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Low available soil nitrogen (N) limits plant productivity in alpine regions, and alpine plants thus resorb and reallocate N from senescing tissues to conserve this limited N during the non‐growing season. However, the destination and extent of N redistribution during plant senescence among above‐ and below‐ground organs, let alone other processes of translocation outside of plants and into the soil components, remain poorly understood.Utilizing 15N stable isotope as a tracer, we quantified N redistribution among above‐ and below‐ground plant organs and different soil components during senescence in an alpine meadow ecosystem, and explored the relationship between 15N partitioning among plant–soil N pools with seasonal fluctuations of plant functional traits.We found a substantial depletion of 15N in fine roots (−40% ± 2.8%) and above‐ground tissues (−51% ± 5.1%), and an enhanced 15N retention primarily in coarse roots (+79% ± 27%) and soil organic matter (+37% ± 10%) during plant senescence, indicating a dual role of roots with coarse roots acting as an N sink and fine roots as a source of N recycling during senescence. In parallel, we observed a temporal variation in plant functional traits, representing a shift from more acquisitive to more conservative strategies as the growing season ends, such as higher coarse root N and coarse root to fine root ratio. The seasonal trait variations were highly correlated with the 15N retention in coarse roots and soil organic matter. Particularly, 15N retention in particulate and mineral‐associated organic matter increased by 30% ± 12% and 24% ± 9%, respectively, suggesting a potential pathway through which fine root and microbial mortality contribute to 15N redistribution into soil N pools during senescence.Synthesis. N redistribution and seasonal plant trait fluctuation facilitate plant N conservation and ecosystem N retention in the alpine system. This study suggests a coupled above‐ground‐below‐ground N conservation strategy that may optimize the temporal coupling between plant N demand and ecosystem N supply in N‐limited alpine ecosystems. [ABSTRACT FROM AUTHOR]

As the Third Pole of the world, the Tibetan Plateau provides a typical alpine grassland environment for soil bacteria with its unique frigid and arid climate. Owing to clear changes in spatial moisture and increased grazing intensity, moisture and livestock grazing have become key factors influencing the microbial communities. Accordingly, we investigated the diversity and composition of soil bacteria in a selected alpine grassland within the dual gradients of moisture and grazing using high-throughput sequencing. Our results showed that grazing changed the soil bacterial diversity and composition, whereas moisture only influenced the relative abundance of the segmental community at the small spatial scale. Species richness was found to be increased by moderate grazing compared with that by high or low-grazing intensity. The relative abundance of dominant species and β-diversity of soil bacteria both showed differences with heavy, moderate, and low grazing. Some dominant bacteria were altered with the moisture content. However, there were no significant differences according to the moisture gradient in terms of the overall bacterial β diversity and composition. These results might be taken account into the small spatial scale as well as the compensation of grazing to moisture on this scale. This work provides new insights into the soil bacterial response to moisture gradients and grazing intensity in alpine steppe habitat. [ABSTRACT FROM AUTHOR]

Plant nutrient resorption, a process by which plant withdraws nutrients from senescing structures to developing tissues, can significantly affect plant growth, litter decomposition and nutrient cycling. Global change factors, such as nitrogen (N) deposition and altered precipitation, may mediate plant nutrient resorption and allocation. The ongoing global change is accompanied with increased N inputs and drought frequency in many regions. However, the interactive effects of increased N availability and drought on plant nutrient-responses remain largely unclear. In a pot experiment, we examined the impacts of N enrichment and drought on leaf N and phosphorous (P) resorption and root nutrient allocation in four species from the Qinghai-Tibet Plateau, including two graminoid species (Kobresia capillifolia and Elymus nutans) and two forb species (Delphinium kamaonense and Aster diplostephioides). Our results showed divergent resorption patterns within the two functional groups. E. nutans and D. kamaonense showed stronger N resorption than K. capillifolia and A. diplostephioides. N addition did not alter their N resorption efficiencies, but decreased the N resorption proficiencies of the former two species. In contrast, drought did not affect N or P resorption proficiencies, but decreased N resorption efficiency of K. capillifolia. Besides, N addition facilitated P resorption in K. capillifolia and D. kamaonense , and drought did the same in A. diplostephioides , suggesting that P resorption plays an important role in nutrient conservation in these species. Moreover, species with stronger N resorption allocated more biomass C or N to aboveground and enhanced their litter quality under N enrichment, while species with weaker resorption allocated more biomass C and/or N to belowground part under drought. Together, these results show that the responses of nutrient resorption and allocation to N enrichment and drought are highly species-specific. Future studies should take these differential responses into consideration to better predict litter decomposition and ecosystem nutrient cycling. Unlabelled Image • There is an evolutionary tradeoff between foliar resorption and allocation to roots. • Species with weaker resorption allocated more nutrient belowground under drought. • Species with stronger resorption enhanced aboveground investment under N enrichment. • Resorption variance should be included into trait measurement and ecosystem models. [ABSTRACT FROM AUTHOR]

Roots account for a major part of plant biomass in Tibetan alpine meadows. Understanding root decomposition with global change is key to predict carbon (C) and nutrient dynamics on the Qinghai-Tibet Plateau. Yet, few experiments have carefully examined root decomposition as influenced by global change. We conducted a field study to investigate the effects of nitrogen (N) addition, air warming, precipitation change, and the presence/absence of living roots on root decomposition in a Tibetan alpine meadow. Our results showed that N addition increased the mass and C remaining, and induced N accumulation in the litter. Increased precipitation significantly amplified the positive effect of N addition on litter mass remaining. The presence of alive roots in the litterbags decreased root litter C remaining but significantly increased N and phosphorus remaining of the litter. However, we did not find any significant effects of air warming on the litter decomposition. In the Qinghai-Tibet Plateau, N deposition is predicted to increase and precipitation regime is predicted to change. Our results suggest that the interaction between increased N and precipitation may reduce root decomposition in the Qinghai-Tibet Plateau in the future, and that the large stock of living roots exert a dominant impact on nutrient dynamics of root decomposition in the Tibetan alpine systems. [ABSTRACT FROM AUTHOR]

The article explores the use of large language models (LLMs) in scientific research, highlighting their potential benefits and limitations. It provides examples of how LLMs can assist in various scientific tasks, such as summarizing documents and improving writing. However, it also acknowledges the need for fact-checking and the potential biases in training data. The authors emphasize the importance of adhering to ethical guidelines and journal policies when using LLMs. While LLMs can be valuable tools, caution should be exercised in their use. [Extracted from the article]

Effect of phosphate on the reduction of U(VI) on nZVI was determined by batch, XPS, XANES and EXAFS techniques. The batch experiments showed that nZVI was quite effective for the removal of uranium under the anaerobic conditions, whereas the addition of phosphate enhanced uranium removal over wide pH range. At low pH, the reduction of U(VI) to U(IV) significantly decreased with increasing phosphate concentration by XPS and XANES analysis. According to EXAFS analysis, the occurrence of U U shell at 10 mg/L phosphate and pH 4.0 was similar to that of U (IV) O 2 (s), whereas the U P and U Fe shells were observed at 50 mg/L phosphate, revealing that reductive co-precipitate (U (IV) O 2 (s)) and precipitation of uranyl-phosphate were observed at low and high phosphate, respectively. The findings are crucial for the prediction of the effect of phosphate on the speciation and binding of uranium by nZVI at low pH, which is significant in controlling the mobility of U(VI) in contaminated environments. [ABSTRACT FROM AUTHOR]

Here, molybdenum sulfide (MoS2) was characterized and its performance as an adsorbent for Co(II)/Ni(II) removal from water was estimated in batch experiments. The nanomaterial exhibits thin-layered structure and contains numerous hydroxyl groups. High pH enhanced Co(II)/Ni(II) sorption, while ionic strength had no effect. The chemical sorption between the binding sites of MoS2 and Co(II)/Ni(II) limited the rate. The Freundlich isotherm correlated better than Langmuir isotherm. The maximum sorption capacity for Co(II)/Ni(II) was 370.10/375.94 mg· g−1, obviously exceeding other adsorbents. Both adsorptions were endothermic and spontaneous processes. This study indicates the intrinsic value of MoS2 in removing heavy metals from water. [ABSTRACT FROM AUTHOR]