Deterministic assembly of grassland soil microbial communities driven by climate warming amplifies soil carbon loss.

Perturbations in soil microbial communities caused by climate warming are expected to have a strong impact on biodiversity and future climate-carbon (C) feedback, especially in vulnerable habitats that are highly sensitive to environmental change. Here, we investigate the impact of four-year experimental warming on soil microbes and C cycling in the Loess Hilly Region of China. The results showed that warming led to soil C loss, mainly from labile C, and this C loss is associated with microbial response. Warming significantly decreased soil bacterial diversity and altered its community structure, especially increasing the abundance of heat-tolerant microorganisms, but had no effect on fungi. Warming also significantly increased the relative importance of homogeneous selection and decreased "drift" of bacterial and fungal communities. Moreover, warming decreased bacterial network stability but increased fungal network stability. Notably, the magnitude of soil C loss was significantly and positively correlated with differences in bacterial community characteristics under ambient and warming conditions, including diversity, composition, network stability, and community assembly. This result suggests that microbial responses to warming may amplify soil C loss. Combined, these results provide insights into soil microbial responses and C feedback in vulnerable ecosystems under climate warming scenarios.

Divergent patterns and drivers of leaf functional traits of Robinia pseudoacacia and Pinus tabulaeformis plantations along a precipitation gradient in the Loess plateau, China.

Changes in precipitation patterns in arid and semi-arid regions can reshape plant functional traits and significantly affect ecosystem functions. However, the synchronous responses of leaf economical, anatomical, photosynthetic, and biochemical traits to precipitation changes and their driving factors have rarely been investigated, which hinders our understanding of plants' ecological adaptation strategies to drought tolerance in arid areas. Therefore, the leaf traits of two typical plantations (Robinia pseudoacacia, RP and Pinus tabulaeformis, PT) along the precipitation gradient in the Loess Plateau, including economical, anatomical, photosynthetic, and biochemical traits, were investigated in this study. The results show that the leaf photosynthetic traits of RP and PT increase along the precipitation gradient, whereas leaf biochemical traits decrease. The anatomical traits of PT decrease with increasing precipitation, whereas no significant variation was observed for RP. Random Forest analysis show that LNC, LDMC, Chl, and PRO are leaf traits that significantly vary with the precipitation gradient in both plantations. Correlation analysis reveals that the traits coordination of RP is better than that of PT. The LMG model was used to determine driving factors. The results suggest that MAP explains the variation of PT leaf traits better (30.38%-36.78%), whereas SCH and SPH contribute more to the variation of RP leaf traits (20.88%-41.76%). In addition, the piecewise Structural Equation Model shows that the climate and soil physical and chemical properties directly affect the selected leaf functional traits of RP, whereas only the soil chemical properties directly affect the selected leaf functional traits of PT. The results of this study contribute to the understanding of the ecological adaptation of plants to environmental gradients and highlight that correlations among leaf traits should be considered when predicting plant adaptation strategies under future global change scenarios.

Natural restoration exhibits better soil bacterial network complexity and stability than artificial restoration on the Loess Plateau, China.

Natural restoration (NR, e.g., secondary succession) and artificial restoration (AR, e.g., afforestation) are key approaches for rehabilitating degraded land; however, a comparative assessment of microbial network between these approaches is lacking. We compared bacterial networks under NR and AR in two different watersheds on the Loess Plateau. Our findings revealed significantly heightened network complexity under NR compared to AR, including metrics such as node, edge, modularity, degree, centrality, and keystone nodes. NR's network robustness exceeded AR by 19.45-35.9% and 7.79-17.74% in the two watersheds, aligning with the ecological principle that complexity begets stability. The significantly higher negative/positive cohesion and natural connectivity under NR also support its better network stability than AR. Integrated analysis of paired sequencing data from five Loess Plateau studies conducted on the Loess Plateau further confirmed the higher complexity and stability of bacterial networks under NR. Further analysis unveiled "biological interactions" as primary drivers of bacterial co-occurrence (on average 84.21% of links), surpassing the influence of environmental filtering (5.17%) or dispersal limitation (4.2%). Importantly, networked communities under NR exhibited generally stronger linkages with various ecosystem function than AR. Overall, our study provides insights into vegetation restoration strategies from the perspective of microbial network, underscoring natural regeneration's potential as a superior remedy for degraded-land restoration.

Enhanced Adsorption of Aromatic Volatile Organic Compounds on a Perchloro Covalent Triazine Framework through Multiple Intermolecular Interactions.

Volatile organic compounds (VOCs) may have short- and long-term adverse health effects. Especially, aromatic VOCs including benzene, toluene, ethylbenzene, and xylene (BTEX) are important indoor air pollutants. Developing highly efficient porous adsorbents with broad applicability remains a major challenge. In this study, a perchlorinated covalent-triazine framework (ClCTF-1-400) is prepared for adsorbing BTEX. ClCTF-1-400 is confirmed as a partially oxidized/chlorinated microporous covalent triazine framework through a variety of characterization. It is found that ClCTF-1-400 is reversible VOCs absorbent with very high absorption capacities, which can adsorb benzene (693 mg g-1 ), toluene (621 mg g-1 ), ethylbenzene (603 mg g-1 ), o-xylene (500 mg g-1 ), m-xylene (538 mg g-1 ), and p-xylene (592 mg g-1 ) at 25 °C and their saturated vapor pressure (≈ 1 kPa). ClCTF-1-400 is of higher adsorption capacities for all selected VOCs than activated carbon and other reported adsorbents. The adsorption mechanism is also inferred through theoretical calculation and in-site Fourier Transform Infrared (FTIR) spectroscopy. The observed excellent BTEX adsorption performance is attributed to the multiple weak interactions between the ClCTF-1-400 frameworks and aromatic molecules through multiple weak interactions (CH… π and CCl… π). The breakthrough experiment demonstrates ClCTF-1-400 has the potential for real VOCs pollutant removal in air.

Synchronously Producing H2 and Purifying Methyl Orange-Polluted Water through the Reaction of an Al-GaInSn Alloy Plate and H2O.

Hydrogen gas (H2) as a fuel has the advantages of high energy density (122 kJ g-1) and zero carbon emissions. To meet the growing demand for H2 in the future, green, efficient, and convenient production technologies must be developed. The Al-H2O reaction, which produces H2 by reacting aluminum (Al) with water (H2O), is considered a rapid method for producing H2. However, Al-H2O creates a protective oxide layer on the surface of Al, preventing the production of H2. In this study, we developed a simple method for forming Al-GaInSn alloy by brushing GaInSn-Al2O3 grease onto an Al plate to form an Al/GaInSn-Al2O3/Al sandwich structure. Al2O3 in the sample supports GaInSn, prevents the leakage of GaInSn, and promotes its penetration into the Al lattice to form Al-GaInSn alloy. By forming a liquid phase within the alloy, GaInSn increases the accessibility of Al to the reaction. As a result, the Al-GaInSn alloy can rapidly react with pure H2O to produce H2 at room temperature conditions, with yields as high as ∼93.2%. It was interesting to find that dye-polluted water (methyl orange) could be synchronically purified by the Al-H2O reaction at the same time.

[Changes in Soil Microbial Carbon-Degrading Enzymes and Their Relationships with Carbon Pool Components During the Restoration Process of Robinia pseudoacacia].

To reveal the change in the characteristics of soil microbial C-degrading enzyme activities and the response to the components of C during the restoration process of Robinia pseudoacacia forests in the Loess Plateau, the components of the soil C pool, C-degrading enzyme activities, and microbial metabolic entropy of R. pseudoacacia in different restoration stages were studied, and the response relationship between C-degrading enzymes and soil C components was explored. The results showed that the microbial respiration (MR) first increased and then decreased with the restored years. We found that the microbial metabolic entropy (qCO2) decreased significantly with the restored years, but the microbial entropy (qMB) increased. Soil C-degrading enzymes increased significantly in the early-stage restoration of R. pseudoacacia; however, oxidizing enzymes (PO and PER) and cellobiohydrolase (CBH) decreased in the late stage of restoration. The soil organic C and recalcitrant organic C increased significantly with the restored years; however, there was no significant difference for the labile organic C. Correlation analysis and the partial least squares-path model (PLS-PM) showed that soil C-degrading enzymes and C components were significantly correlated with microbial respiration and entropy (qCO2 and qMB), respectively. The hydrolytic enzyme (BG+CBH) was significantly positively correlated with SOC, microbial biomass C, qMB, and recalcitrant and labile organic C. The oxidizing enzyme (PO+PER) was significantly positively correlated with the soil clay and qCO2. In addition, the recalcitrant organic C was the key driver of soil microbial metabolism affected by vegetation restoration. Overall, the ecosystem of R. pseudoacacia plantations would gradually stabilize with the increase in restored years and significantly increase the sequestration effect of soil C. These results will be helpful to understand the transformation rule and regulation mechanism of the soil C pool in vulnerable habitats and provide scientific basis for the restoration and management of vegetation in the Loess Plateau.

Dynamics in the rhizosphere and iron-uptake gene expression in peanut induced by intercropping with maize: role in improving iron nutrition in peanut.

The intercropping of maize with peanuts is an effective cropping practice. Indeed, peanut/maize intercropping reportedly improves the iron nutrition of peanuts in calcareous soils. The limited evidence available suggests that the improved Fe nutrition in intercropping is largely attributable to a rhizosphere effect of maize. In this study, the effects of peanut/maize intercropping on the Fe nutritional status of peanut associated with the dynamics of the rhizosphere processes and Fe uptake gene expression induced by the interaction of the two species at various growth days were investigated. The results suggest that an interspecific rhizosphere effect improves Fe nutrition in peanut, as shown by changes in the rhizosphere available Fe concentration, pH, and Olsen-P concentration, based on time-course changes in peanut-maize interaction. The increase in available Fe in the rhizosphere of peanut ranged from 0.2 to 2.64 mg kg(-1). The transition from the vegetative to reproductive stage was a key turning point in the time-course of changes in the rhizosphere processes in intercropping. There was more consistently positive effect of intercropping on peanut Fe nutrition after 53 days. Moreover, the expression of AhFRO1 and AhYSL1 was expressed at significantly higher level in intercropped peanuts compared to monocropped peanut at the vegetative stage, indicating a role for these genes in Fe improvement in intercropped peanuts. We conclude that the enhanced time-course changes in the rhizosphere processes and iron uptake gene expression with a consistent positive interspecific effect appear to be one of the mechanisms underlying the improved Fe nutrition in intercropped peanut plants.