24年12月17日文献情报（3篇）

24年12月17日文献情报

1. 题目: Soil microbial carbon and nitrogen limitation constraints soil organic carbon stability in arid and semi-arid grasslands

文章编号: N24121703
期刊: Journal of Environmental Management
作者: Mengyao Wu, Lin Chen, Shenggang Chen, Yinglong Chen, Jinpeng Ma, Yaqi Zhang, Danbo Pang, Xuebin Li
更新时间: 2024-12-17
摘要: Microorganisms play dual roles in soil organic carbon (SOC) decomposition and accumulation. Despite advancing insights into their involvement in the carbon cycle, understanding the impact of microbial community structure and physiological traits on SOC stabilization in arid and semi-arid grasslands remains elusive. Here, we analyzed arid and semi-arid grasslands SOC stability by comparing the ratio of mineral-associated organic carbon (MAOC) to particulate organic carbon (POC) across a grassland transect in north-south Ningxia, encompassing various grassland types and a broad climatic gradient (ΔMAP = 450 mm). By combining phospholipid fatty acid (PLFA) analysis, enzyme activity vector models and stoichiometric theory, the influence of soil microbial community compositions, metabolic constraints, and carbon use efficiency (CUE) on SOC stability were explored. Results showed that SOC stability was the lowest in desert areas and decreased with increasing mean annual precipitation (MAP) in other grasslands. Microbial physiological traits, including microbial carbon (C) limitation, nitrogen (N) limitation, CUE, and lignocellulose index (LCI) varied among grasslands, with significantly higher LCI and CUE and lower C and N limitation in steppe desert. The variation of microbial physiological characteristics accounted for 53.28% of the variation in SOC stability. Distinct microbial metabolic limitations were evident in these grasslands, with N and C limitation prevailing and exerting strong negative impacts on CUE. Decreased fungal/bacterial (F/B) ratios also reduced microbial CUE and indirectly diminished SOC stability. In addition, clay content emerges as a major factor influencing the stabilization of SOC across environmental gradients. Collectively, our work suggests that mitigating microbial C and N limitation and enhancing microbial CUE under the influence of MAP and clay content are the key mechanisms governing SOC stabilization in regional grasslands. These findings bear significant implications for understanding microbial-mediated carbon cycling processes in arid and semi-arid grasslands.
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2. 题目: Synergetic Effects of Soil Organic Matter Components During Interactions with Minerals

文章编号: N24121702
期刊: Environmental Science & Technology
作者: Odeta Qafoku, Amity Andersen, Qian Zhao, Sebastian T Mergelsberg, William R Kew, Elizabeth K Eder, Charles T Resch, Emily B Graham, Nikolla P Qafoku
更新时间: 2024-12-17
摘要: Mineral-associated soil organic matter (SOM) is critical for stabilizing organic carbon and mitigating climate change. However, mineral-SOM interactions at the molecular scale, particularly synergetic adsorption through organic–organic interaction on the mineral surface known as organic multilayering, remain poorly understood. This study investigates the impact of organic multilayering on mineral-SOM interactions, by integrating macroscale experiments and molecular-scale simulations that assess the individual and sequential adsorption of major SOM compounds–lauric acid (lipid), pentaglycine (amino acid), trehalose (carbohydrate), and lignin onto soil minerals. Ferrihydrite, Al-hydroxide, and calcite are exposed to SOM compounds to determine adsorption affinities and binding energies. Results show that lauric acid has 20–40 times higher K_d than pentaglycine, following the order K_d(ferrihydrite) > K_d(Al-hydroxide) ≫ K_d(calcite). Molecular-scale simulations confirm that lauric acid has a higher binding energy (30.8 kcal/mol) on ferrihydrite than pentaglycine (6.0 kcal/mol), attributed to lipid hydrophobicity. The lower binding energy of pentaglycine results from its hydrophilic amide groups, facilitating partitioning into water. Sequential experiments examine how the first layer of lipid or amino acid affects the adsorption of carbohydrate/lignin, which show little or no individual adsorption affinities. Macroscale results reveal that lipid and amino acid adsorption induce ferrihydrite particle repulsion increasing reactive surface area and enhancing carbohydrate/lignin adsorption independently and synergistically through organic multilayering. Molecular-scale results reveal that amino acid adsorbed on ferrihydrite interacts more readily with lignin macroaggregates (preformed in solution) than with individual lignin units, indicating organic multilayering via H-bonding. These findings reveal the molecular mechanisms of SOM-mineral interactions, crucial for enhancing soil carbon stabilization.
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3. 题目: Drivers of soil organic carbon from temperate to alpine forests: a model-based analysis of the Swiss forest soil inventory with Yasso20

文章编号: N24121701
期刊: Biogeosciences
作者: Claudia Guidi, Sia Gosheva-Oney, Markus Didion, Roman Flury, Lorenz Walthert, Stephan Zimmermann, Brian J Oney, Pascal A Niklaus, Esther Thürig, Toni Viskari, Jari Liski, Frank Hagedorn
更新时间: 2024-12-17
摘要: . Predicting soil organic carbon (SOC) stocks and its dynamics in forest ecosystems is crucial for assessing forest C balance, but the relative importance of key controls – litter inputs, climate, and soil properties – remains uncertain. Here, we linked SOC stocks at 556 old-growth Swiss forest sites from 350 to 2000 m a.s.l. to a comprehensive set of environmental variables, encompassing climate (mean annual precipitation, MAP: 700–2100 mm, mean annual temperature, MAT: 0–12 °C), soil properties, and forest types. In addition, we compared measured SOC stocks with stocks simulated by the Yasso20-model that is widely used for reporting SOC stock changes. Since Yasso20 is driven solely by litter inputs and climate, deviations between modelled and measured stocks can reveal the significance of additional factors such as organo-mineral interactions that we hypothesized to be crucial for SOC stocks. Total SOC stocks exhibited distinct regional patterns, with the highest values in the Southern Alps, where soils are rich in Fe and Al oxides and receive high MAP. On average, total SOC stocks simulated by Yasso20 aligned well with measured SOC stocks (13.7 vs 13.2 kg C m^-2). However, the model did not capture regional SOC variability, underestimating SOC stocks by up to 7 kg C m^-2 in the Southern Alps. The underestimation was primarily explained by soil mineral properties with their influence depending on soil pH. In soils with pH ≤ 5, exchangeable Fe had the strongest effect on Yasso20 deviations from measured stocks, while in soils with pH > 5, exchangeable Ca had the strongest effect on model deviations. Beyond Fe and Ca, MAP emerged as an important driver of total SOC stocks, with SOC stocks increasing with MAP. At higher elevation, this coincided with low MAT and a high share of conifers. While Yasso20 accounted for MAT, Yasso20 underestimated SOC stocks for MAP > 1400 mm. Overall, our results indicate that mineral-driven SOC stabilization and climate are the primary drivers of Yasso20 deviations from measured SOC stocks. Incorporating mineral-driven SOM stabilization and coupling to a soil water model can improve the modeling of SOC stocks. However, further studies are needed to verify how C stabilization mechanisms and soil moisture can be included in model-based estimates of SOC stock changes, which is the primary application of Yasso in greenhouse gas inventories.
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