The analysis of vegetation-environment relationships has always been a study hotspot in ecology. A number of biotic, hydrologic and edaphic factors have great influence on the distribution of macrophytes within salt m...The analysis of vegetation-environment relationships has always been a study hotspot in ecology. A number of biotic, hydrologic and edaphic factors have great influence on the distribution of macrophytes within salt marsh.Since the exotic species Spartina alterniflora（S. alterniflora） was introduced in 1995, a rapid expansion has occurred at Chongming Dongtan Nature Reserve（CDNR） in the Changjiang（Yangtze） River Estuary, China.Several important vegetation-environment factors including soil elevation, tidal channels density（TCD）,vegetation classification and fractional vegetation cover（FVC） were extracted by remote sensing method combined with field measurement. To ignore the details in interaction between biological and physical process,the relationship between them was discussed at a large scale of the whole saltmarsh. The results showed that Scirpus mariqueter（S. mariqueter） can endure the greatest elevation variance with 0.33 m throughout the marsh in CDNR. But it is dominant in the area less than 2.5 m with the occurrence frequency reaching 98%. S. alterniflora has usually been found on the most elevated soils higher than 3.5 m but has a narrow spatial distribution. The rapid decrease of S. mariqueter can be explained by stronger competitive capacity of S. alterniflora on the high tidal flat. FVC increases with elevation which shows significant correlation with elevation（r=0.30, p〈0.001）. But the frequency distribution of FVC indicates that vegetation is not well developed on both elevated banks near tidal channels from the whole scale mainly due to tidal channel lateral swing and human activities. The significant negative correlation（r=–0.20, p〈0.001） was found between FVC and TCD, which shows vegetation is restricted to grow in higher TCD area corresponding to lower elevation mainly occupied by S. mariqueter communities. The maximum occurrence frequency of this species reaches to 97% at the salt marsh with TCD more than 8 m/m2.展开更多
The paper analyzes the distribution pattern of resources, ecological environment, society and economy, and holds that it is conducive to Silk Road countries to carry out Omni-directional and multi-level economic coope...The paper analyzes the distribution pattern of resources, ecological environment, society and economy, and holds that it is conducive to Silk Road countries to carry out Omni-directional and multi-level economic cooperation. Then the article puts forth main modes and paths of sustainable economic development for the Silk Road Economic Belt （SREB）： ecological civilization mode, regional economic integration mode, transportation economic belt mode and international tourism economic zone mode. Finally, the article summarizes the key scientific issues for the sustainable development in the SREB and puts forward several action projects which include establishing International Scientists League and Think Tanks, establishing international information sharing platform and scientific policy-making system of ecological environment and sustainable development of the SREB, starting international science cooperation and technology traineeship program of the SREB, founding the international cooperation committee in the SREB and founding transnational construction and win-win cooperation mechanism of coping with climate change and ecological environment.展开更多
Eco-environmental changes during interglacials with an astronomical background similar to that of the Holocene are potentially helpful for understanding the future climatic evolution.Marine oxygen isotope stage(MIS)19...Eco-environmental changes during interglacials with an astronomical background similar to that of the Holocene are potentially helpful for understanding the future climatic evolution.Marine oxygen isotope stage(MIS)19 is similar to the Holocene in astronomical background,both being characterized by a low eccentricity of the Earth’s orbit.However,MIS 19 has attracted research attention only recently and therefore less is known about eco-environmental changes during this interval,especially based on terrestrial records.In the Chinese Loess Plateau(CLP),the S7 paleosol can provide valuable terrestrial paleoclimatic and paleoenvironmental record for MIS 19.Here,high-resolution terrestrial snail records from the L8–L7 strata of the Huining,Xifeng and Luochuan sequences in the CLP were analyzed in order to characterize spatio-temporal changes in climate and eco-environment during MIS 20–18.The results show that in all three sections the late part of MIS 20 was dominated by abundant cold-aridiphilous mollusc species,indicating that cold and dry climatic conditions prevailed across the entire CLP,under the strong influence of the winter monsoon.The mollusc fauna of MIS 19 were dominated by warmth-loving and thermohumidiphilous species that enable the definition of two climatic stages.The early part of MIS 19(~790–778 ka)was marked by warm and humid conditions,as evidenced by high abundances of warmth-loving and thermo-humidiphilous species.This interval was slightly warmer than today and it lasted for^12 kyr.The climate of the later part of MIS 19(~778–761 ka)was more moderate,and increased proportions of cold-aridiphilous and warmth-loving species were recorded.The warmth of this period was similar to that of today,but the climatic fluctuations were stronger.During the early part of MIS 18(~761–745 ka),the Xifeng and Luochuan sections in the eastern CLP still maintained high abundances of warmth-loving and thermo-humidiphilous species,indicating that the moderate climatic conditions during late MIS 19 continued during early MIS 18,lasting for another^15 kyr,and that the influence of the summer monsoon remained strong in the eastern CLP during early MIS 18.However,in the western CLP,cold-aridiphilous species in the Huining section became dominant during early MIS 18,reflecting the prevalence of a cold and dry glacial climate,with the strong influence of the winter monsoon.These findings indicate that a steeper climatic gradient and a pronounced regional environmental difference existed between the eastern and western CLP during the early part of MIS 18.Comparison of our mollusc results with the variation of Earth orbital parameters suggested that climate changes in the CLP during MIS 20–18 were likely controlled mainly by insolation changes forced by the configuration of Earth orbital parameters.The unique orbital configuration during the low eccentricity interglacial-to-glacial transition could have strengthened the East Asian summer monsoon which favored the amelioration of the eco-environment in the CLP,especially in the eastern CLP where the summer monsoon exerted a strong influence.Thus we speculate that,under natural climatic conditions,the climate of the CLP may remain in a warm,humid state for another 30 kyr,although climatic instability and the seasonal differences between winter and summer could strengthen.展开更多
基金Program Strategic Scientific Alliances between China and the Netherlands under contract No.2008DFB90240Open Research Fund Program for State Key Laboratory of Estuarine and Coastal Research under contract No.SKLEC201207Open Research Fund Program for Shandong Province Key Laboratory of Marine Ecology Environment and Disaster Prevention under contract No.2012011
文摘The analysis of vegetation-environment relationships has always been a study hotspot in ecology. A number of biotic, hydrologic and edaphic factors have great influence on the distribution of macrophytes within salt marsh.Since the exotic species Spartina alterniflora（S. alterniflora） was introduced in 1995, a rapid expansion has occurred at Chongming Dongtan Nature Reserve（CDNR） in the Changjiang（Yangtze） River Estuary, China.Several important vegetation-environment factors including soil elevation, tidal channels density（TCD）,vegetation classification and fractional vegetation cover（FVC） were extracted by remote sensing method combined with field measurement. To ignore the details in interaction between biological and physical process,the relationship between them was discussed at a large scale of the whole saltmarsh. The results showed that Scirpus mariqueter（S. mariqueter） can endure the greatest elevation variance with 0.33 m throughout the marsh in CDNR. But it is dominant in the area less than 2.5 m with the occurrence frequency reaching 98%. S. alterniflora has usually been found on the most elevated soils higher than 3.5 m but has a narrow spatial distribution. The rapid decrease of S. mariqueter can be explained by stronger competitive capacity of S. alterniflora on the high tidal flat. FVC increases with elevation which shows significant correlation with elevation（r=0.30, p〈0.001）. But the frequency distribution of FVC indicates that vegetation is not well developed on both elevated banks near tidal channels from the whole scale mainly due to tidal channel lateral swing and human activities. The significant negative correlation（r=–0.20, p〈0.001） was found between FVC and TCD, which shows vegetation is restricted to grow in higher TCD area corresponding to lower elevation mainly occupied by S. mariqueter communities. The maximum occurrence frequency of this species reaches to 97% at the salt marsh with TCD more than 8 m/m2.
基金National Natural Science Foundation of China(4127155641101117)+1 种基金National Natural Science Foundation of China and Russian Foundation for Basic Research(414110106515-56-53037)
文摘The paper analyzes the distribution pattern of resources, ecological environment, society and economy, and holds that it is conducive to Silk Road countries to carry out Omni-directional and multi-level economic cooperation. Then the article puts forth main modes and paths of sustainable economic development for the Silk Road Economic Belt （SREB）： ecological civilization mode, regional economic integration mode, transportation economic belt mode and international tourism economic zone mode. Finally, the article summarizes the key scientific issues for the sustainable development in the SREB and puts forward several action projects which include establishing International Scientists League and Think Tanks, establishing international information sharing platform and scientific policy-making system of ecological environment and sustainable development of the SREB, starting international science cooperation and technology traineeship program of the SREB, founding the international cooperation committee in the SREB and founding transnational construction and win-win cooperation mechanism of coping with climate change and ecological environment.
基金supported by the National Natural Science Foundation of China(Grant No.41430103)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB26000000)the China Postdoctoral Science Foundation(Grant No.2017M620895)。
文摘Eco-environmental changes during interglacials with an astronomical background similar to that of the Holocene are potentially helpful for understanding the future climatic evolution.Marine oxygen isotope stage(MIS)19 is similar to the Holocene in astronomical background,both being characterized by a low eccentricity of the Earth’s orbit.However,MIS 19 has attracted research attention only recently and therefore less is known about eco-environmental changes during this interval,especially based on terrestrial records.In the Chinese Loess Plateau(CLP),the S7 paleosol can provide valuable terrestrial paleoclimatic and paleoenvironmental record for MIS 19.Here,high-resolution terrestrial snail records from the L8–L7 strata of the Huining,Xifeng and Luochuan sequences in the CLP were analyzed in order to characterize spatio-temporal changes in climate and eco-environment during MIS 20–18.The results show that in all three sections the late part of MIS 20 was dominated by abundant cold-aridiphilous mollusc species,indicating that cold and dry climatic conditions prevailed across the entire CLP,under the strong influence of the winter monsoon.The mollusc fauna of MIS 19 were dominated by warmth-loving and thermohumidiphilous species that enable the definition of two climatic stages.The early part of MIS 19(~790–778 ka)was marked by warm and humid conditions,as evidenced by high abundances of warmth-loving and thermo-humidiphilous species.This interval was slightly warmer than today and it lasted for^12 kyr.The climate of the later part of MIS 19(~778–761 ka)was more moderate,and increased proportions of cold-aridiphilous and warmth-loving species were recorded.The warmth of this period was similar to that of today,but the climatic fluctuations were stronger.During the early part of MIS 18(~761–745 ka),the Xifeng and Luochuan sections in the eastern CLP still maintained high abundances of warmth-loving and thermo-humidiphilous species,indicating that the moderate climatic conditions during late MIS 19 continued during early MIS 18,lasting for another^15 kyr,and that the influence of the summer monsoon remained strong in the eastern CLP during early MIS 18.However,in the western CLP,cold-aridiphilous species in the Huining section became dominant during early MIS 18,reflecting the prevalence of a cold and dry glacial climate,with the strong influence of the winter monsoon.These findings indicate that a steeper climatic gradient and a pronounced regional environmental difference existed between the eastern and western CLP during the early part of MIS 18.Comparison of our mollusc results with the variation of Earth orbital parameters suggested that climate changes in the CLP during MIS 20–18 were likely controlled mainly by insolation changes forced by the configuration of Earth orbital parameters.The unique orbital configuration during the low eccentricity interglacial-to-glacial transition could have strengthened the East Asian summer monsoon which favored the amelioration of the eco-environment in the CLP,especially in the eastern CLP where the summer monsoon exerted a strong influence.Thus we speculate that,under natural climatic conditions,the climate of the CLP may remain in a warm,humid state for another 30 kyr,although climatic instability and the seasonal differences between winter and summer could strengthen.
