Supported by the Rockefeller Foundation, the East Asia regional meeting of the international program on rice biotechnology was held in CNRRI Nov 5—8 1996. About 76 delegates from home and abroad attended the meeting ...Supported by the Rockefeller Foundation, the East Asia regional meeting of the international program on rice biotechnology was held in CNRRI Nov 5—8 1996. About 76 delegates from home and abroad attended the meeting and more than 80 papers were presented or posted. The objective of the meeting was to review the status of rice biotechnology since 1995 and to promote the international collaborative activities. The topic involved anther culture, gene isolation and characterization, transfer and expression of foreign genes, etc.展开更多
The Horqin Sandy Land(HSL), the largest sandy land in the semi-arid agro-pastoral ecotone of Northeast China, has been subject to desertification during the past century. In response, and to control the desertificat...The Horqin Sandy Land(HSL), the largest sandy land in the semi-arid agro-pastoral ecotone of Northeast China, has been subject to desertification during the past century. In response, and to control the desertification,government implemented the Three-North Shelter/Protective Forest Program, world's largest ecological reforestation/afforestation restoration program. The program began in1978 and will continue for 75 years until 2050. Understanding the dynamics of desertification and its driving forces is a precondition for controlling desertification.However, there is little evidence to directly link causal effects with desertification process(i.e., on the changing area of sandy land) because desertification is a complex process,that can be affected by vegetation(including vegetation cover and extent of shelter forests) and water factors such as precipitation, surface soil moisture, and evapotranspiration.The objectives of this study were to identify how influencing factors, especially shelter forests, affected desertification in HSL over a recent decade. We used Landsat TM imagery analysis and path analysis to identify the effects of spatiotemporal changes in water and vegetation parameters during2000–2010. Desertification was controlled during the study period, as indicated by a decrease in desert area at a rate of163.3 km2year-1and an increase in the area with reduced intensity or extent of desertification. Total vegetation cover in HSL increased by 10.6 % during the study period and this factor exerted the greatest direct and indirect effects on slowing desertification. The contribution of total vegetation cover to controlling desertification increased with the intensity of desertification. On slightly and extremely severe desertified areas, vegetation cover contributed 5 and 42 % of the desertification reduction, respectively. There were significant correlations between total vegetation cover and water conditions(i.e., evapotranspiration and precipitation)and the area of shelter forests(P / 0.0001), in which water conditions and the existence of shelter forests contributed49.7 and 12.8 % to total vegetation cover, respectively. The area of shelter forests increased sharply due to program efforts, but only shrub forests had significant direct effects on reducing the area of desertification categorized as slightly desertified. The reason for the lack of direct effect of increased arbor forests(accounting for 95.3 % of the total increase in shelter forests) on reducing desertification might be that the selected arbor species were not suited to water conditions(low precipitation, high evapotranspiration) prevailing at HSL. The establishment of shelter forests aided control of desertification in the HSL region, but the effect was less than expected. Effective control of desertification in the HSL region or other similar sandy areas will require greater improvements in vegetation cover. In particular,shrub species should be selected for plantation with reference to their potential to survive and reproduce in the harsh climatic and weather conditions typical of desertified areas.展开更多
Since the launching of the western regional development program in 1999, the Chinese government has implemented a series of policy measures related to finance, taxation, investment, banking, and other related fields. ...Since the launching of the western regional development program in 1999, the Chinese government has implemented a series of policy measures related to finance, taxation, investment, banking, and other related fields. This combination of policies has stimulated socioeconomic growth and ecological improvement in China's western regions and has effectively curbed the runaway gap between the east and west, even causing the gap to begin shrinking gradually. However, it should be noted that the development gap between China's eastern and western regions remains significant, as demonstrated by the west's low level of industrial^commercial development, local governments' limited capacity to provide public services, and endemic rural poverty. Thus, achieving the targets outlined in the western regional development program remains a challenging task. In the future, China's western development program should emphasize a higher standard of living and coordinated, inclusive growth across regions.展开更多
文摘Supported by the Rockefeller Foundation, the East Asia regional meeting of the international program on rice biotechnology was held in CNRRI Nov 5—8 1996. About 76 delegates from home and abroad attended the meeting and more than 80 papers were presented or posted. The objective of the meeting was to review the status of rice biotechnology since 1995 and to promote the international collaborative activities. The topic involved anther culture, gene isolation and characterization, transfer and expression of foreign genes, etc.
基金supported by grants from the National Nature Science Foundation of China(31025007)the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX1-YW-08-02)
文摘The Horqin Sandy Land(HSL), the largest sandy land in the semi-arid agro-pastoral ecotone of Northeast China, has been subject to desertification during the past century. In response, and to control the desertification,government implemented the Three-North Shelter/Protective Forest Program, world's largest ecological reforestation/afforestation restoration program. The program began in1978 and will continue for 75 years until 2050. Understanding the dynamics of desertification and its driving forces is a precondition for controlling desertification.However, there is little evidence to directly link causal effects with desertification process(i.e., on the changing area of sandy land) because desertification is a complex process,that can be affected by vegetation(including vegetation cover and extent of shelter forests) and water factors such as precipitation, surface soil moisture, and evapotranspiration.The objectives of this study were to identify how influencing factors, especially shelter forests, affected desertification in HSL over a recent decade. We used Landsat TM imagery analysis and path analysis to identify the effects of spatiotemporal changes in water and vegetation parameters during2000–2010. Desertification was controlled during the study period, as indicated by a decrease in desert area at a rate of163.3 km2year-1and an increase in the area with reduced intensity or extent of desertification. Total vegetation cover in HSL increased by 10.6 % during the study period and this factor exerted the greatest direct and indirect effects on slowing desertification. The contribution of total vegetation cover to controlling desertification increased with the intensity of desertification. On slightly and extremely severe desertified areas, vegetation cover contributed 5 and 42 % of the desertification reduction, respectively. There were significant correlations between total vegetation cover and water conditions(i.e., evapotranspiration and precipitation)and the area of shelter forests(P / 0.0001), in which water conditions and the existence of shelter forests contributed49.7 and 12.8 % to total vegetation cover, respectively. The area of shelter forests increased sharply due to program efforts, but only shrub forests had significant direct effects on reducing the area of desertification categorized as slightly desertified. The reason for the lack of direct effect of increased arbor forests(accounting for 95.3 % of the total increase in shelter forests) on reducing desertification might be that the selected arbor species were not suited to water conditions(low precipitation, high evapotranspiration) prevailing at HSL. The establishment of shelter forests aided control of desertification in the HSL region, but the effect was less than expected. Effective control of desertification in the HSL region or other similar sandy areas will require greater improvements in vegetation cover. In particular,shrub species should be selected for plantation with reference to their potential to survive and reproduce in the harsh climatic and weather conditions typical of desertified areas.
文摘Since the launching of the western regional development program in 1999, the Chinese government has implemented a series of policy measures related to finance, taxation, investment, banking, and other related fields. This combination of policies has stimulated socioeconomic growth and ecological improvement in China's western regions and has effectively curbed the runaway gap between the east and west, even causing the gap to begin shrinking gradually. However, it should be noted that the development gap between China's eastern and western regions remains significant, as demonstrated by the west's low level of industrial^commercial development, local governments' limited capacity to provide public services, and endemic rural poverty. Thus, achieving the targets outlined in the western regional development program remains a challenging task. In the future, China's western development program should emphasize a higher standard of living and coordinated, inclusive growth across regions.