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Quantitative analyses of aeolian sediment provenance are necessary to elucidate aeolian sand pathways and define objective targets for control measures. In the present study, annual wind data and remote sensing information were utilized to ascertain the source of aeolian sediments along the Cuona Lake Section of the Qinghai-Tibetan Railway (QTR). Fingerprinting approach with different tracer selection strategies was used to assess contributions of each source types. The results indicated that (1) wind erosion behaviours that contribute to sand sediment occur mainly on the west side of sandy areas during October to April. The resultant drift potential of this period reached 1086.18 VU, indicating a high energy level. (2) The aeolian desertified land within the source area expanded by 8.05 km2 from 2001 to 2017. The degraded alpine meadow, bare hilly land and river courses were identified as potential sources of aeolian sediments. (3) The contributions from degraded alpine meadow, bare hilly land and river courses were estimated as 4%, 58% and 38%, respectively. Synthesising these results, appropriate control measures for the bare hilly land and river courses on the west side of Cuona Lake should be able to greatly restrict sand transport and alleviate the railway sand hazard. This study will provide a firm basis for sand hazard control in the Cuona Lake section and can be utilized as references for other regions encountering threats from aeolian sand. • The Qinghai-Tibetan Railway is under constant threat from aeolian sand. • Multiple tracer selection strategies were applied in fingerprinting procedure. • The bare hilly land and river courses were identified as the main sediment source. • Wind and remote sensing data are valuable in identification of aeolian sand source. [ABSTRACT FROM AUTHOR]

Since the early 21st century, global climate change has been inducing rapid glacier retreat at an unprecedented rate. In this context, the melt ponds impart increasing unique footprints on the periglacial rivers due to their hydrodynamic connection. Given that bacterial communities control numerous ecosystem processes in the glacial ecosystem, exploring the fate of bacterial communities from melt ponds to periglacial rivers yields key knowledge of the biodiversity and biogeochemistry of glacial ecosystems. Here, we analyzed the bacterial community structure, diversity, and co-occurrence network to reveal the community organization in the Zhuxi glacier in the Tibet Plateau. The results showed that the bacterial communities in melt ponds were significantly lower in alpha-diversity but were significantly higher in beta-diversity than those in periglacial rivers. The rare sub-communities significantly contributed to the stability of the bacterial communities in both habitats. The co-occurrence network inferred that the mutually beneficial relationships predominated in the two networks. Nevertheless, the lower ratio of positive to negative edges in melt ponds than periglacial rivers implicated fiercer competition in the former habitat. Based on the significantly higher value of degree, betweenness, and modules, as well as shorter average path length in melt ponds, we speculated that their bacterial communities are less resilient than those of periglacial rivers. [ABSTRACT FROM AUTHOR]