Source of the research subject: The research subject was entrusted and supported by the Knowledge Innovation Project of the Chinese Academy of Sciences.

　　Study period: From January 2001 to December 2004.

　　Awards: The research subject won a First Award of Scientific and Technological Progress of Xinjiang Uygur Autonomous Region in 2007 and a national Second Award of Scientific and Technological Progress of China in 2008.

　　Main accomplishing scientists: 2 Chen Yaning, 3 Tian Changyan, 6 Chen Xi, 9 Li Weihong, 11 Zhang Yuanming

　　Brief introduction of the research subject

　　(1) In the research subject, the middle and lower reaches of the Tarim River were taken as the study area, the objectives of the subject were to increase the productivity of the artificial oases, conserve the natural vegetation and regenerate the “Green Corridor”, the study and regeneration of damage process of the degenerated ecosystems in the lower reaches of the Tarim River were regarded as the emphases, and the experimental and demonstration research was carried out from the aspects of developing the efficient water-saving compound oasis ecological agriculture, optimized modes and ways of returning land for farming to forestry and grassplot, ecological conservation and regeneration in the lower reaches of the Tarim River, etc. A demonstration area of efficient compound oasis ecological agriculture for 2.8×104 mu (1866.7 ha.), 5 experimental and demonstration areas of ecological-economic artificial vegetation and livestock breeding, demonstration area of returning land for farming to forestry and grassplot for 1.5×104 mu (1000 ha.), and a spreading area of 1.8×105 mu (12000 ha.) were built up. All tasks specified in the assignment were satisfactorily accomplished, and the verifiable objectives were achieved; (2) The modes of high-yield cotton growing and efficient water-saving irrigation were developed, the technical indexes of coupling management of irrigation and soil fertilization were put forward, the technologies of biological control, automatic monitoring and early warning of cotton insect pests were developed, and the ways of utilizing brackish water were defined; optimal-growth grazing species were elected, the technologies of speedy breeding and speedy fattening of brand sheep and embryo transfer of cattle were introduced, and the large-scale industrial chain of “grazing planting—livestock breeding—deep processing of livestock products” has been gradually formed in a form of “market—company—farmer household—base”. The strategies, modes and measures were put forward for the coordinated development of the regional economic structure, industrial structure, urban systems, tourist industry and ecology-economy; (3) The evaluation methods of the suitability of returning land for farming to forestry and grassplot were developed, the regional maps of the suitable areas for returning land for farming to forestry and grassplot and the planning maps of returning land for farming to forestry and grassplot in the middle and lower reaches of the Tarim River on scale of 1:100000 were charted, 3 modes of returning land for farming to forestry and 2 modes of returning land for farming to grassplot were put forward, and these modes are suitable in the middle and lower reaches of the Tarim River, an extremely arid area; 64 plant species planted in the project of returning land for farming to forestry and grassplot were elected, 7 optimized planting schemes of species structure were summed up, and a technical system of regenerating vegetation was formed, tested and demonstrated; (4) In the lower reaches of the Tarim River, 9 observation cross-sections and some corresponding observation plots of natural vegetation were designed to reveal the relationship between groundwater level and ecological water conveyance, the rational and stress groundwater depths for the survival and growth of Populus euphratica and Tamarix spp. were derived, the hydrological response process of physiological ecology of the main plant species in the study area was preliminarily explained, the ways of ecological water conveyance for conserving and regenerating the “Green Corridor”, minimum and maintenance conveyed water volumes were suggested, and the relationships between the distribution and succession of natural vegetation communities, damage and degeneration process of ecosystems and the environmental factors were lucubrated; (5) Significant ecological benefits and economic returns were achieved in the demonstration areas, the annual saved water volume and increased income were 6.16×106 m3 and 5.17×106 yuan respectively; after popularizing the cotton growing technique, the annual increased income is 9.975×107 yuan, the annual indirect income is 1.98×107 yuan after implementing the project of returning land for farming to forestry, and the per capita income is 303 yuan.