The Last Interglacial Period strata in the Milanggouwan section in the Salawusu River valley on the Ordos Plateau, China, have 8.5 sedimentary cycles composed alternately of eolian dune sands, fluvio-lacustrine facies...The Last Interglacial Period strata in the Milanggouwan section in the Salawusu River valley on the Ordos Plateau, China, have 8.5 sedimentary cycles composed alternately of eolian dune sands, fluvio-lacustrine facies and paleosols. Based on comprehensive analyses on the distribution of magnetic susceptibility and CaCO3 and paleo-ecology indicated by fossils in the region, it is considered that the sedimentation cycles resulted from dry-cold and warm-humid climate fluctuations. Magnetic susceptibility values and CaCO3 contents in stratigraphic sectors I, III, V and II, IV basically respectively present peaks and low vales, and the former three can in time correlate with MIS5a, MIS5c and MIS5e successively and the latter two with MIS5b and MIS5d. In addition, some horizons of eolian dune sands and the low vales of their magnetic susceptibility and CaCO3 are also correlated with 6 periods of cooling events indicated by the higher content of foraminifer Neogloboquadrina pachyderma (S.) documented in the V29—191 drill in the North Atlantic and the cold events recorded by δ 18O in the ice cores in GRIP, especially with 9 periods of dust events in Chinese Loess Plateau.展开更多
ONCE ocean floor was below the calcite compensation depth (CCD), deeper than 5000 m, it was widely covered with siliceous ooze or abyssal clay without abyssoconite. The samples of sediment core used in the present res...ONCE ocean floor was below the calcite compensation depth (CCD), deeper than 5000 m, it was widely covered with siliceous ooze or abyssal clay without abyssoconite. The samples of sediment core used in the present research were collected at No. 1787 station during DY85-04 cruise and are mostly of siliceous ooze or abyssal clay. Therefore, traditional and well-considered stable isotopic study using foraminifera has to be given up. Instead, stable isotopic展开更多
Aims The physiological responses during dormancy removal and multi-phasic germination were investigated in seeds of Paeonia corsica(Paeoniaceae).Methods Seeds of P.corsica were incubated in the light at a range of tem...Aims The physiological responses during dormancy removal and multi-phasic germination were investigated in seeds of Paeonia corsica(Paeoniaceae).Methods Seeds of P.corsica were incubated in the light at a range of temperatures(10-25 and 25/10℃),without any pre-treatment,after W(3 months at 25℃),C(3 months at 5℃)and W+C(3 months at 25℃followed by 3 months at 5℃)stratification,and a GA_(3)treatment(250 mg·l^(−1)in the germination substrate).Embryo growth,time from testa to endosperm rupture and radicle emergence were assessed as separate phases.Epicotyl-plumule emergence was evaluated incubating the germinated seeds at 15℃for 2 weeks,at 5 and 25℃for 2 months on agar water before transplanting to the soil substrate at 10,15 and 20℃and at 15℃for 2 months on the surface agar water with GA_(3).Important Findings Embryo growth,testa rupture,endosperm rupture(radicle emergence)and growth of the epicotyl were identified as four sequential steps in seeds of P.corsica.Gibberellic acid alone and warm stratification followed by 15℃promoted embryo growth and subsequent seed germination.Cold stratification induced secondary dormancy,even when applied after warm stratification.After radicle emergence,epicotyl-plumule emergence was delayed for ca.3 months.Mean time of epicotyl-plumule emergence was positively affected by cold stratification(2 months at 5℃)and GA_(3).P.corsica seeds exhibited differential temperature sensitivity for the four sequential steps in the removal of dormancy and germination processes that resulted in the precise and optimal timing of seedling emergence.展开更多
[Objective] The aim of the study was to find out the cold/warm change characteristics in crop growing season and their relationship with food production in Heilongjiang Province.[Method] The temporal and spatial varia...[Objective] The aim of the study was to find out the cold/warm change characteristics in crop growing season and their relationship with food production in Heilongjiang Province.[Method] The temporal and spatial variation on the accumulated temperature steadily above 10 ℃ and its lasting days,the beginning date,the ending dates were investigated,and the relationship between food production and cold/warm climate in Heilongjiang Province during 1961-2009 was further analyzed.[Result] The results showed that the provincial average accumulated temperature steadily above 10 ℃ has increased by 355.4 ℃,the lasting days of accumulated temperature steadily above 10 ℃ has extended by 13d,and the beginning date has advanced by 8 d,while the ending date has delayed by 5 d in Heilongjiang Province during 49 years.Climate warming began from the 1980s,and the most significant period of climate warming was after the 1990s.The food production is closely related to cold/warm climate in Heilongjiang Province.[Conclusion] The climate warming was significant in crop growing season of Heilongjiang Province in the past 49 years,providing more favorable climatic conditions for the agricultural production.展开更多
In this study,the climate trend of the annual average air temperature and total annual rainfall in China in the present century has been examined.It is noted that in the Northwest,the Northeast and North China the cli...In this study,the climate trend of the annual average air temperature and total annual rainfall in China in the present century has been examined.It is noted that in the Northwest,the Northeast and North China the climate has become notably warmer this century but the rainfall trend has not been evident,mainly negative.In the 1980s China's rainfall and temperature showed noticeable regional features: warm and dry in North China,cold and dry in the Southwest,warm and wet in the Northeast,cold and wet in the middle-lower reaches of the Changjiang River.Besides,the four interdecadal climate change features and ranges of this century have been studied.It is found that on the scale of several decades there was considerably less rainfall in the most part of China in the warm background than in the cold background.The increase of temperature which started from the 1970s mainly happened in the Northwest and Northeast,while to the south of the Huanghe River the temperature increase did not even as great as in 1940s.The corresponding rainfall feature is that most areas experienced much less rainfall except the area to the south of the Huanghe River and over the Changjiang and Huaihe River basin.展开更多
Using the sea surface temperature and wind anomalies(SSTA and SSWA for short)of the tropical Pacific from January 1970 to December 1989,main spatial patterns of tropical Pacific SSTA and SSWA coupling features in the ...Using the sea surface temperature and wind anomalies(SSTA and SSWA for short)of the tropical Pacific from January 1970 to December 1989,main spatial patterns of tropical Pacific SSTA and SSWA coupling features in the transform course from the warm phase to the cold phase of El Nino-southern Oscillation(ENSO)cycles are discussed. The main conclusions are as follows:(1)air-sea coupling patterns at the mature stage of El Nino(La Nina)are main spatial ones of tropical Pacific SSWA and SSTA coupling:(2)at the mature stage of El Nino,the interaction of the anticyclonic anomaly wind,generated by the forcing of distinct meridional SSTA gradient in the Northern Hemisphere tropical central Pacific.with the California cold current and SSTA is mainly responsible for weakening of El Nino;(3)the second sea temperature increase along the South American coast in the decaying course of El Nino results from the eastward movement of the weakened positive SSTA in the tropical central-eastern Pacific forced by anomalous west wind stress:(4)La Nina results from the joint effect of Walker circulation,Ekman drift and negative SSTA in the tropical central-eastern Pacific.展开更多
基金supported by the National Basic Research Program of China(Grant 2004CB720200)the National Natural Science Foundation of China(Grant 49971009)the Chinese Academy of Sciences(Grant KZCX2-SW-118).
文摘The Last Interglacial Period strata in the Milanggouwan section in the Salawusu River valley on the Ordos Plateau, China, have 8.5 sedimentary cycles composed alternately of eolian dune sands, fluvio-lacustrine facies and paleosols. Based on comprehensive analyses on the distribution of magnetic susceptibility and CaCO3 and paleo-ecology indicated by fossils in the region, it is considered that the sedimentation cycles resulted from dry-cold and warm-humid climate fluctuations. Magnetic susceptibility values and CaCO3 contents in stratigraphic sectors I, III, V and II, IV basically respectively present peaks and low vales, and the former three can in time correlate with MIS5a, MIS5c and MIS5e successively and the latter two with MIS5b and MIS5d. In addition, some horizons of eolian dune sands and the low vales of their magnetic susceptibility and CaCO3 are also correlated with 6 periods of cooling events indicated by the higher content of foraminifer Neogloboquadrina pachyderma (S.) documented in the V29—191 drill in the North Atlantic and the cold events recorded by δ 18O in the ice cores in GRIP, especially with 9 periods of dust events in Chinese Loess Plateau.
文摘ONCE ocean floor was below the calcite compensation depth (CCD), deeper than 5000 m, it was widely covered with siliceous ooze or abyssal clay without abyssoconite. The samples of sediment core used in the present research were collected at No. 1787 station during DY85-04 cruise and are mostly of siliceous ooze or abyssal clay. Therefore, traditional and well-considered stable isotopic study using foraminifera has to be given up. Instead, stable isotopic
基金Sardinia Regional Government:financial support of Marco Porceddu PhD scholarship(P.O.R.Sardegna F.S.E.Operational Programme of the Autonomous Region of Sardinia,European Social Fund 2007-2013-Axis IV Human Resources,Objective l.3,Line of Activity l.3.1.)supported by Ente Foreste della SardegnaThe Royal Botanic Gardens,Kew,receives grant in-aid from Defra,UK.
文摘Aims The physiological responses during dormancy removal and multi-phasic germination were investigated in seeds of Paeonia corsica(Paeoniaceae).Methods Seeds of P.corsica were incubated in the light at a range of temperatures(10-25 and 25/10℃),without any pre-treatment,after W(3 months at 25℃),C(3 months at 5℃)and W+C(3 months at 25℃followed by 3 months at 5℃)stratification,and a GA_(3)treatment(250 mg·l^(−1)in the germination substrate).Embryo growth,time from testa to endosperm rupture and radicle emergence were assessed as separate phases.Epicotyl-plumule emergence was evaluated incubating the germinated seeds at 15℃for 2 weeks,at 5 and 25℃for 2 months on agar water before transplanting to the soil substrate at 10,15 and 20℃and at 15℃for 2 months on the surface agar water with GA_(3).Important Findings Embryo growth,testa rupture,endosperm rupture(radicle emergence)and growth of the epicotyl were identified as four sequential steps in seeds of P.corsica.Gibberellic acid alone and warm stratification followed by 15℃promoted embryo growth and subsequent seed germination.Cold stratification induced secondary dormancy,even when applied after warm stratification.After radicle emergence,epicotyl-plumule emergence was delayed for ca.3 months.Mean time of epicotyl-plumule emergence was positively affected by cold stratification(2 months at 5℃)and GA_(3).P.corsica seeds exhibited differential temperature sensitivity for the four sequential steps in the removal of dormancy and germination processes that resulted in the precise and optimal timing of seedling emergence.
基金Supported by Program for Science and Technology Development in Heilongjiang Province(GC06C103-05)~~
文摘[Objective] The aim of the study was to find out the cold/warm change characteristics in crop growing season and their relationship with food production in Heilongjiang Province.[Method] The temporal and spatial variation on the accumulated temperature steadily above 10 ℃ and its lasting days,the beginning date,the ending dates were investigated,and the relationship between food production and cold/warm climate in Heilongjiang Province during 1961-2009 was further analyzed.[Result] The results showed that the provincial average accumulated temperature steadily above 10 ℃ has increased by 355.4 ℃,the lasting days of accumulated temperature steadily above 10 ℃ has extended by 13d,and the beginning date has advanced by 8 d,while the ending date has delayed by 5 d in Heilongjiang Province during 49 years.Climate warming began from the 1980s,and the most significant period of climate warming was after the 1990s.The food production is closely related to cold/warm climate in Heilongjiang Province.[Conclusion] The climate warming was significant in crop growing season of Heilongjiang Province in the past 49 years,providing more favorable climatic conditions for the agricultural production.
基金This research was supported by the National Natural Science Foundation of China (No: 49475265).
文摘In this study,the climate trend of the annual average air temperature and total annual rainfall in China in the present century has been examined.It is noted that in the Northwest,the Northeast and North China the climate has become notably warmer this century but the rainfall trend has not been evident,mainly negative.In the 1980s China's rainfall and temperature showed noticeable regional features: warm and dry in North China,cold and dry in the Southwest,warm and wet in the Northeast,cold and wet in the middle-lower reaches of the Changjiang River.Besides,the four interdecadal climate change features and ranges of this century have been studied.It is found that on the scale of several decades there was considerably less rainfall in the most part of China in the warm background than in the cold background.The increase of temperature which started from the 1970s mainly happened in the Northwest and Northeast,while to the south of the Huanghe River the temperature increase did not even as great as in 1940s.The corresponding rainfall feature is that most areas experienced much less rainfall except the area to the south of the Huanghe River and over the Changjiang and Huaihe River basin.
基金This work was supported by the National Natural Science Foundation of China under the Grants 49375242.
文摘Using the sea surface temperature and wind anomalies(SSTA and SSWA for short)of the tropical Pacific from January 1970 to December 1989,main spatial patterns of tropical Pacific SSTA and SSWA coupling features in the transform course from the warm phase to the cold phase of El Nino-southern Oscillation(ENSO)cycles are discussed. The main conclusions are as follows:(1)air-sea coupling patterns at the mature stage of El Nino(La Nina)are main spatial ones of tropical Pacific SSWA and SSTA coupling:(2)at the mature stage of El Nino,the interaction of the anticyclonic anomaly wind,generated by the forcing of distinct meridional SSTA gradient in the Northern Hemisphere tropical central Pacific.with the California cold current and SSTA is mainly responsible for weakening of El Nino;(3)the second sea temperature increase along the South American coast in the decaying course of El Nino results from the eastward movement of the weakened positive SSTA in the tropical central-eastern Pacific forced by anomalous west wind stress:(4)La Nina results from the joint effect of Walker circulation,Ekman drift and negative SSTA in the tropical central-eastern Pacific.
