Paratethys retreat makes it difficult to assess the driving mechanism on regional climate change in a particular period. Some recent progress suggests that precisely dated Paratethys transgression/regression cycles appear to have fluctuated over broad regions with low relief in the northern Tibetan Plateau in the middle Eocene&amp;#8211;early Oligocene, when the global climate was characterized by generally continuous cooling followed by the rapid Eocene&amp;#8211;Oligocene climate transition (EOT). Therefore, a middle Eocene&amp;#8211;early Oligocene record from the Asian interior with unambiguous paleoclimatic implications offers an opportunity to distinguish between the climatic effects of the Paratethys retreat and those of global cooling.&lt;/p&gt;&lt;p&gt;Here, we present a complete paleolake salinity record from middle Eocene to early Miocene (~42-29 Ma) in the Qaidam Basin using detailed clay boron content and clay mineralogical investigations. Two independent paleosalimeters, equivalent boron and Couch&amp;#8217;s salinity, collectively present a three-staged salinity evolution, from an oligohaline&amp;#8211;mesohaline environment in the middle Eocene (42-~34 Ma) to a mesosaline environment in late Eocene-early Oligocene (~34-~29 Ma). This clay boron-derived salinity evolution is further supported by the published chloride-based and ostracod-based paleosalinity estimates in the Qaidam Basin. Our quantitative paleolake reconstruction between ~42 and 29 Ma in the Qaidam Basin resembles the hydroclimate change in the neighboring Xining Basin, of which both present good agreement with changes of marine benthic oxygen isotope compositions. We thus speculated that the secular trend of clay boron-derived paleolake salinity in ~42-29 Ma is primarily controlled by global cooling, which regulates regional climate change by influencing the evaporation capacity in the moisture source of Qaidam Basin. Superimposed on this trend, the Paratethys transgression/regression cycles served as an important factor regulating wet/dry fluctuations in the Asian interior between ~42 and ~34 Ma.&lt;/p&gt;

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

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.

scholarly journals Dominant Tree Species and Soil Type Affect the Fungal Community Structure in a Boreal Peatland Forest

2016 ◽  
Vol 82 (9) ◽  
pp. 2632-2643 ◽  
Author(s):  
Hui Sun ◽  
Eeva Terhonen ◽  
Andriy Kovalchuk ◽  
Hanna Tuovila ◽  
Hongxin Chen ◽  
...  
Keyword(s):  
Community Structure ◽  
Community Composition ◽  
High Throughput ◽  
Fungal Community ◽  
Tree Species ◽  
High Throughput Sequencing ◽  
Soil Layer ◽  
Fungal Community Composition ◽  
Content Type ◽  
Boreal Peatlands

ABSTRACTBoreal peatlands play a crucial role in global carbon cycling, acting as an important carbon reservoir. However, little information is available on how peatland microbial communities are influenced by natural variability or human-induced disturbances. In this study, we have investigated the fungal diversity and community structure of both the organic soil layer and buried wood in boreal forest soils using high-throughput sequencing of the internal transcribed spacer (ITS) region. We have also compared the fungal communities during the primary colonization of wood with those of the surrounding soils. A permutational multivariate analysis of variance (PERMANOVA) confirmed that the community composition significantly differed between soil types (P< 0.001) and tree species (P< 0.001). The distance-based linear models analysis showed that environmental variables were significantly correlated with community structure (P< 0.04). The availability of soil nutrients (Ca [P= 0.002], Fe [P= 0.003], and P [P= 0.003]) within the site was an important factor in the fungal community composition. The species richness in wood was significantly lower than in the corresponding soil (P< 0.004). The results of the molecular identification were supplemented by fruiting body surveys. Seven of the genera ofAgaricomycotinaidentified in our surveys were among the top 20 genera observed in pyrosequencing data. Our study is the first, to our knowledge, fungal high-throughput next-generation sequencing study performed on peatlands; it further provides a baseline for the investigation of the dynamics of the fungal community in the boreal peatlands.

scholarly journals Control of Temperature on Microbial Community Structure in Hot Springs of the Tibetan Plateau

PLoS ONE ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. e62901 ◽  
Author(s):  
Shang Wang ◽  
Weiguo Hou ◽  
Hailiang Dong ◽  
Hongchen Jiang ◽  
Liuqin Huang ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Tibetan Plateau ◽  
Microbial Community Structure ◽  
Hot Springs ◽  
The Tibetan Plateau

scholarly journals Late Cenozoic continuous aridification in the western Qaidam Basin: evidence from sporopollen records

2013 ◽  
Vol 9 (2) ◽  
pp. 1485-1508 ◽  
Author(s):  
Y. F. Miao ◽  
X. M. Fang ◽  
F. L. Wu ◽  
M. T. Cai ◽  
C. H. Song ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Middle Miocene ◽  
Qaidam Basin ◽  
East Asian ◽  
The Tibetan Plateau ◽  
Late Cenozoic ◽  
Plateau Uplift ◽  
Western Qaidam Basin ◽  
Global Cooling ◽  
Tibetan Plateau Uplift

Abstract. Cenozoic climate changes in inner Asia provide a basis for understanding linkages between global cooling, the Tibetan Plateau uplift, and possibly the development of the East Asian monsoon. Based on the compiled palynological results from the western Qaidam Basin, this study reconstructed an 18 Ma record of changing vegetation and paleoclimates since the middle Miocene. Thermophilic taxa percentages were highest between 18 and 14 Ma and decreased after 14 Ma, corresponding closely with the Middle Miocene Climatic Optimum (MMCO) between 18 and 14 Ma and the following global climatic cooling. After 3.6 Ma, the thermophilic taxa percentages further decreased, showing the inevitable relations with the ice-sheets enlargement in the North Hemisphere. During the same period of time, the increase in xerophytic taxa percentages and decrease in conifers percentages imply aridification in both the basin and surrounding mountains since 18 Ma. These results indicate that global cooling mainly controlled the climate change from a relative warm-wet stage to a cold-dry stage during the late Cenozoic at the western Qaidam Basin, and that the Tibetan Plateau uplift also contributed in contrast to the East Asian summer monsoon.

scholarly journals Monitoring 40-Year Lake Area Changes of the Qaidam Basin, Tibetan Plateau, Using Landsat Time Series

2019 ◽  
Vol 11 (3) ◽  
pp. 343 ◽  
Author(s):  
Huiying Li ◽  
Dehua Mao ◽  
Xiaoyan Li ◽  
Zongming Wang ◽  
Cuizhen Wang
Keyword(s):  
Tibetan Plateau ◽  
Structural Equation ◽  
Environmental Changes ◽  
Human Impacts ◽  
Qaidam Basin ◽  
Salt Lakes ◽  
Anthropogenic Factors ◽  
The Tibetan Plateau ◽  
Lake Area ◽  
Landsat Images

Areal changes of high-altitude inland lakes on the Qaidam Basin (QB) of the Tibetan Plateau are reliable indicators of climate change and anthropogenic disturbance. Due to the physical difficulties to access, our knowledge of the spatial patterns and processes of climatic and human impacts on the Basin has been limited. Focusing on lake area changes, this study used long-term Landsat images to map the patterns of lakes and glaciers in 1977, 1990, 2000, and 2015, and to monitor the spatially explicit changes of lakes between 1977 and 2015. Results revealed that the total number of lakes (area > 0.5 km2) increased by 18, while their total area expanded by 29.8%, from 1761.5 ± 88.1 km2 to 2285.9 ± 91.4 km2. Meanwhile, glaciers have decreased in area by 259.16 km2 in the past four decades. The structural equation model (SEM) was applied to examine the integrative effects of natural and anthropogenic factors on lake area. Precipitation change exhibited the most significant influence on lake area in the QB from 1977 to 2000, while human activities also played an important role in the expansion of lakes in the QB in the period 2000–2015. In particular, extensive exploitation of salt lakes as mining resources resulted in severe changes in lake area and landscape. The continuously expanding salt lakes inundated the road infrastructure nearby, posing great threats to road safety. This study shed new light on the impacts of recent environmental changes and human interventions on lakes in the Qaidam Basin, which could assist policy-making for protecting the lakes and for strengthening the ecological improvement of this vast, arid basin.

New Olonbulukia material and its related assemblage reveal an early radiation of stem Caprini along the north of the Tibetan Plateau

2018 ◽  
Vol 93 (2) ◽  
pp. 385-397 ◽  
Author(s):  
Shi-Qi Wang ◽  
Qing Yang ◽  
Ya Zhao ◽  
Chun-Xiao Li ◽  
Qin-Qin Shi ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Qaidam Basin ◽  
Northern China ◽  
High Mountain ◽  
The Tibetan Plateau ◽  
The North ◽  
Hemitragus Jemlahicus ◽  
Himalayan Tahr ◽  
Early Radiation ◽  
Mixed Pattern

AbstractLiving Caprini are dominant bovids in the pan-Tibetan area that are strongly adapted to dry steppe and high-mountain meadow habitats. Some taxa with Holarctic distributions, e.g., Ovis Linnaeus, 1758, were thought to originate on the Tibetan Plateau and subsequently dispersed elsewhere, which was depicted as an ‘out of Tibet’ story. However, except for some information on a stem caprine assemblage from the Qaidam Basin, the early evolution of Caprini around the Tibetan Plateau is poorly known. Here, we report new material of Olonbulukia tsaidamensis Bohlin, 1937, which was a member of this stem caprine assemblage, from the Wuzhong region, northern China, confirming the similarity of the Wuzhong Fauna and ‘Qaidam Fauna.’ Based on a biometric study of horncores from the ‘Qaidam’ and Wuzhong faunas, we recognize six taxa from this stem caprine assemblage: O. tsaidamensis, O. sp., Qurliqnoria cheni Bohlin, 1937, Tossunnoria pseudibex Bohlin, 1937, ?Protoryx cf. P. enanus Köhler, 1987, and cf. Pachytragus sp. Among these taxa, Q. cheni and T. pseudibex are probably related to some extant Tibetan endemic species, e.g., the Tibetan antelope, Pantholops hodgsonii (Abel, 1826), and the Himalayan tahr, Hemitragus jemlahicus (Smith, 1826). Others might be ancestral to the Turolian caprine assemblages and even possibly gave rise to the extant Caprina. This work reveals an early radiation of stem caprines along the northern side of the rising Tibetan Plateau and indicates a mixed pattern of pan-Tibetan stem caprine evolution prior to their dispersal out of the Tibetan Plateau.

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