Unlocking Mechanisms for Soil Organic Matter Accumulation: Carbon Use Efficiency and Microbial Necromass as the Keys

Global Change Biology, Journal Year: 2025, Volume and Issue: 31(1)

Published: Jan. 1, 2025

Soil microorganisms transform plant-derived C (carbon) into particulate organic (POC) and mineral-associated (MAOC) pools. While microbial carbon use efficiency (CUE) is widely recognized in current biogeochemical models as a key predictor of soil (SOC) storage, large-scale empirical evidence limited. In this study, we proposed experimentally tested two predictors POC MAOC pool formation: necromass (using amino sugars proxy) CUE (by 18O-H2O approach). sampling (0-10 10-20 cm depth) was conducted along climatic transect 900 km on the Loess Plateau, including cropland, grassland, shrubland, forest ecosystems, to ensure homogeneous parent material. We found highest accumulation occurred zones MAT between 5°C 10°C or MAP 300 500 mm. Microbial more positively related than (p < 0.05), suggesting that residues may improve strongly compared pool. Random linear regression analyses showed increased with fungal C, whereas bacterial drove MAOC. coupled 0.05) but decoupled SOC > 0.05). The have faster turnover rate due lack clay protection, which lead rapid thus their decoupling from CUE. sense, driven by necromass, explains dynamics. Our findings highlight insufficiency relying solely predict bulk storage. Instead, propose should be used together explain dynamics, each influencing distinct

Language: Английский

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Temperature and microbial metabolic limitations govern microbial carbon use efficiency in the Tibetan alpine grassland

Applied Soil Ecology, Journal Year: 2025, Volume and Issue: 206, P. 105880 - 105880

Published: Jan. 13, 2025

Language: Английский

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Soil Organic Carbon Increases With Decreasing Microbial Carbon Use Efficiency During Vegetation Restoration

Global Change Biology, Journal Year: 2024, Volume and Issue: 30(12)

Published: Dec. 1, 2024

ABSTRACT Microbial carbon (C) use efficiency (CUE) describes the proportion of organic C used by microorganisms for anabolic processes, which increases with soil (SOC) content on a global scale. However, it is unclear whether similar relationship exists during natural vegetation restoration in terrestrial ecosystems. Here, we investigated patterns CUE along 160‐year chronosequence (from farmland to climax forest) estimated stoichiometric modeling; additionally, examined between and SOC combined these results meta‐analysis. The combination indicated that decreased from 0.35 0.28. Surprisingly, increased decreasing because forest soils have low pH values high microbial phosphorus limitations compared early ecosystems, implying forests may not sequester as much expected. shift was most important predictor climate, plant, factors. changes were directly induced pH‐induced community. Alkaline acidification tended decrease CUE. This first large‐scale estimate highlights need strengthen sink management mature sustain their sequestration potential.

Language: Английский

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Environment and microbiome drive different microbial traits and functions in the macroscale soil organic carbon cycle

Global Change Biology, Journal Year: 2024, Volume and Issue: 30(8)

Published: Aug. 1, 2024

Soil microbial traits and functions play a central role in soil organic carbon (SOC) dynamics. However, at the macroscale (regional to global) it is still unresolved whether (i) specific environmental attributes (e.g., climate, geology, types) or (ii) community composition drive key directly. To address this knowledge gap, we used 33 grassland topsoils (0-10 cm) from geoclimatic gradient Chile. First, incubated soils for 1 week favorable standardized conditions quantified wide range of such as biomass (MBC), enzyme kinetics, respiration, growth rates well use efficiency (CUE). Second, characterized climatic physicochemical properties bacterial fungal soils. We then applied regression analysis investigate how strongly measured were linked with setting versus composition. show that (predominantly amount matter) determined patterns MBC along gradient, which turn explained respiration rates. normalized (i.e., growth) more than attributes. Notably, both followed distinct trends related different parts community, resulted strong effects on CUE. conclude even macroscale, CUE result physiologically decoupled aspects metabolism, partially by The affect functions, therefore factors need be considered context SOC

Language: Английский

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Are there links between nutrient inputs and the response of microbial carbon use efficiency or soil organic carbon? A meta-analysis

Soil Biology and Biochemistry, Journal Year: 2024, Volume and Issue: unknown, P. 109656 - 109656

Published: Nov. 1, 2024

Language: Английский

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Coupling of microbial-explicit model and machine learning improves the prediction and turnover process simulation of soil organic carbon

Climate smart agriculture., Journal Year: 2024, Volume and Issue: 1(1), P. 100001 - 100001

Published: April 24, 2024

Modeling soil organic carbon (SOC) is helpful for understanding its distribution and turnover processes, which can guide the implementation of effective measures (C) sequestration enhance land productivity. Process-based simulation with high interpretability extrapolation, machine learning modeling flexibility are two common methods investigating SOC turnover. To take advantage both methods, we developed a hybrid model by coupling two-carbon pool microbial modeling. Here, assessed model's predictive, mapping, capabilities process on Ningbo region. The results indicate that density-dependence (β ​= ​2) biomass performed better in parameters microbial-based C cycle, such as use efficiency (CUE), mortality rate, assimilation rate. By integrating this optimal random forest (RF) model, improved prediction accuracy SOC, an increased R2 from 0.74 to 0.84, residual deviation 1.97 2.50, reduced root-mean-square error 4.65 3.67 ​g ​kg−1 compared conventional RF model. As result, predicted exhibited spatial variation provided abundant details. Microbial CUE potential input, represented net primary productivity, emerged factors driving Projections under CMIP6 SSP2-4.5 scenario revealed regional loss areas was mainly caused decreased induced climate change. Our findings highlight combining microbial-explicit improve understand feedback changing climate.

Language: Английский

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Estimating the Importance of Viral Contributions to Soil Carbon Dynamics

Global Change Biology, Journal Year: 2024, Volume and Issue: 30(10)

Published: Oct. 1, 2024

ABSTRACT Biogeochemical models for predicting carbon dynamics increasingly include microbial processes, reflecting the importance of microorganisms in regulating movement between soils and atmosphere. Soil viruses can redirect among various chemical pools, indicating a need quantification development soil that explicitly represent viral dynamics. In this opinion, we derive global estimate potentially released from biomass by infections synthesize quantitative budget existing literature includes impacts. We then adapt known mechanisms which influence cycles marine ecosystems into soil‐explicit framework. Finally, explore diversity virus–host interactions during infection conceptualize how mode may impact fate. Our synthesis highlights key knowledge gaps hindering incorporation cycling research generates specific hypotheses to test pursuit better quantifying explain ecosystem‐scale fluxes. The identifying critical drivers behind dynamics, including these elusive but likely pervasive redistribution, becomes more pressing with climate change.

Language: Английский

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Codon bias, nucleotide selection, and genome size predict in situ bacterial growth rate and transcription in rewetted soil

Proceedings of the National Academy of Sciences, Journal Year: 2025, Volume and Issue: 122(3)

Published: Jan. 13, 2025

In soils, the first rain after a prolonged dry period represents major pulse event impacting soil microbial community function, yet we lack full understanding of genomic traits associated with response to rewetting. Genomic such as codon usage bias and genome size have been linked bacterial growth in soils—however, often through measurements culture. Here, used metagenome-assembled genomes (MAGs) 18 O-water stable isotope probing metatranscriptomics track transcription microorganisms over one week following rewetting grassland soil. We found that ribosomal protein genes was strongest predictor rate. also higher rates bacteria smaller genomes, suggesting reduced enables faster pulses bacteria. Faster transcriptional upregulation high increased nucleotide skew. several these relationships existed within phyla, indicating associations between activity could be generalized characteristics Finally, publicly available metagenomes assess distribution across pH gradient communities soils—which are more water limited driven—have their genes. Together, results provide evidence affect during pose potential fitness advantage for where nutrient availability episodic.

Language: Английский

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Impacts of the Ecosystem Transformation in Red Jujube Commercial Forests on the Soil Organic Carbon Sources and Stability in the Lvliang Mountains

Land Degradation and Development, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 28, 2025

ABSTRACT Soil organic carbon (SOC) stabilization is vital for the mitigation of global climate change and retention soil stocks. The Loess Plateau a crucial ecological zone in China even worldwide major ecosystem protection. However, Plateau, there are knowledge gaps about response SOC sources to different transitions jujube economic forests. Therefore, our study used clean‐cultivated orchards as control (CK) selected five main transformation models abandoned on Lvliang Mountain: farmland (AF), replanted with Astragalus‐Bupleurum (AB), alfalfa (AL), Chinese pine (CP), arborvitae (PO). properties, physical fractions their correlations 0‐ 20‐cm layer at each sample site were analyzed. results show that significantly increased by affecting plant‐ microbe‐derived altering its components. Different treatments have varying impacts content. lignin phenol (VSC) content soils was greater than CK had following ranking: CP > AL PO AF AB ( p < 0.05). also total amino sugar (TAS) content, microbial residue (MRC), contribution carbon. Additionally, it promoted accumulation particulate (POC) mineral‐associated (MAOC) positively impacted stability. Among models, greatest impact phenols, sugars, stability, whereas contributed least SOC. this provide scientific basis assess select optimal modes commercial

Language: Английский

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Nutrient additions have minor impact on microbial carbon use efficiency

Agriculture Ecosystems & Environment, Journal Year: 2025, Volume and Issue: 385, P. 109582 - 109582

Published: March 3, 2025

Language: Английский

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