This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking an...This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking and neutrality goals.This research ana-lyzes the spatial characteristics of carbon metabolism from 2000 to 2020 and uses models to identify stable carbon sink areas,positive carbon flow corridors,and carbon sequestration nodes.The goal is to construct a carbon metabolism spatial security pattern(CMSSP)and propose territorial ecological restoration strategies under different development demand scenarios.The results show the following:1)in 2020,the study area’s carbon sink decreased by 8.29×10^(4) t C/yr compared with that in 2010 and by 10.83×10^(4) t C/yr compared with that in 2000.High-carbon sinks were found mainly in mountainous areas,whereas low-carbon sinks are concentrated in urban con-struction land,rural residential areas,and land margins.2)From 2000 to 2020,the spatial security pattern of carbon metabolism tended to be‘high in the middle of the east and west and low in the gulf.’In 2000,2010,and 2020,16 stable carbon sinks were identified.The carbon energy flow density in Guangxi was greater than that in Guangdong and Hainan,with positive carbon flow corridors located primarily in Guangxi and Guangdong.The number of carbon sequestration nodes remained stable at approximately 15,mainly in Guangxi and Hainan.3)Scenario simulations revealed that under the Nature-based mild restoration scenario,the carbon sink rate will reach 611.85×10^(4) t C/yr by 2030 and increase to 612.45×10^(4) t C/yr by 2060,with stable carbon sinks increasing to 18.In the restora-tion scenario based on Anti-globalization,the carbon sink will decrease from 610.24×10^(4) t C/yr in 2030 to 605.19×10^(4) t C/yr in 2060,with the disappearance of some positive carbon flow corridors and stable carbon sinks.Under the Human-based sustainable restoration scenario,the carbon sink area will decrease from 607.00×10^(4) t C/yr in 2030 to 596.39×10^(4) t C/yr in 2060,with carbon sink areas frag-menting and positive carbon flow corridors becoming less dense.4)On the basis of the current and predicted CMSSPs,this study ex-plores spatial ecological restoration strategies for high-carbon storage areas in bay urban agglomerations at four levels:the land control region,urban agglomeration structure system,carbon sink structure and bay structure control region.展开更多
In order to explore the fertilizing ways and dynamic changes of soil carbon and nitrogen in the main producing areas of tobacco in Guizhou,research was conducted to study the variations of dissolved organic carbon and...In order to explore the fertilizing ways and dynamic changes of soil carbon and nitrogen in the main producing areas of tobacco in Guizhou,research was conducted to study the variations of dissolved organic carbon and nitrogen,total organic carbon and nitrogen and their ratio of tobacco-topsoil in organic fertilization pattern and conventional cultivation pattern （No fertilizer as control） by pot experiment.The results were as follows：（1） The effects of different fertilization patterns on soil dissolved organic carbon and nitrogen and total organic carbon and nitrogen were significantly different.The content of DOC,DON,TOC and TON in tobaccotopsoil was decreased with the advancing of growth period in conventional fertilization pattern.In the conventional fertilization pattern,the accumulation of DOC and TOC was increased first and then decreased,and the accumulation of DON and TON was decreased first and then increased.（2） The TOC content at the different growing stage and DOC content at the middle and later stage of tobacco were significantly improved in organic fertilization patterns.The accumulation of DON and TON in the conventional fertilization pattern was significantly higher than those in the organic fertilizer pattern and control at the rosette stage and vigorous stage.In the harvest period,the content of DOC,DON,TOC and TON of tobacco-topsoil in the conventional fertilization and organic fertilization pattern was significantly higher than those in the control.（3）The DOC/DON ratio and the TOC/TiON ratio was increased gradually with the advancing of growth period in conventional fertilization pattern,but they were increased first and then decreased in the organic fertilization pattern and CK.The DOC/DON and TOC/TON ratio of tobacco-topsoil in different fertilization patterns was showed as Y J＞ CK＞ CG at the different growing stage.The experiment results revealed that：The organic fertilization pattern may improve significantly the accumulation of DOC,DON,TOC and TON of tobacco-topsoil at the middle and later stage and the DOC/DON and TOC/TON ratio at the different growth stage.It contributed to the continuous and balanced supply of nutrients at the middle and later stage of tobacco and the soil fertility.展开更多
Soil humic carbon is an important component of soil organic carbon （SOC） in ter- restrial ecosystems. However, no study to date has investigated its geographical patterns and the main factors that influence it at a ...Soil humic carbon is an important component of soil organic carbon （SOC） in ter- restrial ecosystems. However, no study to date has investigated its geographical patterns and the main factors that influence it at a large scale, despite the fact that it is critical for exploring the influence of climate change on soil C storage and turnover. We measured levels of SOC, humic acid carbon （HAC）, fulvic acid carbon （FAC）, humin carbon （HUC）, and extractable humus carbon （HEC） in the 0-10 cm soil layer in nine typical forests along the 3800-km North-South Transect of Eastern China （NSTEC） to elucidate the latitudinal patterns of soil humic carbon fractions and their main influencing factors. SOC, HAC, FAC, HUC, and HEC increased with increasing latitude （all P〈0.001）, and exhibited a general trend of tropical 〈 subtropical 〈 temperate. The ratios of humic C fractions to SOC were 9.48%-12.27% （HAC）, 20.68%-29.31% （FAC）, and 59.37%-61.38% （HUC）. Climate, soil texture, and soil microbes jointly explained more than 90% of the latitudinal variation in SOC, HAC, FAC, HEC, and HUC and interactive effects were important. These findings elucidate latitudinal patterns of soil humic C fractions in forests at a large scale, and may improve models of soil C turnover and storage.展开更多
Based on the outcrop survey,3D seismic data interpretation,drilling data analysis,the structural patterns and distribution of fault damage zones in carbonate strata of Tazhong Paleo-uplift were established to reveal t...Based on the outcrop survey,3D seismic data interpretation,drilling data analysis,the structural patterns and distribution of fault damage zones in carbonate strata of Tazhong Paleo-uplift were established to reveal the oil and gas enrichment law in the fault damage zones.The following findings were reached:(1)Through the filed survey,the fault damage zone system consists of fault core,damage zone with branch fault and fracture network.Affected by the active nature of the major faults,the fault damage zones differ in planar pattern and scale along the major faults.(2)3D seismic profiles reveal that there are three types of fault damage zones in carbonate strata in Tazhong paleo-uplift,strike-slip fault damage zones,thrust fault damage zones and superimposed fault damage zones.Featuring3 flowers and 3 root belts in vertical,the strike-slip fault damage zone can be subdivided into linear type,oblique type,feather type and horsetail type in plane.Thrust fault damage zones can be further divided into fault anticline type,anticline type and slope type.As the superimposition result of the above two kinds of fault damage zones,superimposed fault damage zones appear in three patterns,intersect type,encompassment type and penetrating type.(3)Cores from wells and geochemical data show oil and gas may migrate along the major fault and laterally.The feather type in strike-slip fault system,fault anticline type in thrust fault damage zone and intersect type in superimposed fault damage zone are possible sites for high production and efficiency wells.展开更多
Land use change and cropping patterns are important factors for controlling carbon sequestration in soils and they may also change the relative importance of different mechanisms of soil organic matter stabilization. ...Land use change and cropping patterns are important factors for controlling carbon sequestration in soils and they may also change the relative importance of different mechanisms of soil organic matter stabilization. The study was conducted to investigate the state of carbon sequestration in soil aggregates under different cropping patterns of Khulna, Jessore and Chapainawabganj districts in Bangladesh. Thirty-six soil samples were collected from (0 - 100 cm depth) above mentioned regions of three physiographic regions: Ganges Meander Floodplain, Ganges Tidal Floodplain and High Barind Tract. The texture of the samples varied within three soil texture groups, Silt Loam, Silty Clay Loam and Silty Clay. The highest NSI value (0.89) was found under Wheat-Fallow-T. Aman cropping pattern in Silty Clay soils (sample No 15) and lowest value (0.59) was found Vegetables/Mustard-Fallow-T. Aman cropping pattern in Silt Loam soils (sample No 17). The highest value (735.20 mg<span style="white-space:nowrap;"><span style="white-space:nowrap;">•</span></span>kg<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup>) of active C was observed under Chickpea/mustard-T. Aman (Sample No 31) and the lowest value (619.23 mg<span style="white-space:nowrap;"><span style="white-space:nowrap;">•</span></span>kg<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup>) was found in case of Wheat-Fallow-T. Aman cropping pattern (Sample No 30). The highest SOC stock (1.62 Kg C m<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>2</sup>) was found in Silty Clay Loam soil under Mungbean/Ash gourd-T. Aman cropping pattern (Sample no 4) and the lowest SOC stock (0.35 Kg C m<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>2</sup>) was found in Silt Loam soil under Cauliflower/Pumkin/Spinach-T. Aman Cropping pattern (Sample No 2). Soil organic carbon associated with different size aggregates was the highest (3.14%) under Mungbean/Ash gourd-T. Aman (Sample No 20) and was the lowest (0.36%) under Cauliflower/Pumkin/Spinach-T. Aman cropping pattern (Sample No 2). Organic carbon content in aggregate size ranges > 2000 μm (SOC1), 2000 - 250 μm (SOC2), 250-53 μm (SOC3), and <53 μm (SOC4) varied from 0.36% - 1.90%, 0.52% - 2.10%, 0.50% - 2.60% and 0.50% - 1.62%, respectively. The percentages of SOC associated with <53 μm aggregates were higher than those of >2000 μm, 2000 - 250 μm and 250 - 53 μm, aggregates. Significant positive correlations were found between SOC stock and SOC1, SOC stock and SOC2, SOC stock and SOC3, SOC stock and SOC4.展开更多
In floodplain wetlands,alterations in hydrological patterns resulting from climate change and human activities could potentially diminish the carbon sequestration capacity of the soils,thereby having a negative impact...In floodplain wetlands,alterations in hydrological patterns resulting from climate change and human activities could potentially diminish the carbon sequestration capacity of the soils,thereby having a negative impact on global climate change.However,the magnitude of the influence of hydrological regime change on soil carbon remains inadequately monitored.To address this research gap,we collected 306 upper layer(0–20 cm)soil samples from the Dongting Lake floodplain between 2013 and 2022.The random forest(RF)algorithm was used to analyze the spatial distribution of soil organic carbon(SOC)in the upper soil layer of Dongting Lake floodplain and the impact of climate and hydrological changes in the past decade on surface SOC in the East Dongting Lake area was studied.In 2022,the SOC concentration of the Dongting Lake floodplain upper layer soil ranged from 3.34 to 17.67 g kg^(-1),averaging 10.43 g kg^(-1),with a corresponding SOC density of(2.65±0.49)kg m^(-2) and total SOC stock of 6.82 Tg C(2.87–13.48 Tg C).From 2013 to 2022,the SOC concentration of the upper soil layer of the East Dongting Lake area decreased from 18.37 to 10.82 g kg^(-1).This reduction could be attributed to climate and hydrological changes which reduce SOC input by reducing vegetation growth and accelerating SOC decomposition.Above 21.4 m elevation,the amount of SOC loss increased with elevation,the loss being related to the decline in Miscanthus community biomass and greater susceptibility of higher altitude areas to climate and hydrological changes.Our results highlight the need for strengthening wetland SOC management to increase SOC in the soils to help combat climate change.展开更多
By analyzing the characteristics of development, structural evolution and reservoir beds of the residual carbonate strata, this study shows that the residual carbonate strata in the Yingmaili low uplift are favorable ...By analyzing the characteristics of development, structural evolution and reservoir beds of the residual carbonate strata, this study shows that the residual carbonate strata in the Yingmaili low uplift are favorable oil and gas accumulation series in the Tabei （northern Tarim uplift） uplift. There are different patterns of hydrocarbon accumulation on the northern and southern slopes of the Yingmaili low uplift. The north-south differentiation of oil reservoirs were caused by different lithologies of the residual carbonate strata and the key constraints on the development of the reservoir beds. The Mesozoic terrestrial organic matter in the Kuqa depression and the Palaeozoic marine organic matter in the Manjiaer sag of the Northern depression are the major hydrocarbon source rocks for the northern slope and southern slope respectively. The hydrocarbon accumulation on the northern and southern slopes is controlled by differences in maturity and thermal evolution history of these two kinds of organic matter. On the southern slope, the oil accumulation formed in the early stage was destroyed completely, and the period from the late Hercynian to the Himalayian is the most important time for hydrocarbon accumulation. However, the time of hydrocarbon accumulation on the northern slope began 5 Ma B.P. Carbonate inner buried anticlines reservoirs are present on the southern slope, while weathered crust and paleo-buried hill karst carbonate reservoirs are present on the northern slope. The northern and southern slopes had different controlling factors of hydrocarbon accumulation respectively. Fracture growth in the reservoir beds is the most important controlling factor on the southern slope; while hydrocarbon accumulation on the northern slope is controlled by weathered crust and cap rock.展开更多
Controlled growth of patterned single-walled carbon nanotubes (SWNTs) is an important issue in many applications. Herein, we demonstrated a method to pattern catalyst via inkjet printing for the growth of SWNTs, using...Controlled growth of patterned single-walled carbon nanotubes (SWNTs) is an important issue in many applications. Herein, we demonstrated a method to pattern catalyst via inkjet printing for the growth of SWNTs, using metal salt solutions as the inks and an ordinary office-use printer. We printed water solutions of cobalt acetate on hydrophilic Si substrates and grew high quality SWNT films. The composition of the precursor solutions and the hydrophilicity of the substrates were crucial factors to the patterning.展开更多
Urban construction land has relatively high human activity and high carbon emissions.Research on urban construction land prediction under carbon peak and neutrality goals(hereafter“dual carbon”goals)is important for...Urban construction land has relatively high human activity and high carbon emissions.Research on urban construction land prediction under carbon peak and neutrality goals(hereafter“dual carbon”goals)is important for territorial spatial planning.This study analyzed quantitative relationships between carbon emissions and urban construction land,and then modified the construction land demand prediction model.Thereafter,an integrated model for urban construction land demand prediction and spatial pattern simulation under“dual carbon”goals was developed,where urban construction land suitability was modified based on carbon source and sink capacity of different land-use types.Using Guangzhou as a case study,the integrated model was validated and applied to simulate the spatiotemporal dynamics of its urban construction land during 2030–2060 under baseline development and“dual carbon”goals scenarios.The simulation results showed that Guangzhou’s urban construction land expanded rapidly until 2030,with the spatial pattern not showing an intensive development trend.Guangzhou’s urban construction land expansion slowed during 2030–2060,with an average annual growth rate of 0.2%,and a centralized spatial pattern trend.Under the“dual carbon”goal scenario,Guangzhou’s urban construction land evolved into a polycentric development pattern in 2030.Compared with the baseline development scenario,urban construction land expansion in Guangzhou during 2030–2060 is slower,with an average annual growth rate of only 0.1%,and the polycentric development pattern of urban construction land was more prominent.Furthermore,land maintenance and growth,that is,a carbon sink,is more obvious under the“dual carbon”goals scenario,with the forest land area nearly 10.6%higher than that under the baseline development scenario.The study of urban construction land demand prediction and spatial pattern simulation under“dual carbon”goals provides a scientific decision-making support tool for territorial spatial planning,aiding in quantifying territorial spatial planning.展开更多
The relationship between paleogeographic pattern and sedimentary differentiation of evaporite-carbonate symbiotic system is examined based on logging,core and thin section data,by taking the sixth sub-member of fifth ...The relationship between paleogeographic pattern and sedimentary differentiation of evaporite-carbonate symbiotic system is examined based on logging,core and thin section data,by taking the sixth sub-member of fifth member of Ordovician Majiagou Formation(M56)in the central-eastern Ordos Basin as an example.(1)Seven sub-geomorphic units(Taolimiao west low,Taolimiao underwater high,Taolimiao east low,Hengshan high,East salt low,North slope and Southwest slope)developed in the study area.(2)The“three lows”from west to east developed dolomitic restricted lagoon,evaporite evaporative lagoon and salt evaporative lagoon sedimentary facies respectively,the"two highs"developed high-energy grain beach and microbial mound,and the north and south slopes developed dolomitic flats around land.(3)The paleogeographic pattern caused natural differentiation of replenishment seawater from the northwest Qilian sea,leading to the eccentric sedimentary differentiation of dolomite,evaporite and salt rock symbiotic system from west to east,which is different from the classic“bull's eye”and“tear drop”distribution patterns.(4)As the Middle Qilian block subducted and collided into the North China Plate,the far-end compression stress transferred,giving rise to the alternate highland and lowland in near north to south direction during the sedimentary period of M56 sub-member.(5)Taolimiao underwater high and Hengshan high developed favorable zones of microbial mounds and grain shoals in south to north strike in M56 sub-member,making them favorable exploration areas with great exploration potential in the future.展开更多
In view of high water cut and low oil recovery caused by the unidirectional flow in linear pattern of horizontal wells for the carbonate reservoirs in the Middle East,this paper provides a novel approach to improve oi...In view of high water cut and low oil recovery caused by the unidirectional flow in linear pattern of horizontal wells for the carbonate reservoirs in the Middle East,this paper provides a novel approach to improve oil recovery by converting linear water injection to cyclic alternating water injection patterns including cyclic alternating water injection with apparent inverted seven-spot pattern or apparent five-spot pattern and cyclic differential alternating water injection.The main advantage of using this strategy is that the swept efficiency is improved by changing injection-production streamlines and displacement directions,which means displacement from two different direction for the same region during a complete cycle.This technology is effective in increasing the swept efficiency and tapping the remaining oil,thus resulting in higher oil recovery.Field application with three new patterns in a carbonate reservoir in the Middle East is successful.By optimizing injection and production parameters based on the cyclic alternating well pattern,the test well group had a maximum increase of daily oil production per well of 23.84 m^(3) and maximum water cut drop of 18%.By further optimizing the distance(keep a long distance)between the heels of injection and production wells,the waterflooding performance could be better with water cut decreasing and oil production increasing.展开更多
Moso bamboo(Phyllostachys edulis)forests are a vital resource in subtropical China,known for their high carbon(C)sequestration capacity.However,the dynamic processes of C fluxes within each component(canopy,culm,and s...Moso bamboo(Phyllostachys edulis)forests are a vital resource in subtropical China,known for their high carbon(C)sequestration capacity.However,the dynamic processes of C fluxes within each component(canopy,culm,and soil)and their individual contributions,particularly during on-and off-years,remain unclear.A 2-year field experiment was conducted to investigate the dynamics of C fluxes from the canopy,culm,and soil(partitioned into heterotrophic,rhizome,and stump respiration)and their contributions to net ecosystem productivity(NEP)in a representative Moso bamboo forest in the subtropical region of China.The average annual NEP of the Moso bamboo forest was 7.31±2.76 t C·ha^(-1).Specifically,the canopy's annual net C uptake was 17.30±3.23 tC·ha^(-1),accounting for 237%of NEP.In contrast,C emissions from heterotrophs,culms,rhizomes,and stumps were 5.37±1.20,2.18±1.05,1.29±0.04,and 1.15±0.33 t C·ha^(-1),accounting for73%,30%,18%,and16%of NEP,respectively.The NEP,net cumulative C uptake in the canopy,and C emissions from the respiration of heterotrophs and stumps were all significantly higher during on-years when compared to off-years,whereas C emissions from bamboo culms displayed opposite trends.These findings offer a new approach for quantifying the C budgets of Moso bamboo forests and provide valuable insights into the C cycling processes in forest ecosystems.展开更多
Global warming underscores the urgent need to enhance carbon sinks to mitigate climate change,yet the role of coastal shellfish aquaculture area as either carbon sinks or sources remains unclear.In this study,we condu...Global warming underscores the urgent need to enhance carbon sinks to mitigate climate change,yet the role of coastal shellfish aquaculture area as either carbon sinks or sources remains unclear.In this study,we conducted high-resolution profiling observations of CO_(2)dynamics and net community production(NCP)in a mussel farm located in the Changjiang(Yangtze)River estuary(CRE)during early autumn.Results indicate that the partial pressure of CO_(2)(pCO_(2))in the water column was consistently higher than the atmospheric level,averaging 74.75±2.44 Pa,signaling that the mussel farm acted as a CO_(2)source.The average air-water CO_(2)exchange flux(FCO_(2))averaged-1.91±1.16 mmol/(m^(2)·h),and NCP in the water column(NCPCOL)averaged-6.66±12.81 mmol/(m^(2)·h),revealing a heterotrophic condition.A significant inverse correlation was found between NCPCOLand sea surface pCO_(2)with a lag time of approximately 3.31 h,highlighting the influence of biological activity in modulating CO_(2)dynamics.Physical processes such as freshwater inputs,vertical mixing,and wind patterns,also played a crucial role in shaping pCO_(2)variations.The study emphasizes the complexity of CO_(2)dynamics in costal aquaculture areas and the need for long-term,high-resolution monitoring to better understand their contribution to climate change mitigation.The high-resolution profiling system provided novel insights into the dynamics of NCP and CO_(2)fluxes,showing its potential as an advanced tool for studying aquaculture systems.Future research should focus on expanding the geographic and temporal scope of studies,combining observational and modeling approaches to better predict the responses of aquaculture systems to environmental changes.展开更多
Understanding the elevational patterns of soil microbial carbon(C)metabolic potentials is instrumental for predicting changes in soil organic C(SOC)stocks in the face of climate change.However,such patterns remain unc...Understanding the elevational patterns of soil microbial carbon(C)metabolic potentials is instrumental for predicting changes in soil organic C(SOC)stocks in the face of climate change.However,such patterns remain uncertain in arid mountain ecosystems,where climosequences are quite different from other ecosystems.To address this gap,this study investigated the distribution determinants of microbial communities,C cycling-related genes,and SOC fractions along an elevational gradient(1707–3548 m),with a mean annual precipitation(MAP)range of 38 to 344 mm,on the north slope of the central part of the Kunlun Mountains,China using a metagenomic approach.The results showed that elevation significantly influenced the α-diversity(Shannon index)and composition of microbial communities as well as the C cycling-related genes.The α-diversities of microbial taxa and C cycling-related genes linearly increased with the increase in MAP along the elevational gradient.The elevational patterns of the genes encoding glycoside hydrolases and glycosyl transferases(GTs)were mainly driven by soil electrical conductivity(EC),mean annual temperature(MAT),MAP,and plant diversity.Furthermore,mineral-associated organic C(MAOC),particulate organic C(POC),and their sum generally increased with elevation.However,the MAOC/POC ratio followed a unimodal pattern,suggesting greater stability of the SOC pool in the mid-elevation regions.This unimodal pattern was likely influenced by the abundances of Actinobacteria and the genes encoding GTs and carbohydrate esterases and the threshold effects of soil EC and MAT.In summary,our findings indicate that the distribution patterns of microbial communities and C cycling-related genes along the elevational gradient in an arid ecosystem are distinct from those in the regions with higher MAP,facilitating the prediction of climate change effects on SOC metabolism under more arid conditions.Soil salinity,plant diversity,precipitation,and temperature are the main regulatory factors of microbial C metabolism processes,and they potentially play a central role in mediating SOC pool stability.展开更多
By integrating core observations,logging data and seismic interpretation,this study takes the massive Cretaceous carbonates in the M block of the Santos Basin,Brazil,as an example to establish the sequence filling pat...By integrating core observations,logging data and seismic interpretation,this study takes the massive Cretaceous carbonates in the M block of the Santos Basin,Brazil,as an example to establish the sequence filling pattern of fault-bounded isolated platforms in rift lake basins,reveal the control mechanisms of shoal-body development and reservoir formation,and reconstruct the evolutionary history of lithofacies paleogeography.The following results are obtained.(1)Three tertiary sequences(SQ1-SQ3)are identified in the Lower Cretaceous Itapema-Barra Velha of the M block.During the depositional period of SQ1,the rift basement faults controlled the stratigraphic distribution pattern of thick on both sides and thin in the middle.The strata overlapped to uplift in the early stage.During the depositional period of SQ2-SQ3,the synsedimentary faults controlled the paleogeomorphic reworking process with subsidence in the northwest and uplifting in the northeast,accompanied with the relative fall of lake level.(2)The Lower Cretaceous in the M block was deposited in a littoral-shallow lake,with the lithofacies paleogeographic pattern transiting from the inner clastic shoals and outer shelly shoals in SQ1 to the alternation of mounds and shoals in SQ2-SQ3.(3)Under the joint control of relative lake-level fluctuation,synsedimentary faults and volcanic activity,the shelly shoals in SQ1 tend to accumulated vertically in the raised area,and the mound-shoal complex in SQ2-SQ3 tends to migrate laterally towards the slope-break belt due to the reduction of accommodation space.(4)The evolution pattern of high-energy mounds and shoals,which were vertically accumulated in the early stage and laterally migrated in the later stage,controlled the transformation of high-quality reservoirs from“centralized”to“ring shaped”distribution.The research findings clarify the sedimentary patterns of mounds and shoals and the distribution of favorable reservoirs in the fault-controlled lacustrine isolated platform,providing support for the deepwater hydrocarbon exploration in the subsalt carbonate rocks in the Santos Basin.展开更多
Digital transformation,as a recent trend in socioeconomic development,is considered as a critical pathway for urban carbon reduction because of its potential to increase productivity and energy efficiency.However,few ...Digital transformation,as a recent trend in socioeconomic development,is considered as a critical pathway for urban carbon reduction because of its potential to increase productivity and energy efficiency.However,few studies have explored the relationship between urban digitalization and carbon emissions(CE).Therefore,this study systematically analyzed the spatiotemporal distribution and interaction mechanism between digitalization and CE in the Yangtze River Delta(YRD)urban agglomerations of China during 2006-2020 based on a multidimensional indicator system,including digitalization industry level,digitalization application level,and urban green digitalization willingness.The findings revealed that both digitalization and CE in the YRD exhibit a significant and synchronously evolving“core-periphery”spatial pattern.Core cities generated substantial positive spillover effect on periphery cities through technology diffusion and policy demonstration,advancing both regional digitalization and the collaborative governance of CE.However,digitalization had dual impact on CE.On the one hand,it promoted the reduction of CE by enhancing energy efficiency,optimizing industrial structures,and promoting the application of green technologies.On the other hand,the expansion of digital infrastructure introduced a potential risk of increased energy consumption.Therefore,targeted policy recommendations are proposed to facilitate the coordination of environmental sustainability and digitalization in the YRD.This study provides empirical support and policy insights for advancing the coordinated development of regional digital transformation and green low-carbon initiatives.展开更多
基金Under the auspices of the National Natural Science Foundation of China(No.52268008)。
文摘This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking and neutrality goals.This research ana-lyzes the spatial characteristics of carbon metabolism from 2000 to 2020 and uses models to identify stable carbon sink areas,positive carbon flow corridors,and carbon sequestration nodes.The goal is to construct a carbon metabolism spatial security pattern(CMSSP)and propose territorial ecological restoration strategies under different development demand scenarios.The results show the following:1)in 2020,the study area’s carbon sink decreased by 8.29×10^(4) t C/yr compared with that in 2010 and by 10.83×10^(4) t C/yr compared with that in 2000.High-carbon sinks were found mainly in mountainous areas,whereas low-carbon sinks are concentrated in urban con-struction land,rural residential areas,and land margins.2)From 2000 to 2020,the spatial security pattern of carbon metabolism tended to be‘high in the middle of the east and west and low in the gulf.’In 2000,2010,and 2020,16 stable carbon sinks were identified.The carbon energy flow density in Guangxi was greater than that in Guangdong and Hainan,with positive carbon flow corridors located primarily in Guangxi and Guangdong.The number of carbon sequestration nodes remained stable at approximately 15,mainly in Guangxi and Hainan.3)Scenario simulations revealed that under the Nature-based mild restoration scenario,the carbon sink rate will reach 611.85×10^(4) t C/yr by 2030 and increase to 612.45×10^(4) t C/yr by 2060,with stable carbon sinks increasing to 18.In the restora-tion scenario based on Anti-globalization,the carbon sink will decrease from 610.24×10^(4) t C/yr in 2030 to 605.19×10^(4) t C/yr in 2060,with the disappearance of some positive carbon flow corridors and stable carbon sinks.Under the Human-based sustainable restoration scenario,the carbon sink area will decrease from 607.00×10^(4) t C/yr in 2030 to 596.39×10^(4) t C/yr in 2060,with carbon sink areas frag-menting and positive carbon flow corridors becoming less dense.4)On the basis of the current and predicted CMSSPs,this study ex-plores spatial ecological restoration strategies for high-carbon storage areas in bay urban agglomerations at four levels:the land control region,urban agglomeration structure system,carbon sink structure and bay structure control region.
基金Supported by The General Program of National Natural Science Foundation of China(312771673)Programs for Science and Technology Development of Tobacco Monopoly Bureau in Guizhou Province(20121126)~~
文摘In order to explore the fertilizing ways and dynamic changes of soil carbon and nitrogen in the main producing areas of tobacco in Guizhou,research was conducted to study the variations of dissolved organic carbon and nitrogen,total organic carbon and nitrogen and their ratio of tobacco-topsoil in organic fertilization pattern and conventional cultivation pattern （No fertilizer as control） by pot experiment.The results were as follows：（1） The effects of different fertilization patterns on soil dissolved organic carbon and nitrogen and total organic carbon and nitrogen were significantly different.The content of DOC,DON,TOC and TON in tobaccotopsoil was decreased with the advancing of growth period in conventional fertilization pattern.In the conventional fertilization pattern,the accumulation of DOC and TOC was increased first and then decreased,and the accumulation of DON and TON was decreased first and then increased.（2） The TOC content at the different growing stage and DOC content at the middle and later stage of tobacco were significantly improved in organic fertilization patterns.The accumulation of DON and TON in the conventional fertilization pattern was significantly higher than those in the organic fertilizer pattern and control at the rosette stage and vigorous stage.In the harvest period,the content of DOC,DON,TOC and TON of tobacco-topsoil in the conventional fertilization and organic fertilization pattern was significantly higher than those in the control.（3）The DOC/DON ratio and the TOC/TiON ratio was increased gradually with the advancing of growth period in conventional fertilization pattern,but they were increased first and then decreased in the organic fertilization pattern and CK.The DOC/DON and TOC/TON ratio of tobacco-topsoil in different fertilization patterns was showed as Y J＞ CK＞ CG at the different growing stage.The experiment results revealed that：The organic fertilization pattern may improve significantly the accumulation of DOC,DON,TOC and TON of tobacco-topsoil at the middle and later stage and the DOC/DON and TOC/TON ratio at the different growth stage.It contributed to the continuous and balanced supply of nutrients at the middle and later stage of tobacco and the soil fertility.
基金National Key Research Project of China,No2016YFC0500202STS of Chinese Academy of Sciences,No.KFJ-SW-STS-167+1 种基金National Natural Science Foundation of China,No.31290221,No.31570471Youth Innovation Research Team Project,No LENOM2016Q0005
文摘Soil humic carbon is an important component of soil organic carbon （SOC） in ter- restrial ecosystems. However, no study to date has investigated its geographical patterns and the main factors that influence it at a large scale, despite the fact that it is critical for exploring the influence of climate change on soil C storage and turnover. We measured levels of SOC, humic acid carbon （HAC）, fulvic acid carbon （FAC）, humin carbon （HUC）, and extractable humus carbon （HEC） in the 0-10 cm soil layer in nine typical forests along the 3800-km North-South Transect of Eastern China （NSTEC） to elucidate the latitudinal patterns of soil humic carbon fractions and their main influencing factors. SOC, HAC, FAC, HUC, and HEC increased with increasing latitude （all P〈0.001）, and exhibited a general trend of tropical 〈 subtropical 〈 temperate. The ratios of humic C fractions to SOC were 9.48%-12.27% （HAC）, 20.68%-29.31% （FAC）, and 59.37%-61.38% （HUC）. Climate, soil texture, and soil microbes jointly explained more than 90% of the latitudinal variation in SOC, HAC, FAC, HEC, and HUC and interactive effects were important. These findings elucidate latitudinal patterns of soil humic C fractions in forests at a large scale, and may improve models of soil C turnover and storage.
基金Supported by the China National Science and Technology Major Project(2016ZX05004-004)
文摘Based on the outcrop survey,3D seismic data interpretation,drilling data analysis,the structural patterns and distribution of fault damage zones in carbonate strata of Tazhong Paleo-uplift were established to reveal the oil and gas enrichment law in the fault damage zones.The following findings were reached:(1)Through the filed survey,the fault damage zone system consists of fault core,damage zone with branch fault and fracture network.Affected by the active nature of the major faults,the fault damage zones differ in planar pattern and scale along the major faults.(2)3D seismic profiles reveal that there are three types of fault damage zones in carbonate strata in Tazhong paleo-uplift,strike-slip fault damage zones,thrust fault damage zones and superimposed fault damage zones.Featuring3 flowers and 3 root belts in vertical,the strike-slip fault damage zone can be subdivided into linear type,oblique type,feather type and horsetail type in plane.Thrust fault damage zones can be further divided into fault anticline type,anticline type and slope type.As the superimposition result of the above two kinds of fault damage zones,superimposed fault damage zones appear in three patterns,intersect type,encompassment type and penetrating type.(3)Cores from wells and geochemical data show oil and gas may migrate along the major fault and laterally.The feather type in strike-slip fault system,fault anticline type in thrust fault damage zone and intersect type in superimposed fault damage zone are possible sites for high production and efficiency wells.
文摘Land use change and cropping patterns are important factors for controlling carbon sequestration in soils and they may also change the relative importance of different mechanisms of soil organic matter stabilization. The study was conducted to investigate the state of carbon sequestration in soil aggregates under different cropping patterns of Khulna, Jessore and Chapainawabganj districts in Bangladesh. Thirty-six soil samples were collected from (0 - 100 cm depth) above mentioned regions of three physiographic regions: Ganges Meander Floodplain, Ganges Tidal Floodplain and High Barind Tract. The texture of the samples varied within three soil texture groups, Silt Loam, Silty Clay Loam and Silty Clay. The highest NSI value (0.89) was found under Wheat-Fallow-T. Aman cropping pattern in Silty Clay soils (sample No 15) and lowest value (0.59) was found Vegetables/Mustard-Fallow-T. Aman cropping pattern in Silt Loam soils (sample No 17). The highest value (735.20 mg<span style="white-space:nowrap;"><span style="white-space:nowrap;">•</span></span>kg<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup>) of active C was observed under Chickpea/mustard-T. Aman (Sample No 31) and the lowest value (619.23 mg<span style="white-space:nowrap;"><span style="white-space:nowrap;">•</span></span>kg<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup>) was found in case of Wheat-Fallow-T. Aman cropping pattern (Sample No 30). The highest SOC stock (1.62 Kg C m<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>2</sup>) was found in Silty Clay Loam soil under Mungbean/Ash gourd-T. Aman cropping pattern (Sample no 4) and the lowest SOC stock (0.35 Kg C m<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>2</sup>) was found in Silt Loam soil under Cauliflower/Pumkin/Spinach-T. Aman Cropping pattern (Sample No 2). Soil organic carbon associated with different size aggregates was the highest (3.14%) under Mungbean/Ash gourd-T. Aman (Sample No 20) and was the lowest (0.36%) under Cauliflower/Pumkin/Spinach-T. Aman cropping pattern (Sample No 2). Organic carbon content in aggregate size ranges > 2000 μm (SOC1), 2000 - 250 μm (SOC2), 250-53 μm (SOC3), and <53 μm (SOC4) varied from 0.36% - 1.90%, 0.52% - 2.10%, 0.50% - 2.60% and 0.50% - 1.62%, respectively. The percentages of SOC associated with <53 μm aggregates were higher than those of >2000 μm, 2000 - 250 μm and 250 - 53 μm, aggregates. Significant positive correlations were found between SOC stock and SOC1, SOC stock and SOC2, SOC stock and SOC3, SOC stock and SOC4.
基金supported by the National Key Research and Development Program of China(2022YFC3204101 and 2023YFF0807202)the National Natural Science Foundation of China(U22A20570 and U2444221)+4 种基金the Youth Promotion Association of the Chinese Academy of Sciences(2021365)the Changsha Outstanding Innovative Youth Project,China(kq2305035)the Science,Technology and Innovation Platform Plan of Hunan Province,China(2022PT1010)the Major Scientific and Technological Projects of the Ministry of Water Resources,China(SKS-2022081)the Comprehensive Investigation and Potential Evaluation of Natural Resources Carbon Sink in Southern Hilly Region,China(DD20220880)。
文摘In floodplain wetlands,alterations in hydrological patterns resulting from climate change and human activities could potentially diminish the carbon sequestration capacity of the soils,thereby having a negative impact on global climate change.However,the magnitude of the influence of hydrological regime change on soil carbon remains inadequately monitored.To address this research gap,we collected 306 upper layer(0–20 cm)soil samples from the Dongting Lake floodplain between 2013 and 2022.The random forest(RF)algorithm was used to analyze the spatial distribution of soil organic carbon(SOC)in the upper soil layer of Dongting Lake floodplain and the impact of climate and hydrological changes in the past decade on surface SOC in the East Dongting Lake area was studied.In 2022,the SOC concentration of the Dongting Lake floodplain upper layer soil ranged from 3.34 to 17.67 g kg^(-1),averaging 10.43 g kg^(-1),with a corresponding SOC density of(2.65±0.49)kg m^(-2) and total SOC stock of 6.82 Tg C(2.87–13.48 Tg C).From 2013 to 2022,the SOC concentration of the upper soil layer of the East Dongting Lake area decreased from 18.37 to 10.82 g kg^(-1).This reduction could be attributed to climate and hydrological changes which reduce SOC input by reducing vegetation growth and accelerating SOC decomposition.Above 21.4 m elevation,the amount of SOC loss increased with elevation,the loss being related to the decline in Miscanthus community biomass and greater susceptibility of higher altitude areas to climate and hydrological changes.Our results highlight the need for strengthening wetland SOC management to increase SOC in the soils to help combat climate change.
基金part of the National Key Fundamental Research Program(No.2005CB422108)the National Natural Science Foundation of China(Grant No.40672092).
文摘By analyzing the characteristics of development, structural evolution and reservoir beds of the residual carbonate strata, this study shows that the residual carbonate strata in the Yingmaili low uplift are favorable oil and gas accumulation series in the Tabei （northern Tarim uplift） uplift. There are different patterns of hydrocarbon accumulation on the northern and southern slopes of the Yingmaili low uplift. The north-south differentiation of oil reservoirs were caused by different lithologies of the residual carbonate strata and the key constraints on the development of the reservoir beds. The Mesozoic terrestrial organic matter in the Kuqa depression and the Palaeozoic marine organic matter in the Manjiaer sag of the Northern depression are the major hydrocarbon source rocks for the northern slope and southern slope respectively. The hydrocarbon accumulation on the northern and southern slopes is controlled by differences in maturity and thermal evolution history of these two kinds of organic matter. On the southern slope, the oil accumulation formed in the early stage was destroyed completely, and the period from the late Hercynian to the Himalayian is the most important time for hydrocarbon accumulation. However, the time of hydrocarbon accumulation on the northern slope began 5 Ma B.P. Carbonate inner buried anticlines reservoirs are present on the southern slope, while weathered crust and paleo-buried hill karst carbonate reservoirs are present on the northern slope. The northern and southern slopes had different controlling factors of hydrocarbon accumulation respectively. Fracture growth in the reservoir beds is the most important controlling factor on the southern slope; while hydrocarbon accumulation on the northern slope is controlled by weathered crust and cap rock.
基金financially supported by Ministry of Science and Technology of the People's Republic of China(No. 2016YFA0201904)the National Natural Science Foundation of China (Nos. 21631002, U1632119 and 91333105)
文摘Controlled growth of patterned single-walled carbon nanotubes (SWNTs) is an important issue in many applications. Herein, we demonstrated a method to pattern catalyst via inkjet printing for the growth of SWNTs, using metal salt solutions as the inks and an ordinary office-use printer. We printed water solutions of cobalt acetate on hydrophilic Si substrates and grew high quality SWNT films. The composition of the precursor solutions and the hydrophilicity of the substrates were crucial factors to the patterning.
基金National Natural Science Foundation of China,No.41971233。
文摘Urban construction land has relatively high human activity and high carbon emissions.Research on urban construction land prediction under carbon peak and neutrality goals(hereafter“dual carbon”goals)is important for territorial spatial planning.This study analyzed quantitative relationships between carbon emissions and urban construction land,and then modified the construction land demand prediction model.Thereafter,an integrated model for urban construction land demand prediction and spatial pattern simulation under“dual carbon”goals was developed,where urban construction land suitability was modified based on carbon source and sink capacity of different land-use types.Using Guangzhou as a case study,the integrated model was validated and applied to simulate the spatiotemporal dynamics of its urban construction land during 2030–2060 under baseline development and“dual carbon”goals scenarios.The simulation results showed that Guangzhou’s urban construction land expanded rapidly until 2030,with the spatial pattern not showing an intensive development trend.Guangzhou’s urban construction land expansion slowed during 2030–2060,with an average annual growth rate of 0.2%,and a centralized spatial pattern trend.Under the“dual carbon”goal scenario,Guangzhou’s urban construction land evolved into a polycentric development pattern in 2030.Compared with the baseline development scenario,urban construction land expansion in Guangzhou during 2030–2060 is slower,with an average annual growth rate of only 0.1%,and the polycentric development pattern of urban construction land was more prominent.Furthermore,land maintenance and growth,that is,a carbon sink,is more obvious under the“dual carbon”goals scenario,with the forest land area nearly 10.6%higher than that under the baseline development scenario.The study of urban construction land demand prediction and spatial pattern simulation under“dual carbon”goals provides a scientific decision-making support tool for territorial spatial planning,aiding in quantifying territorial spatial planning.
基金Supported by the Fundamental Project of China National Petroleum Corporation(2021DJ0501).
文摘The relationship between paleogeographic pattern and sedimentary differentiation of evaporite-carbonate symbiotic system is examined based on logging,core and thin section data,by taking the sixth sub-member of fifth member of Ordovician Majiagou Formation(M56)in the central-eastern Ordos Basin as an example.(1)Seven sub-geomorphic units(Taolimiao west low,Taolimiao underwater high,Taolimiao east low,Hengshan high,East salt low,North slope and Southwest slope)developed in the study area.(2)The“three lows”from west to east developed dolomitic restricted lagoon,evaporite evaporative lagoon and salt evaporative lagoon sedimentary facies respectively,the"two highs"developed high-energy grain beach and microbial mound,and the north and south slopes developed dolomitic flats around land.(3)The paleogeographic pattern caused natural differentiation of replenishment seawater from the northwest Qilian sea,leading to the eccentric sedimentary differentiation of dolomite,evaporite and salt rock symbiotic system from west to east,which is different from the classic“bull's eye”and“tear drop”distribution patterns.(4)As the Middle Qilian block subducted and collided into the North China Plate,the far-end compression stress transferred,giving rise to the alternate highland and lowland in near north to south direction during the sedimentary period of M56 sub-member.(5)Taolimiao underwater high and Hengshan high developed favorable zones of microbial mounds and grain shoals in south to north strike in M56 sub-member,making them favorable exploration areas with great exploration potential in the future.
基金Supported by the China National Science and Technology Major Project(2017ZX05030)。
文摘In view of high water cut and low oil recovery caused by the unidirectional flow in linear pattern of horizontal wells for the carbonate reservoirs in the Middle East,this paper provides a novel approach to improve oil recovery by converting linear water injection to cyclic alternating water injection patterns including cyclic alternating water injection with apparent inverted seven-spot pattern or apparent five-spot pattern and cyclic differential alternating water injection.The main advantage of using this strategy is that the swept efficiency is improved by changing injection-production streamlines and displacement directions,which means displacement from two different direction for the same region during a complete cycle.This technology is effective in increasing the swept efficiency and tapping the remaining oil,thus resulting in higher oil recovery.Field application with three new patterns in a carbonate reservoir in the Middle East is successful.By optimizing injection and production parameters based on the cyclic alternating well pattern,the test well group had a maximum increase of daily oil production per well of 23.84 m^(3) and maximum water cut drop of 18%.By further optimizing the distance(keep a long distance)between the heels of injection and production wells,the waterflooding performance could be better with water cut decreasing and oil production increasing.
基金sponsored by the National Natural Science Foundation of China(Grant Nos.32125027,31930075)Zhejiang A&F University Research and Development Fund(No.2022LFR006).
文摘Moso bamboo(Phyllostachys edulis)forests are a vital resource in subtropical China,known for their high carbon(C)sequestration capacity.However,the dynamic processes of C fluxes within each component(canopy,culm,and soil)and their individual contributions,particularly during on-and off-years,remain unclear.A 2-year field experiment was conducted to investigate the dynamics of C fluxes from the canopy,culm,and soil(partitioned into heterotrophic,rhizome,and stump respiration)and their contributions to net ecosystem productivity(NEP)in a representative Moso bamboo forest in the subtropical region of China.The average annual NEP of the Moso bamboo forest was 7.31±2.76 t C·ha^(-1).Specifically,the canopy's annual net C uptake was 17.30±3.23 tC·ha^(-1),accounting for 237%of NEP.In contrast,C emissions from heterotrophs,culms,rhizomes,and stumps were 5.37±1.20,2.18±1.05,1.29±0.04,and 1.15±0.33 t C·ha^(-1),accounting for73%,30%,18%,and16%of NEP,respectively.The NEP,net cumulative C uptake in the canopy,and C emissions from the respiration of heterotrophs and stumps were all significantly higher during on-years when compared to off-years,whereas C emissions from bamboo culms displayed opposite trends.These findings offer a new approach for quantifying the C budgets of Moso bamboo forests and provide valuable insights into the C cycling processes in forest ecosystems.
基金Supported by the National Natural Science Foundation of China(Nos.U23A2033,41976154)the Key R&D Program of Zhejiang Province,China(No.2023C03011)+2 种基金the Key R&D Program of Guangxi,China(No.Guike AB22080099)the Science Foundation of Donghai Laboratory(No.DH-2022KF0205)the Bureau of Science and Technology of Zhoushan(No.2022C81006)。
文摘Global warming underscores the urgent need to enhance carbon sinks to mitigate climate change,yet the role of coastal shellfish aquaculture area as either carbon sinks or sources remains unclear.In this study,we conducted high-resolution profiling observations of CO_(2)dynamics and net community production(NCP)in a mussel farm located in the Changjiang(Yangtze)River estuary(CRE)during early autumn.Results indicate that the partial pressure of CO_(2)(pCO_(2))in the water column was consistently higher than the atmospheric level,averaging 74.75±2.44 Pa,signaling that the mussel farm acted as a CO_(2)source.The average air-water CO_(2)exchange flux(FCO_(2))averaged-1.91±1.16 mmol/(m^(2)·h),and NCP in the water column(NCPCOL)averaged-6.66±12.81 mmol/(m^(2)·h),revealing a heterotrophic condition.A significant inverse correlation was found between NCPCOLand sea surface pCO_(2)with a lag time of approximately 3.31 h,highlighting the influence of biological activity in modulating CO_(2)dynamics.Physical processes such as freshwater inputs,vertical mixing,and wind patterns,also played a crucial role in shaping pCO_(2)variations.The study emphasizes the complexity of CO_(2)dynamics in costal aquaculture areas and the need for long-term,high-resolution monitoring to better understand their contribution to climate change mitigation.The high-resolution profiling system provided novel insights into the dynamics of NCP and CO_(2)fluxes,showing its potential as an advanced tool for studying aquaculture systems.Future research should focus on expanding the geographic and temporal scope of studies,combining observational and modeling approaches to better predict the responses of aquaculture systems to environmental changes.
基金sponsored by the Natural Science Foundation of Xinjiang Uygur Autonomous Region,China(No.2022D01B213)the Key Scientific and Technological Research Projects in the Xinjiang Production and Construction Corps,China(No.2023AB017-02)+1 种基金the West Light Foundation for Young Scholar of Chinese Academy of Sciences(No.2021-XBQNXZ-018)the National Key Research and Development Program of China(No.2022YFF1302504)。
文摘Understanding the elevational patterns of soil microbial carbon(C)metabolic potentials is instrumental for predicting changes in soil organic C(SOC)stocks in the face of climate change.However,such patterns remain uncertain in arid mountain ecosystems,where climosequences are quite different from other ecosystems.To address this gap,this study investigated the distribution determinants of microbial communities,C cycling-related genes,and SOC fractions along an elevational gradient(1707–3548 m),with a mean annual precipitation(MAP)range of 38 to 344 mm,on the north slope of the central part of the Kunlun Mountains,China using a metagenomic approach.The results showed that elevation significantly influenced the α-diversity(Shannon index)and composition of microbial communities as well as the C cycling-related genes.The α-diversities of microbial taxa and C cycling-related genes linearly increased with the increase in MAP along the elevational gradient.The elevational patterns of the genes encoding glycoside hydrolases and glycosyl transferases(GTs)were mainly driven by soil electrical conductivity(EC),mean annual temperature(MAT),MAP,and plant diversity.Furthermore,mineral-associated organic C(MAOC),particulate organic C(POC),and their sum generally increased with elevation.However,the MAOC/POC ratio followed a unimodal pattern,suggesting greater stability of the SOC pool in the mid-elevation regions.This unimodal pattern was likely influenced by the abundances of Actinobacteria and the genes encoding GTs and carbohydrate esterases and the threshold effects of soil EC and MAT.In summary,our findings indicate that the distribution patterns of microbial communities and C cycling-related genes along the elevational gradient in an arid ecosystem are distinct from those in the regions with higher MAP,facilitating the prediction of climate change effects on SOC metabolism under more arid conditions.Soil salinity,plant diversity,precipitation,and temperature are the main regulatory factors of microbial C metabolism processes,and they potentially play a central role in mediating SOC pool stability.
基金Supported by the China National Science and Technology Major Project(2025ZD1403000)CNPC Major Science and Technology Project(2023ZZ19).
文摘By integrating core observations,logging data and seismic interpretation,this study takes the massive Cretaceous carbonates in the M block of the Santos Basin,Brazil,as an example to establish the sequence filling pattern of fault-bounded isolated platforms in rift lake basins,reveal the control mechanisms of shoal-body development and reservoir formation,and reconstruct the evolutionary history of lithofacies paleogeography.The following results are obtained.(1)Three tertiary sequences(SQ1-SQ3)are identified in the Lower Cretaceous Itapema-Barra Velha of the M block.During the depositional period of SQ1,the rift basement faults controlled the stratigraphic distribution pattern of thick on both sides and thin in the middle.The strata overlapped to uplift in the early stage.During the depositional period of SQ2-SQ3,the synsedimentary faults controlled the paleogeomorphic reworking process with subsidence in the northwest and uplifting in the northeast,accompanied with the relative fall of lake level.(2)The Lower Cretaceous in the M block was deposited in a littoral-shallow lake,with the lithofacies paleogeographic pattern transiting from the inner clastic shoals and outer shelly shoals in SQ1 to the alternation of mounds and shoals in SQ2-SQ3.(3)Under the joint control of relative lake-level fluctuation,synsedimentary faults and volcanic activity,the shelly shoals in SQ1 tend to accumulated vertically in the raised area,and the mound-shoal complex in SQ2-SQ3 tends to migrate laterally towards the slope-break belt due to the reduction of accommodation space.(4)The evolution pattern of high-energy mounds and shoals,which were vertically accumulated in the early stage and laterally migrated in the later stage,controlled the transformation of high-quality reservoirs from“centralized”to“ring shaped”distribution.The research findings clarify the sedimentary patterns of mounds and shoals and the distribution of favorable reservoirs in the fault-controlled lacustrine isolated platform,providing support for the deepwater hydrocarbon exploration in the subsalt carbonate rocks in the Santos Basin.
文摘Digital transformation,as a recent trend in socioeconomic development,is considered as a critical pathway for urban carbon reduction because of its potential to increase productivity and energy efficiency.However,few studies have explored the relationship between urban digitalization and carbon emissions(CE).Therefore,this study systematically analyzed the spatiotemporal distribution and interaction mechanism between digitalization and CE in the Yangtze River Delta(YRD)urban agglomerations of China during 2006-2020 based on a multidimensional indicator system,including digitalization industry level,digitalization application level,and urban green digitalization willingness.The findings revealed that both digitalization and CE in the YRD exhibit a significant and synchronously evolving“core-periphery”spatial pattern.Core cities generated substantial positive spillover effect on periphery cities through technology diffusion and policy demonstration,advancing both regional digitalization and the collaborative governance of CE.However,digitalization had dual impact on CE.On the one hand,it promoted the reduction of CE by enhancing energy efficiency,optimizing industrial structures,and promoting the application of green technologies.On the other hand,the expansion of digital infrastructure introduced a potential risk of increased energy consumption.Therefore,targeted policy recommendations are proposed to facilitate the coordination of environmental sustainability and digitalization in the YRD.This study provides empirical support and policy insights for advancing the coordinated development of regional digital transformation and green low-carbon initiatives.
