Variations and driving factors for concentrations and carbon isotopes of dissolved CO in lake water across different Chinese lakes.

Carbon dioxide (CO) stands as the primary driver of Earth's greenhouse effect, and it's suggested that the global contribution of CO emissions from lakes cannot be ignored. Despite the numerous estimations of CO fluxes from lakes, limited focus has been directed towards the carbon isotopes (δC) of dissolved CO in lake water. Particularly, the potential use of δC values in tracing the CO concentrations in lake water remains as an understudied area, warranting further exploration and investigation.

Salinity decreases methane concentrations in Chinese lakes.

Lakes are important sources of methane (CH), and understanding the influence of environmental factors on CH concentration in lake water is crucial for accurately assessing CH emission from lakes. In this study, we investigated CH concentration in two connected Tibetan Plateau lakes, Lake Keluke (an open freshwater lake) and Lake Tuosu (a closed saline lake), through in-situ continuous measurements taken in different months from 2021 to 2023. The results show substantial spatial and seasonal variations in CH concentrations in the two lakes, while the CH concentrations in Lake Keluke are consistently higher than those in Lake Tuosu for each month.

Spatial patterns of Holocene temperature changes over mid-latitude Eurasia.

The Holocene temperature conundrum, the discrepancy between proxy-based Holocene global cooling and simulated global annual warming trends, remains controversial. Meanwhile, reconstructions and simulations show inconsistent spatial patterns of terrestrial temperature changes. Here we report Holocene alkenone records to address spatial patterns over mid-latitude Eurasia.

Apparent fractionation of hydrogen isotope from precipitation to leaf wax n-alkanes from natural environments and manipulation experiments.

Knowledge of hydrogen isotopic fractionation (ε) of plant leaf waxes is the foundation for applying hydrogen isotope values (δH) in environmental reconstructions. In this work, we systematically investigated plant ε values (ε, ε, ε and ε, representing the isotopic fractionation between plant n-alkane δH and precipitation δH, soil water δH, leaf water δH and lake water δH) from the natural environments and manipulation experiments. The results show that the ε values of terrestrial plants have large variations (from -190 ‰ to -20 ‰) and become more negative with increasing aridity index.

Ancient Great Wall building materials reveal environmental changes associated with oases in northwestern China.

Plant materials used in the construction of segments and beacon towers of the ancient Great Wall in northwestern China contain untapped potential for revealing local paleoclimatic and environmental conditions. For the first time, we characterize the molecular preservation and stable carbon and nitrogen isotope compositions of AMS-dated common reeds (Phragmites) collected from ancient Great Wall fascines in today's Gansu and Xinjiang using a combination of chromatographic techniques and isotope analyses. Our molecular data, along with Scanning Electron Microscopy, demonstrate excellent preservation of these ancient reeds, which were harvested from nearby habitats during periods of significant expansion of Imperial China when climate conditions sustained sizeable oases in the region.

800-kyr land temperature variations modulated by vegetation changes on Chinese Loess Plateau.

The complicity of long-term land surface temperature (LST) changes has been under investigated and less understood, hindering our understanding of the history and mechanism of terrestrial climate change. Here, we report the longest (800 thousand years) LSTs based on distributions of soil fossil bacterial glycerol dialkyl glycerol tetraethers preserved in well-dated loess-paleosol sequences at the center of the Chinese Loess Plateau. We have found a previously-unrecognized increasing early and prolonged warming pattern toward the northwestern plateau at the onset of the past seven deglaciations, corresponding to the decrease in vegetation coverage, suggesting underlying surface vegetation or lack of has played an important role in regulating LSTs, superimposed on the fundamental global glacial-interglacial changes.

Late Miocene episodic lakes in the arid Tarim Basin, western China.

The Tibetan Plateau uplift and Cenozoic global cooling are thought to induce enhanced aridification in the Asian interior. Although the onset of Asian desertification is proposed to have started in the earliest Miocene, prevailing desert environment in the Tarim Basin, currently providing much of the Asian eolian dust sources, is only a geologically recent phenomenon. Here we report episodic occurrences of lacustrine environments during the Late Miocene and investigate how the episodic lakes vanished in the basin.

amoA-encoding archaea and thaumarchaeol in the lakes on the northeastern Qinghai-Tibetan Plateau, China.

All known ammonia-oxidizing archaea (AOA) belong to the phylum Thaumarchaeota within the domain Archaea. AOA possess the diagnostic amoA gene (encoding the alpha subunit of ammonia monooxygenase) and produce lipid biomarker thaumarchaeol. Although the abundance and diversity of amoA gene-encoding archaea (AEA) in freshwater lakes have been well-studied, little is known about AEA ecology in saline/hypersaline lakes.

Impacts of temperature and pH on the distribution of archaeal lipids in Yunnan hot springs, China.

In culture experiments and many low temperature environments, the distribution of isoprenoid glycerol dialkyl glycerol tetraethers (GDGTs) commonly shows a strong correlation with temperature; however, this is often not the case in hot springs. We studied 26 hot springs in Yunnan, China, in order to determine whether temperature or other factors control the distribution of GDGTs in these environments. The hot springs ranged in temperature from 39.