Search

In order to explore the glaciochemistry of Shiyi glacier in the central Qilian Mountains, a total of 142 samples have been collected for fresh snow, surface snow, snowpit and meltwater from July 2012 to November 2013. The results indicated cations dominated the glaciochemistry, especially the high Ca 2+ concentration. Relatively high Cl − and Na + concentrations were mainly contributed by desert dust aerosols and the atmospheric aerosols from warm water bodies such as the Black, Caspian, and Aral seas. The analysis also confirmed the chemical ions in fresh snow are mainly contributed by atmospheric wet deposition. Surface snow is mainly influenced by dry deposition, and snowpits are influenced by both atmospheric deposition and leaching process, while meltwater is influenced by water–rock interactions. The profile of ionic concentration in the snowpit became more smoothed during ablation period owing to the influence of leaching. The elution sequence of the snowpit in the Shiyi Glacier was: SO 4 2− > K + > Ca 2+ > Mg 2+ > Na + > Cl − > NO 3 − . The chemical concentrations for meltwater are mainly influenced by water dilution and soil thawing. The ions in snow in the central Qilian Mountains showed relatively lower concentrations than in the western Qilian Mountains, Tianshan Mountains and Altai Mountains. It was closer to balance than in glaciers in the central Tibetan Plateau, but was higher than in the southern Tibetan Plateau. Different ionic sources and dissolution process had caused the differences of chemical composition for fresh snow, surface snow, snowpit and meltwater, and these chemical compositions reflected the atmospheric background values in the northern Tibetan Plateau. [ABSTRACT FROM AUTHOR]

• LPC, C/P and N/P of arbors, herbs and shrubs belong to strong variation indicators; • Altitude was also one of the main factors affecting plant functional traits; • Soil factors and leaf functional traits of different types plants respond to each other. Subsequent findings reveal the combination characteristics and spatial patterns of plant functional traits, and their response and adaptation to environmental changes in the Qinghai-Tibet Plateau. We analyzed the variation in characteristics and the influence of environmental factors on leaf functional traits from 78 quadrats in July 2021, using: one-way ANOVA, Tukey's Honest Significant Difference (HSD) post hoc test, Pearson correlation coefficient (r) analysis, and redundancy analysis (RDA) in the Qilian Mountains. Only the leaf carbon content (LCC) of arbors was a weak variation indicator in leaf function traits of different plant types, whereas other leaf function traits including: the LCC of herbaceous plants (herbs) and shrub plants (shrubs), and the leaf nitrogen content (LNC) and carbon to nitrogen (C/N) ratio of arbors were medium variation indicators. The LNC, leaf phosphorus content (LPC), C/N ratio(C/N), C/P ratio(C/P), and N/P ratio (N/P)of herbs and shrubs, and the LPC, C/P, and N/P of arboreal plants (arbors) were strong variation indicators. Altitude was also one of the main factors affecting functional traits of plants in cold regions. Electrical conductivity (EC) and soil phosphorus content (SPC) were the main factors affecting changes in the leaf functional traits of herbs. Soil bulk density (SBD) and Soil salinity (SAL) were the main factors affecting changes in the leaf functional traits of shrubs. Soil nitrogen content (SNC) and soil temperature (ST) were the main factors affecting changes in the leaf functional traits of arbors. [ABSTRACT FROM AUTHOR]

• Similar to herb and shrub, arbor plant shows significant differences with altitude. • LA, LL, LW, LC, and SC showed the same trend among different vegetation types. • There was negative correlation between soil temperature and NBI, ChI, FIv, and SC. Plant functional traits are adaptive traits formed by interactions between plants and the environment. Considering the Three-River Headwaters Region as a case study, this study systematically analyzed the relationship between plant functional traits and environmental factors in cold regions. The results show that there were significant differences in plant functional traits among the different vegetation types (herbs, shrubs, and arbor plants). Leaf traits such as leaf area (LA), leaf length (LL), leaf width (LW), leaf circumference (LC), and shape coefficient (SC) showed the same trends among herbs, shrubs, and arbor plants. The correlation between leaf functional traits of plants in alpine regions shows that the unique growth mode of different plants and their degree of adaptation to alpine environments ultimately determine the leaf functional trait variations. Moreover, there was a negative correlation between soil temperature and the nitrogen balance index (NBI), chlorophyll content (Chl), flavonoid content (Flv), and SC, whereas there was a trend of first increasing and then decreasing relationship between soil temperature, LL (P < 0.05), and LC (P < 0.05). Similar to herb and shrub plants, arbor plants also showed significant differences in altitude in cold regions. There were significant negative correlations between altitude and NBI (P < 0.05), Chl (P < 0.05), Flv (P < 0.05), and anthocyanin content (P < 0.05), whereas LA (P < 0.05), LL (P < 0.05), and LC (P > 0.05) were significantly positively correlated with altitude. Conversely, there was no significant negative correlation between LW and altitude (P > 0.05). We conclude that climate factors play a decisive role in the distribution of plant functional traits at a global scale, whereas land use and disturbances play a major role at a regional scale, and topographic and soil factors determine the distribution of local characteristics. [ABSTRACT FROM AUTHOR]