Numerous new records of Ferganiella, Podozamites, and Schidolepium, including a new species, Ferganiella ivantsovii sp. nov., are described from the Early Jurassic(Toarcian) Middle Subformation of the Prisayan Formati...Numerous new records of Ferganiella, Podozamites, and Schidolepium, including a new species, Ferganiella ivantsovii sp. nov., are described from the Early Jurassic(Toarcian) Middle Subformation of the Prisayan Formation from the Euro-Sinian paleofloristic region in the Irkutsk Basin, Eastern Siberia, Russia. An analysis of the paleogeographic distribution of Ferganiella and Podozamites shows that both genera were the most diverse and numerous in the East Asian province of the Euro-Sinian region and in the Northern Chinese province of the Siberian region during the Early and Middle Jurassic. These phytochoria were located in the subtropical and temperate subtropical climate zones, which allows us to consider Ferganiella and Podozamites as thermophilic plants, which are important indicators of the Early Toarcian climatic optimum. Their abundance in the Irkutsk Basin thus may indicate Early Toarcian warming;further abundant Schidolepium cones, which produced Araucariacites pollen, typical for Euro-Sinian flora complement the scenario. Thus, the new finds are the first macrofloristic indicators of the Toarcian climatic optimum in the Irkutsk Basin.展开更多
The Mediterranean,a sea with an already eventful history,is again undergoing an extreme change.A combination of general warming of the Mediterranean Sea and contact with the Indopacific world through the Suez Canal ha...The Mediterranean,a sea with an already eventful history,is again undergoing an extreme change.A combination of general warming of the Mediterranean Sea and contact with the Indopacific world through the Suez Canal has set the stage for massive changes in the biota that inhabit this sea.For over a century,tropical species of all taxa have been migrating back into the Mediterranean,suggesting a duplication or restoration of a mid-Pliocene Piacenzian or late Miocene Tortonian situation.Test cases are presented in three major taxa.It is not a serial invasion by individual rogue exotic and damaging species,as often wrongly assumed and asserted.Despite its unique biogeographic magnitude being recognized,an opportunity to study the progress of this phenomenon is being missed.This is because of the changed priorities in research,the acute taxonomic impediment and to the geopolitical difficulties in cooperation.Nonetheless,the limitations of the restoration process are defined and a careful future outlook is presented.展开更多
The response of mangrove ecosystems to the Asian monsoon in the future global warming can be understood by reconstructing the development of mangrove forests during the Holocene climatic optimum（HCO）, using proxies ...The response of mangrove ecosystems to the Asian monsoon in the future global warming can be understood by reconstructing the development of mangrove forests during the Holocene climatic optimum（HCO）, using proxies preserved in coastal sediments. The total organic matter in sediments of a segmented core, with calibrated age ranges between 5.6 and 7.7 cal. ka BP and corresponding to the HCO, from the Qinzhou Bay in Guangxi, China, is quantitatively partitioned into three end-members according to their sources： mangrove-derived, terrigenous,and marine phytoplanktonic, using a three-end-member model depicted by organic carbon isotope（δ13Corg） and the molar ratio of total organic carbon to total nitrogen（C/N）. The percentage of mangrove-derived organic matter（MOM） contribution is used as a proxy for mangrove development. Three visible drops in MOM contribution occurred at ca. 7.3, ca. 6.9, and ca. 6.2 cal. ka BP, respectively, are recognized against a relatively stable and higher MOM contribution level, indicating that three distinct mangrove forest degradations occurred in the Qinzhou Bay during the HCO. The three mangrove forest degradations approximately correspond to the time of the strengthened/weakened Asian winter/summer monsoon. This indicates that even during a period favorable for the mangrove development, such as the HCO, climatic extremes, such as cold and dry events driven by the strengthened/weakened Asian winter/summer monsoon, can trigger the degradation of mangrove forests.展开更多
The paper presents an analysis of characteristic karst tufa from Guangxi, China, which has not been studied before. A comparison with tufa from Dinaric Karst of Croatia is discussed in view of the C-type climate. The ...The paper presents an analysis of characteristic karst tufa from Guangxi, China, which has not been studied before. A comparison with tufa from Dinaric Karst of Croatia is discussed in view of the C-type climate. The major mineral is calcite. Minor minerals are quartz and dolomite, depending on location. The content of calcium carbonate varies from 65% to 92%, and that of magnesium carbonate from 0.03% to 1.77%. Among other elements, the most abundant are Fe, from 0.02% to 1.50%, and Ti, from 0.15% to 0.27%. Many other trace elements (V, Cr, Mn, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Y, Zr, Hg and Pb) are also present. Specific activity of radionuclides 40K, 232Th, 137Cs, 226Ra and 238U varies from sample to sample. Concentration of U in tufa is close to that reported for sedimentary carbonate. Low concentration of 137Cs indicates that this part of the world was not exposed to nuclear explosions. The concentration of 226Ra is the highest in Mashan County. The ratio 238U/226Ra (0.21-0.71) in tufa from Mashan County is significantly lower than the theoretical value of 1. In 5 of the 11 studied samples, stable isotopes δ13C and δ18O were analyzed. They were dated by means of the 14C method. One tufa sample originated in the Pleistocene and the others in the Holocene. Because all of the tufa samples contain traces of Na and K, and K < Na, the tufa from Guangxi belong to the CO2-outgassing 'N' type according to the classification of Liu and He (1994).展开更多
The article describes a possible impact of demographic explosion during the Neolith on local ecosystems and on the global climate as well as the role of this explosion in aggravating the course of 4.2 ka cooling event...The article describes a possible impact of demographic explosion during the Neolith on local ecosystems and on the global climate as well as the role of this explosion in aggravating the course of 4.2 ka cooling event. A possible role of human activity in changing the pattern of mid-latitudes westerlies, monsoons and Walker circulation throughout the Holocene is analyzed. It is explained why during the Holocene Climatic Optimum (HCO) monsoons could have been weaker than today, not stronger, as it is commonly stated. It is described how during the HCO the humid Tibetan Plateau could have repelled the Indian monsoon to the west and the East Asian monsoon to the north. The explanation for weaker El Niño-Southern Oscillation (ENSO) during HCO is proposed.展开更多
Fossil record data on the mammal diversity and species richness are of importance for the reconstruction of the evolution of terrestrial ecosystems during the Late Pleistocene-Holocene transition.In Eastern Europe,the...Fossil record data on the mammal diversity and species richness are of importance for the reconstruction of the evolution of terrestrial ecosystems during the Late Pleistocene-Holocene transition.In Eastern Europe,the transformations during the Pleistocene-Holocene transition consisted mainly in changes in zonal structure and local fauna composition(Markova&Kolfschoten 2008).We investigated the species richness and the analogues of theα,βdiversity indexes(in the sense of Whittaker 1972)of large and medium size mammals for 13 climate-stratigraphic units dating to the Late Pleistocene and the Holocene,from the Hasselo Stadial(44-39 kBP)to the Subatlantic period and the present day.The biological diversity of the Last Glacial Maximum(LGM)and the Holocene thermal optimum was investigated in more detail using information about all mammalian taxa(PALEOFAUNA database;Markova 1995).One of our results show that theα,βdiversity values show only a negative correlation with the temperature conditions during the Late Pleistocene,the period that is characterized by the so-called‘Mammoth Fauna’complex.For the Holocene faunas the diversity indexes are nearly independent from physical conditions;theαdiversity index decreased and theβdiversity index increased.The relatively lowαdiversity and highβdiversity indexes for the present-day faunas are referred to the decrease of the population number of some forest species in historical time and the increase of the dominance of unspecialized species or the species connected with intra-zonal ecosystems.The study shows furthermore the occurrence of several East European‘centers’with a high mammal diversity,which are relatively stable during the Pleistocene-Holocene transition.The orientation of the boundaries between the large geographical mammal assemblages depended,particularly in the northwestern part of Eastern Europe,on the expansion of the Scandinavian ice sheet.展开更多
文摘Numerous new records of Ferganiella, Podozamites, and Schidolepium, including a new species, Ferganiella ivantsovii sp. nov., are described from the Early Jurassic(Toarcian) Middle Subformation of the Prisayan Formation from the Euro-Sinian paleofloristic region in the Irkutsk Basin, Eastern Siberia, Russia. An analysis of the paleogeographic distribution of Ferganiella and Podozamites shows that both genera were the most diverse and numerous in the East Asian province of the Euro-Sinian region and in the Northern Chinese province of the Siberian region during the Early and Middle Jurassic. These phytochoria were located in the subtropical and temperate subtropical climate zones, which allows us to consider Ferganiella and Podozamites as thermophilic plants, which are important indicators of the Early Toarcian climatic optimum. Their abundance in the Irkutsk Basin thus may indicate Early Toarcian warming;further abundant Schidolepium cones, which produced Araucariacites pollen, typical for Euro-Sinian flora complement the scenario. Thus, the new finds are the first macrofloristic indicators of the Toarcian climatic optimum in the Irkutsk Basin.
基金the ISZ Sinternational research program Biological Consequencesof Global Change(BCGC)sponsored by Bureau of Inter-national Cooperation,Chinese Academy of Sciences(GJHZ200810).
文摘The Mediterranean,a sea with an already eventful history,is again undergoing an extreme change.A combination of general warming of the Mediterranean Sea and contact with the Indopacific world through the Suez Canal has set the stage for massive changes in the biota that inhabit this sea.For over a century,tropical species of all taxa have been migrating back into the Mediterranean,suggesting a duplication or restoration of a mid-Pliocene Piacenzian or late Miocene Tortonian situation.Test cases are presented in three major taxa.It is not a serial invasion by individual rogue exotic and damaging species,as often wrongly assumed and asserted.Despite its unique biogeographic magnitude being recognized,an opportunity to study the progress of this phenomenon is being missed.This is because of the changed priorities in research,the acute taxonomic impediment and to the geopolitical difficulties in cooperation.Nonetheless,the limitations of the restoration process are defined and a careful future outlook is presented.
基金The National Basic Research Program (973 Program) of China under contract No.2010CB951203the National Natural Science Foundation of China under contract Nos 41376075,41576061 and 41206057
文摘The response of mangrove ecosystems to the Asian monsoon in the future global warming can be understood by reconstructing the development of mangrove forests during the Holocene climatic optimum（HCO）, using proxies preserved in coastal sediments. The total organic matter in sediments of a segmented core, with calibrated age ranges between 5.6 and 7.7 cal. ka BP and corresponding to the HCO, from the Qinzhou Bay in Guangxi, China, is quantitatively partitioned into three end-members according to their sources： mangrove-derived, terrigenous,and marine phytoplanktonic, using a three-end-member model depicted by organic carbon isotope（δ13Corg） and the molar ratio of total organic carbon to total nitrogen（C/N）. The percentage of mangrove-derived organic matter（MOM） contribution is used as a proxy for mangrove development. Three visible drops in MOM contribution occurred at ca. 7.3, ca. 6.9, and ca. 6.2 cal. ka BP, respectively, are recognized against a relatively stable and higher MOM contribution level, indicating that three distinct mangrove forest degradations occurred in the Qinzhou Bay during the HCO. The three mangrove forest degradations approximately correspond to the time of the strengthened/weakened Asian winter/summer monsoon. This indicates that even during a period favorable for the mangrove development, such as the HCO, climatic extremes, such as cold and dry events driven by the strengthened/weakened Asian winter/summer monsoon, can trigger the degradation of mangrove forests.
文摘The paper presents an analysis of characteristic karst tufa from Guangxi, China, which has not been studied before. A comparison with tufa from Dinaric Karst of Croatia is discussed in view of the C-type climate. The major mineral is calcite. Minor minerals are quartz and dolomite, depending on location. The content of calcium carbonate varies from 65% to 92%, and that of magnesium carbonate from 0.03% to 1.77%. Among other elements, the most abundant are Fe, from 0.02% to 1.50%, and Ti, from 0.15% to 0.27%. Many other trace elements (V, Cr, Mn, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Y, Zr, Hg and Pb) are also present. Specific activity of radionuclides 40K, 232Th, 137Cs, 226Ra and 238U varies from sample to sample. Concentration of U in tufa is close to that reported for sedimentary carbonate. Low concentration of 137Cs indicates that this part of the world was not exposed to nuclear explosions. The concentration of 226Ra is the highest in Mashan County. The ratio 238U/226Ra (0.21-0.71) in tufa from Mashan County is significantly lower than the theoretical value of 1. In 5 of the 11 studied samples, stable isotopes δ13C and δ18O were analyzed. They were dated by means of the 14C method. One tufa sample originated in the Pleistocene and the others in the Holocene. Because all of the tufa samples contain traces of Na and K, and K < Na, the tufa from Guangxi belong to the CO2-outgassing 'N' type according to the classification of Liu and He (1994).
文摘The article describes a possible impact of demographic explosion during the Neolith on local ecosystems and on the global climate as well as the role of this explosion in aggravating the course of 4.2 ka cooling event. A possible role of human activity in changing the pattern of mid-latitudes westerlies, monsoons and Walker circulation throughout the Holocene is analyzed. It is explained why during the Holocene Climatic Optimum (HCO) monsoons could have been weaker than today, not stronger, as it is commonly stated. It is described how during the HCO the humid Tibetan Plateau could have repelled the Indian monsoon to the west and the East Asian monsoon to the north. The explanation for weaker El Niño-Southern Oscillation (ENSO) during HCO is proposed.
基金The work was performed with the financial support from RFBR(grant№10-05-00111).We would like to thank our reviewers for their very constructive remarks.We are very grateful to Maria Rita Palombo for her suggestion to contribute to this volume.
文摘Fossil record data on the mammal diversity and species richness are of importance for the reconstruction of the evolution of terrestrial ecosystems during the Late Pleistocene-Holocene transition.In Eastern Europe,the transformations during the Pleistocene-Holocene transition consisted mainly in changes in zonal structure and local fauna composition(Markova&Kolfschoten 2008).We investigated the species richness and the analogues of theα,βdiversity indexes(in the sense of Whittaker 1972)of large and medium size mammals for 13 climate-stratigraphic units dating to the Late Pleistocene and the Holocene,from the Hasselo Stadial(44-39 kBP)to the Subatlantic period and the present day.The biological diversity of the Last Glacial Maximum(LGM)and the Holocene thermal optimum was investigated in more detail using information about all mammalian taxa(PALEOFAUNA database;Markova 1995).One of our results show that theα,βdiversity values show only a negative correlation with the temperature conditions during the Late Pleistocene,the period that is characterized by the so-called‘Mammoth Fauna’complex.For the Holocene faunas the diversity indexes are nearly independent from physical conditions;theαdiversity index decreased and theβdiversity index increased.The relatively lowαdiversity and highβdiversity indexes for the present-day faunas are referred to the decrease of the population number of some forest species in historical time and the increase of the dominance of unspecialized species or the species connected with intra-zonal ecosystems.The study shows furthermore the occurrence of several East European‘centers’with a high mammal diversity,which are relatively stable during the Pleistocene-Holocene transition.The orientation of the boundaries between the large geographical mammal assemblages depended,particularly in the northwestern part of Eastern Europe,on the expansion of the Scandinavian ice sheet.
