Geoderma最新文献

{"title":"The addition of chemical compounds extracted from leaf litter leachates enhances short term methane uptake by forest soils","authors":"Vincent Arricastres ,&nbsp;Dorine Desalme ,&nbsp;Thomas Z. Lerch ,&nbsp;Marie-Noëlle Vaultier ,&nbsp;Caroline Plain","doi":"10.1016/j.geoderma.2025.117347","DOIUrl":"10.1016/j.geoderma.2025.117347","url":null,"abstract":"<div><div>Upland forest soils are recognized as the primary biological sink for methane. The influence of litter on soil methane uptake has not been clearly elucidated: litter could reduce methane uptake, have no influence or enhance it. Until now, the role of litter has only been studied for the diffusion of gases. The chemical influence of leachate compounds from litter is a dominant process in forest ecosystems. In this study, we investigated this influence on soil methane fluxes. We extracted leaf litter compounds from four temperate tree species (beech, oak, pine and spruce) and determined their biochemical composition by spectrophotometry. The leachates, or pure water for the control treatment, were added to three different types of sieved forest soil (alocrisol, cambisol and luvisol) to determine their influences on methane fluxes. The methane fluxes were monitored for 48-h. We found that the chemical compounds leached from leaf litter enhanced methane uptake by 8.2 % with no significant effect of the species from which the leachates were extracted. The enhancement depended on the type of soil and was correlated to initial methane uptake. These results indicate that the role played by litter in the methane balance of forest soils, which has so far been thought to affect only the availability of the substrate (methane and dioxygen), is more complex than that.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"459 ","pages":"Article 117347"},"PeriodicalIF":5.6,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144107734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Developing a multi-criteria assessment model for soil primary productivity in double cropping systems: Insights from the North China Plain","authors":"Yizan Li ,&nbsp;Carmen Vazquez ,&nbsp;Jiyu Jia ,&nbsp;Jiangzhou Zhang ,&nbsp;Ron de Goede ,&nbsp;Marko Debeljak ,&nbsp;Fusuo Zhang ,&nbsp;Junling Zhang ,&nbsp;Rachel Creamer","doi":"10.1016/j.geoderma.2025.117346","DOIUrl":"10.1016/j.geoderma.2025.117346","url":null,"abstract":"<div><div>Soil, one of the Earth’s most critical natural resources, supports global agricultural production and underpins key ecosystem services. Among the multiple functions soil performs, primary productivity stands out as a crucial element, pivotal for ensuring food security as the basis of the agricultural system. This study aimed to develop a multi-criteria assessment model for soil primary productivity at field scale, drawing insights from the winter wheat − summer maize rotation systems in the North China Plain. The development of the model followed the Decision Expert (DEX) methodology, using an integrated approach that combines knowledge graph and data mining techniques. We systematically structured the knowledge underpinning soil primary productivity. Utilising datasets derived from long-term field experiments and smallholder farms, the model was subjected to an iterative process of calibration and validation, enhancing both its predictive accuracy and operational applicability. The developed DEX model consists of 28 input attributes that encompass soil properties, field management practices, and meteorological conditions. The model achieved an accuracy of 71% in assessing soil primary productivity in the experimental field dataset after calibration, and 62% in the smallholder farm dataset as model validation. The developed model can effectively assess soil primary productivity function and facilitate the improvement of soil management. The innovative integration of knowledge-based and data-driven approaches proved to be effective. It is expected that the developed model can be integrated with other soil function models into a soil health decision support system that provides a holistic approach to soil health assessment and optimisation of field practices.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"459 ","pages":"Article 117346"},"PeriodicalIF":5.6,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144107736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aggregate pore and shape properties were more strongly correlated to soil organic carbon in large aggregates: Evidence from a long-term management-induced soil carbon gradient","authors":"Weijun Zhang ,&nbsp;Lars J. Munkholm ,&nbsp;Richard J. Heck ,&nbsp;Christopher W. Watts ,&nbsp;Johannes L. Jensen","doi":"10.1016/j.geoderma.2025.117357","DOIUrl":"10.1016/j.geoderma.2025.117357","url":null,"abstract":"<div><div>The interplay between soil structure and soil organic carbon (SOC) is complex and affects key soil functions. There is limited knowledge on how this relationship changes with the size of the structural unit studied. The objective of this study was to quantify the pore and shape characteristics of soil aggregates of varying sizes, and their relationships with SOC under different soil management regimes. Soils were sampled in March 2015 from the Highfield Ley-Arable Long-Term Experiment at Rothamsted Research. This experiment includes bare fallow, continuous arable rotation, ley-arable rotation, and grass treatments. A total of 24 aggregates from each treatment and size class (2–4, 4–8, and 8–16 mm) were subjected to X-ray micro-CT scanning at 40 μm voxel resolution. Results showed that permanent grass not only increased SOC accumulation, but also promoted pore connectivity of soil aggregates compared to bare fallow, regardless of aggregate size. Additionally, the pore and shape characteristics of larger aggregates (4–8 and 8–16 mm) were more sensitive to soil management compared to smaller aggregates (2–4 mm). The relationships between SOC and aggregate structural characteristics were strong for both 8–16 and 4–8 mm aggregates but weak for 2–4 mm aggregates. Furthermore, the responses of pore connectivity and sphericity to SOC increased with aggregate size. The results suggest that organic matter input plays an essential role in shaping aggregate structural characteristics and aggregate rearrangement (especially in larger aggregates).</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"459 ","pages":"Article 117357"},"PeriodicalIF":5.6,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144107735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LimeSoDa: A dataset collection for benchmarking of machine learning regressors in digital soil mapping","authors":"Jonas Schmidinger ,&nbsp;Sebastian Vogel ,&nbsp;Viacheslav Barkov ,&nbsp;Anh-Duy Pham ,&nbsp;Robin Gebbers ,&nbsp;Hamed Tavakoli ,&nbsp;Jose Correa ,&nbsp;Tiago R. Tavares ,&nbsp;Patrick Filippi ,&nbsp;Edward J. Jones ,&nbsp;Vojtech Lukas ,&nbsp;Eric Boenecke ,&nbsp;Joerg Ruehlmann ,&nbsp;Ingmar Schroeter ,&nbsp;Eckart Kramer ,&nbsp;Stefan Paetzold ,&nbsp;Masakazu Kodaira ,&nbsp;Alexandre M.J.-C. Wadoux ,&nbsp;Luca Bragazza ,&nbsp;Konrad Metzger ,&nbsp;Martin Atzmueller","doi":"10.1016/j.geoderma.2025.117337","DOIUrl":"10.1016/j.geoderma.2025.117337","url":null,"abstract":"<div><div>Digital soil mapping (DSM) relies on a broad pool of statistical methods, yet determining the optimal method for a given context remains challenging and contentious. Benchmarking studies on multiple datasets are needed to reveal strengths and limitations of commonly used methods. Existing DSM studies usually rely on a single dataset with restricted access, leading to incomplete and potentially misleading conclusions. To address these issues, we introduce an open-access dataset collection called Precision Liming Soil Datasets (LimeSoDa). LimeSoDa consists of 31 field- and farm-scale datasets from various countries. Each dataset has three target soil properties: (1) soil organic matter or soil organic carbon, (2) clay content and (3) pH, alongside a set of features. Features are dataset-specific and were obtained by optical spectroscopy, proximal- and remote soil sensing. All datasets were aligned to a tabular format and are ready-to-use for modeling. We demonstrated the use of LimeSoDa for benchmarking by comparing the predictive performance of four learning algorithms across all datasets. This comparison included multiple linear regression (MLR), support vector regression (SVR), categorical boosting (CatBoost) and random forest (RF). The results showed that although no single algorithm was universally superior, certain algorithms performed better in specific contexts. MLR and SVR performed better on high-dimensional spectral datasets, likely due to better compatibility with principal components. In contrast, CatBoost and RF exhibited considerably better performances when applied to datasets with a moderate number (&lt;20) of features. These benchmarking results illustrate that the performance of statistical methods can be highly context-dependent. LimeSoDa therefore provides an important resource for improving the development and evaluation of statistical methods in DSM.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"459 ","pages":"Article 117337"},"PeriodicalIF":5.6,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144090576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects and mechanisms of warming on the relationship between soil organic matter degradation and methylmercury production in Hg-contaminated soil","authors":"Siqi Zhang ,&nbsp;Sihua Zhu ,&nbsp;Shanyi Tian ,&nbsp;Jianxu Wang ,&nbsp;Yongguang Yin ,&nbsp;Jitao Lv ,&nbsp;Yongmin Wang ,&nbsp;Tao Jiang ,&nbsp;Zhenwu Tang ,&nbsp;Dingyong Wang","doi":"10.1016/j.geoderma.2025.117326","DOIUrl":"10.1016/j.geoderma.2025.117326","url":null,"abstract":"<div><div>The degradation of soil organic matter (SOM) is an essential process that not only drives the production of greenhouse gases (GHGs) but also influences the environmental fate of pollutants, such as mercury (Hg), specifically methylmercury (MeHg) production. However, the relationship between these processes and their response to warming remains unclear. To address this gap, we conducted a 60-day microcosm incubation period using mimic-contaminated soils with varying Hg levels to investigate the effects of warming on SOM degradation and MeHg production. These results indicate that Hg stress does not significantly affect GHG production but increases the temperature sensitivity (Q₁₀) of SOM degradation. This implies that warming increases the feedback of carbon release in contaminated soil, particularly when considering seasonal temperature dynamics or prospective global warming scenarios. Additionally, warming can significantly promote GHG production. However, warming did not significantly affect MeHg production, except in the high Hg treatment (i.e., HgH), due to minimal changes in the Hg fractions that regulate MeHg production. Furthermore, regardless of temperature changes, the relationship between GHGs and MeHg shifted from positive to negative as Hg levels increased. This highlights the need to balance carbon emission reduction and pollutant treatment policies to effectively reduce risks in contaminated sites. In conclusion, in terms of the current development of C management strategies for mitigating climate change and enhancing carbon sequestration, the turnover of SOM and its ecological implications for contaminated soils should be revisited. Future research should incorporate contaminated soils into global carbon models to improve SOM turnover predictions in terrestrial systems.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"458 ","pages":"Article 117326"},"PeriodicalIF":5.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144084588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combining temperature ramp dry combustion and mid-infrared spectroscopy for enhanced soil organic carbon characterisation","authors":"Lewis Walden,&nbsp;Raphael A. Viscarra Rossel","doi":"10.1016/j.geoderma.2025.117316","DOIUrl":"10.1016/j.geoderma.2025.117316","url":null,"abstract":"<div><div>Soil organic carbon (SOC) is comprised of a complex mixture of plant and microbial-derived compounds with varying chemical compositions and stability. Understanding these components is crucial for modelling SOC turnover and stability. Conventional fractionation methods moslty use physical or chemical separations, but techniques such as mid-infrared (MIR) spectroscopy and thermal ramp dry combustion (TRDC) offer complementary, rapid approaches for SOC characterisation. This study integrates MIR spectroscopy and TRDC to characterise plant-derived compounds in soils. Using soils dosed with six plant-derived compounds (cellulose, lignin, starch, pectin, xylose, and biochar), we investigated their thermograms and MIR spectra. Each compound exhibited unique thermal decomposition peaks and MIR absorptions, reflecting their distinct chemical structures and oxidative stability. Correlation analyses revealed strong relationships between thermal peaks and MIR features. Models that combined MIR and TDRC spectra could estimate cellulose (<span><math><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>92</mn></mrow></math></span>), biochar (<span><math><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>95</mn></mrow></math></span>), pectin (<span><math><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>77</mn></mrow></math></span>) and starch (<span><math><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>87</mn></mrow></math></span>). Our findings show the potential for combining MIR spectroscopy and TRDC to characterise SOC chemical composition. By identifying distinct thermal and spectral features of plant-derived compounds, the combined approach could identify contributions of plant-derived compounds to labile and stable carbon pools, for enhancing our understanding of SOC decomposability. These methods may provide new insights into SOC turnover and stability mechanisms when applied to fractionated soils.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"458 ","pages":"Article 117316"},"PeriodicalIF":5.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144084587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal variations in soil erosion resistance under tap and fibrous root systems grasslands on the Chinese Loess Plateau","authors":"JianFang Wang ,&nbsp;YanFen Yang ,&nbsp;Bing Wang ,&nbsp;GuoBin Liu","doi":"10.1016/j.geoderma.2025.117350","DOIUrl":"10.1016/j.geoderma.2025.117350","url":null,"abstract":"<div><div>Vegetation growth can induce the seasonal variation in soil erosion resistance during a growing season, reflected by rill erodibility (<em>Kr</em>) and critical shear stress (<em>τ_c</em>).</div><div>However, few studies have been conducted to quantify the seasonal variations in erosion resistance under different root type grasslands. This study was conducted on the seasonal variations in soil erosion resistance under tap and fibrous root systems grasslands on the Chinese Loess Plateau, and quantified the potential influencing factors of soil erosion resistance. The undisturbed soil samples were collected over 30-day intervals from April to September 2021. Soil detachment capacity by concentrated flow was measured in a hydraulic flume with the fixed bed under six shear stresses to determine soil erosion resistance. The results showed that the <em>Kr</em> decreased over the growing season as a power function, and the <em>Kr</em> of annual herbaceous plants decreased faster than that of perennial herbaceous plants. Compared with the bare control soil, the <em>Kr</em> of grasslands decreased by 4.07–95.78 %, <em>τ_c</em> increased by 141.26–176.35 %. Generally, the <em>Kr</em> of annual herbaceous plants was 11.58 times higher, and <em>τ_c</em> was 15.48 % lower than perennial herbaceous plants. Differences in <em>Kr</em> were also observed between plants with tap and fibrous root systems. Plants with tap root systems had a higher <em>Kr</em>, which was 2.83 times that of plants with fibrous root systems. Plant root systems and soil were all affected in terms of <em>Kr</em> and <em>τ_c</em>, root system and soil contributions were 41.0 and 3.4 % for <em>Kr</em>, and 9.1 % and 18.8 % for <em>τ_c</em>, respectively. In addition, <em>Kr</em> decreased exponentially with increasing root mass, length, and surface area density, and also decreased with increasing bulk density, cohesion, and water-stable aggregate content. The <em>τ_c</em> increased with increasing bulk density as a power function. Finally, <em>Kr</em> was effectively predicted from using water-stable aggregates content and root surface area density. The performance of the developed model is satisfactory (<em>NSE</em> = 0.85).</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"458 ","pages":"Article 117350"},"PeriodicalIF":5.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144084589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term management effects on depth gradients of 13C, 15N and C/N ratio in agricultural soils","authors":"Laura E. Skadell ,&nbsp;Florian Schneider ,&nbsp;Sara L. Bauke ,&nbsp;Wulf Amelung ,&nbsp;Axel Don","doi":"10.1016/j.geoderma.2025.117341","DOIUrl":"10.1016/j.geoderma.2025.117341","url":null,"abstract":"<div><div>Agricultural management practices influence the turnover and residence time of soil organic matter (SOM) and thus can contribute to carbon (C) removal from the atmosphere. However, advanced analytical techniques are needed to disentangle the interlinked processes of SOM stabilisation and destabilisation, as well as its built-up and decomposition. Stable isotopes of C (δ¹³C) and nitrogen (N; δ¹⁵N) as well as the carbon-to-nitrogen (C/N) ratio provide information about the quality and thus origin and turnover SOM. The aim of this study was to quantify the effect of different agricultural management practices (mineral fertilisation, farmyard manure (FYM) application, straw incorporation, crop rotations, liming, irrigation and reduced tillage) on these indicators in topsoil and subsoil. Ten German long-term experiments (LTEs) were sampled down to 100 cm depth. Changes in SOC and N content were assessed as indicators of SOM quantity and changes in δ¹³C, δ¹⁵N and C/N ratios were assessed as indicators of SOM quality. Increases in C and N content were mainly affected in topsoil by mineral fertilisation, FYM, straw and irrigation. Changes in δ¹³C were limited to crop rotations (+0.62 ‰) and FYM (−0.27 ‰) in topsoil, but liming effects also reached down to 70 cm (−0.46 ‰ on average). Mineral fertilisation reduced the δ¹⁵N values in topsoil (−0.12 ‰), while the application of FYM increased them (+0.53 ‰), indicating different N sources. The δ¹⁵N values in the subsoil changed due to crop rotations (+0.62 ‰) and reduced tillage (−0.96 ‰). Specific management practices did not change C/N ratios significantly, with the exception of NPK fertilisation in topsoil (−1.32). Variations in SOC and total N content were more than 50 % greater in subsoil than in topsoil, but ¹³C and ¹⁵N did not follow this trend, indicating a decoupling of changes in C and N content and changes in SOM quality. This study revealed challenges in the detection of subsoil effects due to the low SOM content that in some LTEs unexplained large spatial variability in δ¹⁵N in subsoil. Since agricultural management practices change ¹³C, ¹⁵N and C/N ratios at least in topsoil, these variations need to be considered in isotope studies.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"458 ","pages":"Article 117341"},"PeriodicalIF":5.6,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144070713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Permafrost thawing by soil transplantation alters the functional genetic potential of the alpine permafrost microbiome","authors":"Maomao Feng ,&nbsp;Gilda Varliero ,&nbsp;Carla Perez-Mon ,&nbsp;Serina Robinson ,&nbsp;Weihong Qi ,&nbsp;Beat Stierli ,&nbsp;Beat Frey","doi":"10.1016/j.geoderma.2025.117339","DOIUrl":"10.1016/j.geoderma.2025.117339","url":null,"abstract":"<div><div>Global warming has led to permafrost thawing in mid-latitude alpine regions, resulting in greater availability of carbon (C) and nutrients in soils. However, how these changes will impact the functional genetic potential of permafrost soil microbiomes, and subsequently, how they will influence the microbially mediated feedback of mountain soils under climate change remains unknown. To help answer this question, we conducted a permafrost thawing experiment on the north-facing slope near the summit of Muot da Barba Peider (2979 m above sea level) in the Swiss Alps. Specifically, we transplanted permafrost soils from a depth of 160 cm to the active-layer topsoils (0–18 cm) and incubated the soils <em>in situ</em> for three years. Using shotgun metagenomics, we found that transplantation significantly altered the gene structure of the permafrost microbiome, with changes occurring in the short term (&lt; one year) and remaining stable over time. Transplanted soils exhibited an enhanced functional genetic potential, particularly for genes related to “Information storage and processing”, “Cellular processes and signaling” and “Metabolism” functions, which suggests increased cellular processes and metabolism. Carbohydrate-active enzymes involved in the degradation of both labile (such as starch) and recalcitrant (such as lignin) C substrates were enriched in transplanted soils, indicating an enhanced C-degradation potential. Nitrogen (N)-cycling genes related to the degradation and synthesis of N compounds, denitrification, assimilation and dissimilatory nitrate reduction were overrepresented in the transplanted soil, pointing to enhanced N assimilation and transformation potential. Our study elucidates how the permafrost microbiome may functionally respond to warming in the European Alps. This research complements observations from Tibetan and Arctic regions, improving our understanding of functional changes in thawing permafrost globally.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"458 ","pages":"Article 117339"},"PeriodicalIF":5.6,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144070712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controls on soil organic carbon across soil depths in tropical and temperate non-volcanic regions","authors":"Han Lyu ,&nbsp;Kenta Ashida ,&nbsp;Satomi Urayama ,&nbsp;Arief Hartono ,&nbsp;Method Kilasara ,&nbsp;Antoine David Mvondo Ze ,&nbsp;Atsushi Nakao ,&nbsp;Soh Sugihara ,&nbsp;Randy A. Dahlgren ,&nbsp;Shinya Funakawa ,&nbsp;Tetsuhiro Watanabe","doi":"10.1016/j.geoderma.2025.117335","DOIUrl":"10.1016/j.geoderma.2025.117335","url":null,"abstract":"<div><div>Soil organic carbon (SOC) is fundamental for climate regulation, soil fertility, biodiversity, and healthy terrestrial ecosystems. Understanding the key controllers and their pathways is required to estimate SOC distribution and predict C sequestration potential. Previous research emphasized the significant impact of active Al/Fe (acid-oxalate extractable) on SOC content, especially in volcanic soils, yet gaps persist in understanding the interactions among SOC, active Al/Fe, climate, and non-volcanic parent materials across different soil depths. Herein, we explore these dynamics using random forest regression (RFR) and structural equation modeling (SEM). Our analysis included 17 SOC-related physicochemical soil variables and 4 climatic properties across topsoil and subsoil horizons at 211 sites (2 depths). The study covers 178 tropical and 33 temperate sites from sub-humid to humid non-volcanic regions, predominantly with acidic to neutral soil pH. We found that SOC variance explained by SEMs (54 % for topsoil, 75 % for subsoil) closely matched RFR outcomes (61 % for topsoil, 72 % for subsoil), highlighting the efficacy of our SEMs in identifying key SOC controllers: mean annual temperature (MAT) and excess precipitation (moisture index: precipitation – potential evapotranspiration) for climate, Al₂O₃ + Fe₂O₃ (total Al and Fe contents expressed as oxides) for parent material, and active Al/Fe and pH for soil properties. Partial dependence in RFRs and path coefficients in SEM indicated MAT, active Al/Fe, and pH directly contribute to topsoil SOC, whereas active Al/Fe directly controls SOC in subsoil. Furthermore, SEMs indicated bidirectional interaction between SOC and active Al/Fe in topsoil, where active Al/Fe increased SOC and vice versa, while in subsoil, active Al/Fe has substantial unidirectional control over SOC. Importantly, both climate and parent material indirectly affected SOC by regulating active Al/Fe contents, particularly in subsoil. These findings enable predicting SOC distribution and refining SOC dynamics models by focusing on the direct and indirect impacts of active Al/Fe, climate and parent material across different soil depths and climatic zones in non-volcanic regions.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"458 ","pages":"Article 117335"},"PeriodicalIF":5.6,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}