The study aims at exploring the possibility of using the recovery ability af- ter drought stress-rewatering at vegetative growth stage as the evaluating index in water use efficiency （WUE） of winter wheat varieties....The study aims at exploring the possibility of using the recovery ability af- ter drought stress-rewatering at vegetative growth stage as the evaluating index in water use efficiency （WUE） of winter wheat varieties. ＇Jing 411 ＇, ＇Jinmai 47＇ and their 34 near isogenic lines （NILs） were used as test materials. Semi-automatic rainproof shelter and the percolating pools were used for simulating drought treat- ment. After suffering severe drought stress, winter wheat crops were rewatered at early jointing stage. The biomass accumulation after rewatering was determined as recovery ability index. In the meanwhile, plant height in the end of vegetative growth stage was measured, and WUE of varieties/lines was also determined. Thereafter, the differences in recovery ability, plant height and the population WUE, together with the correlation between recovery ability and population WUE were analyzed, respectively. The results showed that there were significant differences in recovery ability among some varieties/lines. The recovery ability was affected by both geno- type and environment, and the interaction existed in these two factors. Significant differences existed in plant height and population WUE among the 34 NILs along with their parents. There was a significantly positive correlation between recovery ability and plant height of varieties/lines. Recovery ability and plant height were very significantly and positively correlated with population yield WUE respectively. The re- sults indicated that recovery ability after drought stress-rewatering could be used as an evaluating index of population WUE under drought condition.展开更多
A review of the period of unregulated exploitation of forests in the state of West Virginia (U.S.) and in Shaanxi Province, PRC was presented. Economic and ecological recovery from exploitation has been different in t...A review of the period of unregulated exploitation of forests in the state of West Virginia (U.S.) and in Shaanxi Province, PRC was presented. Economic and ecological recovery from exploitation has been different in the two regions due to basic differences in nature of the forest and in the degree and persistence of exploitive pressures. After a century since unregulated exploitation, West Virginia forests are well on the road to management for sustainability and conservation. Shaanxi's recovery from overuse and unregulated exploitation is less certain; forests are still in the early phases of ecological recovery there. Full recovery to a period of sustainability will take a century or longer. Suggestions are made for measures needed to enhance the forest recovery. Keywords Forests - Shaanxi - West Virginia - Central China - Forest exploitation - Recovery CLC number S754 Document code A Article ID 1007-662X(2004)01-0049-06 Foundation item: The project was sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2002–2004) and Shaanxi Provincial Foreign Expert Bureau (2003).Biography: Jack E. Coster (1935-), male, professor of West Virginia University, Morgantown, West Virginia. U.S.A.Responsible editor: Song Funan展开更多
There are about 1.27 million ha of upland red soils derived from Quaternary red clay facing the degradation in the low-hilly region of the middle subtropical China. From the aspects of chemistry, physics and microbiol...There are about 1.27 million ha of upland red soils derived from Quaternary red clay facing the degradation in the low-hilly region of the middle subtropical China. From the aspects of chemistry, physics and microbiology, the processes of soil fertility restoration in the surface layer (0～20 cm) under three types of land use patterns (i.e. citrus orchard, tea garden and upland) in two provinces were studied in this work. Results showed that the reclamation of eroded waste land improved most of soil properties. Soil organic matter, total N and P, available P and K, and exchangeable Ca and Mg increased, but soil total K and exchangeable Al decreased. Soil PH decreased by 0.5 unit in the pure tea plantation for 20 years. Soil reclamation increased the percentage of soil microaggregates (<0.25 mm), especially those with a diameter of 0.02～0.002 mm. Soil total porosity increased in the cultivated lands with the increase of soil aeration and capillary porosity. The number of soil microorganisms increased with reclamation caused mainly by the huge increase of the total amount of bacteria. With the cultivation, the activity of soil urease and acid phosphatase increased, but that of invertase dropped.展开更多
The sustained growth of Chinese economy in the new century is a silver lining in the continuouslydepressed global economy. Meanwhile, the rapid development of Chinese economy is still confronted withconstraints from d...The sustained growth of Chinese economy in the new century is a silver lining in the continuouslydepressed global economy. Meanwhile, the rapid development of Chinese economy is still confronted withconstraints from deteriorating environment and rural poverty issues. It has become a significant policyoption in maintaining high speed, efficiency and sound development of Chinese economy to rehabilitateforest resources, improve ecological conditions, increase farmers income and get on a sustainable roadfeaturing coordinated development of population, resources and environment. The Grain for Green Program,as a CDM activity of Chinese style, launched on trial in 1999 and implemented in 2002 across the country,is the biggest land use transition, watershed management and poverty alleviation program involving thelargest population in Chinese history and across the globe. It covers 25 provinces/regions/cities and gets over1 600 counties, 15 million households and 60 million farmers were involved. Hence the Grain for Tree policyhas a significant bearing on ecological protection and farmers poverty alleviation in the soil and watererosion-prone region. A review and assessment of the background, essentials, effects, problems and trend ofthe Grain for Tree policy is of great significance for both China and the other developing countries in theworld in their efforts to combat the deteriorating environment and alleviate poverty.展开更多
文摘The study aims at exploring the possibility of using the recovery ability af- ter drought stress-rewatering at vegetative growth stage as the evaluating index in water use efficiency （WUE） of winter wheat varieties. ＇Jing 411 ＇, ＇Jinmai 47＇ and their 34 near isogenic lines （NILs） were used as test materials. Semi-automatic rainproof shelter and the percolating pools were used for simulating drought treat- ment. After suffering severe drought stress, winter wheat crops were rewatered at early jointing stage. The biomass accumulation after rewatering was determined as recovery ability index. In the meanwhile, plant height in the end of vegetative growth stage was measured, and WUE of varieties/lines was also determined. Thereafter, the differences in recovery ability, plant height and the population WUE, together with the correlation between recovery ability and population WUE were analyzed, respectively. The results showed that there were significant differences in recovery ability among some varieties/lines. The recovery ability was affected by both geno- type and environment, and the interaction existed in these two factors. Significant differences existed in plant height and population WUE among the 34 NILs along with their parents. There was a significantly positive correlation between recovery ability and plant height of varieties/lines. Recovery ability and plant height were very significantly and positively correlated with population yield WUE respectively. The re- sults indicated that recovery ability after drought stress-rewatering could be used as an evaluating index of population WUE under drought condition.
基金The Scientific Research Foundation for the Returned Overseas Chinese Scholars State Education Ministry(2002-2004)and Shaanxi Provincial Foreign Expert Bureau (2003).
文摘A review of the period of unregulated exploitation of forests in the state of West Virginia (U.S.) and in Shaanxi Province, PRC was presented. Economic and ecological recovery from exploitation has been different in the two regions due to basic differences in nature of the forest and in the degree and persistence of exploitive pressures. After a century since unregulated exploitation, West Virginia forests are well on the road to management for sustainability and conservation. Shaanxi's recovery from overuse and unregulated exploitation is less certain; forests are still in the early phases of ecological recovery there. Full recovery to a period of sustainability will take a century or longer. Suggestions are made for measures needed to enhance the forest recovery. Keywords Forests - Shaanxi - West Virginia - Central China - Forest exploitation - Recovery CLC number S754 Document code A Article ID 1007-662X(2004)01-0049-06 Foundation item: The project was sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2002–2004) and Shaanxi Provincial Foreign Expert Bureau (2003).Biography: Jack E. Coster (1935-), male, professor of West Virginia University, Morgantown, West Virginia. U.S.A.Responsible editor: Song Funan
文摘There are about 1.27 million ha of upland red soils derived from Quaternary red clay facing the degradation in the low-hilly region of the middle subtropical China. From the aspects of chemistry, physics and microbiology, the processes of soil fertility restoration in the surface layer (0～20 cm) under three types of land use patterns (i.e. citrus orchard, tea garden and upland) in two provinces were studied in this work. Results showed that the reclamation of eroded waste land improved most of soil properties. Soil organic matter, total N and P, available P and K, and exchangeable Ca and Mg increased, but soil total K and exchangeable Al decreased. Soil PH decreased by 0.5 unit in the pure tea plantation for 20 years. Soil reclamation increased the percentage of soil microaggregates (<0.25 mm), especially those with a diameter of 0.02～0.002 mm. Soil total porosity increased in the cultivated lands with the increase of soil aeration and capillary porosity. The number of soil microorganisms increased with reclamation caused mainly by the huge increase of the total amount of bacteria. With the cultivation, the activity of soil urease and acid phosphatase increased, but that of invertase dropped.
文摘The sustained growth of Chinese economy in the new century is a silver lining in the continuouslydepressed global economy. Meanwhile, the rapid development of Chinese economy is still confronted withconstraints from deteriorating environment and rural poverty issues. It has become a significant policyoption in maintaining high speed, efficiency and sound development of Chinese economy to rehabilitateforest resources, improve ecological conditions, increase farmers income and get on a sustainable roadfeaturing coordinated development of population, resources and environment. The Grain for Green Program,as a CDM activity of Chinese style, launched on trial in 1999 and implemented in 2002 across the country,is the biggest land use transition, watershed management and poverty alleviation program involving thelargest population in Chinese history and across the globe. It covers 25 provinces/regions/cities and gets over1 600 counties, 15 million households and 60 million farmers were involved. Hence the Grain for Tree policyhas a significant bearing on ecological protection and farmers poverty alleviation in the soil and watererosion-prone region. A review and assessment of the background, essentials, effects, problems and trend ofthe Grain for Tree policy is of great significance for both China and the other developing countries in theworld in their efforts to combat the deteriorating environment and alleviate poverty.
