Catena最新文献

{"title":"Natural susceptibility and human intervention in gullies sidewalls in tropical environments of southeastern Brazil","authors":"Estêvão Botura Stefanuto ,&nbsp;Cenira Maria Lupinacci ,&nbsp;Higor Lourenzoni Bonzanini ,&nbsp;Danilo Marques de Magalhães ,&nbsp;Filipe Carvalho ,&nbsp;Estela Nadal-Romero ,&nbsp;Melina Fushimi ,&nbsp;Fabiano Tomazini da Conceição ,&nbsp;Archimedes Perez Filho","doi":"10.1016/j.catena.2025.109783","DOIUrl":"10.1016/j.catena.2025.109783","url":null,"abstract":"<div><div>It is crucial to distinguish between gully erosion responses derived from the inherent fragility of the environment and those induced by human activities. This study examines gully sidewall erosion in relation to soil physical variables and land use, with particular attention to livestock farming. Sidewall data were collected and analysed during both wet and dry seasons, including grain size, soil resistance to penetration, and infiltration. Land use data were also compiled before and after the implementation of a restoration technique. These data were compared with three years of erosion monitoring on the gully sidewall. The results indicate that tropical environments with two well-defined seasons (summer and winter) also require careful consideration of transitional periods (spring and fall), as soil drying and crack formation increase erosion risk. Sandy fractions demonstrate high susceptibility to erosion; however, the role of finer fractions, especially silt, is equally critical, since their presence, together with higher soil penetration resistance during dry periods, indicates areas with high erosive potential. Infiltration measured under field conditions shows high variability, which complicates the assessment of its contribution to gully development. The adoption of simple measures, such as fencing off eroded areas, proved effective in reducing soil loss from gullies in pastures under livestock farming. Overall, the findings underline that the combined effect of environmental fragility and grazing pressure constitutes a major driver of gully erosion in tropical regions. Recognising these interactions is fundamental for designing appropriate soil conservation strategies in livestock-dominated landscapes.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109783"},"PeriodicalIF":5.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973833","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":"Comparison of alternative chemical density and physical methods for isolating soil organic matter fractions in high carbon soils","authors":"Hamond Motsi ,&nbsp;Catherine E. Clarke ,&nbsp;Ailsa G. Hardie ,&nbsp;Michele L. Francis ,&nbsp;Alastair J. Potts","doi":"10.1016/j.catena.2025.109788","DOIUrl":"10.1016/j.catena.2025.109788","url":null,"abstract":"<div><div>Soils beneath <em>Portulacaria afra</em> (spekboom) within the evergreen Albany Subtropical Thicket of South Africa contain unusually high soil organic carbon concentrations despite the biome's semi-arid climate. Fractionation of soil organic matter (SOM) into particulate organic matter (POM) and mineral-associated organic matter (MAOM) provide insights into the mechanisms of soil carbon (C) accumulation. Conventionally, sodium polytungstate (SPT) is used in density fractionation, but its high-cost limits sample numbers. Cheaper, reliable alternatives to SPT are therefore required to understand the C dynamics of spekboom and other high-C soils. Particle size (PS) sieving has been proposed as cheaper alternative to density fractionation, but its application in spekboom soils is unknown. This study compared SPT with PS fractionation and density fractionation using cheaper, highly soluble salts: sodium iodide (NaI), potassium iodide (KI), and calcium chloride (CaCl₂). The relationship between permanganate oxidizable carbon (POXC) and POM-C was also explored. High C (&gt;5 %) topsoils with a range of POM:MAOM ratios from the spekboom thicket, a pine forest, a wetland, and a grassland were evaluated. Results demonstrated that fractionation methods significantly affected (<em>p</em> &lt; 0.05) fractions in each soil. NaI showed similar performance to SPT in SOM fractionation followed by KI. The PS method used in this study compared poorly to SPT, underestimating POM-C (34–39 %) and overestimating MAOM-C (39–51 %) in high POM soils (spekboom and pine forest soils) with the opposite effect in lower POM soils (wetland and grassland). The CaCl₂ method was also not ideal due to salt entrainment. Some soils did not conform to the expected linear relationship between POM-C and POXC demonstrating that POXC method is not always suitable. Thus, NaI is proposed as a cheaper alternative to replace SPT in density fractionation of spekboom soils. Findings from this study have significant implications in appropriate method selection for SOM fractionation of high C soils.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109788"},"PeriodicalIF":5.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973835","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":"Topography and rainfall variability shaping dryland vegetation self-organisation: Insights from a numerical modelling study","authors":"Daniel Caviedes-Voullième ,&nbsp;Yolanda Pueyo ,&nbsp;Christoph Hinz","doi":"10.1016/j.catena.2026.109791","DOIUrl":"10.1016/j.catena.2026.109791","url":null,"abstract":"<div><div>The coevolution of hydrological and vegetation dynamics in semi-arid regions often leads to vegetation self-organisation (VSO). While numerous hypotheses on the ecohydrological processes driving VSO have been explored through mathematical models, these have struggled to capture the multiscale complexity emerging from short-term surface runoff over heterogeneous topographies under variable rainfall. This limitation hinders understanding of how natural topography and rainfall variability shape long-term vegetation patterns.</div><div>Previous studies suggest that intra-storm water redistribution at the hillslope scale – controlled by topography and storm intensity – plays a key role in VSO. However, these factors have rarely been considered together due to methodological constraints in numerical solvers. We argue that accurately representing these processes is essential to investigate their interactions.</div><div>This study systematically examines the effects of hillslope topography and intra-annual rainfall distributions on vegetation band formation using a physically based model that couples the Zero-Inertia (Diffusive Wave) approximation of the shallow water equations with the HilleRisLambers–Rietkerk vegetation model. Idealised 30-year simulations were conducted at second-scale hydrodynamic resolution across different hillslope forms (plane, convex, concave), slopes, and rainfall regimes along a semi-arid gradient.</div><div>Results show that both topography and rainfall variability strongly influence band formation through their control on water redistribution and hydrological balance. Steeper slopes enhance runoff over infiltration, reducing water availability and altering band geometry and migration. Concave hillslopes exhibit distinct runoff convergence and redistribution patterns compared to plane or convex slopes. Rainfall intermittency interacts with topography to further affect pattern stability and morphology. While both drivers shape pattern characteristics differently, their joint effects mainly influence band migration without providing a strong stabilising mechanism.</div><div>These results demonstrate the feasibility of long-term, physically based ecohydrological simulations, paving the way for more comprehensive models including sediment transport and geomorphic feedbacks.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109791"},"PeriodicalIF":5.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973920","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":"Measures of pyrogenic carbon in native forest and plantations of northern Australia","authors":"Freddy Jontara Hutapea ,&nbsp;Liubov Volkova ,&nbsp;Daniel S. Mendham ,&nbsp;Michael I. Bird ,&nbsp;Senani Karunaratne ,&nbsp;Jacqueline R. England ,&nbsp;Michael Brand ,&nbsp;Christopher J. Weston","doi":"10.1016/j.catena.2025.109784","DOIUrl":"10.1016/j.catena.2025.109784","url":null,"abstract":"<div><div>Pyrogenic carbon (PyC) is a highly stable fraction of soil organic carbon that plays an important role in the global carbon budget and biogeochemical processes. However, the stocks and dynamics of PyC in soils remain insufficiently characterized, largely due to longstanding challenges in obtaining accurate and reliable assessments. On Melville Island, northern Australia, fire is a common land management tool likely to influence both soil total organic carbon (TOC) and PyC. This study compared PyC to 50 cm depth and TOC to 100 cm depth in soils under three land uses (native <em>Eucalyptus</em> forests, <em>Eucalyptus pellita</em> plantations and <em>Acacia mangium</em> plantations) with differing recent fire frequencies. This study also compared the performance of nitric acid‑hydrogen peroxide digestion (PyC_KMD) and mid-infrared spectroscopy (PyC_MIRS) in estimating PyC, using hydrogen pyrolysis (PyC_Hypy) as the reference technique. The results showed strong evidence that TOC stocks (0–10 cm soil) were lower under <em>E. pellita</em> plantation (18 Mg ha⁻¹) than either <em>A. mangium</em> plantations or native forests (each about 25 Mg ha⁻¹) (<em>p</em> &lt; 0.01), and in all cases declined with increasing soil depth. PyC_hypy stock was distributed relatively evenly to 50 cm depth in each land use, at about 4–5 Mg ha⁻¹ per 10 cm depth interval. Although native forests were subject to prescribed burns approximately every two years (compared with fire exclusion over 15+ years in the plantations), the ratio of PyC_hypy to TOC (PyC_hypy/TOC) under native forests was lower than under <em>A. mangium</em> and <em>E. pellita</em>, suggesting that repeated fire events may lead to re-combustion of PyC. PyC_hypy/TOC increased with increasing soil depth, strongly suggesting the preferential translocation of PyC into deeper soil layers relative to TOC in the sandy and highly porous soils of Melville Island.</div><div>Among the three methods used to estimate PyC, PyC_KMD was not well correlated with PyC_Hypy, while PyC_MIRS, based on the available calibration database, explained 23 % of the variation in PyC_Hypy. Compared to direct measurements by Hypy, MIRS tended to underestimate PyC in soil with TOC less than 45 g kg⁻¹ and overestimate PyC in soil with TOC greater than 45 g kg⁻¹. Expanded calibration datasets are required to improve the performance of MIRS for estimating PyC in the sandy forest soils of tropical Australia.</div><div>Further work is required to quantify PyC beyond 50 cm deep soil, to track temporal changes in soil PyC across different land uses and fire histories, and to evaluate the performance of different methods in quantifying PyC across diverse soil types.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109784"},"PeriodicalIF":5.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923113","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":"Soil pH and latitude as a major predictor of C:N:P stoichiometry in Germany","authors":"Pegah Khosravani ,&nbsp;Ndiye Michael Kebonye ,&nbsp;Ruhollah Taghizadeh-Mehrjardi ,&nbsp;Hadi Shokati ,&nbsp;Ling Hu ,&nbsp;Thomas Scholten","doi":"10.1016/j.catena.2025.109785","DOIUrl":"10.1016/j.catena.2025.109785","url":null,"abstract":"<div><div>Soil stoichiometry governs nutrient cycling to ensure optimal ecosystem functionality. Although the soil carbon‑nitrogen‑phosphorus (C:N:P) stoichiometry and ecosystem functioning are closely related, much less is known about how environmental predictors regulate the spatial distribution of these ratios in temperate regions. Specifically, the statistical relationships of soil properties (such as soil pH and clay content), climate variables (like precipitation and temperature), and topographic features (i.e., slope and aspect) on C:N:P stoichiometric patterns at regional scales remain poorly understood. In our study, we combined Cubist machine learning for spatial predictions with state-of-the-art statistical approaches—generalized additive models and structural equation modeling—to disentangle the quantitative relationships between environmental predictors and soil C:N, C:P, and N:P ratios across Germany. The relative importance analysis of environmental predictors shows that soil pH is the major predictor of stoichiometric ratios, acting through its fundamental control on nutrient availability. Higher soil pH corresponded to lower stoichiometric ratios and vice versa. Latitude emerged as another important predictor due to its effect on temperature, which plays a crucial role in these ratios, such that increasing latitude corresponds to lower ratios. As expected, wall-to-wall spatial distribution maps of the stoichiometric ratios showed varying patterns due to different environmental predictor influences. These findings enhance our understanding of environmental-stoichiometric interactions and offer valuable insights needed for sustainable soil management in temperate regions.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109785"},"PeriodicalIF":5.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923169","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":"Shrub encroachment enhances soil multifunctionality by promoting interdomain interactions and reducing bacterial network complexity and competition","authors":"Yudu Jing ,&nbsp;Xiaowei Liu ,&nbsp;Junhao Feng ,&nbsp;Ke Liang ,&nbsp;Zhiyou Yuan ,&nbsp;Jianchu Xu ,&nbsp;Changhui Peng ,&nbsp;Qiang Yu ,&nbsp;Liang Guo","doi":"10.1016/j.catena.2026.109798","DOIUrl":"10.1016/j.catena.2026.109798","url":null,"abstract":"<div><div>Shrub encroachment significantly alters both above- and below-ground ecological processes in semi-arid grasslands. However, its effects on soil multifunctionality and the underlying microbial mechanisms are not well understood. This study explored the impact of shrub encroachment on soil multifunctionality, microbial diversity, community composition, and microbial networks (both intra- and interdomain) in a typical semi-arid grassland on the Chinese Loess Plateau. Our findings revealed that shrub encroachment profoundly enhanced soil multifunctionality, closely linked to increased microbial diversity, restructured community composition, and altered patterns of microbial interactions. Specifically, bacterial intradomain links—particularly negative links—decreased, resulting in less complex and potentially less competitive bacterial networks. In contrast, the complexity of bacteria-fungi interdomain networks increased significantly, indicating strengthened interdomain connections. This shift from intense intradomain co-exclusion to enhanced interdomain co-occurrence played key roles in enhancing soil multifunctionality, as supported by the Partial least-square pathway model. Collectively, these findings highlight a strategic shift of soil microbial interaction networks under shrub encroachment, illustrating that the adaptive balance between microbial positive and negative interactions plays a pivotal role in regulating soil multifunctionality. This study advances our understanding of the ecological consequences and mechanisms of shrub encroachment in semi-arid grasslands.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109798"},"PeriodicalIF":5.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923183","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":"The carbon dynamic and driving mechanisms of peatland in the Changbaishan volcanic field of China","authors":"Mingming Zhang ,&nbsp;Wenkai Liu ,&nbsp;Li Wang ,&nbsp;Frank M. Chambers","doi":"10.1016/j.catena.2026.109825","DOIUrl":"10.1016/j.catena.2026.109825","url":null,"abstract":"<div><div>The Changbaishan volcanic field ranks as one of China's largest active volcanic fields. Numerous peatlands developed in this area, serving as crucial carbon sink within the country. In this well-known volcanic field, climatic changes and volcanic eruptions are likely to have exerted a notable impact on the carbon accumulation processes of peatlands. That said, the specific carbon dynamics in these peatlands and the possible driving mechanisms remain insufficiently understood. To address these unresolved questions, this study chose the Dongfanghongnan peatland as research subject. Findings from the investigations indicate that this particular peatland began to store carbon during the Late Holocene epoch. From 4344 to 1000 cal. yr BP, temperature and precipitation functioned as major factors that regulating carbon dynamics of the Dongfanghongnan peatland. Nevertheless, since 1000 cal. yr BP up to now, tephra deposition has been the major affecting factor for the carbon dynamics of peatlands. Furthermore, two distinct types of high-efficiency carbon sequestration patterns can be distinguished in the Dongfanghongnan peatland. The first pattern is named the climate-nutrient type. In an environment with increased rainfall and intense solar radiation, higher temperature may boost the productivity of <em>Carex</em>. At the same time, moist conditions are beneficial for the conservation of peat, which in turn helps trap carbon. In addition, nutrient phosphorus was transported into peatland with a phosphorus accumulation rate (PAR) of 0.058 g P m⁻² yr⁻¹, raising the net primary productivity of plants growing in the peatland. These combined effects led to a high-efficiency apparent carbon accumulation rate (aCAR), reaching 21.88 g C m⁻² yr⁻¹. The second pattern is referred to as the tephra fertilization type. Tephra released a large amount of phosphorus (with a PAR of 0.071 g P m⁻² yr⁻¹). Abundant phosphorus supply promoted the net primary productivity of both <em>Carex</em> and mosses. This promotion eventually resulted in a high-efficiency aCAR, which was measured at 24.90 g C m⁻² yr⁻¹. These findings deepen understanding of the relationship between climate variations, volcanic activities, and carbon sequestration of peatlands. They also establish important basis for making forecasts about the future carbon dynamics of peatlands in Northeast Asia.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"264 ","pages":"Article 109825"},"PeriodicalIF":5.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973831","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":"2026-03-01","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":"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":"2026-03-01","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":"2026-03-01","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}