World's Largest Plateau Research Articles

Evaluation of water environment quality in a typical wetland on the Qinghai-Tibet Plateau using positive matrix factorization and self-organizing map

The Qinghai-Tibet Plateau (QTP), the world's largest plateau, harbors rich lake resources but is ecologically fragile. Vulnerable river ecosystems in these areas face significant threats from environmental and anthropogenic pressures. Thus, comprehensive water quality monitoring is essential prior to conservation efforts. This study focuses on the Selin Co International Wetland in Tibet, a model of natural wetland ecosystems. We employed methods including water quality assessment, source apportionment, and clustering analysis to evaluate the water environment. Results from the Water Quality Index (WQI) indicate overall good water quality; however, parameters such as COD, DO, TN, TP, and As require monitoring for potential exceedance. Positive Matrix Factorization (PMF) analysis reveals that the primary sources of substances are identified as natural sources (37.17%), animal disturbance sources (32.93%), and anthropogenic activities (22.31%). The results of the water source analysis using the PMF and the cluster analysis based on the self-organizing map (SOM) indicate that natural and geographical environmental factors are the primary determinants of water quality, with minimal influence from human activities. This research emphasizes the importance of these natural influences, providing a scientific foundation for the protection and management of wetlands in the QTP, which is critical for ensuring regional water resource security.

Marsh decrease was much faster than the water increase among the Yellow River Source wetlands during 1986–2022

Wetlands are valuable and sensitive ecosystems that make them imperative to tracking the dynamics in their extent for sustainable management under global warming. Here we focused on the Yellow River Source (YRS) wetlands, which is renowned for hosting one of the world's largest plateau peat bog, unfortunately, it had experienced sharp degradation, threatening the safety of water supply for approximately 110 million people of the lower Yellow River basin. However, the lack of long-term, dense time-series data makes it challenging to assess its evolution trends and driving factors. Therefore, we developed a decision tree sample migration method based on Euclidean distance and Land Surface Water Index, and successfully generated annual wetland mapping of YRS from 1986 to 2022 by utilizing the Landsat 5/7/8 datasets and Random Forest method. The average sample migration rate was 89.21 %, with an average overall accuracy of 95.49 %. We observed that the marsh area decreased by 2031 km2, marking a decline of 12.98 %, while the water area increased by 710 km2 (31.24 %) compared to 1986. Spatially, 10.96 % of marsh composition presents significant (P < 0.05) decline trend, which are mainly converted to grass (86 %), followed by impervious (10 %). There were 6.69 % of water composition showing significant (P < 0.05) increase trend, which are mainly sourced from impervious (82 %) and marsh (12 %). Grazing activities were more important driving forces than climate change for marsh degradation, while the water expansion was associated with recent rising temperature in YRS. The sample migration method is proved to be feasible, robust, and effective for long-term wetland mapping. We suggest that wetland decision-makers need to focus on marsh degradation and reduce grazing intensity, so that fostering the sustainable and healthy wetlands in the Qinghai-Tibetan Plateau.

Study the Impact of Plateau Pika Activity on the Ecological Dynamics of the Qinghai-Tibet Plateau

The Tibetan Plateau, the world's largest plateau, harbors diverse ecosystems that play vital roles in the global environment. This study aims to investigate the ecological impact of the plateau pika, an endemic species, on the plateau's water resources, carbon storage, biodiversity, and climate. The research advocates for a balanced approach to pika control, emphasizing ecological preservation while addressing the associated challenges. Various statistical tests were employed to quantify the relationship between plateau pika activity and ecological dynamics. Correlation analysis revealed a significant negative correlation between pika burrow density and soil moisture content. T-tests demonstrated a significant difference in soil carbon content between areas with high and low pika burrow densities. A chi-squared test found no significant association between pika population density and the presence of vulnerable species. Ecological protection and sustainable development are crucial, with plant-based pesticides like ricin offering an effective and environmentally friendly means of pika control. However, ecological restoration should be the core of rodent control efforts to maintain a balanced ecosystem. Combining grazing policies with ecological grassland control measures can help mitigate rodent damage while improving grassland productivity.

Integrated transcriptome provides resources and insights into the adaptive evolution of colonized brown trout (Salmo trutta fario) in the Tibetan Plateau

AbstractThe Tibetan Plateau is the world's largest plateau that is characterized by low temperature, low oxygen, and strong ultraviolet radiation. Colonized species that invade the plateau must change their characteristics to adapt to the harsh environment. However, research on the adaptation of introduced species on plateaus is limited. In this study, brown trout (Salmo trutta fario) was studied as a colonized species of the Tibetan Plateau, and a de novo transcriptome assembly was conducted to explore the genetic basis of plateau adaptation. A total of 38,606 unigenes were assembled, with over 90% of the unigenes annotated. Using comparative transcriptomics analysis, we identified 129 positively selected genes and 126 species‐specific gene families in colonized brown trout that were associated with energy metabolism, angiogenesis, heart development, ammonium transport, and DNA damage and repair, which may play essential roles in the adaptation to high altitude of colonized brown trout compared to other inland Salmonidae species. Our results provide an integrated and comprehensive transcriptomic resource for brown trout colonized in Tibet. These results potentially contribute to future studies aiming to identify candidate genes and pathways underlying the genetic basis of adaptation in the Tibetan plateau and assist in the population protection and aquaculture of brown trout in Tibet.

Complexation and reduction of iron by phenolic substances: Implications for transport of dissolved Fe from peatlands to aquatic ecosystems and global iron cycling

Iron (Fe) is among the limiting nutrients in marine environments and mainly originates from terrigenous sources. Dissolved organic carbon (DOC), an important natural organic ligand, plays a key role in the dissolution and transport of terrestrial iron. Peat-derived DOC contains a large number of phenolics, and a systematic study of the geochemical interaction between DOC and Fe will contribute to the understanding of the global carbon and iron cycles. Phenolics, including phenolic acids, are secondary metabolites from plants and fungi. These compounds possess an aromatic ring bearing one or more hydroxyl groups and their structures may range from that of a simple phenolic molecule to that of a complex high-molecular weight polymer. Despite the extensive literature describing the biological effects of phenolic acids, the effect of phenolics on the iron cycle in peatlands is not known very well. Zoige peatland, the world's largest plateau peat wetland, was studied through field investigation and laboratory simulated experiments. The content of phenolics, filterable Fe and some physicochemical parameters in the rivers of the area were investigated. The waters are generally alkaline, with an average pH of 8.04, and aqueous Fe(III) and Fe(II) concentrations are higher than most of the common rivers in the world. The results of our experiments suggested that the high iron solubility was closely related to the phenolic content of the DOC. In particular, phenolics with catechol or galloy moieties forming complexes with iron and significantly impede the oxidation of complexed Fe(II). In addition, some phenolic substances are able to reduce ferric iron to ferrous iron. The combination of complexation and reduction in Fe by phenolics effectively increased the proportion of ferrous iron to total iron and slowed the oxidation and precipitation in the waters, maintaining a high content of “soluble iron” in the peatland. This mechanism has great implications for the effective transport of soluble iron from peatlands to aquatic ecosystems and the global coupled iron and carbon cycles.

Shrinkage of the Ruoergai Swamp and changes to landscape connectivity, Qinghai-Tibet Plateau

The Ruoergai Swamp (Zoige) at the eastern margin of the Qinghai-Tibet Plateau in western China is the world's largest plateau peat wetland. Rapid shrinkage of the swamp since the 1950s has endangered the local terrestrial and aquatic ecosystems and the water supply of the upper Yellow River. The causes of the swamp shrinkage were evaluated based upon field investigations in 2011–2013 and analyses of remote sensing images and meteorological and hydrological data. Although a slight rise in the temperature was evident, there was no obvious decrease in the precipitation, indicating that climate change was not the primary cause of the recent swamp shrinkage. Remote sensing images indicated that roughly 920km of artificial ditches excavated from the 1960s to 1990s have affected around 648km2 of swamp, accounting for 27% of the total shrinkage area (approximately 2400km2). Bed incision of the upper Yellow River was considered to be the primary cause for the long-term degradation of the Ruoergai Swamp. Ensuing headcut erosion of countless tributaries has induced drainage network extension, draining large areas of the swamp and lowering the groundwater levels. Headcut erosion and construction of the artificial channels have markedly increased the flow and sediment movement in this landscape.