First Published:2020 ISBN:9781421438740 Published by John Hopkins Press https://www.press.jhu.edu“The geological imagination of India,its landscapes,people,past and destiny,drive the narrative of this book”,Pratik C...First Published:2020 ISBN:9781421438740 Published by John Hopkins Press https://www.press.jhu.edu“The geological imagination of India,its landscapes,people,past and destiny,drive the narrative of this book”,Pratik Chakrabarti writes in his introduction to Inscriptions of Nature.His ambitious work examines the development of the natural and anthropological sciences on the Indian subcontinent since the early 19th century,and the shaping of knowledge about Indian nature through the exploration of its deep past:an exploration that dug not only into the depths of the earth,but also into ancient history,texts,myths,legends,folklore and the genealogies of local populations.This in-depth study not only combines the history of geology,paleontology,anthropology and ethnography,it also finely analyzes the interactions between the theoretical framework of scientific knowledge imported from Europe and local history,mythologies and indigenous beliefs.展开更多
One potential drawback of compost-based passive bioreactors,which is a promising biotechnology for acid mine drainage（AMD） treatment,is the transport of dissolved organic matter（DOM）-metal complexes in surface wat...One potential drawback of compost-based passive bioreactors,which is a promising biotechnology for acid mine drainage（AMD） treatment,is the transport of dissolved organic matter（DOM）-metal complexes in surface waters.To address this problem,the objective of this study was to assess the maximum capacity of organic substrates to release soluble DOM-metal complexes in treated water. The reactivities of DOM in maple wood chips and sawdust,composted poultry manure,and leaf compost were quantified toward Cd2＋,Ni2＋,Fe2＋,and Cu2＋ using fluorescence quenching.The DOM showed the highest reactivity toward Fe,but a limited number of available sites for sorption,whereas DOM-Cd complexes exhibited the lowest fluorescence quenching.Overall,the DOM from a mixture of wastes formed higher concentrations of DOM-metal complexes relative to sole substrates.Among DOM-metal complexes, the concentrations of DOM-Ni complexes were the highest.After reaching steady-state,low concentrations of DOM-metal complexes were released in treated water,which is in agreement with theoretical predictions based on geochemical modeling.Therefore,in addition to physicochemical characterization,fluorescence quenching technique is recommended for the substrate selection of bioreactors.展开更多
Throughout the shores of the world, a confluence of different sources of pollution is common, e.g., through outlets releasing brine, industrial, and domestic sewage. In this study, we assessed whether a combined dispo...Throughout the shores of the world, a confluence of different sources of pollution is common, e.g., through outlets releasing brine, industrial, and domestic sewage. In this study, we assessed whether a combined disposal of domestic sewage and brine altered the patterns of abundance and assemblage structure of sub- tidal macrofauna inhabiting sandy seabeds on the south coast of Gran Canaria （Canary Islands, NE Atlantic Ocean）. Samples were collected in two surveys （May 2008 and January 2009） at three distances （0, 15, and 30 m） away from the discharge point. Macrofaunal abundances showed different patterns with varying proximity from the disposal point in the two surveys. In May 2008, lower abundances were observed at 0 m （53.89±46.82 ind.） than at 15 m （120±91.7 ind.） and 30 m （283.89±189.33 ind.） away from the dis- posal point. In January 2009, however, higher abundances were observed at 0 m （131.33±58.69 ind.） than at 30 m （100±24.44 ind.） and 15 m （84.78±58.39 ind.） away from the disposal point. Significant differ- ences in macrofaunal assemblage structure were found with varying proximity from the discharge point in both surveys. The effect of proximity from the disposal point was confounded by changes in sedimen- tary composition between surveys, which contributed to explain differences in macrofaunal abundances and assemblage structure with varying proximity from the discharge point. As a result, confounding driver- s of macrofaunal assemblage structure, here, changes in sediment composition, accounted for changes in macrofaunal abundances and assemblage structure with varying proximity from a combined disposal point of brine and sewage.展开更多
The miniaturization of organisms during the Permian-Triassic mass extinction,as an ecological strategy in response to environmental devastation,has been widely recognized in diverse marine invertebrates.Previous studi...The miniaturization of organisms during the Permian-Triassic mass extinction,as an ecological strategy in response to environmental devastation,has been widely recognized in diverse marine invertebrates.Previous studies on the extinction process and miniaturization of foraminifers in the Permian-Triassic interval have relied on the fossil record of the low-latitude Paleotethys or a global database,although data and materials from the high-latitude Neotethys region are still rare.To reveal the evolutionary patterns and spatial variability of foraminifers at different latitudes and paleogeographic contexts,here we investigated the fossil distribution and size variation of foraminifers in the Selong Section of southern Xizang,located in the mid-latitude Neotethys of the Southern Hemisphere during the Permian-Triassic transition.The results show that the foraminifer of the Selong Section experienced a two-pulsed extinction(total species extinction rate of 71%),consistent with the time in South China but with a lower magnitude of extinction.Meanwhile,the data show that foraminiferal test volume was significantly miniaturized following the first pulse of extinction event:the mean size of post-extinction foraminifer was only 15%of that in the pre-extinction,mainly reflected by the disappearance of large forms as well as occurrences of smaller survivors and originators.Combined with the South China record,size data from southern Xizang indicate that the miniaturization of foraminifera is synchronous in the Paleotethys and Neotethys but smaller in magnitude in the Neotethys.We propose that ocean anoxia and acidification may be the environmental pressures leading to local and global foraminiferal miniaturizations,along with global warming,which might play a dominant role.展开更多
The objective of this study was to describe the trend of reproductive performance of primiparous and multiparous cows that grazed rice crop residues located in a Dry Tropical Forest of Colombia, taking into account th...The objective of this study was to describe the trend of reproductive performance of primiparous and multiparous cows that grazed rice crop residues located in a Dry Tropical Forest of Colombia, taking into account the rainfall pattern of the place. In this study, 89 primiparous and 309 multiparous Cebu cattle records were analyzed. Mean, mean standard deviation for age at first calving and open days of primipar-ous Cebu cattle were 41.05± 1.85 months and 269.7±36.25 days respectively. Confidence intervals (95%) for both reproductive parameters were 36.8-45.3 months and 202.7-336.6 days respectively. For multiparous Cebu cattle, the mean and mean standard deviation for open days and calving interval were 245.6±36.8 days and 17.5±0.9 months respectively. Confidence intervals 207.1-366.9 days and 13.9-20.7 months respectively. The mean rainfall since 1999 until 2012 was1202 mmper year. The reproduc-tive trend of the primiparous cattle showed an increasing behavior of age at first calving since 1999 until 2012, that can possibly be explained due to the decreasing behavior of the rainfall throughout the years, that can affect the nutritional value and offer of the grass that can grow in the borders of the crop, such as Guinea and Star grass, and eventually affect the body condition and weight necessary to be ready for the first estrous. An inverse behavior of open days occurred, showing a decreased trend along the last years of research. This fact could have happened due to the intensive use of the enriched rice straw with urea and molasses lately. Regarding to the reproductive trend of the multiparous cattle, there is no an evident pat-tern of it. Factors such as rainfall, temperature, nutrition and management should have affected it. Further research on this topic is needed.展开更多
Sericostaehys seandens is a monocarpic and heliophilous liana, native in tropical African forests. In the montane forests of the Kahuzi-Biega National Park （KBNP） （East of DR Congo）, it has been expanding very str...Sericostaehys seandens is a monocarpic and heliophilous liana, native in tropical African forests. In the montane forests of the Kahuzi-Biega National Park （KBNP） （East of DR Congo）, it has been expanding very strongly for a decade, and is currently considered as having negative impacts on biodiversity conservation. In this paper, we test if S. scandens differs from three co-occurring, native, non spreading lianas （Gouania longispicata, Tacazzea apiculata and Adenia bequaertii） for functional traits which might influence plant expansion. For leaf traits （SLA, dry matter content, nitrogen concentration）, S. scandens did not show extreme values compared to those of the three other lianas. In contrast, S. scandens had much higher biomass allocation to sexual reproduction. It also differs from the three other lianas for its reproductive strategy that combines both vegetative propagation and sexual reproduct/on, and propagule dispersal by wind. Moreover, S. scandens has larger leaves and a greater number of lateral branches per unit stem length. It is argued that the particular combination of functional traits exhibited by S.scandens may in part explain its propensity to behave as an opportunistic weed in the disturbed areas in the montane forests of Kahuzi-Biega.展开更多
The study highlights the complex dynamics governing the growth of forest stands,particularly in eucalyptus plantations in Congo.Factors such as soil fertility,planting density,clone genetics,and resource competition s...The study highlights the complex dynamics governing the growth of forest stands,particularly in eucalyptus plantations in Congo.Factors such as soil fertility,planting density,clone genetics,and resource competition significantly influence forest productivity.Thinning practices,when well implemented,help to rebalance competition among trees and maximize diameter growth.However,forest growth models,like Vanclay’s model,must be adapted to local conditions to provide more accurate and relevant predictions.Despite the progress made,questions remain about the best way to optimize forest stand management.The use of more sophisticated models that can account for the diversity of ecological conditions and management practices represents a major challenge for researchers and forest managers.展开更多
The Paraiba do Sul(PSR)and Guandu Rivers(GR)water diversion system(120 km long)is located in the main industrial pole of Brazil and supplies drinking water for 9.4 million people in the metropolitan region of Rio de J...The Paraiba do Sul(PSR)and Guandu Rivers(GR)water diversion system(120 km long)is located in the main industrial pole of Brazil and supplies drinking water for 9.4 million people in the metropolitan region of Rio de Janeiro.This study aims to discern the trace metals dynamics in this complex aquatic system.We used a combined approach of geochemical tools such as geochemical partitioning,Zn isotopes signatures,and multivariate statistics.Zinc and Pb concentrations in Suspended Particulate Matter(SPM)and sediments were considerably higher in some sites.The sediment partition of As,Cr,and Cu revealed the residual fraction(F4)as the main fraction for these elements,indicating low mobility.Zinc and Pb were mostly associated with the exchangeable/carbonate(F1)and the reducible(F2)fractions,respectively,implying a higher susceptibility of these elements to being released from sediments.Zinc isotopic compositions of sediments and SPM fell in a binary mixing source process between lithogenic(δ^(66/64)Zn_(JMC)≈+0.30‰)and anthropogenic(δ^(66/64)Zn_(JMC)≈+0.15‰)end members.The lighterδ^(66/64)Zn_(JMC)values accompanied by high Zn concentrations in exchangeable/carbonate fraction(ZnF1)enable the tracking of Zn anthropogenic sources in the studied rivers.Overall,the results indicated that Hg,Pb,and Zn had a dominant anthropogenic origin linked to the industrial activities,while As,Cr,and Cu were mainly associated with lithogenic sources.This work demonstrates how integrating geochemical tools is valuable for assessing geochemical processes and mixing source effects in anthropized river watersheds.展开更多
“Plasmas” up to a kilometer in size and behaving similarly to multicellular organisms have been filmed on 10 separate NASA space shuttle missions, over 200 miles above Earth within the thermosphere. These self-illum...“Plasmas” up to a kilometer in size and behaving similarly to multicellular organisms have been filmed on 10 separate NASA space shuttle missions, over 200 miles above Earth within the thermosphere. These self-illuminated “plasmas” are attracted to and may “feed on” electromagnetic radiation. They have different morphologies: 1) cone, 2) cloud, 3) donut, 4) spherical-cylindrical;and have been filmed flying towards and descending from the thermosphere into thunderstorms;congregating by the hundreds and interacting with satellites generating electromagnetic activity;approaching the Space Shuttles. Computerized analysis of flight path trajectories documents these plasmas travel at different velocities from different directions and change their angle of trajectory making 45°, 90°, and 180° shifts and follow each other. They’ve been filmed accelerating, slowing down, stopping, congregating, engaging in “hunter-predatory” behavior and intersecting plasmas leaving a plasma dust trail in their wake. Similar life-like behaviors have been demonstrated by plasmas created experimentally. “Plasmas” may have been photographed in the 1940s by WWII pilots (identified as “Foo fighters”);repeatedly observed and filmed by astronauts and military pilots and classified as Unidentified Aerial—Anomalous Phenomenon. Plasmas are not biological but may represent a form of pre-life that via the incorporation of elements common in space, could result in the synthesis of RNA. Plasmas constitute a fourth state of matter, are attracted to electromagnetic activity, and when observed in the lower atmosphere likely account for many of the UFO-UAP sightings over the centuries.展开更多
Following votes by the Barremian Working Group,the International Subcommission on Cretaceous Stratigraphy and the International Commission on Stratigraphy,the Executive Committee of the International Union of Geologic...Following votes by the Barremian Working Group,the International Subcommission on Cretaceous Stratigraphy and the International Commission on Stratigraphy,the Executive Committee of the International Union of Geological Sciences unanimously approved in March 2023 the Global Stratotype Section and Point(GSSP)for the Barremian Stage(Lower Cretaceous).The base of the Barremian Stage is defined at the base of bed 171 of the Río Argos section,near Caravaca(SE Spain)and correlated by the first appearance of the ammonite species Taveraidiscus hugii.This event falls within the NC5C calcareous nannofossil Subzone,the Lilliputianella semielongata planktonic foraminiferal Zone,and the Dorothia ouachensis benthic foraminiferal Zone.It roughly coincides with the beginning of a slightly negative trend interval in theδ^(13)C curve.Indirect calibration to the magnetostratigraphic scale suggests that the boundary falls in the lowermost part of polarity chron M3r.According to the astrochronological analysis,a time interval of 0.74 myr separates the beginning of the late Hauterivian Faraoni Episode from the base of the Barremian,which is dated at 125.77 MA.展开更多
This study focuses on the landscape dynamics of the savannahs’ region in the far north of Togo. Based on a literature review and satellite images analysis using GIS and remote sensing, the study aims to ascertain the...This study focuses on the landscape dynamics of the savannahs’ region in the far north of Togo. Based on a literature review and satellite images analysis using GIS and remote sensing, the study aims to ascertain the effects of anthropogenic threats on the forest coverage of the Savannahs’ Region between 1984 to 2020. The objective is to clarify the dynamics of land use in the region from 1984 to 2000 and from 2000 to 2020. The findings indicate a significant decline in forest coverage within the region from 1984 to 2020, a trend attributed to land use patterns. Dry forests in the Savannah region are largely converted to farmlands, housing, dry savannahs or agroforestry parks, leading to a steady reduction in forest areas.展开更多
Environmental stressors such as drought,salinity,and heavy metals pose significant obstacles to achieving sustainable food security,necessitating the development of universally applicable and cost-effective solutions ...Environmental stressors such as drought,salinity,and heavy metals pose significant obstacles to achieving sustainable food security,necessitating the development of universally applicable and cost-effective solutions to ameliorate soil under stress.Biochar,an eco-friendly material to increase crop yield,has been researched for almost two decades and has great potential for global use in enhancing stress resistance.However,there hasn’t been comprehensive research on the impact of biochar application on soil properties,and root and crop growth.To optimize and promote biochar application in agriculture under stress,this study integrates over 100 peer-reviewed articles to explain how biochar promotes crop growth by enhancing soil resistance to stress.Biochar’s distinctive properties,such as porous structure,alkaline nature,enriched surface functional groups,and nutrient content,are responsible for the following soil environment benefits:improved soil physiochemical properties,increased nutrient cycling,and boosted microbial growth.Moreover,the research emphasizes that the enhanced stress resistance of biochar optimizes nutrient absorption,alleviates soil pollutants,and thereby enhances overall crop productivity.The study discusses the roles and mechanisms of biochar on soil under stress,as well as the challenges linked to the sustainable and economical implementation of biochar in extreme soil conditions.This review aims to provide a theoretical basis for the widespread and cost-effective use of biochar in improving soil under stresses,thereby enhancing soil health and food security.展开更多
Aims Relationships between local habitat heterogeneity and tree commu-nities in miombo woodlands have been very little studied.While some studies have addressed this topic at broad scales and based on few environmenta...Aims Relationships between local habitat heterogeneity and tree commu-nities in miombo woodlands have been very little studied.While some studies have addressed this topic at broad scales and based on few environmental parameters,this study aims at(i)detecting fine-scale habitats(≤10 ha)on the basis of a detailed characterisation of soil explicitly considering past anthropogenic disturbances,and an exhaustive census of the tree community,and at(ii)searching for indicator tree species corresponding to the resulting habitats.Methods The study was carried out in the miombo woodland of Mikembo Forest Reserve,Upper Katanga,The Democratic Republic of the congo.A complete census of the tree community was conducted in a 10-ha forest dynamics plot comprising 160 adjacent quadrats of 25×25 m,with a total of 4604 trees(diameter at breast height>10 cm).Thirty-six physicochemical soil parameters were measured.Studying the frequency distribution of soil charcoal content allowed identifying local signature of past human agriculture in the soil.Two strategies were used to define habitats:(i)a combination of principal component analysis(PcA)on soil variables and Ward clustering and(ii)multivariate regression trees(MRT)to search for key soil parameters allowing the best prediction of species composition.Tree-habitat associations were tested by means of a robust statistical framework combining the IndVal index and torus randomisations.Important Findings The forest contained 82 tree species and a significant proportion of wet miombo species(e.g.Marquesia macroura).We detected a strong east-west edaphic gradient driven by soil texture;most chemical soil parameters followed this pattern.Five habitats were identified based on soil factors and floristic composition.Nine indicator species of these habitats were found.The key soil fac-tors discriminating habitats were total calcium,available forms of phosphorus and clay content.Even though past agricultural practices were successfully detected in soils,they did not display any significant influence neither on habitat differentiation nor on the associated tree communities.Based on an unprecedented large number of soil parameters,fine-scale soil heterogeneity and niche partitioning were shown to contribute to the variabil-ity of the floristic composition in this forest.Our results indicated that considering the most variable environmental parameters,as in PcA,is a poor manner for defining habitats.In contrast,combining MRT with the IndVal index and torus randomisation has proved to be a much more robust and sensitive approach to highlight tree-habitat associations at this scale.The common dichotomous viewpoint of considering deterministic and neutral effects as acting at broad and fine scales,respectively,is not confirmed when measuring suitable environmental variables,even in a case where the physical environment does not exhibit strong heterogeneity.展开更多
A Lagrangian model is used to evaluate source regions of particles collected in the sediment traps at the DYFAMED （Dy namique des Flux Atmospheriques en Mediterranee） station by tracking particles backwards from Mar...A Lagrangian model is used to evaluate source regions of particles collected in the sediment traps at the DYFAMED （Dy namique des Flux Atmospheriques en Mediterranee） station by tracking particles backwards from March 1 to August 31, 2001. The analysis suggests that source regions depend on the flow fields, the settling speed of the particles, and the deployment depths of the traps. Monthly variation is observed in the distribution patterns of source regions, which is caused by the currents The source regions are located around the traps and up to hundreds of kilometers away. As the settling speed increases with the particle diameters, the distance to the source regions decreases. The vertical flux can be approximately estimated in 1D for the particles with diameters larger than 500 lain. Furthermore, traps moored at various depths at the DYFAMED can collect parti- cles that originated from different regions in the Ligurian Sea.展开更多
Extinction selectivity determines the direction of macroevolution,especially during mass extinction;however,its driving mechanisms remain poorly understood.By investigating the physiological selectivity of marine anim...Extinction selectivity determines the direction of macroevolution,especially during mass extinction;however,its driving mechanisms remain poorly understood.By investigating the physiological selectivity of marine animals during the Permian-Triassic mass extinction,we found that marine clades with lower O2-carrying capacity hemerythrin proteins and those relying on O2 diffusion experienced significantly greater extinction intensity and body-size reduction than those with higher O2-carrying capacity hemoglobin or hemocyanin proteins.Our findings suggest that animals with high O2-carrying capacity obtained the necessary O2 even under hypoxia and compensated for the increased energy requirements caused by ocean acidification,which enabled their survival during the Permian-Triassic mass extinction.Thus,high O2-carrying capacity may have been crucial for the transition from the Paleozoic to the Modern Evolutionary Fauna.展开更多
文摘First Published:2020 ISBN:9781421438740 Published by John Hopkins Press https://www.press.jhu.edu“The geological imagination of India,its landscapes,people,past and destiny,drive the narrative of this book”,Pratik Chakrabarti writes in his introduction to Inscriptions of Nature.His ambitious work examines the development of the natural and anthropological sciences on the Indian subcontinent since the early 19th century,and the shaping of knowledge about Indian nature through the exploration of its deep past:an exploration that dug not only into the depths of the earth,but also into ancient history,texts,myths,legends,folklore and the genealogies of local populations.This in-depth study not only combines the history of geology,paleontology,anthropology and ethnography,it also finely analyzes the interactions between the theoretical framework of scientific knowledge imported from Europe and local history,mythologies and indigenous beliefs.
基金supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) through the Industrial NSERC Polytechnique/UQAT Chair in Environment and Mine Waste Management and the Chair’s partners
文摘One potential drawback of compost-based passive bioreactors,which is a promising biotechnology for acid mine drainage（AMD） treatment,is the transport of dissolved organic matter（DOM）-metal complexes in surface waters.To address this problem,the objective of this study was to assess the maximum capacity of organic substrates to release soluble DOM-metal complexes in treated water. The reactivities of DOM in maple wood chips and sawdust,composted poultry manure,and leaf compost were quantified toward Cd2＋,Ni2＋,Fe2＋,and Cu2＋ using fluorescence quenching.The DOM showed the highest reactivity toward Fe,but a limited number of available sites for sorption,whereas DOM-Cd complexes exhibited the lowest fluorescence quenching.Overall,the DOM from a mixture of wastes formed higher concentrations of DOM-metal complexes relative to sole substrates.Among DOM-metal complexes, the concentrations of DOM-Ni complexes were the highest.After reaching steady-state,low concentrations of DOM-metal complexes were released in treated water,which is in agreement with theoretical predictions based on geochemical modeling.Therefore,in addition to physicochemical characterization,fluorescence quenching technique is recommended for the substrate selection of bioreactors.
基金The Spanish Ministry of the Environment and Rural and Marine Affairs (Project:"Minimisation of environmental impacts from brine disposals over marine seabed biodiversity,with special reference to Cymodocea nodosa seagrass meadows"2007–2010) under contract No.056/SGTB/2007/2.4
文摘Throughout the shores of the world, a confluence of different sources of pollution is common, e.g., through outlets releasing brine, industrial, and domestic sewage. In this study, we assessed whether a combined disposal of domestic sewage and brine altered the patterns of abundance and assemblage structure of sub- tidal macrofauna inhabiting sandy seabeds on the south coast of Gran Canaria （Canary Islands, NE Atlantic Ocean）. Samples were collected in two surveys （May 2008 and January 2009） at three distances （0, 15, and 30 m） away from the discharge point. Macrofaunal abundances showed different patterns with varying proximity from the disposal point in the two surveys. In May 2008, lower abundances were observed at 0 m （53.89±46.82 ind.） than at 15 m （120±91.7 ind.） and 30 m （283.89±189.33 ind.） away from the dis- posal point. In January 2009, however, higher abundances were observed at 0 m （131.33±58.69 ind.） than at 30 m （100±24.44 ind.） and 15 m （84.78±58.39 ind.） away from the disposal point. Significant differ- ences in macrofaunal assemblage structure were found with varying proximity from the discharge point in both surveys. The effect of proximity from the disposal point was confounded by changes in sedimen- tary composition between surveys, which contributed to explain differences in macrofaunal abundances and assemblage structure with varying proximity from the discharge point. As a result, confounding driver- s of macrofaunal assemblage structure, here, changes in sediment composition, accounted for changes in macrofaunal abundances and assemblage structure with varying proximity from a combined disposal point of brine and sewage.
基金supported by the State Key R&D Project of China(No.2023YFF0804000)the National Natural Science Foundation of China(Nos.92155201,92255303)a BQR of the Universit'e de Bourgogne。
文摘The miniaturization of organisms during the Permian-Triassic mass extinction,as an ecological strategy in response to environmental devastation,has been widely recognized in diverse marine invertebrates.Previous studies on the extinction process and miniaturization of foraminifers in the Permian-Triassic interval have relied on the fossil record of the low-latitude Paleotethys or a global database,although data and materials from the high-latitude Neotethys region are still rare.To reveal the evolutionary patterns and spatial variability of foraminifers at different latitudes and paleogeographic contexts,here we investigated the fossil distribution and size variation of foraminifers in the Selong Section of southern Xizang,located in the mid-latitude Neotethys of the Southern Hemisphere during the Permian-Triassic transition.The results show that the foraminifer of the Selong Section experienced a two-pulsed extinction(total species extinction rate of 71%),consistent with the time in South China but with a lower magnitude of extinction.Meanwhile,the data show that foraminiferal test volume was significantly miniaturized following the first pulse of extinction event:the mean size of post-extinction foraminifer was only 15%of that in the pre-extinction,mainly reflected by the disappearance of large forms as well as occurrences of smaller survivors and originators.Combined with the South China record,size data from southern Xizang indicate that the miniaturization of foraminifera is synchronous in the Paleotethys and Neotethys but smaller in magnitude in the Neotethys.We propose that ocean anoxia and acidification may be the environmental pressures leading to local and global foraminiferal miniaturizations,along with global warming,which might play a dominant role.
文摘The objective of this study was to describe the trend of reproductive performance of primiparous and multiparous cows that grazed rice crop residues located in a Dry Tropical Forest of Colombia, taking into account the rainfall pattern of the place. In this study, 89 primiparous and 309 multiparous Cebu cattle records were analyzed. Mean, mean standard deviation for age at first calving and open days of primipar-ous Cebu cattle were 41.05± 1.85 months and 269.7±36.25 days respectively. Confidence intervals (95%) for both reproductive parameters were 36.8-45.3 months and 202.7-336.6 days respectively. For multiparous Cebu cattle, the mean and mean standard deviation for open days and calving interval were 245.6±36.8 days and 17.5±0.9 months respectively. Confidence intervals 207.1-366.9 days and 13.9-20.7 months respectively. The mean rainfall since 1999 until 2012 was1202 mmper year. The reproduc-tive trend of the primiparous cattle showed an increasing behavior of age at first calving since 1999 until 2012, that can possibly be explained due to the decreasing behavior of the rainfall throughout the years, that can affect the nutritional value and offer of the grass that can grow in the borders of the crop, such as Guinea and Star grass, and eventually affect the body condition and weight necessary to be ready for the first estrous. An inverse behavior of open days occurred, showing a decreased trend along the last years of research. This fact could have happened due to the intensive use of the enriched rice straw with urea and molasses lately. Regarding to the reproductive trend of the multiparous cattle, there is no an evident pat-tern of it. Factors such as rainfall, temperature, nutrition and management should have affected it. Further research on this topic is needed.
基金the Belgian Development Cooperation for the financial help
文摘Sericostaehys seandens is a monocarpic and heliophilous liana, native in tropical African forests. In the montane forests of the Kahuzi-Biega National Park （KBNP） （East of DR Congo）, it has been expanding very strongly for a decade, and is currently considered as having negative impacts on biodiversity conservation. In this paper, we test if S. scandens differs from three co-occurring, native, non spreading lianas （Gouania longispicata, Tacazzea apiculata and Adenia bequaertii） for functional traits which might influence plant expansion. For leaf traits （SLA, dry matter content, nitrogen concentration）, S. scandens did not show extreme values compared to those of the three other lianas. In contrast, S. scandens had much higher biomass allocation to sexual reproduction. It also differs from the three other lianas for its reproductive strategy that combines both vegetative propagation and sexual reproduct/on, and propagule dispersal by wind. Moreover, S. scandens has larger leaves and a greater number of lateral branches per unit stem length. It is argued that the particular combination of functional traits exhibited by S.scandens may in part explain its propensity to behave as an opportunistic weed in the disturbed areas in the montane forests of Kahuzi-Biega.
文摘The study highlights the complex dynamics governing the growth of forest stands,particularly in eucalyptus plantations in Congo.Factors such as soil fertility,planting density,clone genetics,and resource competition significantly influence forest productivity.Thinning practices,when well implemented,help to rebalance competition among trees and maximize diameter growth.However,forest growth models,like Vanclay’s model,must be adapted to local conditions to provide more accurate and relevant predictions.Despite the progress made,questions remain about the best way to optimize forest stand management.The use of more sophisticated models that can account for the diversity of ecological conditions and management practices represents a major challenge for researchers and forest managers.
基金partly funded by the LMI-OCE and CNPq 400029/2015-4,420697/2018-7Jeremie Garnier was supported by CNPq grant 302722/2018-1。
文摘The Paraiba do Sul(PSR)and Guandu Rivers(GR)water diversion system(120 km long)is located in the main industrial pole of Brazil and supplies drinking water for 9.4 million people in the metropolitan region of Rio de Janeiro.This study aims to discern the trace metals dynamics in this complex aquatic system.We used a combined approach of geochemical tools such as geochemical partitioning,Zn isotopes signatures,and multivariate statistics.Zinc and Pb concentrations in Suspended Particulate Matter(SPM)and sediments were considerably higher in some sites.The sediment partition of As,Cr,and Cu revealed the residual fraction(F4)as the main fraction for these elements,indicating low mobility.Zinc and Pb were mostly associated with the exchangeable/carbonate(F1)and the reducible(F2)fractions,respectively,implying a higher susceptibility of these elements to being released from sediments.Zinc isotopic compositions of sediments and SPM fell in a binary mixing source process between lithogenic(δ^(66/64)Zn_(JMC)≈+0.30‰)and anthropogenic(δ^(66/64)Zn_(JMC)≈+0.15‰)end members.The lighterδ^(66/64)Zn_(JMC)values accompanied by high Zn concentrations in exchangeable/carbonate fraction(ZnF1)enable the tracking of Zn anthropogenic sources in the studied rivers.Overall,the results indicated that Hg,Pb,and Zn had a dominant anthropogenic origin linked to the industrial activities,while As,Cr,and Cu were mainly associated with lithogenic sources.This work demonstrates how integrating geochemical tools is valuable for assessing geochemical processes and mixing source effects in anthropized river watersheds.
文摘“Plasmas” up to a kilometer in size and behaving similarly to multicellular organisms have been filmed on 10 separate NASA space shuttle missions, over 200 miles above Earth within the thermosphere. These self-illuminated “plasmas” are attracted to and may “feed on” electromagnetic radiation. They have different morphologies: 1) cone, 2) cloud, 3) donut, 4) spherical-cylindrical;and have been filmed flying towards and descending from the thermosphere into thunderstorms;congregating by the hundreds and interacting with satellites generating electromagnetic activity;approaching the Space Shuttles. Computerized analysis of flight path trajectories documents these plasmas travel at different velocities from different directions and change their angle of trajectory making 45°, 90°, and 180° shifts and follow each other. They’ve been filmed accelerating, slowing down, stopping, congregating, engaging in “hunter-predatory” behavior and intersecting plasmas leaving a plasma dust trail in their wake. Similar life-like behaviors have been demonstrated by plasmas created experimentally. “Plasmas” may have been photographed in the 1940s by WWII pilots (identified as “Foo fighters”);repeatedly observed and filmed by astronauts and military pilots and classified as Unidentified Aerial—Anomalous Phenomenon. Plasmas are not biological but may represent a form of pre-life that via the incorporation of elements common in space, could result in the synthesis of RNA. Plasmas constitute a fourth state of matter, are attracted to electromagnetic activity, and when observed in the lower atmosphere likely account for many of the UFO-UAP sightings over the centuries.
文摘Following votes by the Barremian Working Group,the International Subcommission on Cretaceous Stratigraphy and the International Commission on Stratigraphy,the Executive Committee of the International Union of Geological Sciences unanimously approved in March 2023 the Global Stratotype Section and Point(GSSP)for the Barremian Stage(Lower Cretaceous).The base of the Barremian Stage is defined at the base of bed 171 of the Río Argos section,near Caravaca(SE Spain)and correlated by the first appearance of the ammonite species Taveraidiscus hugii.This event falls within the NC5C calcareous nannofossil Subzone,the Lilliputianella semielongata planktonic foraminiferal Zone,and the Dorothia ouachensis benthic foraminiferal Zone.It roughly coincides with the beginning of a slightly negative trend interval in theδ^(13)C curve.Indirect calibration to the magnetostratigraphic scale suggests that the boundary falls in the lowermost part of polarity chron M3r.According to the astrochronological analysis,a time interval of 0.74 myr separates the beginning of the late Hauterivian Faraoni Episode from the base of the Barremian,which is dated at 125.77 MA.
文摘This study focuses on the landscape dynamics of the savannahs’ region in the far north of Togo. Based on a literature review and satellite images analysis using GIS and remote sensing, the study aims to ascertain the effects of anthropogenic threats on the forest coverage of the Savannahs’ Region between 1984 to 2020. The objective is to clarify the dynamics of land use in the region from 1984 to 2000 and from 2000 to 2020. The findings indicate a significant decline in forest coverage within the region from 1984 to 2020, a trend attributed to land use patterns. Dry forests in the Savannah region are largely converted to farmlands, housing, dry savannahs or agroforestry parks, leading to a steady reduction in forest areas.
基金the National Natural Science Foundation of China[Grant Nos.42077032 and 41571241]the National Key Technology Research and Development Program of the Ministry of Science and Technology of China[Grant No.2015BAC02B01]the China Scholarship Council[Grant No.202106320251].
文摘Environmental stressors such as drought,salinity,and heavy metals pose significant obstacles to achieving sustainable food security,necessitating the development of universally applicable and cost-effective solutions to ameliorate soil under stress.Biochar,an eco-friendly material to increase crop yield,has been researched for almost two decades and has great potential for global use in enhancing stress resistance.However,there hasn’t been comprehensive research on the impact of biochar application on soil properties,and root and crop growth.To optimize and promote biochar application in agriculture under stress,this study integrates over 100 peer-reviewed articles to explain how biochar promotes crop growth by enhancing soil resistance to stress.Biochar’s distinctive properties,such as porous structure,alkaline nature,enriched surface functional groups,and nutrient content,are responsible for the following soil environment benefits:improved soil physiochemical properties,increased nutrient cycling,and boosted microbial growth.Moreover,the research emphasizes that the enhanced stress resistance of biochar optimizes nutrient absorption,alleviates soil pollutants,and thereby enhances overall crop productivity.The study discusses the roles and mechanisms of biochar on soil under stress,as well as the challenges linked to the sustainable and economical implementation of biochar in extreme soil conditions.This review aims to provide a theoretical basis for the widespread and cost-effective use of biochar in improving soil under stresses,thereby enhancing soil health and food security.
文摘Aims Relationships between local habitat heterogeneity and tree commu-nities in miombo woodlands have been very little studied.While some studies have addressed this topic at broad scales and based on few environmental parameters,this study aims at(i)detecting fine-scale habitats(≤10 ha)on the basis of a detailed characterisation of soil explicitly considering past anthropogenic disturbances,and an exhaustive census of the tree community,and at(ii)searching for indicator tree species corresponding to the resulting habitats.Methods The study was carried out in the miombo woodland of Mikembo Forest Reserve,Upper Katanga,The Democratic Republic of the congo.A complete census of the tree community was conducted in a 10-ha forest dynamics plot comprising 160 adjacent quadrats of 25×25 m,with a total of 4604 trees(diameter at breast height>10 cm).Thirty-six physicochemical soil parameters were measured.Studying the frequency distribution of soil charcoal content allowed identifying local signature of past human agriculture in the soil.Two strategies were used to define habitats:(i)a combination of principal component analysis(PcA)on soil variables and Ward clustering and(ii)multivariate regression trees(MRT)to search for key soil parameters allowing the best prediction of species composition.Tree-habitat associations were tested by means of a robust statistical framework combining the IndVal index and torus randomisations.Important Findings The forest contained 82 tree species and a significant proportion of wet miombo species(e.g.Marquesia macroura).We detected a strong east-west edaphic gradient driven by soil texture;most chemical soil parameters followed this pattern.Five habitats were identified based on soil factors and floristic composition.Nine indicator species of these habitats were found.The key soil fac-tors discriminating habitats were total calcium,available forms of phosphorus and clay content.Even though past agricultural practices were successfully detected in soils,they did not display any significant influence neither on habitat differentiation nor on the associated tree communities.Based on an unprecedented large number of soil parameters,fine-scale soil heterogeneity and niche partitioning were shown to contribute to the variabil-ity of the floristic composition in this forest.Our results indicated that considering the most variable environmental parameters,as in PcA,is a poor manner for defining habitats.In contrast,combining MRT with the IndVal index and torus randomisation has proved to be a much more robust and sensitive approach to highlight tree-habitat associations at this scale.The common dichotomous viewpoint of considering deterministic and neutral effects as acting at broad and fine scales,respectively,is not confirmed when measuring suitable environmental variables,even in a case where the physical environment does not exhibit strong heterogeneity.
基金supported by the National Natural Science Foundation of China(Grant No.40821004)Public Science and Technology Research Funds Projects of Ocean(Grant No.201005030)+1 种基金the National Natural Science Foundation of China(Grant No.41276186)the Program of Nanjing University of Information Science and Technology(Grant No.S8111005001)
文摘A Lagrangian model is used to evaluate source regions of particles collected in the sediment traps at the DYFAMED （Dy namique des Flux Atmospheriques en Mediterranee） station by tracking particles backwards from March 1 to August 31, 2001. The analysis suggests that source regions depend on the flow fields, the settling speed of the particles, and the deployment depths of the traps. Monthly variation is observed in the distribution patterns of source regions, which is caused by the currents The source regions are located around the traps and up to hundreds of kilometers away. As the settling speed increases with the particle diameters, the distance to the source regions decreases. The vertical flux can be approximately estimated in 1D for the particles with diameters larger than 500 lain. Furthermore, traps moored at various depths at the DYFAMED can collect parti- cles that originated from different regions in the Ligurian Sea.
基金State Key R&D Project of China(2023YFF0804000)National Natural Science Foundation of China(42325202,92155201,and 92255303),the 111 Project(B08030)+1 种基金Natural Science Foundation of Hubei(2023 AFA006)Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan).
文摘Extinction selectivity determines the direction of macroevolution,especially during mass extinction;however,its driving mechanisms remain poorly understood.By investigating the physiological selectivity of marine animals during the Permian-Triassic mass extinction,we found that marine clades with lower O2-carrying capacity hemerythrin proteins and those relying on O2 diffusion experienced significantly greater extinction intensity and body-size reduction than those with higher O2-carrying capacity hemoglobin or hemocyanin proteins.Our findings suggest that animals with high O2-carrying capacity obtained the necessary O2 even under hypoxia and compensated for the increased energy requirements caused by ocean acidification,which enabled their survival during the Permian-Triassic mass extinction.Thus,high O2-carrying capacity may have been crucial for the transition from the Paleozoic to the Modern Evolutionary Fauna.
