The hydrographic eastern Mediterranean Basin of Turkey is a drought sensitive area.The basin is an important agricultural area and it is necessary to determine the extent of extreme regional climatic changes as they o...The hydrographic eastern Mediterranean Basin of Turkey is a drought sensitive area.The basin is an important agricultural area and it is necessary to determine the extent of extreme regional climatic changes as they occur in this basin.Pearson’s correlation coefficient was used to show the correlation between standardized precipitation index(SPI)and standardized streamflow index(SSI)values on different time scales.Data from five meteorological stations and seven stream gauging stations in four sub-basins of the eastern Mediterranean Basin were analyzed over the period from 1967 to 2017.The correlation between SSI and SPI indicated that in response to meteorological drought,hydrological drought experiences a one-year delay then occurs in the following year.This is more evident at all stations from the mid-1990 s.The main factor causing hydrological drought is prolonged low precipitation or the presence of a particularly dry year.Results showed that over a long period(12 months),hydrological drought is longer and more severe in the upper part than the lower part of the sub-basins.According to SPI-12 values,an uninterrupted drought period is observed from 2002–2003 to 2008–2009.Results indicated that among the drought events,moderate drought is the most common on all timescales in all sub-basins during the past 51 years.Long-term dry periods with moderate and severe droughts are observed for up to 10 years or more since the late 1990 s,especially in the upper part of the sub-basins.As precipitation increases in late autumn and early winter,the stream flow also increases and thus the highest and most positive correlation values(0.26–0.54)are found in January.Correlation values(ranging between–0.11 and–0.01)are weaker and negative in summer and autumn due to low rainfall.This is more evident at all stations in September.The relation between hydrological and meteorological droughts is more evident,with the correlation values above 0.50 on longer timescales(12-and 24-months).The results presented in this study allow an understanding of the characteristics of drought events and are instructive for overcoming drought.This will facilitate the development of strategies for the appropriate management of water resources in the eastern Mediterranean Basin,which has a high agricultural potential.展开更多
The evolution of the Mediterranean area since the Oligocene-Lower Miocene has been driven by the convergence of the surrounding plates. This implies that the observed deformation pattern in that region must be the mos...The evolution of the Mediterranean area since the Oligocene-Lower Miocene has been driven by the convergence of the surrounding plates. This implies that the observed deformation pattern in that region must be the most convenient shortening pattern, i.e. the one controlled by the minimum action principle. To understand why the fulfilment of such condition has required a complex spatio-temporal distribution of major tectonic events, such as uplift, lateral displacement and bending of orogenic belts, consumption of large lithospheric domains and formation of back arc basins, it may be very useful to take into account a basic tectonic concept, which helps to identify the process that can minimize the resistance of tectonic forces. Such concept starts from the fact that the most convenient consumption process is the one that involves low buoyancy oceanic lithosphere (Tethyan domains). However, such process is highly favoured where the oceanic lithosphere is stressed by vertical forces, a situation that develops when orogenic wedges are forced to over thrust and load the oceanic domain to be consumed. This interpretation can provide plausible and coherent explanations for the complex pattern of the observed deformations. In this view, the generation of back arc basins is taken as a side effect of an extrusion process, as suggested by numerical and mechanical experiments.展开更多
Numerical modeling of sea states has been developed for years,and used for varied fields such as coastal work sizing,navigation safety,beaches and water leisure stability study.The third-generation ocean wind-wave spe...Numerical modeling of sea states has been developed for years,and used for varied fields such as coastal work sizing,navigation safety,beaches and water leisure stability study.The third-generation ocean wind-wave spectral model WAVEWATCH III(WW3)software was adopted and developed to simulate wave propagation in the Mediterranean basin.In this work,a more detailed study was carried out on the port of Algiers.Two different atmospheric models have been used to get the wind forcing:ALADIN(Area Limited Dynamic Adaptation Inter National Development)with an 8 km resolution.And AROME(Application to Operational Research at Meso-scale)with a 3 km resolution.The results obtained using both of the atmospheric models have been compared and analyzed.展开更多
Over the past decade,the Mg/Ca ratio in foraminiferal tests has emerged as a valuable paleotemperature proxy.In this study we describe the application of the Mg/Ca paleothermometer with the aim of illustrate its use i...Over the past decade,the Mg/Ca ratio in foraminiferal tests has emerged as a valuable paleotemperature proxy.In this study we describe the application of the Mg/Ca paleothermometer with the aim of illustrate its use in the Mediterranean Basin.We value the influence of the salinity and diagenetic carbonate processes besides temperature as an important environmental factor controlling the foraminiferal Mg/Ca.For this purpose 3 species of展开更多
A critical review of the evolutionary biology of Iberian and North African lizard members of the genus Podarcis(Lacertidae)based on phylogeny,phylogeography,morphometrics,behavior,ecology and physiology is presented.T...A critical review of the evolutionary biology of Iberian and North African lizard members of the genus Podarcis(Lacertidae)based on phylogeny,phylogeography,morphometrics,behavior,ecology and physiology is presented.The Iberomaghrebian region is inhabited by at least 12 different evolutionary lineages that group into a monophyl-etic clade(except Podarcis muralis).In contrast to the current taxonomy,the saxicolous‘Podarcis hispanica’is paraphyletic with respect to Podarcis bocagei and Podarcis carbonelli,two currently recognized species.Nodes in the phylogenetic tree are deep,resulting from old divergences,clearly preceding the Pleistocene.Nevertheless,more recent range changes as a result of glaciations are also evident.The most plausible evolutionary scenario for this group indicates both vicariant and dispersal events.Although parapatry between lineages is the rule,sympatry and even syntopy are frequent,but usually between ground-dwelling and saxicolous forms.Contacts between forms with similar habitat use are rare and local.Morphological distinctiveness between lineages has been demonstrated,indicating historical constraints.However,other characters have repeatedly evolved under similar environmental pressures independently of the evolutionary lineage.Strong sexual dimorphism derives from sexual selection and is attained before sexual maturity,although developmental restrictions exist.Variation between popu-lations is also important and derives from local variation in both natural(habitat,climate)and sexual(density)selective pressures.Evidence for short-term changes has already been found,particularly in insular populations.Reproductive isolation between syntopic forms and partner recognition are based on male–male competition and on visual and chemical recognition of females by conspecific males.Despite this ancient diversification,most forms maintain a degree of reproductive compatibility.Hybridisation may occur,but is limited,and there is evidence of selection against hybrids.The ecological analysis presented here does not support exploitative competition,but rather behavioral interference between forms.Ecomorph classification of lineages suggests character displacement between those with extensive range overlap.Finally,a critical assessment of the specific status of all lineages is provided and directions for further research are suggested.展开更多
Background:Pyrogeography is a major field of investigation in wildfire science because of its capacity to describe the spatial and temporal variations of fire disturbance.We propose a systematic pyrogeographic analyti...Background:Pyrogeography is a major field of investigation in wildfire science because of its capacity to describe the spatial and temporal variations of fire disturbance.We propose a systematic pyrogeographic analytical approach to cluster regions on the basis of their pyrosimilarities.We employed the Affinity Propagation algorithm to cluster pyroregions using Italian landscape as a test bed and its current wildfire metrics in terms of density,seasonality and stand replacing fire ratio.A discussion follows on how pyrogeography varies according to differences in the human,biophysical,socioeconomic,and climatic spheres.Results:The algorithm identified seven different pyroregion clusters.Two main gradients were identified that partly explain the variability of wildfire metrics observed in the current pyroregions.First,a gradient characterized by increasing temperatures and exposure to droughts,which coincides with a decreasing latitude,and second,a human pressure gradient displaying increasing population density in areas at lower elevation.These drivers exerted a major influence on wildfire density,burnt area over available fuels and stand replacing,which were associated to warmdry climate and high human pressure.The study statistically highlighted the importance of a North–South gradient,which represents one of the most important drivers of wildfire regimes resulting from the variations in climatic conditions but showing collinearity with socioeconomic aspects as well.Conclusion:Our fully replicable analytical approach can be applied at multiple scales and used for the entire European continent to uncover new and larger pyroregions.This could create a basis for the European Commission to promote innovative and collaborative funding programs between regions that demonstrate pyrosimilarities.展开更多
Background:Wildfires play a key role in shaping Mediterranean landscapes and ecosystems and in impacting species dynamics.Numerous studies have investigated the wildfire occurrences and the influence of their drivers ...Background:Wildfires play a key role in shaping Mediterranean landscapes and ecosystems and in impacting species dynamics.Numerous studies have investigated the wildfire occurrences and the influence of their drivers in many countries of the Mediterranean Basin.However,in this regard,no studies have attempted to compare different Mediterranean regions,which may appear similar under many aspects.In response to this gap,climatic,topographic,anthropic,and landscape drivers were analyzed and compared to assess the patterns of fire ignition points in terms of fire occurrence and frequency in Catalonia(Spain),Sardinia,and Apulia(Italy).Therefore,the objectives of the study were to(1)assess fire ignition occurrence in terms of probability and frequency,(2)compare the main drivers affecting fire occurrence,and(3)produce fire probability and frequency maps for each region.Results:In pursuit of the above,the probability of fire ignition occurrence and frequency was mapped using Negative Binomial Hurdle models,while the models’performances were evaluated using several metrics(AUC,prediction accuracy,RMSE,and the Pearson correlation coefficient).The results showed an inverse correlation between distance from infrastructures(i.e.,urban roads and areas)and the occurrence of fires in all three study regions.This relationship became more significant when the frequency of fire ignition points was assessed.Moreover,a positive correlation was found between fire occurrence and landscape drivers according to region.The land cover classes more significantly affected were forest,agriculture,and grassland for Catalonia,Sardinia,and Apulia,respectively.Conclusions:Compared to the climatic,topographic,and landscape drivers,anthropic activity significantly influences fire ignition and frequency in all three regions.When the distance from urban roads and areas decreases,the probability of fire ignition occurrence and frequency increases.Consequently,it is essential to implement long-to medium-term intervention plans to reduce the proximity between potential ignition points and fuels.In this perspective,the present study provides an applicable decision-making tool to improve wildfire prevention strategies at the European level in an area like the Mediterranean Basin where a profuse number of wildfires take place.展开更多
A high-resolution integrated study has been performed in a super-expanded marine record(sedimentation rate spanning from 11 cm/100 years to 20 cm/100 years)from the continental shelf area of the southeastern Tyrrhe...A high-resolution integrated study has been performed in a super-expanded marine record(sedimentation rate spanning from 11 cm/100 years to 20 cm/100 years)from the continental shelf area of the southeastern Tyrrhenian Sea.Planktonic foraminiferal distribution illustrates 6 major environmental changes during the past 2000 years:(i)the Roman Period-Dark Age transition(from herbivorous-opportunistic to carnivorous species);(ii)the Dark Age-MCA transition(from carnivorous to herbivorous-opportunistic species);(iii)the Medieval Classic Anomaly-Little Ice Age transition(a further and definitive change from carnivorous to herbivorous-opportunistic species);(iv)the period during the Maunder event between approximately 1720 AD and 1740 AD(turnover from the carnivorous planktonic foraminifer Globigerinodes ruber to the herbivorous-opportunistic planktonic foraminifer Turborotalita quinqueloba);(v)the Industrial Period(dominance of herbivorous-opportunistic planktonic foraminifera);and(vi)the Modern Warm Period at approximately 1940 AD(the last turnover in favor of herbivorous-opportunistic planktonic foraminifers,associated with an increase in benthic foraminifera).Our studies lead us to link this latter feature to an anthropogenic impact associated with the damming of Sele River(Salerno Gulf)at 1934 AD,which induced a change in the sediment input with a strong decrease in coarse-grained fraction and a probable alteration in nutrient supply.Theδ^(18)O_(G.ruber) record of the past 2000 years shows the alternation of warm/wet and cold/dry events related to the Roman Period,the Dark Age,the Medieval Classic Anomaly,the Little Ice Age,the Industrial Period and the Modern Warm Period.The 5 evidentδ^(18)O_(G.ruber) oscillations(between approximately 1325 AD and 1940 AD)coincide with the 5 minima in the solar activity record(Wolf,Spörer,Maunder,Dalton and Damon events).展开更多
文摘The hydrographic eastern Mediterranean Basin of Turkey is a drought sensitive area.The basin is an important agricultural area and it is necessary to determine the extent of extreme regional climatic changes as they occur in this basin.Pearson’s correlation coefficient was used to show the correlation between standardized precipitation index(SPI)and standardized streamflow index(SSI)values on different time scales.Data from five meteorological stations and seven stream gauging stations in four sub-basins of the eastern Mediterranean Basin were analyzed over the period from 1967 to 2017.The correlation between SSI and SPI indicated that in response to meteorological drought,hydrological drought experiences a one-year delay then occurs in the following year.This is more evident at all stations from the mid-1990 s.The main factor causing hydrological drought is prolonged low precipitation or the presence of a particularly dry year.Results showed that over a long period(12 months),hydrological drought is longer and more severe in the upper part than the lower part of the sub-basins.According to SPI-12 values,an uninterrupted drought period is observed from 2002–2003 to 2008–2009.Results indicated that among the drought events,moderate drought is the most common on all timescales in all sub-basins during the past 51 years.Long-term dry periods with moderate and severe droughts are observed for up to 10 years or more since the late 1990 s,especially in the upper part of the sub-basins.As precipitation increases in late autumn and early winter,the stream flow also increases and thus the highest and most positive correlation values(0.26–0.54)are found in January.Correlation values(ranging between–0.11 and–0.01)are weaker and negative in summer and autumn due to low rainfall.This is more evident at all stations in September.The relation between hydrological and meteorological droughts is more evident,with the correlation values above 0.50 on longer timescales(12-and 24-months).The results presented in this study allow an understanding of the characteristics of drought events and are instructive for overcoming drought.This will facilitate the development of strategies for the appropriate management of water resources in the eastern Mediterranean Basin,which has a high agricultural potential.
文摘The evolution of the Mediterranean area since the Oligocene-Lower Miocene has been driven by the convergence of the surrounding plates. This implies that the observed deformation pattern in that region must be the most convenient shortening pattern, i.e. the one controlled by the minimum action principle. To understand why the fulfilment of such condition has required a complex spatio-temporal distribution of major tectonic events, such as uplift, lateral displacement and bending of orogenic belts, consumption of large lithospheric domains and formation of back arc basins, it may be very useful to take into account a basic tectonic concept, which helps to identify the process that can minimize the resistance of tectonic forces. Such concept starts from the fact that the most convenient consumption process is the one that involves low buoyancy oceanic lithosphere (Tethyan domains). However, such process is highly favoured where the oceanic lithosphere is stressed by vertical forces, a situation that develops when orogenic wedges are forced to over thrust and load the oceanic domain to be consumed. This interpretation can provide plausible and coherent explanations for the complex pattern of the observed deformations. In this view, the generation of back arc basins is taken as a side effect of an extrusion process, as suggested by numerical and mechanical experiments.
文摘Numerical modeling of sea states has been developed for years,and used for varied fields such as coastal work sizing,navigation safety,beaches and water leisure stability study.The third-generation ocean wind-wave spectral model WAVEWATCH III(WW3)software was adopted and developed to simulate wave propagation in the Mediterranean basin.In this work,a more detailed study was carried out on the port of Algiers.Two different atmospheric models have been used to get the wind forcing:ALADIN(Area Limited Dynamic Adaptation Inter National Development)with an 8 km resolution.And AROME(Application to Operational Research at Meso-scale)with a 3 km resolution.The results obtained using both of the atmospheric models have been compared and analyzed.
文摘Over the past decade,the Mg/Ca ratio in foraminiferal tests has emerged as a valuable paleotemperature proxy.In this study we describe the application of the Mg/Ca paleothermometer with the aim of illustrate its use in the Mediterranean Basin.We value the influence of the salinity and diagenetic carbonate processes besides temperature as an important environmental factor controlling the foraminiferal Mg/Ca.For this purpose 3 species of
文摘A critical review of the evolutionary biology of Iberian and North African lizard members of the genus Podarcis(Lacertidae)based on phylogeny,phylogeography,morphometrics,behavior,ecology and physiology is presented.The Iberomaghrebian region is inhabited by at least 12 different evolutionary lineages that group into a monophyl-etic clade(except Podarcis muralis).In contrast to the current taxonomy,the saxicolous‘Podarcis hispanica’is paraphyletic with respect to Podarcis bocagei and Podarcis carbonelli,two currently recognized species.Nodes in the phylogenetic tree are deep,resulting from old divergences,clearly preceding the Pleistocene.Nevertheless,more recent range changes as a result of glaciations are also evident.The most plausible evolutionary scenario for this group indicates both vicariant and dispersal events.Although parapatry between lineages is the rule,sympatry and even syntopy are frequent,but usually between ground-dwelling and saxicolous forms.Contacts between forms with similar habitat use are rare and local.Morphological distinctiveness between lineages has been demonstrated,indicating historical constraints.However,other characters have repeatedly evolved under similar environmental pressures independently of the evolutionary lineage.Strong sexual dimorphism derives from sexual selection and is attained before sexual maturity,although developmental restrictions exist.Variation between popu-lations is also important and derives from local variation in both natural(habitat,climate)and sexual(density)selective pressures.Evidence for short-term changes has already been found,particularly in insular populations.Reproductive isolation between syntopic forms and partner recognition are based on male–male competition and on visual and chemical recognition of females by conspecific males.Despite this ancient diversification,most forms maintain a degree of reproductive compatibility.Hybridisation may occur,but is limited,and there is evidence of selection against hybrids.The ecological analysis presented here does not support exploitative competition,but rather behavioral interference between forms.Ecomorph classification of lineages suggests character displacement between those with extensive range overlap.Finally,a critical assessment of the specific status of all lineages is provided and directions for further research are suggested.
文摘Background:Pyrogeography is a major field of investigation in wildfire science because of its capacity to describe the spatial and temporal variations of fire disturbance.We propose a systematic pyrogeographic analytical approach to cluster regions on the basis of their pyrosimilarities.We employed the Affinity Propagation algorithm to cluster pyroregions using Italian landscape as a test bed and its current wildfire metrics in terms of density,seasonality and stand replacing fire ratio.A discussion follows on how pyrogeography varies according to differences in the human,biophysical,socioeconomic,and climatic spheres.Results:The algorithm identified seven different pyroregion clusters.Two main gradients were identified that partly explain the variability of wildfire metrics observed in the current pyroregions.First,a gradient characterized by increasing temperatures and exposure to droughts,which coincides with a decreasing latitude,and second,a human pressure gradient displaying increasing population density in areas at lower elevation.These drivers exerted a major influence on wildfire density,burnt area over available fuels and stand replacing,which were associated to warmdry climate and high human pressure.The study statistically highlighted the importance of a North–South gradient,which represents one of the most important drivers of wildfire regimes resulting from the variations in climatic conditions but showing collinearity with socioeconomic aspects as well.Conclusion:Our fully replicable analytical approach can be applied at multiple scales and used for the entire European continent to uncover new and larger pyroregions.This could create a basis for the European Commission to promote innovative and collaborative funding programs between regions that demonstrate pyrosimilarities.
文摘Background:Wildfires play a key role in shaping Mediterranean landscapes and ecosystems and in impacting species dynamics.Numerous studies have investigated the wildfire occurrences and the influence of their drivers in many countries of the Mediterranean Basin.However,in this regard,no studies have attempted to compare different Mediterranean regions,which may appear similar under many aspects.In response to this gap,climatic,topographic,anthropic,and landscape drivers were analyzed and compared to assess the patterns of fire ignition points in terms of fire occurrence and frequency in Catalonia(Spain),Sardinia,and Apulia(Italy).Therefore,the objectives of the study were to(1)assess fire ignition occurrence in terms of probability and frequency,(2)compare the main drivers affecting fire occurrence,and(3)produce fire probability and frequency maps for each region.Results:In pursuit of the above,the probability of fire ignition occurrence and frequency was mapped using Negative Binomial Hurdle models,while the models’performances were evaluated using several metrics(AUC,prediction accuracy,RMSE,and the Pearson correlation coefficient).The results showed an inverse correlation between distance from infrastructures(i.e.,urban roads and areas)and the occurrence of fires in all three study regions.This relationship became more significant when the frequency of fire ignition points was assessed.Moreover,a positive correlation was found between fire occurrence and landscape drivers according to region.The land cover classes more significantly affected were forest,agriculture,and grassland for Catalonia,Sardinia,and Apulia,respectively.Conclusions:Compared to the climatic,topographic,and landscape drivers,anthropic activity significantly influences fire ignition and frequency in all three regions.When the distance from urban roads and areas decreases,the probability of fire ignition occurrence and frequency increases.Consequently,it is essential to implement long-to medium-term intervention plans to reduce the proximity between potential ignition points and fuels.In this perspective,the present study provides an applicable decision-making tool to improve wildfire prevention strategies at the European level in an area like the Mediterranean Basin where a profuse number of wildfires take place.
基金C90 and C836 gravity-cores have been collected by the IAMC-CNR(Napoli)aboard the CNR-Urania vessel while C90_1m gravity core has been acquired(using the core system SW104)aboard the CNR-Thetis vessel.The authors thank Werner Piller and Luca Maria Foresi for their useful comments and suggestions.Moreover,many thanks are given to Rita Barra for a final revision of the English text.This research has been financially supported by the Project of Strategic Interest NextData PNR 2011-2013(www.nextdataproject.it).This is an ISMAR-CNR contribution(no.1787).
文摘A high-resolution integrated study has been performed in a super-expanded marine record(sedimentation rate spanning from 11 cm/100 years to 20 cm/100 years)from the continental shelf area of the southeastern Tyrrhenian Sea.Planktonic foraminiferal distribution illustrates 6 major environmental changes during the past 2000 years:(i)the Roman Period-Dark Age transition(from herbivorous-opportunistic to carnivorous species);(ii)the Dark Age-MCA transition(from carnivorous to herbivorous-opportunistic species);(iii)the Medieval Classic Anomaly-Little Ice Age transition(a further and definitive change from carnivorous to herbivorous-opportunistic species);(iv)the period during the Maunder event between approximately 1720 AD and 1740 AD(turnover from the carnivorous planktonic foraminifer Globigerinodes ruber to the herbivorous-opportunistic planktonic foraminifer Turborotalita quinqueloba);(v)the Industrial Period(dominance of herbivorous-opportunistic planktonic foraminifera);and(vi)the Modern Warm Period at approximately 1940 AD(the last turnover in favor of herbivorous-opportunistic planktonic foraminifers,associated with an increase in benthic foraminifera).Our studies lead us to link this latter feature to an anthropogenic impact associated with the damming of Sele River(Salerno Gulf)at 1934 AD,which induced a change in the sediment input with a strong decrease in coarse-grained fraction and a probable alteration in nutrient supply.Theδ^(18)O_(G.ruber) record of the past 2000 years shows the alternation of warm/wet and cold/dry events related to the Roman Period,the Dark Age,the Medieval Classic Anomaly,the Little Ice Age,the Industrial Period and the Modern Warm Period.The 5 evidentδ^(18)O_(G.ruber) oscillations(between approximately 1325 AD and 1940 AD)coincide with the 5 minima in the solar activity record(Wolf,Spörer,Maunder,Dalton and Damon events).
