Catena最新文献

{"title":"Factors controlling basalt weathering in the Deccan traps: A small catchment perspective","authors":"Ravi Kant Prasad ,&nbsp;Naman Deep Singh ,&nbsp;Sunil Kumar Singh ,&nbsp;Vikrant Jain","doi":"10.1016/j.catena.2024.108566","DOIUrl":"10.1016/j.catena.2024.108566","url":null,"abstract":"<div><div>Chemical weathering fluxes from small basalt catchments, the Ambika and the Girna in the Deccan Traps, have been compared. The two catchments are characterized by distinct climates: humid in the Ambika and semi-arid in the Girna River. We collected water samples at the sub- catchment scale of these basins and analysed concentrations of major ions and dissolved Sr in them to estimate the weathering rates and to assess their controlling factors. The catchment area, slope and relief of the catchments were derived using Digital Elevation Model (DEM) on ArcGIS platform whereas the Soil and Water Assessment Tool (SWAT) was used to derive the sub-catchment scale runoffs. The SWAT simulated annual discharge shows a nearly three times larger discharge in the Ambika River compared to the Girna River. The various sources, viz., basalt, carbonates, sea-salts and saline alkaline soils (SAS) contributing to major ions in dissolved load, were quantified using inverse modelling approach. The total chemical denudation rates (TCDR*) during monsoon, 1033 ± 512 tons km⁻² y^-1, is ∼ 12 times higher compared to non-monsoon (82 ± 42 tons km⁻² y^-1) in the Ambika River, and ∼ 3 times higher in the Girna River (monsoon: 185 ± 155 tons km⁻² y^-1 vs. non-monsoon: 51 ± 25 tons km⁻² y^-1). Annually, TCDR* is around 6-fold higher in the Ambika River (∼683 tons km⁻² y^-1) than in the Girna River (∼113 tons km⁻² y^-1) at their outlets. Basalt (silicate) weathering rates (<em>Bas</em>WR) in the Ambika and the Girna rivers are 88 ± 19 and 12 ± 3 tons km⁻² y^-1, respectively. The chemical weathering rates in the two adjacent catchments is primarily controlled by rainfall/runoff, while relief plays secondary control. CO₂ consumption rates (CCR) of the Ambika with higher rainfall are much higher ((13 ± 4) × 10⁵ mol km⁻² y^-1) compared to most of the inactive basalt cathchments globally.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"249 ","pages":"Article 108566"},"PeriodicalIF":5.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182648","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":"National-scale assessment of salt-affected areas in Portugal: Learning from legacy data to establish a framework for comprehensive monitoring and management","authors":"Tiago B. Ramos ,&nbsp;Ana Horta ,&nbsp;Leonardo Azevedo ,&nbsp;Nádia Castanheira ,&nbsp;Mohammad Farzamian ,&nbsp;Maria C. Gonçalves ,&nbsp;José C. Martins","doi":"10.1016/j.catena.2025.108773","DOIUrl":"10.1016/j.catena.2025.108773","url":null,"abstract":"<div><div>Developing efficient, cost-effective frameworks to assess the spatial and temporal distribution of salt-affected areas at multiple scales is essential for effective soil management. This study enhanced the Portuguese INFOSOLO soil information system by incorporating legacy data on soil salinization and sodification from 1979 to 2020. National-scale soil maps were then generated using geostatistical stochastic sequential simulation. Soil salinity was mapped based on electrical conductivity data from soil saturation paste extracts of topsoil samples collected in 2015 and 2018, while soil sodicity was mapped using the full coverage of exchangeable sodium percentage data across multiple soil layers. The resulting maps effectively captured significant salinization and sodification trends across Portugal, identifying both natural and human-induced hotspots of salinity and sodicity. However, they did not fully represent the extent of highly saline and sodic areas. Given the absence of a comprehensive monitoring framework for soil salinity and sodicity in Portugal, these findings highlight the necessity of establishing targeted monitoring efforts in identified high-risk areas. Consequently, a well-designed framework is proposed to monitor soil salinity and sodicity in Portugal’s most sensitive regions, particularly important in light of intensified agricultural activities and increasing water scarcity driven by climate change.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"250 ","pages":"Article 108773"},"PeriodicalIF":5.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143100332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature effects on microbial carbon use efficiency and priming effects in soils under vegetation restoration","authors":"Jingyi Yang ,&nbsp;Zitong Wang ,&nbsp;Qing Chang ,&nbsp;Ziping Liu ,&nbsp;Qian Jiang ,&nbsp;Xianlei Fan ,&nbsp;Di Meng ,&nbsp;Edith Bai","doi":"10.1016/j.catena.2024.108632","DOIUrl":"10.1016/j.catena.2024.108632","url":null,"abstract":"<div><div>Soil organic carbon (SOC) sequestration through vegetation restoration may be hindered by increased soil carbon emissions under global warming. Soil microbial carbon use efficiency (CUE) and priming effects (PEs) are crucial to SOC dynamics. Here we selected croplands and forests restored from croplands 40 years ago to evaluate the simultaneous effects of temperature and vegetation restoration on microbial CUE and PEs. Microbial CUE was measured using ¹⁸O-labeled water, ¹³C-labeled glucose, ¹³C-labeled litter, and stoichiometric modeling methods, respectively. Glucose and litter were used as labile and complex substrates, respectively, to study how substrate quality affects CUE and PEs. Our results showed that microbial CUE estimated by the four methods ranged from 0.10 to 0.84, with the lowest and the highest CUE being estimated by the ¹⁸O-method (0.10 ∼ 0.21) and ¹³C-method (0.50 ∼ 0.84), respectively. All methods showed restoration reduced the ratio of soil dissolved organic carbon to dissolved nitrogen, implying increased substrate quality and thus microbial CUE. Microbial CUE declined with rising temperature, with greater declines in forests (-31 %) than that in croplands (-19 %) when estimated by the ¹⁸O-method. Positive PEs were observed and dominated by the nitrogen-mining mechanism. Vegetation restoration alleviated microbial nitrogen limitation and reduced relative PEs. Glucose-induced absolute PEs increased but litter-induced absolute PEs decreased with rising temperature due to higher nitrogen limitation with glucose addition compared to litter addition. The relative PEs declined with rising temperature under either glucose or litter addition, with greater declines in croplands (-45 %∼-81 %) than in forests (-40 %∼-70 %). Overall, vegetation restoration contributes to SOC accumulation by increasing microbial CUE and decreasing PEs, but warming would counteract the positive effects of forests and be detrimental to increasing SOC sequestration through vegetation restoration. Understanding the ecosystem-specific response of microbial CUE and PEs to climate change is urgently needed to identify ecosystem management that benefits soil carbon sequestration.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"249 ","pages":"Article 108632"},"PeriodicalIF":5.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143180659","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":"Construction of ecological security patterns in typical arid regions based on the synergy of efficient ecological water utilization and environmental quality enhancement","authors":"Xiaolin Qin ,&nbsp;Hongbo Ling ,&nbsp;Qianjuan Shan ,&nbsp;Guangpeng Zhang ,&nbsp;Junjie Yan ,&nbsp;Yanming Gong ,&nbsp;Jia Xu ,&nbsp;Xiangdong Meng","doi":"10.1016/j.catena.2025.108713","DOIUrl":"10.1016/j.catena.2025.108713","url":null,"abstract":"<div><div>The ecological security pattern (ESP) represents a crucial spatial strategy for ensuring ecological security and promoting sustainable development in arid regions. However, there remains a significant lack of in-depth research on how to construct such a pattern under the dual objectives of efficient ecological water utilization (EWU) and enhancement of ecological environment quality (EEQ). This study evaluates the benefits of ecological water conveyance (EWC) in the lower reaches of the Tarim River, utilizing the modified remote sensing ecological index (MRSEI) model and Maxent model to identify ecological sources. Ecological corridors were further delineated using circuit theory to construct a comprehensive ESP. The findings indicate that increased EWC elevates groundwater levels in the riparian zone to saturation point, subsequently boosting water inflow into Taitema Lake. As water conditions improve, vegetation coverage tends to stabilize, with no significant further increase observed. To further enhance the efficiency of EWU and strengthen the EEQ, the study identifies ecological patches and potential <em>P. euphratica</em> distribution areas requiring urgent protection and restoration under current and potential conditions. By integrating the corridors linking these ecological sources with the river system, the EWU paths are optimized. Additionally, to improve corridor connectivity and facilitate ecological restoration, ecological pinch points and barrier points were identified, and protection zones of varying levels were delineated based on proximity to the corridors. The ESP developed in this research provides a valuable reference for achieving efficient EWU and fostering sustainable environmental development in arid regions.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"249 ","pages":"Article 108713"},"PeriodicalIF":5.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143180684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of microbial communities and organic carbon pools in karst wetland soils","authors":"Yutian Xiao ,&nbsp;Congyu Cheng ,&nbsp;Aoqi Cheng ,&nbsp;Weihua Kang ,&nbsp;Taiming Shen ,&nbsp;Qingrong Yang ,&nbsp;Cong Peng ,&nbsp;Longjiang Yu ,&nbsp;Wei Li","doi":"10.1016/j.catena.2024.108691","DOIUrl":"10.1016/j.catena.2024.108691","url":null,"abstract":"<div><div>Understanding dynamic changes in soil organic carbon (SOC) and microbial communities in karst wetlands is of great importance for the restoration and protection of these environments. The purpose of this study was to characterize the composition and abundance of microbial communities and enzyme activities related to SOC pools in three states of the Huixian karst wetland, representing primary, naturally degraded and human interference conditions (reclaimed cropland). This study employed 16S/ITS2 high-throughput sequencing to characterize the spatiotemporal dynamics of microbial communities. The microbial taxa and enzymes closely associated with variations in SOC pools were analyzed. Significant differences in organic carbon fractions, physicochemical properties, and enzyme activities varied by season and generally showed vertical distribution patterns. The species composition of microbial communities in the three wetland states was broadly similar, but some dominant bacterial species differed significantly in relative abundance. The prokaryotic communities were closely related to changes in organic carbon pools and mainly included <em>Anaeromyxobacter</em>, <em>Bacillus</em>, <em>Bryobacter</em>, <em>Flavisolibacter</em>, <em>Gemmatimonas</em> and <em>Haliangium</em>, of which members of the family <em>Anaeromyxobacteraceae</em> were relatively abundant in reclaimed wetland in summer; <em>Flavisolibacter</em> and <em>Gemmatimonas</em> were relatively abundant in degraded wetland in spring and winter, respectively. Among fungi, <em>Clonostachys</em>, <em>Fusarium</em>, <em>Talaromyces</em>, <em>Conlarium</em>, <em>Westerdykella</em>, <em>Ascobolus</em>, <em>Chaetomium</em>, <em>Polyschema</em>, and <em>Aspergillus</em> were the major taxa closely associated with changes in organic carbon pools. Among them, <em>Fusarium</em>, <em>Talaromyces</em> and <em>Polyschema</em> were relatively abundant in reclaimed wetland in autumn, spring and winter, respectively; <em>Chaetomium</em> and <em>Aspergillus</em> were relatively abundant in degraded wetland in winter and in primary wetland in summer. The enzyme activities closely associated with the variations of organic carbon fractions in karst wetland soils were carbonic anhydrase, sucrase and polyphenol oxidase.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"249 ","pages":"Article 108691"},"PeriodicalIF":5.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181878","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":"Local diversity of soil forming processes in the semi-arid tropics and its environmental drivers: An example from Otavi Mountains, northern Namibia","authors":"Tereza Zádorová ,&nbsp;Vít Penížek ,&nbsp;Martin Mihaljevič ,&nbsp;Magdaléna Koubová ,&nbsp;Lenka Lisá ,&nbsp;Vojtěch Ettler ,&nbsp;Václav Tejnecký ,&nbsp;Ondřej Drábek ,&nbsp;Lenka Pavlů ,&nbsp;Bohdan Kříbek ,&nbsp;Aleš Vaněk ,&nbsp;Ondra Sracek ,&nbsp;Jessica Reyes Rojas ,&nbsp;Tomáš Hrdlička ,&nbsp;Petra Vokurková ,&nbsp;Benjamin Mapani","doi":"10.1016/j.catena.2024.108671","DOIUrl":"10.1016/j.catena.2024.108671","url":null,"abstract":"<div><div>Local diversity of soil units and properties in a semi-arid tropical climate is controlled by a number of interacting factors, whose contribution to the final form of individual soil characteristics is often difficult to discern. The present study focuses on a detailed assessment of five diverse soil profiles located in the flat foothills of the Otavi Mountains in northern Namibia. A multi-proxy approach consisting of clay mineralogy, micromorphology and geochemical analyses was used to disentangle the drivers of an extraordinary local pedodiversity and to identify the patterns of recent and relict pedogenesis. Significant differences in profile stratigraphy were observed in the soils studied, represented by more weathered Chromic Cambisols and humus-rich soils with mollic horizons (Haplic Phaeozems, Calcic Kastanozem) and vertic features (Vertic Phaeozem). Complex lithology with a dominant influence of unconsolidated sediments of mainly fluvial origin, duration of pedogenesis and subtle changes in local topography and hydric soil regimes were identified as the main factors for the sharp transitions between the patches of each soil group. The studied soils differed significantly in the proportions of clay minerals and iron forms, partly inherited from the allochthonous soil-forming material, and partly developed in-situ. More intensive processes of soil weathering and clay translocation were retarded by limited leaching and base-saturated soil solution. The development of the vertic features was mainly conditioned by the localization of the profile in a minor local depression with prolonged water stagnation and abundance of the finest clay fraction rich in expanding clays. The formation of the thick mollic horizons was probably related to the former dominance of grassland vegetation and further enhanced by stabilization of soil organic carbon by various processes. Specific features that indicate a change in vegetation and a decreasing intensity of redox processes suggest a gradual aridification of the environment in the study region.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"249 ","pages":"Article 108671"},"PeriodicalIF":5.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fine-resolution baseline maps of soil nutrients in farmland of Jiangxi Province using digital soil mapping and interpretable machine learning","authors":"Bifeng Hu ,&nbsp;Yibo Geng ,&nbsp;Kejian Shi ,&nbsp;Modian Xie ,&nbsp;Hanjie Ni ,&nbsp;Qian Zhu ,&nbsp;Yanru Qiu ,&nbsp;Yuan Zhang ,&nbsp;Hocine Bourennane","doi":"10.1016/j.catena.2024.108635","DOIUrl":"10.1016/j.catena.2024.108635","url":null,"abstract":"<div><div>Detailed maps of soil nutrients are crucial for farmland management and agricultural production. However, soil nutrients are largely affected by various natural and anthropogenic factors, making it a challenging task to make clear its spatial distribution. To fill this gap, we produced the fine maps (30 m) of total content of nitrogen (TN), phosphorus (TP), and potassium (TK) in the farmland across Jiangxi Province in Southern China and quantified overall contribution of different covariates, as well as mapped the location-specific primary variable for predicting soil nutrients using an interpretable machine learning model. Our results reveal that random forest outperformed Cubist and XGBoost for mapping TN, TP and TK. The optimal models achieved R² of 0.29, 0.29, 0.52 and RMSE of 0.43, 0.15 and 3.42 g kg⁻¹ for TN, TP and TK, respectively. Moreover, we found both introducing competitive adaptive reweighted sampling algorithm and incorporating remote sensing images as well as soil management factors failed to clearly improve prediction accuracy of TN, TP and TK. In addition, climate variables had dominant overall effects on mapping TN (60.2 %) and TK (62.7 %), while soil properties made the largest contribution to mapping TP (34.3 %). The aridity index (46.90 %), mean annual solar radiation (34.94 %), and mean annual temperature (26.92 %) is the location-specific primary variable for mapping TN, TP, and TK in largest proportion of the study area, respectively. The soil nutrients maps we produced could function as baseline maps for monitoring spatio-temporal variation of soil nutrients, and our results could provide valuable implications for making more specific and efficient measures for soil management.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"249 ","pages":"Article 108635"},"PeriodicalIF":5.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181864","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":"Human settlements lie on paleolandslide deposits:Risk, evidence and formation of an ancient river-blocking landslide in the Jinsha River tributary, SE Tibetan Plateau","authors":"Runing Hou ,&nbsp;Mingyang Wu ,&nbsp;Ningsheng Chen ,&nbsp;Kanglin Wu ,&nbsp;Xiaohu Chen ,&nbsp;Debin She ,&nbsp;Na Huang ,&nbsp;Miaoyuan Xiao","doi":"10.1016/j.catena.2024.108664","DOIUrl":"10.1016/j.catena.2024.108664","url":null,"abstract":"<div><div>The upper reaches of the Jinsha River, known as the “Three Parallel Rivers” region, situated on the southeastern margin of the Qinghai-Tibet Plateau, are susceptible to frequent large-scale river-blocking landslides. The Dingqu River, a tributary of the Jinsha River, accommodates four paleolandslides that serve as crucial land resources for the survival and development of the local population. The county seat of Derong is situated on the largest paleolandslide deposits among them. However, this fact has not been verified or disclosed in prior engineering geological investigations, resulting in inadequate long-term management and prevention of geological hazards that pose a threat to the county seat. This study aims to clarify the mechanisms of regional geological hazards using field investigations, optically stimulated luminescence (OSL) dating, stratigraphic drilling, and river profile analysis. The key objectives are to identify crucial evidence of paleolandslide deposits, determine their ages, and explore the role of river geomorphology in their formation. The results indicate that the age of the paleolandslide is 1.41 ± 0.12 ka, with a minimum deposit thickness of 100 <em>m</em> and an estimated volume of 250 million <em>m³</em>. The headward migration of knickpoint from the Dingqu River outlet caused rapid river incision at a high rate of 5.25 ± 0.38 <em>mm/yr</em>, providing the geomorphic conditions for the formation of the landslide. The lack of evidence for dammed landforms, such as lake deposits, vertical-step knickpoints, and outburst flood deposits, except for landslide deposits, can be primarily attributed to the limited lifespan of landslide dams and the erosion of flood deposits caused by the high river incision rate. It is recommended to prioritize measures to prevent river incision and manage water usage above the paleolandslide deposit to ensure the safety of towns located on these paleolandslide deposits. This study enriches the database of damming rockslide in the Jinsha River tributaries and provides a detailed case for exploring the coevolution of active orogenic rivers and slopes, reflecting potential risks faced by human settlements on paleolandslide deposits.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"249 ","pages":"Article 108664"},"PeriodicalIF":5.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181599","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":"Sediment particle size distribution, source of organic matter and environmental implications in the Liao River, northeast China","authors":"Panpan Cui ,&nbsp;Haifu Li ,&nbsp;Lijuan Cui ,&nbsp;Fangli Su","doi":"10.1016/j.catena.2024.108696","DOIUrl":"10.1016/j.catena.2024.108696","url":null,"abstract":"<div><div>The Liao River Basin, one of China’s most severely affected coastal regions by soil erosion, necessitates a thorough quantitative evaluation of the sources of organic matter (OM) across sediment particle sizes to enhance understanding of carbon biogeochemical cycling. This study examined total organic carbon (TOC), total nitrogen (TN), the TOC/TN ratio (C/N ratio), and δ¹³C and δ¹⁵N isotope signatures in four distinct sediment particle size fractions from Liao River sediments, sampled during the summer and winter of 2023. The results demonstrated that the highest concentrations of TOC, TN, and C/N ratio were found in the &lt;2 µm particle fraction (<em>p</em> &lt;0.05), with summer values of 2.50 ± 0.43 %, 0.19 ± 0.06 %, and 13.89 ± 2.40, respectively, and winter values of 2.71 ± 0.42 %, 0.19 ± 0.05 %, and 14.66 ± 2.55. OM sources were characterized using δ¹³C and C/N ratio analysis, and the MixSIAR Bayesian model was employed to quantify their contributions. Aquatic plants were identified as the dominant OM source in the &lt;2 µm fraction, whereas soil and sewage predominated in the &gt;2 µm fractions. These results indicate that exogenous OM in the Liao River’s mainstem is primarily influenced by sewage discharge and soil erosion. This process facilitates the continuous release of nutrients from sediment particles into the water column, contributing to secondary pollution. Therefore, enhanced management of sewage discharge and erosion control is essential. Carbon and nitrogen isotope fingerprinting within sediment particle size fractions provides novel insights into biogeochemical processes within soil microenvironments.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"249 ","pages":"Article 108696"},"PeriodicalIF":5.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181624","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":"Aggregation of tropical urban soils in the metropolis of São Paulo, southern Brazil","authors":"Jéssica Costa ,&nbsp;Sheila Furquim","doi":"10.1016/j.catena.2024.108681","DOIUrl":"10.1016/j.catena.2024.108681","url":null,"abstract":"<div><div>This study investigated the interplay between the mechanisms of natural soil formation and human-induced alterations in tropical urban soils in São Paulo, Brazil, in order to understand soil dynamics, which are crucial for sustainable urban soil management. Through comprehensive field surveys and laboratory analyses, three soil pedons from Villa Lobos Park (São Paulo city), which was inaugurated in 1994, were studied. To carry out the research, morphological, chemical, physical and micromorphological analyses, as well as aggregate scanning, were conducted. A correlation matrix was created for each pedon to statically analyze the data. The results revealed that the soil composition and aggregation dynamics in Villa Lobos Park were influenced by both natural pedogenic processes and anthropogenic interventions. Over three decades, organic carbon enrichment from root decay and grass biomass decomposition has improved soil quality through melanization. Additionally, inherited organic matter (OM) amounts from technogenic deposits and deliberate OM additions during the establishment of the park have enhanced the organic content near the soil surface. Also, calcification is present. Aggregation dynamics are governed by factors such as aromatic humus, polysaccharide polymers, the synergistic action of fauna and roots, and facilitated by the wetting–drying cycles of the tropical climate and the abundance of cations, notably Ca²⁺. Rapid macroaggregate formation driven by the wetting–drying cycles and the extensive root networks was observed, combined with slower microaggregate development facilitated by the interaction of polysaccharides and organic-minerals complexes. Anthropogenic inputs, including clayey layers, construction residues, organic matter supplements, earthworm populations, and grass cultivation, significantly shaped soil aggregation dynamics, accelerating pedogenic transformations and improving the overall quality of the soil within the park. Understanding these dynamics is crucial for sustainable soil management in urban green spaces like the Villa Lobos Park, offering insights into effective conservation and restoration strategies in similar urban environments worldwide.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"249 ","pages":"Article 108681"},"PeriodicalIF":5.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182827","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}