The Yingxiu-Beichuan fault zone(YBFZ)has long been active and experienced repeated large earthquakes.The physicochemical properties of the deep fault zone(>1000 m)are the key to understanding the deformation mechan...The Yingxiu-Beichuan fault zone(YBFZ)has long been active and experienced repeated large earthquakes.The physicochemical properties of the deep fault zone(>1000 m)are the key to understanding the deformation mechanism of large earthquakes.This study uses rock magnetic,microstructural,and geochemical analyses of representative samples exposed in FZ1681 within the Wenchuan Earthquake Fault Scientific Drilling borehole 2(WFSD-2)cores.Fault gouge and fault breccia have higher magnetic susceptibility values than wall rocks,and they contain abundant paramagnetic minerals and small quantities of magnetite and monoclinic pyrrhotite.The magnetite and monoclinic pyrrhotite in the fault gouge were mainly formed by coseismic frictional heating,indicating that large earthquakes with frictional heating temperatures of~500-900℃once occurred in the YBFZ.The seismogenic and coseismic environment was reducing with a relatively high sulfur content.The monoclinic pyrrhotite in the fault breccia was formed mainly by low-temperature hydrothermal fluid.This indicates that the fault zone experienced reducing and low-temperature(<400℃)hydrothermal fluid with a relatively high sulfur content after the earthquake.The YBFZ,which experiences frequent large earthquakes,is weakly oxidizing environment at different depths,but the effect of the low-temperature hydrothermal fluid is weaker at depth.展开更多
The Guanxian-Anxian fault zone in the Longmen Shan,Sichuan,China,exhibits long-term creep-slip but ruptured during the 2008 Wenchuan earthquake,challenging the view that creeping faults rarely generate strong earthqua...The Guanxian-Anxian fault zone in the Longmen Shan,Sichuan,China,exhibits long-term creep-slip but ruptured during the 2008 Wenchuan earthquake,challenging the view that creeping faults rarely generate strong earthquakes.To investigate the transition from creep-slip to stick-slip,we analyzed fault rocks from the WFSD-3,using microstructural observations,XRD,μXRF,Raman spectroscopy,and quartz grain size statistics.Fault rocks show intense foliation,pressure-solution structures,and abundant clay minerals,reflecting long-term aseismic creep.At the interface between black and gray fault gouges at~1249.98 m,microstructures indicate stick-slip behavior,including truncated grains,angular fragments,and finer grain sizes.Here,clay content drops sharply while strong minerals(quartz,feldspar,calcite,dolomite)increase.Elemental mapping shows Al and K enriched in black gouge,whereas Ca and Si in gray gouge;Raman spectroscopy indicates possible graphitization;the finest quartz grains occur in black gouge.These features mark co-seismic principal slip zone of the Wenchuan earthquake.We propose that fluid-driven transformation of strong minerals into clays facilitates creep-slip,whereas localized precipitation of strong minerals strengthens the fault,causing stress accumulation and controlling the creep-slip to stick-slip transition.This mechanism has implications for reassessing seismic hazards of creeping faults.展开更多
Reforestation initiatives are often limited by insufficient seeds,a problem exacerbated by natural variability in tree flowering and seed production and climate change and other environmental challenges.Innovative and...Reforestation initiatives are often limited by insufficient seeds,a problem exacerbated by natural variability in tree flowering and seed production and climate change and other environmental challenges.Innovative and adaptive solutions such as in vitro propagation are thus needed.Tissue culture can provide high-quality propagation material for tree conservation and mass propagation,but faces technical,economic,regulatory,and social barriers.Obstacles related to the academia-industry interface and to stakeholder concerns are discussed and actions suggested to overcome these barriers to realize the full potential of tree micropropagation.These include refining techniques to improve efficiency and reduce costs;establishing collaborations among researchers,industry,and foresters;and reducing points of contention and misinformation regarding genetic diversity and public perception.International collaborative initiatives,exemplified by the EU COST Action CA21157 COPYTREE,are elementary for achieving these goals.展开更多
This study examines a 1.32 m thick sediment sequence from the Cunge sag pond in the Litang Basin,eastern Tibetan Plateau,to assess the seismicity of the Litang fault during the Holocene.High-resolution geochemical,gra...This study examines a 1.32 m thick sediment sequence from the Cunge sag pond in the Litang Basin,eastern Tibetan Plateau,to assess the seismicity of the Litang fault during the Holocene.High-resolution geochemical,grain size,magnetic susceptibility,and total organic carbon indicators are employed to obtain a continuous record of changes in elemental,physical,and biological properties within the profile to identify seismic events.The seismic event layer generally comprises two sedimentary rhythms:a lower coarse sand layer and an upper fine silt-clay layer.These layers represent rapid deposition associated with fault activity(Earthquake A)and slower deposition during calm periods or earthquake recurrence intervals(Seismic interval A).Through six^(14)C dating,five seismic events have been identified in the Cunge sag pond section:E1(before 3955 a B.P.),E2(3713-3703 a B.P.),E3(3492-3392 a B.P.),E4(2031-1894 a B.P.),and E5(1384-1321 a B.P.).E1-E4 had shown a good consistency with the paleo-earthquake recorded by the trench,and whereas E5 is a newly identified seismic event,further improving the continuous earthquake sequence of the Litang fault.Based on existing trench data and the seismic event record from the Cunge sag pond,a total of 11 paleo-earthquakes are identified along the Litang fault since the Holocene.The paleo-earthquake activity of the Litang fault exhibits a clustered pattern,with recurrence intervals of both long periods(1000 a)and short periods(500 a).Since 5000 a,the interval between strong earthquake recurrences gradually decreases,indicating an increasing risk of strong earthquakes along the Litang fault.This study presents a continuous record of paleo-earthquakes along the Litang fault,eastern Tibetan Plateau,and can enhance the understanding of regional seismic activity.展开更多
Phosphorus (P) is an essential nutrient element that is critical for plant growth and ecosystem functionality.The soil P cycle plays multiple roles,such as sustaining plant growth and productivity,regulating nutrient ...Phosphorus (P) is an essential nutrient element that is critical for plant growth and ecosystem functionality.The soil P cycle plays multiple roles,such as sustaining plant growth and productivity,regulating nutrient balance within ecosystems,and enhancing ecosystem adaptability and resilience.This cycle is influenced by factors such as the restoration approach and microbial community dynamics.However,the extent to which the restoration approach alters the P cycle in karst ecosystems and the underlying microbial mechanisms remain poorly understood.The P-cycle multifunctionality index (P-cycle MFI) serves as a comprehensive indicator for evaluating soil P cycle function,and it provides insights into changes in the P cycle between different restoration approaches.To investigate the shifts in soil P-cycle MFI and microbial mechanisms between different restoration approaches,we analyzed soil available P (AP),total P (TP),microbial biomass P (MBP),and the activities of acid phosphatase (ACP) and alkaline phosphatase (ALP).These data were used to calculate the P-cycle MFI by averaging the Z-scores between two restoration approaches(artificial restoration of forest (AF) and natural restoration of forest (NF)) and a control (cropland,CP) at six subtropical karst ecosystem sites in China.We also determined the soil organic carbon (SOC),exchangeable calcium (Ca) and magnesium (Mg),pH,bulk density (BD),microbial biomass C (MBC),and microbial biomass nitrogen (MBN),as well as the community structure,relative abundance,diversity indices,and co-occurrence networks of phoD-harboring bacteria.The results showed that the community structure of phoD-harboring bacteria varied significantly among AF,NF,and CP and across different temperature gradients.These bacteria exhibited increasing complexity and tightness in co-occurrence networks from CP to AF and then to NF,along with the ACP and ALP activities,but not the TP and AP contents.The P-cycle MFI values were significantly higher in NF compared to AF and CP,and the variation was significantly explained by restoration approach,temperature,MBC,MBN,SOC,exchangeable Ca,BD,community structure of phoD-harboring bacteria,and exchangeable Mg.Furthermore,natural restoration had a more substantial impact on the P-cycle MFI than temperature by enhancing SOC,microbial biomass,the complexity and co-occurrence network tightness of the phoD-harboring bacterial community structure,and ACP and ALP activities,but it reduced soil BD.The rare genera of phoD-harboring bacteria significantly influenced the variation of soil P-cycle MFI compared to the dominant genera.This study highlights the importance of rare genera of phoD-harboring bacteria in driving soil P-cycle multifunctionality in karst ecosystems,with natural restoration being more effective than artificial methods for enhancing soil organic matter and microbial community complexity.展开更多
Background: Remote sensing-based mapping of forest Ecosystem Service(ES) indicators has become increasingly popular. The resulting maps may enable to spatially assess the provisioning potential of ESs and prioritize t...Background: Remote sensing-based mapping of forest Ecosystem Service(ES) indicators has become increasingly popular. The resulting maps may enable to spatially assess the provisioning potential of ESs and prioritize the land use in subsequent decision analyses. However, the mapping is often based on readily available data, such as land cover maps and other publicly available databases, and ignoring the related uncertainties.Methods: This study tested the potential to improve the robustness of the decisions by means of local model fitting and uncertainty analysis. The quality of forest land use prioritization was evaluated under two different decision support models: either using the developed models deterministically or in corporation with the uncertainties of the models.Results: Prediction models based on Airborne Laser Scanning(ALS) data explained the variation in proxies of the suitability of forest plots for maintaining biodiversity, producing timber, storing carbon, or providing recreational uses(berry picking and visual amenity) with RMSEs of 15%–30%, depending on the ES. The RMSEs of the ALS-based predictions were 47%–97%of those derived from forest resource maps with a similar resolution. Due to applying a similar field calibration step on both of the data sources, the difference can be attributed to the better ability of ALS to explain the variation in the ES proxies.Conclusions: Despite the different accuracies, proxy values predicted by both the data sources could be used for a pixel-based prioritization of land use at a resolution of 250 m~2, i.e., in a considerably more detailed scale than required by current operational forest management. The uncertainty analysis indicated that maps of the ES provisioning potential should be prepared separately based on expected and extreme outcomes of the ES proxy models to fully describe the production possibilities of the landscape under the uncertainties in the models.展开更多
The plant samples of Bidens pilosa were collected from a coal gangue vacant site and its surrounding area,located in central China,to study the remediation effect of the plant species on heavy metal(HM)contamination i...The plant samples of Bidens pilosa were collected from a coal gangue vacant site and its surrounding area,located in central China,to study the remediation effect of the plant species on heavy metal(HM)contamination in both natural and electrokinetic(EK)conditions.The analytical results showed that the effect of phytoextraction and bioconcentration on the heavy metals in the sample of the EK group is more significant than those in the other control group.Compared with the results of natural condition,under the EK condition the concentrations of cadmium(Cd),lead(Pb),copper(Cu)and zinc(Zn)in the stems and leaves of the Bidens pilosa increased to 0.40 mg/kg,4.23 mg/kg,7.27 mg/kg,830.24 mg/kg,respectively,with their increments of 292%,1731%,141%,2076%.For root samples,the Cd,Pb,Cu and Zn concentrations increased to 0.52 mg/kg,4.36 mg/kg,10.87 mg/kg,and 98.12 mg/kg and the increase rates were 1034%,140%,29%,and 181%,respectively.The phytoextraction efficiency of the Bidens pilosa was significantly higher than that of control group.The removal efficiency of Cd,Pb,Cu and Zn in soil increased to 26%,72%,27%,and 79%with the EK applied.In addition,the mechanism of HM migration,extraction and enrichment in Bidens pilosa under the EK condition was discussed.展开更多
Although geothermal energy has many clear advantages,including its sustainability and environmentally friendly nature,research into potential geothermal resources across the Longgang Block,Northeast China,has been lim...Although geothermal energy has many clear advantages,including its sustainability and environmentally friendly nature,research into potential geothermal resources across the Longgang Block,Northeast China,has been limited.Here we present the first analysis of the potential geothermal resources in this region that employs joint geological and non-seismic geophysical methods to identify target areas that may be economically viable.We acquire and analyze high-precision gravity,magnetic,and magnetotelluric sounding data,which are constrained using the petrophysical parameters of outcropping rocks across the Longgang Block,to conduct a comprehensive evaluation of the region’s deep geological structures and their geothermal resources potential,with a focus on identifying faults,rock masses,and thermal storage structures.We find that Archean granitic gneiss and Mesozoic rock masses in the deeper section of the Longgang Block possess weak gravity anomalies and high resistivities.We also identify thermal storage structures near these deeper geological units based on their extremely low resistivities.The data are used to infer the dip and depth of known or hidden faults,to constrain the spatial distribution of intrusive rock masses,and to determine the spatial distribution of subsurface thermal storage structures.The potential of the target areas for geothermal resources exploitation is divided into three grades based on contact depths between faults and thermal storage structures,and the scale of their thermal storage structures.Our results suggest that a joint non-seismic geophysical approach can be effective in locating and evaluating geothermal resources in complex geological settings.展开更多
A number of numerical experiments with artificial random signals (the second order autoregressive processes), which have important statistical properties similar to that of the observed instrumental temperature (1850-...A number of numerical experiments with artificial random signals (the second order autoregressive processes), which have important statistical properties similar to that of the observed instrumental temperature (1850-2015), were carried out. The results show that in frame of the selected mathematical model the return period of climatic events, analogous to the current global warming (linear increase of temperature for 0.95°C during the last 135 years) is 2849-5180 years (one event per 2849-5180 years). This means that global warming (GW) of the last 135 years can unlikely be fully explained by inherent oscillations of the climatic system. It was found however, that natural fluctuations of climate may appreciably contribute to the GW. The return period of climatic episodes with 0.5°C warming during the 135 years (half of the observed GW) was less than 500 years. The result testifies that the role of external factors (emission of greenhouse gases, solar activity etc.) in the GW could be less than often presumed.展开更多
This paper brings out the issues related to natural resource exists, management and erosion right from the ancient to modern era. The natural resource such as forests and forest products were found as a basic source o...This paper brings out the issues related to natural resource exists, management and erosion right from the ancient to modern era. The natural resource such as forests and forest products were found as a basic source of survival for living organisms during the initial period. Later, the natural resources started degrading slowly and steadily due to increased human activities. In the beginning, natural resources were the primary assets for the growth of agriculture, industry, urbanization etc. Subsequently, increased anthropogenic activities started degrading the forest cover on a large scale through extending the agricultural land scape and other developmental activities in the country. The importance of traditional knowledge regarding resource conservation, protection of sacred grooves, endangered species etc. started declining in modern India. Innovativeness and policy framework for resource conservation and utilization became unfriendly in addition to gradual decline of community management. The key findings of the study point to major gaps existing such as between line departments and institutions in the promotion and management of forests, human welfare, agriculture, animal husbandry etc. Moreover, people tend to be more inclined towards the utilization of natural resources rather than conservation. From an observational and practical point of view, the natural resource has been declining rapidly in India. Therefore, this study strongly suggests that a due attention be directed towards developing people-friendly and environment friendly conservation strategies.展开更多
The Litang fault zone is an important seismogenic structure along the southeastern margin of the Tibetan Plateau.It caused the M71/4 earthquake in Litang in 1948 AD.The fault zone intersects the Sichuan-Xizang transpo...The Litang fault zone is an important seismogenic structure along the southeastern margin of the Tibetan Plateau.It caused the M71/4 earthquake in Litang in 1948 AD.The fault zone intersects the Sichuan-Xizang transportation corridor and poses a serious risk to its safe operation.This study,utilizing high-resolution remote sensing interpretation,field geological verification,UAV photogrammetry,UAV LiDAR,paleoearthquake trench excavation,and AMS^(14)C and OSL dating methods,reveals the geometric structure,slip rates,paleoearthquake sequence,and earthquake rupture segmentation of the Litang fault zone;analyzes the rupture distribution range of the 1729 AD Litang earthquake and estimates its magnitude.The study indicates that the Litang fault zone is a relatively immature strike-slip fault,which has developed as a new active fault zone within the Northwestern Sichuan sub-block during the southeastward material migration of the southeastern margin of the Tibetan Plateau.This reflects a transformation in the deformation model of the Northwestern Sichuan sub-block crust from the‘Rigid Block’model to the‘Continuous Deformation’model.展开更多
Twelve new dinosaur teeth have recently been recovered from three localities in the Upper Cretaceous Nenjiang Formation of the Songliao Basin.Although fragmentary,the material offers enough evidence to identify the fo...Twelve new dinosaur teeth have recently been recovered from three localities in the Upper Cretaceous Nenjiang Formation of the Songliao Basin.Although fragmentary,the material offers enough evidence to identify the following taxa:tyrannosaurids,dromaeosaurines,velociraptorines,hadrosauroids,and titanosaurs.In addition to the previously known dinosaurs from the basin,several new ones have been identified,extending the paleogeographic range of related taxa.The discovery of these new fossil remains provides valuable insights into dinosaur diversity and sheds light on the terrestrial ecosystem during the Late Cretaceous in the Songliao Basin.展开更多
Deciphering high-pressure granulite-facies metamorphism and anatexis within a collisional orogeny can provide crucial constraints on geodynamic evolution and melt activity during subduction and exhumation.Combining pe...Deciphering high-pressure granulite-facies metamorphism and anatexis within a collisional orogeny can provide crucial constraints on geodynamic evolution and melt activity during subduction and exhumation.Combining petrographic observations,mineral chemistry,REE in Grt-Cpx thermobarometry,and previous work,at least four stages are suggested for the metamorphic evolution of the mafic granulites in the South Altun,including the protolith stage,the high-pressure granulite-facies stage(909-1037℃and 17.3-30 kbar),medium-pressure granulite-facies overprint(9.1-11.9 kbar and 753-816℃),and subsequent late amphibolite-greenschist-facies metamorphism.Zircon U-Pb dating shows that the mafic granulites underwent high-pressure granulite-facies metamorphism at 497.2±3.7 Ma,while the leucosome formed at 498.2±2.9 Ma.Thus,the leucosomes from the host mafic granulite may have been formed at the high-pressure granulite-facies metamorphic event.The characteristics of zircon morphology,mineral inclusions,low Th/U values,HREE enrichment,and negative Eu anomalies indicate that these zircons from the leucosome were formed from the metamorphic melts.The characteristics of whole-rock major and trace elements as well as Hf isotopic features of zircons between the leucosomes and the host mafic granulite indicate that the melt may have been generated by the partial melting of the host mafic granulite.展开更多
The current Tanzanian policy guidelines regarding ecological restoration encourage total protection (enclosure system) against grazing activities, fires and wood extraction to allow regeneration in state-based Miombo ...The current Tanzanian policy guidelines regarding ecological restoration encourage total protection (enclosure system) against grazing activities, fires and wood extraction to allow regeneration in state-based Miombo woodlands. However, there is little evidence on how such treatments would promote restoration. We fetched the pieces of evidence from studies that evaluated the impact of management treatments on the lightly degraded Miombo woodlands at Kitulangalo Forest Reserve in eastern Tanzania. Plot fencing and fire exclusion constrained woody species regeneration due to competition compared to unfenced plots. Adopting quota grazing policies and controlled burning systems can be the shortest and most eco-friendly pathways towards Miombo restoration. The results pointed out that stand disturbances and silvicultural practices can promote regeneration, which is crucial to promoting ecological restoration in Miombo woodlands.展开更多
The current trends in forestry in Europe include the increased use of continuous cover forestry(CCF)and the increased availability of tree-level forest inventory data.Accordingly,recent literature suggests methodologi...The current trends in forestry in Europe include the increased use of continuous cover forestry(CCF)and the increased availability of tree-level forest inventory data.Accordingly,recent literature suggests methodologies for optimizing the harvest decisions at the tree level.Using tree-level optimization for all trees of the stand is computationally demanding.This study proposed a two-level optimization method for CCF where the harvest prescriptions are optimized at the tree level for only a part of the trees or the first cuttings.The higher-level algorithm optimizes the cutting years and the harvest rates of those diameter classes for which tree-level optimization is not used.The lower-level algorithm allocates the individually optimized trees to different cutting events.The most detailed problem formulations,employing much tree-level optimization,resulted in the highest net present value and longest optimization time.However,restricting tree-level optimization to the largest trees and first cuttings did not significantly alter the time,intensity,or type of first cutting.Computing times could also be shortened by applying accumulated knowledge from previous optimizations,implementing learning aspects in heuristic search,and optimizing the search algorithms for short computing time and good-quality solutions.展开更多
A prevailing theory suggests that volcanic eruptions triggered environmental changes,which compelled dinosaurs to migrate in search of new habitats.Compelling evidence for this hypothesis has now been discovered in th...A prevailing theory suggests that volcanic eruptions triggered environmental changes,which compelled dinosaurs to migrate in search of new habitats.Compelling evidence for this hypothesis has now been discovered in the Tunxi Basin of eastern China.During the Late Mesozoic,the subduction of the Pacific Plate beneath southeastern China led to multi-stage volcanic activity.The Tunxi Formation in the basin,the first reported Upper Jurassic volcanic unit in the eastern Jiangnan orogen.It overlies the stratum bearing the easternmost mamenchisaurids,which is the dominant Asian sauropod lineage.Geochemical analyses suggest its affinity with coeval magmatism in southeastern China,while new rhyolite zircon U-Pb dating yields an age of 151.6±2.2 Ma,further indicating a transition from arc magmatism to back-arc extension driven by Paleo-Pacific subduction during the Late Jurassic.These studies also confirm that,as early as 156 Ma,the Tunxi Basin was already a key habitat for mamenchisaurids.The Late Jurassic subduction of the Paleo-Pacific Plate caused extensive magmatism across eastern China.This intense tectonic shift likely induced abrupt environmental changes in relative basins.Severe volcanic activity drastically reduced the habitat of mamenchisaurids,prompting a northwestward and southward radiation trend-presents a coherent scene of volcanic eruptions,environmental catastrophe,and dinosaurs migrating.展开更多
The acclimation capacity of Betula pendula and Betula pubescens was studied over 4 years in common gardens in central Italy(43°N)and southern(61°N)and northern Finland(67°N),representing drastically dif...The acclimation capacity of Betula pendula and Betula pubescens was studied over 4 years in common gardens in central Italy(43°N)and southern(61°N)and northern Finland(67°N),representing drastically different photoperiod and climate in temperate,boreal and subarctic vegetation zones.Two study sites that differed in soil fertility were established at each location,giving a total of six common gardens.The birch material was micropropagated from naturally regenerated stands of B.pendula and B.pubescens from Susa Valley and Rochemolle Valley in northern Italy,Punkaharju in southern Finland and Kittilä in northern Finland.The plants were measured for height growth,stem diameter,leaf chlorophyll content,leaf herbivory and pathogen damage.The effects of soil fertility on the common garden results were also analyzed.The results showed high acclimation capacity of B.pendula and B.pubescens after a long-range transfer from southern to northern Europe,despite the major shift in climate and photoperiod.First-year growth on average was best in boreal southern Finland for all origins.Betula pendula grew more than B.pubescens in Italy and southern Finland,while B.pubescens grew more in northern Finland and better tolerated the northward transfer.The height growth of origins showed a clear latitude gradient from slowly growing northern to fast growing southern origins in the nursery and laboratory,but not in the field.Soil fertility explained a significant part of variation among locations not only for growth variables,but also for leaf chlorophyll content and leaf herbivory and pathogen damage.Leaf herbivore and pathogen damage was greatest in southern Finland.Our results demonstrate good survival of birch from northern Italy in Finnish conditions and support the possibility of long-range south-to-north transfer of Betula species to provide resistant planting material in boreal forests for the rapidly changing climate.展开更多
Dengue virus(DENV)is a positive-sense single-stranded RNA virus belonging to the genus Flavivirus within the Flaviviridae family.Four serotypes,DENV 1-4,are distributed globally[1].Hanoi metropolitan city is an endemi...Dengue virus(DENV)is a positive-sense single-stranded RNA virus belonging to the genus Flavivirus within the Flaviviridae family.Four serotypes,DENV 1-4,are distributed globally[1].Hanoi metropolitan city is an endemic hotspot for DENV transmission in Vietnam[2,3].The largest outbreak occurred in 2017,with more than 36000 cases and 7 deaths reported,causing by all four serotypes with the predominance of DENV1,following by DENV2[4,5].During the following dengue season,we collected 390 blood and serum samples from 197 hospitalized patients in a national hospital in Hanoi city,Northern Vietnam to identify the circulating DENV serotypes responsible for the 2018-2019 outbreak.展开更多
Although previous researchers have attempted to decipher ore genesis and mineralization in the Erdaokan Ag-Pb-Zn deposit,some uncertainties regarding the mineralization process and evolution of both ore-forming fluids...Although previous researchers have attempted to decipher ore genesis and mineralization in the Erdaokan Ag-Pb-Zn deposit,some uncertainties regarding the mineralization process and evolution of both ore-forming fluids and magnetite types still need to be addressed.In this study,we obtained new EPMA,LA-ICP-MS,and in situ Fe isotope data from magnetite from the Erdaokan deposit,in order to better understand the mineralization mechanism and evolution of both magnetite and the ore-forming fluids.Our results identified seven types of magnetite at Erdaokan:disseminated magnetite(Mag1),coarse-grained magnetite(Mag2a),radial magnetite(Mag2b),fragmented fine-grained magnetite(Mag2c),vermicular gel magnetite(Mag3a1 and Mag3a2),colloidal magnetite(Mag3b)and dark gray magnetite(Mag4).All of the magnetite types were hydrothermal in origin and generally low in Ti(<400 ppm)and Ni(<800 ppm),while being enriched in light Fe isotopes(δ^(56)Fe ranging from−1.54‰to−0.06‰).However,they exhibit different geochemical signatures and are thus classified into high-manganese magnetite(Mag1,MnO>5 wt%),low-silicon magnetite(Mag2a-c,SiO_(2)<1 wt%),high-silicon magnetite(Mag3a-b,SiO_(2)from 1 to 7 wt%)and high-silicon-manganese magnetite(Mag4,SiO_(2)>1 wt%,MnO>0.2 wt%),each being formed within distinct hydrothermal environments.Based on mineralogy,elemental geochemistry,Fe isotopes,temperature trends,TMg-mag and(Ti+V)vs.(Al+Mn)diagrams,we propose that the Erdaokan Ag-Pb-Zn deposit underwent multi-stage mineralization,which can be broken down into four stages and nine sub-stages.Mag1,Mag2a-c,Mag3a-b and Mag4 were formed during the first sub-stage of each of the four stages,respectively.Additionally,fluid mixing,cooling and depressurization boiling were identified as the main mechanisms for mineral precipitation.The enrichment of Ag was significantly enhanced by the superposition of multi-stage ore-forming hydrothermal fluids in the Erdaokan Ag-Pb-Zn deposit.展开更多
1.Objectives Dinosaur fossils were first discovered from Guangxi Zhuang Autonomous Region in 1960s,mainly including fossil bones and teeth from the Cretaceous.Only one dorsal vertebra and one ischium were reported fro...1.Objectives Dinosaur fossils were first discovered from Guangxi Zhuang Autonomous Region in 1960s,mainly including fossil bones and teeth from the Cretaceous.Only one dorsal vertebra and one ischium were reported from the Late Jurassic at Jiangshan Island of Fangchenggang City in 2007.展开更多
基金supported by the Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(2024ZD1000500)the National Natural Science Foundation of China(42172262 and 42372266)+1 种基金the China Geological Survey(DD20240041)the Fundamental Research Funds of the Institute of Geomechanics(DZLXJK202516).
文摘The Yingxiu-Beichuan fault zone(YBFZ)has long been active and experienced repeated large earthquakes.The physicochemical properties of the deep fault zone(>1000 m)are the key to understanding the deformation mechanism of large earthquakes.This study uses rock magnetic,microstructural,and geochemical analyses of representative samples exposed in FZ1681 within the Wenchuan Earthquake Fault Scientific Drilling borehole 2(WFSD-2)cores.Fault gouge and fault breccia have higher magnetic susceptibility values than wall rocks,and they contain abundant paramagnetic minerals and small quantities of magnetite and monoclinic pyrrhotite.The magnetite and monoclinic pyrrhotite in the fault gouge were mainly formed by coseismic frictional heating,indicating that large earthquakes with frictional heating temperatures of~500-900℃once occurred in the YBFZ.The seismogenic and coseismic environment was reducing with a relatively high sulfur content.The monoclinic pyrrhotite in the fault breccia was formed mainly by low-temperature hydrothermal fluid.This indicates that the fault zone experienced reducing and low-temperature(<400℃)hydrothermal fluid with a relatively high sulfur content after the earthquake.The YBFZ,which experiences frequent large earthquakes,is weakly oxidizing environment at different depths,but the effect of the low-temperature hydrothermal fluid is weaker at depth.
基金supported by the National Natural Science Foundation of China(42230312,42272270,42172262,42372266)the Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(2024ZD1000500)the China Geological Survey Project(DD20240041).
文摘The Guanxian-Anxian fault zone in the Longmen Shan,Sichuan,China,exhibits long-term creep-slip but ruptured during the 2008 Wenchuan earthquake,challenging the view that creeping faults rarely generate strong earthquakes.To investigate the transition from creep-slip to stick-slip,we analyzed fault rocks from the WFSD-3,using microstructural observations,XRD,μXRF,Raman spectroscopy,and quartz grain size statistics.Fault rocks show intense foliation,pressure-solution structures,and abundant clay minerals,reflecting long-term aseismic creep.At the interface between black and gray fault gouges at~1249.98 m,microstructures indicate stick-slip behavior,including truncated grains,angular fragments,and finer grain sizes.Here,clay content drops sharply while strong minerals(quartz,feldspar,calcite,dolomite)increase.Elemental mapping shows Al and K enriched in black gouge,whereas Ca and Si in gray gouge;Raman spectroscopy indicates possible graphitization;the finest quartz grains occur in black gouge.These features mark co-seismic principal slip zone of the Wenchuan earthquake.We propose that fluid-driven transformation of strong minerals into clays facilitates creep-slip,whereas localized precipitation of strong minerals strengthens the fault,causing stress accumulation and controlling the creep-slip to stick-slip transition.This mechanism has implications for reassessing seismic hazards of creeping faults.
基金funded by COST Action CA21157“European Network for Innovative Woody Plant Cloning”www.cost.eusupported by COST(European Cooperation in Science and Technology)www.cost.eu。
文摘Reforestation initiatives are often limited by insufficient seeds,a problem exacerbated by natural variability in tree flowering and seed production and climate change and other environmental challenges.Innovative and adaptive solutions such as in vitro propagation are thus needed.Tissue culture can provide high-quality propagation material for tree conservation and mass propagation,but faces technical,economic,regulatory,and social barriers.Obstacles related to the academia-industry interface and to stakeholder concerns are discussed and actions suggested to overcome these barriers to realize the full potential of tree micropropagation.These include refining techniques to improve efficiency and reduce costs;establishing collaborations among researchers,industry,and foresters;and reducing points of contention and misinformation regarding genetic diversity and public perception.International collaborative initiatives,exemplified by the EU COST Action CA21157 COPYTREE,are elementary for achieving these goals.
基金supported by the National Natural Science Foundation of China(42202131 and 42177184).
文摘This study examines a 1.32 m thick sediment sequence from the Cunge sag pond in the Litang Basin,eastern Tibetan Plateau,to assess the seismicity of the Litang fault during the Holocene.High-resolution geochemical,grain size,magnetic susceptibility,and total organic carbon indicators are employed to obtain a continuous record of changes in elemental,physical,and biological properties within the profile to identify seismic events.The seismic event layer generally comprises two sedimentary rhythms:a lower coarse sand layer and an upper fine silt-clay layer.These layers represent rapid deposition associated with fault activity(Earthquake A)and slower deposition during calm periods or earthquake recurrence intervals(Seismic interval A).Through six^(14)C dating,five seismic events have been identified in the Cunge sag pond section:E1(before 3955 a B.P.),E2(3713-3703 a B.P.),E3(3492-3392 a B.P.),E4(2031-1894 a B.P.),and E5(1384-1321 a B.P.).E1-E4 had shown a good consistency with the paleo-earthquake recorded by the trench,and whereas E5 is a newly identified seismic event,further improving the continuous earthquake sequence of the Litang fault.Based on existing trench data and the seismic event record from the Cunge sag pond,a total of 11 paleo-earthquakes are identified along the Litang fault since the Holocene.The paleo-earthquake activity of the Litang fault exhibits a clustered pattern,with recurrence intervals of both long periods(1000 a)and short periods(500 a).Since 5000 a,the interval between strong earthquake recurrences gradually decreases,indicating an increasing risk of strong earthquakes along the Litang fault.This study presents a continuous record of paleo-earthquakes along the Litang fault,eastern Tibetan Plateau,and can enhance the understanding of regional seismic activity.
基金supported by the National Key Research and Development Program of China (2022YFF1300705)the Key Research and Development Project of Guangxi,China (Guike AB24010051)+1 种基金the National Natural Science Foundation of China (42261011,32271730 and U20A2011)the Central Public Welfare Research Institutes,Chinese Academy of Geological Sciences (2023020)。
文摘Phosphorus (P) is an essential nutrient element that is critical for plant growth and ecosystem functionality.The soil P cycle plays multiple roles,such as sustaining plant growth and productivity,regulating nutrient balance within ecosystems,and enhancing ecosystem adaptability and resilience.This cycle is influenced by factors such as the restoration approach and microbial community dynamics.However,the extent to which the restoration approach alters the P cycle in karst ecosystems and the underlying microbial mechanisms remain poorly understood.The P-cycle multifunctionality index (P-cycle MFI) serves as a comprehensive indicator for evaluating soil P cycle function,and it provides insights into changes in the P cycle between different restoration approaches.To investigate the shifts in soil P-cycle MFI and microbial mechanisms between different restoration approaches,we analyzed soil available P (AP),total P (TP),microbial biomass P (MBP),and the activities of acid phosphatase (ACP) and alkaline phosphatase (ALP).These data were used to calculate the P-cycle MFI by averaging the Z-scores between two restoration approaches(artificial restoration of forest (AF) and natural restoration of forest (NF)) and a control (cropland,CP) at six subtropical karst ecosystem sites in China.We also determined the soil organic carbon (SOC),exchangeable calcium (Ca) and magnesium (Mg),pH,bulk density (BD),microbial biomass C (MBC),and microbial biomass nitrogen (MBN),as well as the community structure,relative abundance,diversity indices,and co-occurrence networks of phoD-harboring bacteria.The results showed that the community structure of phoD-harboring bacteria varied significantly among AF,NF,and CP and across different temperature gradients.These bacteria exhibited increasing complexity and tightness in co-occurrence networks from CP to AF and then to NF,along with the ACP and ALP activities,but not the TP and AP contents.The P-cycle MFI values were significantly higher in NF compared to AF and CP,and the variation was significantly explained by restoration approach,temperature,MBC,MBN,SOC,exchangeable Ca,BD,community structure of phoD-harboring bacteria,and exchangeable Mg.Furthermore,natural restoration had a more substantial impact on the P-cycle MFI than temperature by enhancing SOC,microbial biomass,the complexity and co-occurrence network tightness of the phoD-harboring bacterial community structure,and ACP and ALP activities,but it reduced soil BD.The rare genera of phoD-harboring bacteria significantly influenced the variation of soil P-cycle MFI compared to the dominant genera.This study highlights the importance of rare genera of phoD-harboring bacteria in driving soil P-cycle multifunctionality in karst ecosystems,with natural restoration being more effective than artificial methods for enhancing soil organic matter and microbial community complexity.
基金originally supported by the Research Funds of University of Helsinki
文摘Background: Remote sensing-based mapping of forest Ecosystem Service(ES) indicators has become increasingly popular. The resulting maps may enable to spatially assess the provisioning potential of ESs and prioritize the land use in subsequent decision analyses. However, the mapping is often based on readily available data, such as land cover maps and other publicly available databases, and ignoring the related uncertainties.Methods: This study tested the potential to improve the robustness of the decisions by means of local model fitting and uncertainty analysis. The quality of forest land use prioritization was evaluated under two different decision support models: either using the developed models deterministically or in corporation with the uncertainties of the models.Results: Prediction models based on Airborne Laser Scanning(ALS) data explained the variation in proxies of the suitability of forest plots for maintaining biodiversity, producing timber, storing carbon, or providing recreational uses(berry picking and visual amenity) with RMSEs of 15%–30%, depending on the ES. The RMSEs of the ALS-based predictions were 47%–97%of those derived from forest resource maps with a similar resolution. Due to applying a similar field calibration step on both of the data sources, the difference can be attributed to the better ability of ALS to explain the variation in the ES proxies.Conclusions: Despite the different accuracies, proxy values predicted by both the data sources could be used for a pixel-based prioritization of land use at a resolution of 250 m~2, i.e., in a considerably more detailed scale than required by current operational forest management. The uncertainty analysis indicated that maps of the ES provisioning potential should be prepared separately based on expected and extreme outcomes of the ES proxy models to fully describe the production possibilities of the landscape under the uncertainties in the models.
基金This study was financially supported by Henan Land and Resources Department(2011-622-38).
文摘The plant samples of Bidens pilosa were collected from a coal gangue vacant site and its surrounding area,located in central China,to study the remediation effect of the plant species on heavy metal(HM)contamination in both natural and electrokinetic(EK)conditions.The analytical results showed that the effect of phytoextraction and bioconcentration on the heavy metals in the sample of the EK group is more significant than those in the other control group.Compared with the results of natural condition,under the EK condition the concentrations of cadmium(Cd),lead(Pb),copper(Cu)and zinc(Zn)in the stems and leaves of the Bidens pilosa increased to 0.40 mg/kg,4.23 mg/kg,7.27 mg/kg,830.24 mg/kg,respectively,with their increments of 292%,1731%,141%,2076%.For root samples,the Cd,Pb,Cu and Zn concentrations increased to 0.52 mg/kg,4.36 mg/kg,10.87 mg/kg,and 98.12 mg/kg and the increase rates were 1034%,140%,29%,and 181%,respectively.The phytoextraction efficiency of the Bidens pilosa was significantly higher than that of control group.The removal efficiency of Cd,Pb,Cu and Zn in soil increased to 26%,72%,27%,and 79%with the EK applied.In addition,the mechanism of HM migration,extraction and enrichment in Bidens pilosa under the EK condition was discussed.
基金jointly supported by the open fund from the Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources, Institute of Geology, Chinese Academy of Geological Sciences (Award Number J1901-16)the project of graduate education and teaching reform in Shanxi Province (Award Number 2021YJJG147)+4 种基金the teaching reform project “Geographic Modeling, Simulation and Visualization” established by Shanxi Normal University (Award Number 2019JGXM-39)the “Deep Geological Survey in Benxi-Linjiang Area”, a pilot project set up by the China Geological Survey, China (grant number 1212011220247)“The Research Start-up Fund of Shanxi Normal University for Dr. Peng Chong in 2016” (Award Number 0505/ 02070438)“The Research Start-up Fund of Shanxi Normal University for Dr. Liu Haiyan in 2017” (Award Number 0505/02070458)“The Research Fund for Outstanding Doctor in 2017” (Award Number 0503/02010168), established by the Education Department of Shanxi Province for Dr. Liu Haiyan
文摘Although geothermal energy has many clear advantages,including its sustainability and environmentally friendly nature,research into potential geothermal resources across the Longgang Block,Northeast China,has been limited.Here we present the first analysis of the potential geothermal resources in this region that employs joint geological and non-seismic geophysical methods to identify target areas that may be economically viable.We acquire and analyze high-precision gravity,magnetic,and magnetotelluric sounding data,which are constrained using the petrophysical parameters of outcropping rocks across the Longgang Block,to conduct a comprehensive evaluation of the region’s deep geological structures and their geothermal resources potential,with a focus on identifying faults,rock masses,and thermal storage structures.We find that Archean granitic gneiss and Mesozoic rock masses in the deeper section of the Longgang Block possess weak gravity anomalies and high resistivities.We also identify thermal storage structures near these deeper geological units based on their extremely low resistivities.The data are used to infer the dip and depth of known or hidden faults,to constrain the spatial distribution of intrusive rock masses,and to determine the spatial distribution of subsurface thermal storage structures.The potential of the target areas for geothermal resources exploitation is divided into three grades based on contact depths between faults and thermal storage structures,and the scale of their thermal storage structures.Our results suggest that a joint non-seismic geophysical approach can be effective in locating and evaluating geothermal resources in complex geological settings.
文摘A number of numerical experiments with artificial random signals (the second order autoregressive processes), which have important statistical properties similar to that of the observed instrumental temperature (1850-2015), were carried out. The results show that in frame of the selected mathematical model the return period of climatic events, analogous to the current global warming (linear increase of temperature for 0.95°C during the last 135 years) is 2849-5180 years (one event per 2849-5180 years). This means that global warming (GW) of the last 135 years can unlikely be fully explained by inherent oscillations of the climatic system. It was found however, that natural fluctuations of climate may appreciably contribute to the GW. The return period of climatic episodes with 0.5°C warming during the 135 years (half of the observed GW) was less than 500 years. The result testifies that the role of external factors (emission of greenhouse gases, solar activity etc.) in the GW could be less than often presumed.
文摘This paper brings out the issues related to natural resource exists, management and erosion right from the ancient to modern era. The natural resource such as forests and forest products were found as a basic source of survival for living organisms during the initial period. Later, the natural resources started degrading slowly and steadily due to increased human activities. In the beginning, natural resources were the primary assets for the growth of agriculture, industry, urbanization etc. Subsequently, increased anthropogenic activities started degrading the forest cover on a large scale through extending the agricultural land scape and other developmental activities in the country. The importance of traditional knowledge regarding resource conservation, protection of sacred grooves, endangered species etc. started declining in modern India. Innovativeness and policy framework for resource conservation and utilization became unfriendly in addition to gradual decline of community management. The key findings of the study point to major gaps existing such as between line departments and institutions in the promotion and management of forests, human welfare, agriculture, animal husbandry etc. Moreover, people tend to be more inclined towards the utilization of natural resources rather than conservation. From an observational and practical point of view, the natural resource has been declining rapidly in India. Therefore, this study strongly suggests that a due attention be directed towards developing people-friendly and environment friendly conservation strategies.
基金supported by the National Natural Science Foundation of China(No.42177184)。
文摘The Litang fault zone is an important seismogenic structure along the southeastern margin of the Tibetan Plateau.It caused the M71/4 earthquake in Litang in 1948 AD.The fault zone intersects the Sichuan-Xizang transportation corridor and poses a serious risk to its safe operation.This study,utilizing high-resolution remote sensing interpretation,field geological verification,UAV photogrammetry,UAV LiDAR,paleoearthquake trench excavation,and AMS^(14)C and OSL dating methods,reveals the geometric structure,slip rates,paleoearthquake sequence,and earthquake rupture segmentation of the Litang fault zone;analyzes the rupture distribution range of the 1729 AD Litang earthquake and estimates its magnitude.The study indicates that the Litang fault zone is a relatively immature strike-slip fault,which has developed as a new active fault zone within the Northwestern Sichuan sub-block during the southeastward material migration of the southeastern margin of the Tibetan Plateau.This reflects a transformation in the deformation model of the Northwestern Sichuan sub-block crust from the‘Rigid Block’model to the‘Continuous Deformation’model.
基金supported financially by China Geological Survey(Grant No.DD20230221)the Key Laboratory of Stratigraphy and Palaeontology,Ministry of Natural Resources(Grant No.KLSP SP202301)National Nature Science Foundation of China(Grant No.41202012).
文摘Twelve new dinosaur teeth have recently been recovered from three localities in the Upper Cretaceous Nenjiang Formation of the Songliao Basin.Although fragmentary,the material offers enough evidence to identify the following taxa:tyrannosaurids,dromaeosaurines,velociraptorines,hadrosauroids,and titanosaurs.In addition to the previously known dinosaurs from the basin,several new ones have been identified,extending the paleogeographic range of related taxa.The discovery of these new fossil remains provides valuable insights into dinosaur diversity and sheds light on the terrestrial ecosystem during the Late Cretaceous in the Songliao Basin.
基金financially supported by the Basic Foundation of Tianjin University of Commercethe Fund from the Key Laboratory of Continental Dynamics of Ministry of Natural Resources(J2306)。
文摘Deciphering high-pressure granulite-facies metamorphism and anatexis within a collisional orogeny can provide crucial constraints on geodynamic evolution and melt activity during subduction and exhumation.Combining petrographic observations,mineral chemistry,REE in Grt-Cpx thermobarometry,and previous work,at least four stages are suggested for the metamorphic evolution of the mafic granulites in the South Altun,including the protolith stage,the high-pressure granulite-facies stage(909-1037℃and 17.3-30 kbar),medium-pressure granulite-facies overprint(9.1-11.9 kbar and 753-816℃),and subsequent late amphibolite-greenschist-facies metamorphism.Zircon U-Pb dating shows that the mafic granulites underwent high-pressure granulite-facies metamorphism at 497.2±3.7 Ma,while the leucosome formed at 498.2±2.9 Ma.Thus,the leucosomes from the host mafic granulite may have been formed at the high-pressure granulite-facies metamorphic event.The characteristics of zircon morphology,mineral inclusions,low Th/U values,HREE enrichment,and negative Eu anomalies indicate that these zircons from the leucosome were formed from the metamorphic melts.The characteristics of whole-rock major and trace elements as well as Hf isotopic features of zircons between the leucosomes and the host mafic granulite indicate that the melt may have been generated by the partial melting of the host mafic granulite.
文摘The current Tanzanian policy guidelines regarding ecological restoration encourage total protection (enclosure system) against grazing activities, fires and wood extraction to allow regeneration in state-based Miombo woodlands. However, there is little evidence on how such treatments would promote restoration. We fetched the pieces of evidence from studies that evaluated the impact of management treatments on the lightly degraded Miombo woodlands at Kitulangalo Forest Reserve in eastern Tanzania. Plot fencing and fire exclusion constrained woody species regeneration due to competition compared to unfenced plots. Adopting quota grazing policies and controlled burning systems can be the shortest and most eco-friendly pathways towards Miombo restoration. The results pointed out that stand disturbances and silvicultural practices can promote regeneration, which is crucial to promoting ecological restoration in Miombo woodlands.
基金supported by the KESTO project (Planning and implementation of the harvesting of climate-resilient continuous cover forests (CCF) using digitalization in North Karelia),Grant Number 41007-00241901funded by the European Regional Development Fund (ERDF)funding provided by University of Eastern Finland (including Kuopio University Hospital)
文摘The current trends in forestry in Europe include the increased use of continuous cover forestry(CCF)and the increased availability of tree-level forest inventory data.Accordingly,recent literature suggests methodologies for optimizing the harvest decisions at the tree level.Using tree-level optimization for all trees of the stand is computationally demanding.This study proposed a two-level optimization method for CCF where the harvest prescriptions are optimized at the tree level for only a part of the trees or the first cuttings.The higher-level algorithm optimizes the cutting years and the harvest rates of those diameter classes for which tree-level optimization is not used.The lower-level algorithm allocates the individually optimized trees to different cutting events.The most detailed problem formulations,employing much tree-level optimization,resulted in the highest net present value and longest optimization time.However,restricting tree-level optimization to the largest trees and first cuttings did not significantly alter the time,intensity,or type of first cutting.Computing times could also be shortened by applying accumulated knowledge from previous optimizations,implementing learning aspects in heuristic search,and optimizing the search algorithms for short computing time and good-quality solutions.
基金supported by the China Geological Survey(DD20230221)the National Natural Science Foundation of China(42102018)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB26000000).
文摘A prevailing theory suggests that volcanic eruptions triggered environmental changes,which compelled dinosaurs to migrate in search of new habitats.Compelling evidence for this hypothesis has now been discovered in the Tunxi Basin of eastern China.During the Late Mesozoic,the subduction of the Pacific Plate beneath southeastern China led to multi-stage volcanic activity.The Tunxi Formation in the basin,the first reported Upper Jurassic volcanic unit in the eastern Jiangnan orogen.It overlies the stratum bearing the easternmost mamenchisaurids,which is the dominant Asian sauropod lineage.Geochemical analyses suggest its affinity with coeval magmatism in southeastern China,while new rhyolite zircon U-Pb dating yields an age of 151.6±2.2 Ma,further indicating a transition from arc magmatism to back-arc extension driven by Paleo-Pacific subduction during the Late Jurassic.These studies also confirm that,as early as 156 Ma,the Tunxi Basin was already a key habitat for mamenchisaurids.The Late Jurassic subduction of the Paleo-Pacific Plate caused extensive magmatism across eastern China.This intense tectonic shift likely induced abrupt environmental changes in relative basins.Severe volcanic activity drastically reduced the habitat of mamenchisaurids,prompting a northwestward and southward radiation trend-presents a coherent scene of volcanic eruptions,environmental catastrophe,and dinosaurs migrating.
基金supported by Academy of Finland(project 284931)the Finnish Cultural Foundation/Eva Barbara WilhelminaFoundation(Decision 27.2.2021).
文摘The acclimation capacity of Betula pendula and Betula pubescens was studied over 4 years in common gardens in central Italy(43°N)and southern(61°N)and northern Finland(67°N),representing drastically different photoperiod and climate in temperate,boreal and subarctic vegetation zones.Two study sites that differed in soil fertility were established at each location,giving a total of six common gardens.The birch material was micropropagated from naturally regenerated stands of B.pendula and B.pubescens from Susa Valley and Rochemolle Valley in northern Italy,Punkaharju in southern Finland and Kittilä in northern Finland.The plants were measured for height growth,stem diameter,leaf chlorophyll content,leaf herbivory and pathogen damage.The effects of soil fertility on the common garden results were also analyzed.The results showed high acclimation capacity of B.pendula and B.pubescens after a long-range transfer from southern to northern Europe,despite the major shift in climate and photoperiod.First-year growth on average was best in boreal southern Finland for all origins.Betula pendula grew more than B.pubescens in Italy and southern Finland,while B.pubescens grew more in northern Finland and better tolerated the northward transfer.The height growth of origins showed a clear latitude gradient from slowly growing northern to fast growing southern origins in the nursery and laboratory,but not in the field.Soil fertility explained a significant part of variation among locations not only for growth variables,but also for leaf chlorophyll content and leaf herbivory and pathogen damage.Leaf herbivore and pathogen damage was greatest in southern Finland.Our results demonstrate good survival of birch from northern Italy in Finnish conditions and support the possibility of long-range south-to-north transfer of Betula species to provide resistant planting material in boreal forests for the rapidly changing climate.
基金the“Metropolitan Mosquitoes Project”funded by the Swedish Research Council for Environment,Agricultural Sciences and Spatial Planning(Formas,grant number 2016-00364).
文摘Dengue virus(DENV)is a positive-sense single-stranded RNA virus belonging to the genus Flavivirus within the Flaviviridae family.Four serotypes,DENV 1-4,are distributed globally[1].Hanoi metropolitan city is an endemic hotspot for DENV transmission in Vietnam[2,3].The largest outbreak occurred in 2017,with more than 36000 cases and 7 deaths reported,causing by all four serotypes with the predominance of DENV1,following by DENV2[4,5].During the following dengue season,we collected 390 blood and serum samples from 197 hospitalized patients in a national hospital in Hanoi city,Northern Vietnam to identify the circulating DENV serotypes responsible for the 2018-2019 outbreak.
基金financially supported by the Heilongjiang Provincial Key R&D Program Project(No.GA21A204)Heilongjiang Provincial Natural Science Foundation of China(No.LH2022D031)the Research Project of Heilongjiang Province Bureau of Geology and Mineral Resources(No.HKY202302).
文摘Although previous researchers have attempted to decipher ore genesis and mineralization in the Erdaokan Ag-Pb-Zn deposit,some uncertainties regarding the mineralization process and evolution of both ore-forming fluids and magnetite types still need to be addressed.In this study,we obtained new EPMA,LA-ICP-MS,and in situ Fe isotope data from magnetite from the Erdaokan deposit,in order to better understand the mineralization mechanism and evolution of both magnetite and the ore-forming fluids.Our results identified seven types of magnetite at Erdaokan:disseminated magnetite(Mag1),coarse-grained magnetite(Mag2a),radial magnetite(Mag2b),fragmented fine-grained magnetite(Mag2c),vermicular gel magnetite(Mag3a1 and Mag3a2),colloidal magnetite(Mag3b)and dark gray magnetite(Mag4).All of the magnetite types were hydrothermal in origin and generally low in Ti(<400 ppm)and Ni(<800 ppm),while being enriched in light Fe isotopes(δ^(56)Fe ranging from−1.54‰to−0.06‰).However,they exhibit different geochemical signatures and are thus classified into high-manganese magnetite(Mag1,MnO>5 wt%),low-silicon magnetite(Mag2a-c,SiO_(2)<1 wt%),high-silicon magnetite(Mag3a-b,SiO_(2)from 1 to 7 wt%)and high-silicon-manganese magnetite(Mag4,SiO_(2)>1 wt%,MnO>0.2 wt%),each being formed within distinct hydrothermal environments.Based on mineralogy,elemental geochemistry,Fe isotopes,temperature trends,TMg-mag and(Ti+V)vs.(Al+Mn)diagrams,we propose that the Erdaokan Ag-Pb-Zn deposit underwent multi-stage mineralization,which can be broken down into four stages and nine sub-stages.Mag1,Mag2a-c,Mag3a-b and Mag4 were formed during the first sub-stage of each of the four stages,respectively.Additionally,fluid mixing,cooling and depressurization boiling were identified as the main mechanisms for mineral precipitation.The enrichment of Ag was significantly enhanced by the superposition of multi-stage ore-forming hydrothermal fluids in the Erdaokan Ag-Pb-Zn deposit.
基金This work is supported by China Geological Survey(DD20230221)Department of Natural Resources of Guangxi Zhuang Autonomous Region(GXZC2022-C3-001314-GXCJ).
文摘1.Objectives Dinosaur fossils were first discovered from Guangxi Zhuang Autonomous Region in 1960s,mainly including fossil bones and teeth from the Cretaceous.Only one dorsal vertebra and one ischium were reported from the Late Jurassic at Jiangshan Island of Fangchenggang City in 2007.
