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{"title":"Key factors influencing the spatial distribution of soil organic carbon and its fractions in Mollisols","authors":"Xiaoguang Niu,&nbsp;Shaoliang Zhang,&nbsp;Chengbo Zhang,&nbsp;Pengke Yan,&nbsp;Hao Wang,&nbsp;Weitao Xu,&nbsp;Mingke Song,&nbsp;Muhammad Aurangzeib","doi":"10.1016/j.catena.2024.108522","DOIUrl":"10.1016/j.catena.2024.108522","url":null,"abstract":"<div><div>Soil organic carbon (SOC) is a key component of the global carbon pool, which is crucial to the fertility and health of soils and deeply influences global carbon cycling. “Mollisols belts” with high SOC storage are considered as the natural breadbasket of the world, and SOC transformation between the sources and sinks profoundly affects global climate change. In this review, based on the newest publications, the effects of both natural and anthropic factors on the decomposition, migration, and transformation of SOC and further influencing the spatial distribution of SOC and its fractions in Mollisols were summarized. Furthermore, we summarized the debates on the spatial changes of SOC and its fractions in Mollisols from publications and analyzed the causes of these debates. Generally, climate change, land use types, fertilization, tillage practices combined with topographic factors, hydrologic process, and soil erosion process significantly influence the spatial distribution of SOC. As well, in the Mollisols, (1) Global warming and elevated CO₂ may increase the content of labile organic carbon fractions and affect the soil-atmosphere carbon cycle. (2) The conversion of abandoned cropland to forest or grassland, and the conversion of dry cropland to paddy field may improve the carbon sequestration capacity of terrestrial ecosystems, while rational fertilization and organic inputs reduce the SOC loss of natural ecosystems converting to cropland. (3) Conservation tillage in cropland improves the SOC storage by increasing the pool of labile organic carbon in soils. (4) A reasonable combination ratio of organic and chemical fertilization is crucial for achieving the stability of the SOC pool and the increase of the SOC storage in soils. At the end of this review, the key issues on the spatial distribution of SOC and the driving mechanisms were prospected in the future.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"247 ","pages":"Article 108522"},"PeriodicalIF":5.4,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662917","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":"A comprehensive assessment of greenhouse gas emissions research in the Cerrado region, Brazil","authors":"Jorge Luiz Locatelli ,&nbsp;Gustavo Vicentini Popin ,&nbsp;Rafael Silva Santos ,&nbsp;Wanderlei Bieluczyk ,&nbsp;Letícia Thomaz Cipriani ,&nbsp;Maurício Roberto Cherubin ,&nbsp;Carlos Eduardo Pellegrino Cerri","doi":"10.1016/j.catena.2024.108538","DOIUrl":"10.1016/j.catena.2024.108538","url":null,"abstract":"<div><div>The increasing demand for food, fiber, and (bio)energy boosted by population growth has accentuated agricultural expansion, increasing global greenhouse gas (GHG) emissions. This scenario is valid in Brazil, where agriculture accounts for the largest part of the nation’s GHG emissions, primarily associated with the expansion of agriculture over areas of native vegetation, especially in the Cerrado region. However, despite the contribution of this sector to GHG emissions, there is a limited understanding of how different systems affect these emissions, as well as the current state of the art on this topic. Therefore, we performed a comprehensive literature review to synthesize the information about GHG emissions in the region, including cropping systems where GHG was measured, methodological procedures, and the main results achieved. Our review shows that the subject of “GHG” has been poorly investigated, with a huge discrepancy compared to other related topics such as soil organic matter. Most studies (31 % of 236) only mentioned GHG-related terms but did not measure them. The studies that measured GHG (n = 39) were conducted mainly in the south-central part of the region and were mostly limited to short-term experiments (&lt; 5 years) or monitoring periods (&lt; 1 year), using manual static chambers. The analysis of the available GHG data indicated that converting Cerrado into agriculture increases N₂O emissions by ∼ 0.45 kg ha⁻¹ year⁻¹ while decreasing CH₄ influx by ∼ 3 kg ha⁻¹ year⁻¹. Despite that, no-tillage combined with cover crops effectively reduces N₂O emissions (∼-0.3 kg ha⁻¹ year⁻¹). Our findings reveal a significant gap in monitoring GHG fluxes in the Cerrado region, particularly in the northern part where Brazil's new agricultural frontier, the Matopiba region, is located. Efforts should prioritize generating comprehensive GHG data for Cerrado agriculture by employing more robust monitoring protocols. This would help guide producers, researchers, and policymakers to enhance agricultural management practices toward greater sustainability.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"247 ","pages":"Article 108538"},"PeriodicalIF":5.4,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663058","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":"Feasibility of proximal sensing for predicting soil loss tolerance","authors":"Hasan Mozaffari ,&nbsp;Ali Akbar Moosavi ,&nbsp;Yaser Ostovari","doi":"10.1016/j.catena.2024.108503","DOIUrl":"10.1016/j.catena.2024.108503","url":null,"abstract":"<div><div>Soil loss tolerance (T-value) is a vital parameter in soil conservation programs aiming to reduce erosion. Measuring the T-value is expensive, difficult, and time-consuming. No study was found that investigated the capability of the spectroscopy approach in visible (Vis) and near-infrared (NIR) regions to predict the T-value. Hence, we aimed to predict the T-value by the Vis-NIR spectroscopy. 60 soil profiles were excavated to measure the T-values according to the soil thickness method (STM), along with physico-chemical attributes and Vis-NIR spectra in the calcareous soils of southern Iran. The T-value was predicted using Vis-NIR reflectance spectra via applying different modeling approaches, including partial least square regression (PLSR), principal component regression (PCR), multiple linear and non-linear regressions-based spectrotransfer functions (MLR-STF and MNLR-STF), and support vector regression (SVR). The Vis-NIR reflectance spectroscopy can detect functional groups of organic matter and carbonate components in soil, so if the T-value is significantly correlated with these parameters, it is evidence that the Vis-NIR spectroscopy may be an effective approach in predicting the T-value. Hence, results revealed that the soil organic matter and calcium carbonate equivalent were significantly correlated (<em>p</em> &lt; 0.05) with the T-value by correlation coefficients (r) of 0.77 and 0.32, respectively. Among the applied SVR algorithms to predict the T-value by Vis-NIR spectra, the Epsilon type with linear kernel algorithm (Epsilon-SVR-L) showed the best performance. The T-value was predicted with acceptable accuracy using the Vis-NIR spectroscopy and applying the PLSR, PCR, MLR-STF, MNLR-STF, and Epsilon-SVR-L models with the cross-validation R² values of 0.60, 0.57, 0.61, 0.61, and 0.64, respectively. The reflectance values at wavelengths of 420, 564, 698, 1098, 1407, 1899, 1939, 2139, 2259, 2342, and 2456 nm were recognized as the most effective and predictive bands to predict the T-value and appeared in both developed STFs. Considering accuracy, simplicity, and applicability, the developed MLR-STF is recommended to predict the T-value and recognize eroded regions to conserve the soil resources of calcareous soils.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"247 ","pages":"Article 108503"},"PeriodicalIF":5.4,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663054","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 erosion prediction in multiple scenarios based on climate change and land use regulation policies in context of sustainable agriculture","authors":"Nian Li ,&nbsp;Hongying Zhao ,&nbsp;Zhibang Luo ,&nbsp;Tianwei Wang ,&nbsp;Jiawei Yang ,&nbsp;Lu Li ,&nbsp;Shuxin Que","doi":"10.1016/j.catena.2024.108525","DOIUrl":"10.1016/j.catena.2024.108525","url":null,"abstract":"<div><div>It remains a great challenge to develop feasible land use regulation strategies to control soil erosion under environmental constraints and agricultural demands. This study aims to explore the future outcomes of soil erosion under different land use regulation strategies and the impacts of climate change, while trying to incorporate regional differences in agricultural system development into these strategies. Based on historical data from 2000 to 2020 in 69 cities in South China, this study revealed the reciprocal cross-regulation patterns between soil and water conservation (SWC) and agricultural system development (ASD), highlighting the dynamic and evolving nature of their bidirectional interaction. Taking this historical experience into account, we designed an explorative scenario called discriminatory regulation with regional characteristics (DRC). This scenario assigned different sustainable regulation priorities to regions at different stages of agricultural system development based on the strength of the interaction between SWC and ASD. We also designed two reference scenarios: business as usual (BAU) and ecological and economic balance (EEB), to compare with the exploratory DRC scenario. The DRC scenario involved no additional interventions and continued the land use change trends of the past five years, while the EEB scenario implements uniform sustainable land use regulation across all regions. Ultimately, we used the CSLE model to project soil erosion outcomes under three scenarios and discussed the influencing factors. The SSP2-RCP4.5 scenario from the CMIP6 archive was chosen to provide the climate change background for the soil erosion predictions. The results of the BAU scenario show that the soil erosion modulus is predicted to be 975.75 t·km⁻²·a⁻¹ by the year 2050, exhibiting a significant increase relative to the average value of 729.03 t·km⁻²·a⁻¹ over the period 2000–2020. By 2050, climate change is projected to increase rainfall erosivity by 46.80 %, indicating that climate change will be the major driver of increased soil erosion in the future. In the EEB scenario, soil erosion will be reduced by 11.59 % compared to the BAU scenario when sustainable management is applied region-wide without discrimination. In the DRC scenario, soil erosion will be reduced by 15.68 % compared to the BAU scenario via promoting ecological restoration and encouraging conservation agriculture practices. Comparison of the three scenarios establishes that the DRC scenario is a meaningful attempt to integrate regional disparities in agricultural system development into land use regulation strategies. This study provides valuable references for policy makers to develop a holistic approach to soil resource management and coordinated regional development.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"247 ","pages":"Article 108525"},"PeriodicalIF":5.4,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663055","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":"Annual dynamics of periglacial alluvial fans mapped and quantified using time series of UAV data in Svalbard","authors":"Aleksandra M. Tomczyk ,&nbsp;Marek W. Ewertowski ,&nbsp;Wojciech Ewertowski ,&nbsp;Szymon Śledź","doi":"10.1016/j.catena.2024.108531","DOIUrl":"10.1016/j.catena.2024.108531","url":null,"abstract":"<div><div>The location of alluvial fans at the intersection of the lithosphere, hydrosphere, and atmosphere makes them valuable in recording long-term environmental changes. Short-term (annual) surface morphological changes of fans are also important, as they provide a geomorphological record of high-magnitude, low-frequency processes like debris flows or avalanches, which can pose a risk to human life, infrastructure, and cultural heritage. Our study focused on the annual dynamics of fans in Spitsbergen, Svalbard. This high-Arctic location is essential because it provides insight into the dynamics of fans in an area where climate warming is progressing at one of the highest rates on Earth, which can potentially lead to an increase in the frequency and/or magnitude of geomorphological processes. We quantified the geomorphological changes in surfaces of four debris-flow-dominated alluvial fans non-affected by direct human activity. High-resolution (cm-scale) elevation data were collected using a time series of UAV surveys conducted annually between 2015 and 2019. Our research has shown that most of the area (88–99 %) of individual fans remained stable during the studied period. However, we were still able to identify significant morphological changes using UAV data when high-magnitude, low-frequency processes such as debris flow, avalanche, or ground collapse occurred. The area of the individual fan that experienced elevation changes greater than the minimum level of detection (0.10 m) varied depending on the year, ranging from 0.2 % to approximately 8 %, with significant spatial and temporal variability. The volume of changes ranged from −2200 m³ to +4000 m³ per year, with the highest recorded erosion being 5 m and the highest deposition being 2.1 m per year. The variation in geomorphological response was caused by multiple factors, including fan and catchment morphometry, surface composition, timing of specific events, presence of permafrost, and the diversity of geomorphological processes that transformed fan surfaces.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"247 ","pages":"Article 108531"},"PeriodicalIF":5.4,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663059","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":"Spatiotemporal refinement of hydro-sediment processes in small disturbed permafrost watershed during rainfall and snowmelt events","authors":"Xiaonan Shi ,&nbsp;Ying Zheng ,&nbsp;Jiawei Su ,&nbsp;Fan Zhang ,&nbsp;Jianhang Zhu ,&nbsp;Chen Zeng","doi":"10.1016/j.catena.2024.108511","DOIUrl":"10.1016/j.catena.2024.108511","url":null,"abstract":"<div><div>Under climate change, the hydro-sediment processes in permafrost watersheds have been visibly changed, impacting the function of water conservation and ecological barrier of river source areas. However, the lack of observational data and understanding of underlying mechanisms limits the evaluation of hydro-sediment variation and its environmental response. Here, we selected a small permafrost watershed in the northern Tibetan Plateau and conducted daily and event scale observations at four cross-sections: sunny slope tributary, shady slope tributary, confluence, and watershed outlet. Results indicate that during spring, there is a stronger correlation between runoff and sediment concentration, alongside higher sediment transport efficiency per unit of runoff at the watershed outlet. The sunny slope tributary is characterized by rapid runoff generation, high peak flow and sediment load. It predominantly influences the outlet processes, contributing 83% runoff and 125% sediment load in summer rainfall events and 59% runoff and 52% sediment in spring snowmelt events. Thermokarst trench networks also contribute significantly during spring. Conversely, the shady slope tributary demonstrates a slow, sustained runoff release and low sediment concentrations, contributing minimally to the outlet. The lower mainstream channel functions as a dynamic interchange between sources and sinks of runoff and sediment. The temporal and spatial differences are discussed in relation to climate factors, soil properties, soil freeze–thaw dynamics, and land coverage. This study provides valuable insights into hydrological and sedimentary processes in high-altitude cold region and their responses to environmental changes.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"247 ","pages":"Article 108511"},"PeriodicalIF":5.4,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662914","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":"How do trade-offs between ecological construction and urbanization affect regional carbon balance? A case study from China’s Yellow River Basin","authors":"Wenle Yang,&nbsp;Jinghu Pan","doi":"10.1016/j.catena.2024.108534","DOIUrl":"10.1016/j.catena.2024.108534","url":null,"abstract":"<div><div>Anthropogenic activities, including trade-offs between ecological construction and urbanization, alter land use by either adding or subtracting from the carbon balance. Therefore, it is unknown how the trade-offs between ecological construction and urbanization impact the regional carbon balance. We selected the Yellow River Basin for this study to shed light on how human activity affects the carbon balance and promote the advancement of the objective of becoming carbon–neutral. Using panel data, soil respiration data, and GEM-CO₂ models, carbon emissions and sinks in multiple fields were quantified on a raster scale based on multi-source remote sensing data. The trade-offs between urbanization and ecological construction were then spatially illustrated through changes in ground cover. Finally, a raster-scale study was conducted to investigate the ways in which trade-offs between urbanization and ecological construction impact the regional carbon balance. The basin was able to maintain a carbon balance in 2001; however, by 2019, it experienced a severe carbon imbalance. The primary causes of this were rapid growth in energy consumption and direct household waste incineration. By 2019, 84.79% of rasters had a trade-off connection, indicating an increasing trend in the degree of trade-off between ecological construction and urbanization. This affected the pattern of land use in the basin, which in turn affected the carbon balance. Rapid urbanization has exacerbated the carbon imbalance, but ecological construction can reverse this trend. The carbon balance was negatively correlated with the trade-off between ecological construction and urbanization, and the conversion of natural resources by human activity hastened the spread of regional carbon imbalances.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"247 ","pages":"Article 108534"},"PeriodicalIF":5.4,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662915","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":"Holocene Stable Isotope (δ13C and δ15N) record of peatland development in Stavsåkra, southern Sweden","authors":"Supriyo Kumar Das ,&nbsp;Alf Ekblad ,&nbsp;Ksenija Stojanović ,&nbsp;Anna Mikusinska ,&nbsp;Marie-José Gaillard ,&nbsp;Danica Mitrović ,&nbsp;Qiao-Yu Cui","doi":"10.1016/j.catena.2024.108510","DOIUrl":"10.1016/j.catena.2024.108510","url":null,"abstract":"<div><div>Understanding the environmental and climate influence on the Holocene stable isotope record in peat is essential for applying the proxies in the paleoenvironmental reconstruction of lake and bog ecosystems. Here, we report total organic carbon (TOC), TOC to total nitrogen (N) ratio (C/N), and stable isotope ratios of organic carbon (δ¹³C) and nitrogen (δ¹⁵N) of bulk sediment and peat organic matter (OM) from a radiocarbon-dated core collected from Stavsåkra bog in southern Sweden. Changes in the TOC, C/N, δ¹³C and δ¹⁵N between 12 ka and 10.4 ka BP represent shifts in the OM source from aquatic primary producers to terrestrial swamp vegetation and pinpoint the transition of a highly productive water body into a reed swamp. The variation in δ¹³C values and increase in peat accumulation rate (AR) from 10.8 ka BP imply a rapid transition of the aquatic body into a peat-forming swamp and a shift from aquatic to atmospheric CO₂ as the source of carbon (C) to the vegetation at the site. A sharp drop in N and δ¹⁵N in the reed swamp peat may indicate fixed-N in the soil as the source of N to the growing vegetation. Heavier δ¹³C and higher C/N ratio at the bottom of wood carr peat may reflect fire events. The rapid increase in peat AR between 7 ka and 6.5 ka BP suggests increased peat deposition under warmer and drier conditions. Lighter δ¹⁵N and δ¹³C, lower N, and TOC concentrations between 1.1 ka and 0.8 ka BP likely suggest warmer conditions related to the ‘Medieval Climate Anomaly’. The research demonstrates the successful application of stable C and N isotope ratios of bulk peat in palaeoenvironment and palaeoecological interpretations.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"247 ","pages":"Article 108510"},"PeriodicalIF":5.4,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662916","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 influence of tree species on small scale spatial soil properties and microbial activities in a mixed bamboo and broad-leaved forest","authors":"Meiman Zhang ,&nbsp;Zixu Yin ,&nbsp;Fengying Guan ,&nbsp;Zhibing Wan","doi":"10.1016/j.catena.2024.108527","DOIUrl":"10.1016/j.catena.2024.108527","url":null,"abstract":"<div><div>Soil enzyme activity and microbial biomass play a critical role in myriad ecological processes. Bamboo and broad-leaved mixed forests have received widespread attention as important forestry models for ecological restoration and sustainable development; however, our understanding the influences of broad-leaved tree species in mixed bamboo forests on soil properties and microbial activity remains unclear. Here we sampled twenty-seven spatially interspersed stands of bamboo-<em>Castanopsis chinensis</em> Hance mixed forest (CCB), bamboo-<em>Alniphyllum fortune</em> (Hemsl.) Makino mixed forest (AFB), and bamboo-<em>Choerospondias axillaris</em> mixed forest (CAB), with different mixing ratios (0–10 %, 10–20 %, 20–40 % canopy proportions) in subtropical China, to examine the effects of tree species and mixed ratio on soil nutrients, microbial biomass, and enzyme activity. We found that the different forests exhibited variations in soil nutrient levels. CAB forests exhibit notably higher mean C, N, and P contents than AFB and CCB, particularly at a 10–20 % mixing ratio where SOC concentration reached 46.50 g/kg. CAB forests demonstrated significantly higher activities of invertase (mean 701.83U/g), urease (8393.44U/g), and catalase (501.73U/g) compared to AFB and CCB forests, with peak enzyme activities observed at a 10–20 % mixing ratio. Soil microbial biomass C and N were notably greater in CAB and CCB forests than in AFB forests. CAB forests also exhibited the highest soil microbial biomass P (mean 48.68 mg/kg), which rose consistently with an increased mixing ratio. Multiple factor analysis revealed that the enzyme activities were significantly correlated with the annual growth of fine roots in the forest and were positively correlated with resident C, total N, total P, C: N, and C: P. Overall, the results provide insights into the importance of tree species and crown size in bamboo and broadleaved tree mixed forest in soil features and the microbial activity while providing management guidance for the selection of mixed tree species for sustainable management of bamboo forest soil microenvironment.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"247 ","pages":"Article 108527"},"PeriodicalIF":5.4,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662995","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":"Contrasting responses of soil organic carbon dynamics to long-term canopy and understory nitrogen addition in a subtropical forest","authors":"Xiaofei Lu ,&nbsp;Heng Yu ,&nbsp;Frank S. Gilliam ,&nbsp;Xu Yue ,&nbsp;Jingchao Huang ,&nbsp;Songbo Tang ,&nbsp;Yuanwen Kuang","doi":"10.1016/j.catena.2024.108536","DOIUrl":"10.1016/j.catena.2024.108536","url":null,"abstract":"<div><div>Elucidating the impacts of chronic atmospheric nitrogen (N) deposition on soil organic carbon (SOC) is crucial for predicting the dynamics of terrestrial C sinks, particularly in N-rich subtropical forests. Experiments using understory N addition (UN) have provided valuable insights into these impacts, but unavoidably neglect processes such as interception and absorption of N within forest canopy. We assessed the effects of long-term (11-yr) fertilization via both canopy N addition (CN) and UN on SOC in a subtropical forest. Our results showed significantly different responses of SOC between the approaches, with UN displaying greater effects on SOC than CN. Specifically, both low and high rates of UN substantially increased the concentrations of particulate organic C (POC), whereas the high rate of CN significantly increased those of mineral-associated organic C (MAOC) rather than POC. Long-term CN and UN treatments had distinct effects on plant- and microbial-derived C processes. UN treatments significantly increased soil available N and improved the litter quality, enhancing the formation of POC, and suppressing microbial decomposition of POC due to the significant decreases in soil pH. However, CN treatments significantly improved litter quality and mitigated soil acidification, thus stimulating microbial C utilization and accelerating the microbial transformation of POC to MAOC. Our findings imply that the underlying mechanisms of natural N deposition influencing forest SOC may differ from those obtained from UN, and conventional fertilization experiments may overestimate the benefits of elevated N deposition to forest SOC.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"247 ","pages":"Article 108536"},"PeriodicalIF":5.4,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662994","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}