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{"title":"Soil geochemistry as a geochronologic tool: application to mapping composite fluvial terraces, Four Mile Creek, Ohio","authors":"Abigale O'Connor,&nbsp;Jason A. Rech,&nbsp;Christina N. Tenison","doi":"10.1016/j.catena.2026.109827","DOIUrl":"10.1016/j.catena.2026.109827","url":null,"abstract":"<div><div>Delineating ‘active’ (500-year) floodplains as well as Holocene and Late Pleistocene fluvial terraces is vital to determining flood and erosion risk within a river valley. Traditional geomorphic techniques to delineate the active floodplain and fluvial terraces include assessing surface roughness and mapping terrace scarps. However, agriculture and land use changes have disturbed the original surface morphology of floodplains in many locations, and streams often aggrade to the same elevation multiple times, creating composite fluvial terraces. Additional methodologies are necessary to better identify and map such composite terraces.</div><div>In this study, a portable X-ray fluorescence analyzer (pXRF) was used to measure the geochemistry of nine radiocarbon-dated soil pedons on fluvial terraces along Four Mile Creek, Ohio, ranging between ∼50 and 17,000 cal yrs. BP. Soil chronofunctions were calculated to quantify changes in weathering index values of Fe/Ca, Zr/Ca, and Ti/Ca within these pedons over time. Fe/Ca values of samples collected at 20−30 cm yielded a coefficient of determination of 0.9527 (<em>p</em> = 6.82E−06) and Fe/Ca values of samples collected at 0−10 cm yielded a coefficient of determination of 0.947 (<em>p</em> = 1.02E−05). These relationships were then used to infer soil age at 163 locations within mapping zone 1 and 147 locations within mapping zone 2 in the Four Mile Creek watershed. Different sampling densities (25 m and 50 m) were used in mapping zones 1 and 2 to determine the density required to map fluvial terraces along Four Mile Creek. In mapping zone 3, pXRF measurements were performed in the field at 78 locations along transects to determine if this faster approach yielded similar results. The active floodplain as well as Holocene and Late Pleistocene fluvial terraces were delineated based on the inferred soil age and a surficial geologic map was created. Results indicate the ideal sampling strategy is a grid of sampling locations with 50 m spacing as this is sufficient to constrain boundaries of the active floodplain and fluvial terraces while limiting time required to perform the analysis. Field-based analysis also provided reliable results. Weathering index chronofunctions were found to be a viable tool for mapping floodplains that have been altered by land use, for making flood and erosion risk evaluations, and can be used in conjunction with traditional mapping techniques.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109827"},"PeriodicalIF":5.7,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034977","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":"Runoff hydrodynamic variations on terraced slopes with different soil types in the dry–hot valley region, Southwest China","authors":"Dan Yang ,&nbsp;Donghong Xiong ,&nbsp;Shasha Han ,&nbsp;Baojun Zhang ,&nbsp;Qihua Liao ,&nbsp;Linpeng Wu","doi":"10.1016/j.catena.2026.109854","DOIUrl":"10.1016/j.catena.2026.109854","url":null,"abstract":"<div><div>Soil erosion on terraced slopes is widespread in the Jinsha dry–hot valley region, resulting in substantial soil loss. Soil type plays a crucial role in shaping hydrodynamic properties, which in turn affect the patterns and intensity of soil erosion. To investigate the impact of soil type on runoff hydrodynamics on terraced slopes, a series of artificial rainfall experiments were conducted on selected terraced slopes with varying soil types. The results revealed that soil types primarily influenced the variation in runoff shear stress (<em>τ</em>) during the initial 40 min of rainfall. Interestingly, the temporal evolution of runoff shear stress (<em>τ</em>) exhibited notable similarities among different soil types during the final 80 min. Distinct logarithmic functions effectively depicted the relationship between runoff shear stress (<em>τ</em>) and rainfall duration. The soil type of terraced slopes influenced not only the temporal variation but also the fluctuation characteristics of runoff hydrodynamic properties, including fluctuation range, rates of increase and decrease, and mean values. Specifically, the fluctuation of flow resistance (<em>f</em>) on terraced Dry red soil slope was 1.808–8.938 times greater than those observed on terraced Leptosol and Vertisol slopes. The critical dynamic conditions were also closely related to the soil types of terraced slopes and could be determined by both the shear stress (<em>τ</em>) and the ratio of shear stress to resistance (<em>Dsr</em>). The identified critical dynamic conditions for sheet, rill, and gully erosion on terraced slopes in the Yuanmou dry–hot valley region were as follows: shear stresses (<em>τ</em>) of 2.265–3.781 Pa, 3.546–6.316 Pa, and 5.251–6.253 Pa, respectively, and corresponding <em>Dsr</em> values of 0.037–0.471, 0.089–0.489, and 0.061–0.327, respectively. These findings provide valuable insights into the mechanisms of soil erosion on terraced slopes and offer a scientific basis for erosion prevention and ecological efforts in the Jinsha River Basin.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109854"},"PeriodicalIF":5.7,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034911","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":"Investigating the effect of microbial inoculation on raindrop splash erosion: Indoor simulated rainfall and Hairsine-Rose model analysis","authors":"Zhaoxing Xiao ,&nbsp;Tianxiao Li ,&nbsp;Qiang Fu ,&nbsp;Renjie Hou ,&nbsp;Mo Li ,&nbsp;Dong Liu ,&nbsp;Fanying Kong ,&nbsp;Qingyuan Liu ,&nbsp;Guoqing Li","doi":"10.1016/j.catena.2026.109826","DOIUrl":"10.1016/j.catena.2026.109826","url":null,"abstract":"<div><div>The core physical mechanism of rainfall erosion is primarily driven by the raindrop splash erosion process. The application of microorganisms to inhibit rainfall erosion has been confirmed. However, the process and mechanism of raindrop splash erosion under microbial application conditions remain unclear. Therefore, in this study, different types of microbial inoculants were applied to the surface of silty clay loam black soil under simulated heavy rainfall conditions, setting different concentrations and inoculation methods, to investigate the response characteristics and underlying mechanisms of microbial effects on the splash erosion process. The raindrop splash erosion process was simulated and analysed using COMSOL Multiphysics in conjunction with the Hairsine-Rose soil erosion model. The experimental results showed that among the different inoculant concentration treatments, the 10⁷ CFU·mL⁻¹ concentration had the highest infiltration rate and the lowest surface runoff. At this concentration, the Suspended Sediment Concentration (SSC) of the <em>Bacillus subtilis</em> inoculation treatment (B7), <em>Cyanobacteria</em> inoculation treatment (C7), and combined inoculation treatment (BC7) were reduced by 26.33%, 23.45%, and 6.48% respectively, compared with the control group. Meanwhile, different types and application methods of inoculants significantly affect the raindrop splash erosion process. Among them, the individual inoculation treatment has a better inhibitory effect on SSC and SS than the combined inoculation treatment, and the individual inoculations of <em>Bacillus subtilis</em> showed the optimal inhibitory effect. The model simulation results indicated that microbial inoculation treatments effectively inhibited raindrop splash erosion by reducing the bare soil detachability (<span><math><mi>a</mi></math></span>) and the fraction of eroded sediment (<em>β</em>), while increasing the material required to completely shield the soil (<em>Md</em>). However, considering the dynamic changes of microorganisms in the soil and the ongoing debate regarding their applicability to different soil types and environments, further research is needed to achieve the practical application of this technology in soil erosion control.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109826"},"PeriodicalIF":5.7,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034975","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":"Grassland type exerts a stronger influence than grazing on the abundance, structure, and diversity of active diazotrophic communities in Mongolian natural grassland soils","authors":"Kunlong Liang ,&nbsp;Hangai Bai ,&nbsp;Jia Zhao ,&nbsp;Chaojun Wang ,&nbsp;Tumentsogt Anuundari ,&nbsp;Zheng Wang ,&nbsp;Hugjiltu Minggagud ,&nbsp;Huhe ,&nbsp;Tiejun Bao ,&nbsp;Xinyu Wang ,&nbsp;Wenhong Ma ,&nbsp;Wei Guo ,&nbsp;Ariuntsetseg Lkhagva ,&nbsp;Frank Yonghong Li ,&nbsp;Zhihua Bao","doi":"10.1016/j.catena.2026.109840","DOIUrl":"10.1016/j.catena.2026.109840","url":null,"abstract":"<div><div>Biological nitrogen fixation by diazotrophs plays a pivotal role in nitrogen input to natural grassland ecosystems. Although animal grazing is the predominant land-use practice in these systems, its influence on diazotrophic communities are poorly understood. In this study, transcript-based quantitative PCR and <em>nifH</em> amplicon sequencing were employed to assess the effects of grazing on the diversity, composition, and abundance of active soil diazotrophic communities across three major steppe types along a climatic gradient in Mongolia. The abundance of <em>nifH</em> transcripts in meadow steppe soils (1.17 × 10⁵–2.54 × 10⁵ copies/g dry soil) was significantly higher than that in typical (2.66 × 10⁴–5.10 × 10⁴) and desert steppes (1.93 × 10⁴–2.66 × 10⁴), whereas no significant differences were observed among grazing intensities within the same steppe type. RNA-based sequencing revealed that the diversity of active diazotrophs was the highest in the meadow steppe. Steppe type exerted a stronger influence on diazotrophic community structure than on grazing management. Active diazotrophic communities were dominated by Gammaproteobacteria (31.22%) in typical and desert steppes and by Alphaproteobacteria (58.32%) in the meadow steppe. Transcript <em>nifH</em> gene abundance was significantly and positively correlated with soil physicochemical properties, climatic variables, and vegetation characteristics. Soil and climate factors were the primary drivers of diazotrophic community patterns. This study provides the first characterization of active diazotrophic community structure and abundance in Mongolian steppe soils subjected to centuries of nomadic grazing.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109840"},"PeriodicalIF":5.7,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034986","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":"Impact of dams on river regime and extreme flow events in MIÑO–SIL river basin (NW of the IBERIAN peninsula)","authors":"J. González-Cao,&nbsp;D. Fernández-Nóvoa,&nbsp;N.G. deCastro,&nbsp;H. Barreiro-Fonta,&nbsp;M. deCastro,&nbsp;M. Gómez-Gesteira","doi":"10.1016/j.catena.2026.109836","DOIUrl":"10.1016/j.catena.2026.109836","url":null,"abstract":"<div><div>River regulation is a major driver of hydrological change, yet its long-term effects relative to climate and land-use variability remain poorly constrained in many river basins. In the Miño–Sil River Basin (NW Iberian Peninsula), this study evaluates the respective roles of precipitation variability, land-use change, and dam regulation on river flow regimes and extreme flood events using hydro-meteorological records spanning 1944–2023. Two contrasting periods were analysed: a quasi-natural phase prior to large-scale regulation (1944–1959) and a fully regulated phase (1995–2023), based on observations from key gauging stations in regulated and unregulated river sections.</div><div>Results indicate that land use and basin-scale precipitation remained relatively stable over the study period, whereas dam regulation caused substantial modifications to river flow. In regulated reaches, reservoirs reduced winter discharges and enhanced summer flows, producing a clear seasonal redistribution of streamflow and a marked decoupling between discharge and precipitation. Unregulated sections preserved a natural flow regime closely linked to rainfall variability. Analysis of historical extreme events further shows that flood attenuation strongly depends on reservoir storage conditions prior to an event, leading to contrasting flood responses under similar precipitation forcing.</div><div>These results demonstrate that reservoir operation fundamentally reshapes river regimes and modulates extreme flows beyond climatic controls. Accounting for dam management is therefore essential for flood risk assessment and climate-adaptive water management in regulated river basins.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109836"},"PeriodicalIF":5.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034916","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":"Environmental filtering of microbial specialists drives divergent C, N, and S cycling in grasslands: Vegetation buffering maintains microbial diversity amidst soil moisture contrasts","authors":"Yiming Dai ,&nbsp;Haining Wang ,&nbsp;Qixiu Cheng ,&nbsp;Yiming Zhang ,&nbsp;Ye Cui ,&nbsp;Huan Ma ,&nbsp;Xiaoyu Li ,&nbsp;Daolong Xu ,&nbsp;Jin Chen","doi":"10.1016/j.catena.2026.109819","DOIUrl":"10.1016/j.catena.2026.109819","url":null,"abstract":"<div><div>Grasslands are a critical component of terrestrial ecosystems, with their soil microbial communities driving key biogeochemical cycles and energy flows. These communities regulate nutrient fluxes and are highly sensitive to environmental change. However, understanding how environmental differences between grassland types affect microbial structure and associated C, N, and S cycling genes remains limited. We collected soil samples during the rainy season from typical and meadow steppe in Inner Mongolia and analyzed using high-throughput sequencing and metagenomics. Distinct microbial community structure differed significantly between different grassland soil types. Moreover, the top 20 genera driving community dissimilarity were exclusively specialists, with no generalists identified. Functional gene abundance showed significantly higher C fixation genes in typical steppe. Meadow steppe exhibited increased abundance of denitrification (<em>narG</em>, <em>nirK</em>, <em>norB</em>/<em>C</em>, <em>nosZ</em>), polysulfide reductase genes (<em>hydA</em>, <em>psrA</em>), and organic sulfur metabolism genes (<em>soxABCDXYZ</em>). Variation partitioning revealed vegetation cover as the primary driver of C, N, and S cycling gene variation, explaining 48.3% on average. PLS path modeling indicated bacterial specialists contributed more to functional gene abundance than fungal specialists, likely reflecting niche differentiation. Soil properties most strongly influenced C cycling genes, while vegetation characteristics were most closely linked to N and S cycling genes. These findings provide new insights into grassland microbial responses to environmental variation and elucidate their mechanisms in driving C, N, and S cycling processes.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109819"},"PeriodicalIF":5.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034917","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":"Evolutionary dynamics of the Holocene alluvial fan system of Las Carreras Valley (Sierras Pampeanas, NW Argentina)","authors":"María Marta Sampietro-Vattuone ,&nbsp;José Luis Peña-Monné ,&nbsp;Walter Ariel Báez","doi":"10.1016/j.catena.2026.109851","DOIUrl":"10.1016/j.catena.2026.109851","url":null,"abstract":"<div><div>The Las Carreras Valley, part of the Tafí Valley in Northwestern Argentina, offers a detailed geomorphological record of Holocene evolution within a tectonic intermontane depression in the Sierras Pampeanas. This study aimed to examine the evolutionary morphology of the main alluvial fans along the western edge of the Las Carreras Valley, at the piedmont of the Sierra de Aconquija. Through geomorphological mapping, stratigraphic profiling, and chronological analyses, this study examines the complex interplay between sedimentary processes, tectonic activity, climatic variability, and human occupation across the three principal alluvial fans: Rodeo, Las Carreras, and Los Alisos. Key findings highlight the influence of Pleistocene-Holocene glacial phases (Younger Dryas, Pre-Boreal Oscillation, Neoglacial Cold Phase) on the formation of Unit H1 (13–4.2 kyr BP) and the dominance of Unit H2 (4.2 kyr BP–600 BP) across fan surfaces. Late Holocene transformations include significant basin captures —such as the Muñoz River headwaters by the Los Alisos River basin— avulsion processes, and neotectonic activity linked to the Las Carreras double fault. These geomorphological changes shaped alluvial fan dynamics, altering drainage networks, fan morphologies, and sedimentary deposits. Stratigraphic profiles reveal Pleistocene deposits as foundational layers, overlain by Holocene units, with volcanic ash markers (V1, V0) serving as chronological indicators. The geomorphology further correlates with human settlement patterns, notably the Tafí culture (360 BCE–1000 CE), whose agricultural adaptations relied on alluvial fan resources. This comprehensive analysis underscores the critical role of tectonic, fluvial, and climatic processes in shaping alluvial fan systems. It provides a framework for assessing environmental risks, land-use strategies, and conservation efforts in tectonically active and semiarid regions.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109851"},"PeriodicalIF":5.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034918","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":"Unearthing historical pedology: An analysis of soil science concepts in 1200 years of Persian poetry","authors":"Ali Shahriari ,&nbsp;Isa Esfandiarpour-Boroujeni ,&nbsp;Leila Kordbacheh ,&nbsp;Zohreh Mosleh ,&nbsp;Reyhaneh Nejadasadi ,&nbsp;Hosnie Shahriari ,&nbsp;Fatemeh Aliabbasi ,&nbsp;Reza Mohajer","doi":"10.1016/j.catena.2025.109760","DOIUrl":"10.1016/j.catena.2025.109760","url":null,"abstract":"<div><div>Literature serves as a cultural repository for enduring knowledge, offering unique insights into the historical evolution of scientific and philosophical thought. This study investigates the semantic understanding of soil, from the perspective of pedology, across 1200 years of Persian poetry. The word <em>khāk</em> (soil) was analyzed in the works of major Persian poets from the third to the fourteenth century SH. Poems demonstrating a strong thematic relevance with soil science principles were selected and systematically categorized according to the discipline's specialized subfields. The results yielded ten distinct thematic categories, encompassing soil's agricultural functions (e.g., soil-water-plant relationships), ecological challenges (e.g., salinity, erosion), physical and biological properties, and its role in human health. The analysis of poetic themes reveals a significant focus on soil erosion, and the soil-water-plant relationship was the next most significant theme. Conversely, topics such as soil quality and land capability and modern humanity and soil were minimally represented. The findings reveal that soil holds a dual status in Persian poetry: it is simultaneously a tangible, natural element and a profound symbolic concept. On one hand, it is recognized as the substrate for life, reflecting practical agricultural knowledge and principles of sustainable resource management. On the other, its physical and chemical properties inspire rich metaphors for life, death, humility, and other core ontological themes. This long-standing integration of scientific observation and artistic expression demonstrates a deep-rooted connection between humanity and the environment. It also provides a valuable historical framework for contemporary interdisciplinary fields such as ecopoetry and offers a model for bridging the humanities and the natural sciences.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109760"},"PeriodicalIF":5.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034987","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":"Comparative studies of bench-scale experiments examining the effect of pipe flows on landslide initiation","authors":"Yasutaka Tanaka ,&nbsp;Taro Uchida","doi":"10.1016/j.catena.2026.109804","DOIUrl":"10.1016/j.catena.2026.109804","url":null,"abstract":"<div><div>Several bench-scale studies have been conducted to investigate the effect of pipe flows on landslide initiation. However, these studies focused solely on a single factor, overlooking the combined influence of multiple factors on slope instability and landslide occurrence. Thus, the intercomparison of these experimental results may provide a comprehensive understanding of pipe-flow effects on landslide initiation. Therefore, the objective of this review is to examine the effects of pipe flows on slope stability through an intercomparison of bench-scale experiments. We consider that pipe flows induce landslides when the water flow rate exceeds the maximum admissible flow rate of the soil pipes, referred to as the critical flow rate. At this critical point, the water flow cannot be confined to the soil pipes. Multiple studies have demonstrated that clogging, joints, gradient change, and air entrapment are factors influencing the critical flow rate of soil pipes. Additionally, the pore water pressure has been shown to increase at the area where the critical flow rate of the soil pipe decreases in the longitudinal direction, causing slope instability. Thus, we propose that the decrease in the critical flow rate of the soil pipe in the longitudinal direction induces slope instability and an increase in the pore water pressure.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109804"},"PeriodicalIF":5.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034915","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":"Elevational shifts in diazotrophic communities in subalpine forests: joint effects of temperature and soil properties","authors":"Min Li ,&nbsp;Jipeng Wang ,&nbsp;Yongping Kou ,&nbsp;Dungang Wang ,&nbsp;Huangxin Zhang ,&nbsp;Qiuhong Feng ,&nbsp;Na Li ,&nbsp;Huajun Yin","doi":"10.1016/j.catena.2026.109820","DOIUrl":"10.1016/j.catena.2026.109820","url":null,"abstract":"<div><div>Soil diazotrophs introduce significant amounts of new nitrogen (N) into forest ecosystems through the process of free-living N fixation. However, the factors influencing their community structure and function remain elusive, particularly in subalpine forests that are often characterized by N limitation. Here, we explored the patterns and drivers of the diazotrophic community structure (abundance, diversity, composition, and inter-specific interactions) and N fixation potential (<em>nifH</em> mRNA copy number) along a 400-m elevational gradient in subalpine forests on the eastern edge of Tibetan Plateau, using droplet digital PCR, <em>nifH</em> gene sequencing, and metagenomic sequencing. The results showed that the diazotrophic community varied significantly across different elevations, with <em>Bradyrhizobium</em> consistently identified as the key taxa. Our findings also demonstrated the predominant role of environmental filtering in shaping the diazotrophic community. Specifically, the elevational pattern of diazotrophic abundance was primarily driven by soil resource availability, while those of α-diversity, community composition, and co-occurrence network were jointly modulated by temperature and soil properties. In comparison to total bacteria, the α-diversity of diazotrophs was more sensitive to changes in temperature. The positive relationship between temperature and diazotrophic diversity indicates that future subalpine forests may support more diverse soil diazotrophic communities due to projected increases in temperature. Moreover, we found a weak linkage between diazotrophic community structure and N fixation potential, indicating the complexity of the diazotrophic structure-function relationship in subalpine forests. Overall, our work highlights the sensitivity of diazotrophic community structure to future environmental changes in subalpine forests. Further studies are needed to simultaneously monitor the diazotrophic community structure and N fixation rates across a broader range of sites.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109820"},"PeriodicalIF":5.7,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035029","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}