PDF《中国北方小叶杨》

s living standards. The small-leaf poplar Populus simonii Carr. has always been an important tree species in Northern China, with a vast natural distribution, a long history of cultivation, and a large planting area. It is considered among one of the most valuable species in the region. According to statistics dating from the early 1980s, China has more than 6.6 million ha of planted poplar forest, of which P. simonii accounts for 0.64 million ha, or 10% by area. P. simonii is drought and frost resistant, tolerant to infertile soils, very adaptable, fast growing and long-living, which make it one of tree species widely used for early plantation establishment and cross-breeding in China. It has played an important role in environmental improvement programs, including rehabilitation of degraded lands, and in the development of the local economy in Northern China. However, in recent times interest in the species has diminished, and remaining stands are rapidly disappearing. Starting in 1990, the Project Afforestation, Forestry Research, Planning and Development in the Three North Region (FAO/GCP/CPR/009/BEL) financed by the Governments of Belgium and China (State Forestry Administration), with technical assistance provided by FAO, has carried out research on history, distribution, development, protection and utilization of P. simonii resources in northern China. A unique gene conservation bank of P. simonii collected in the Three-North Region has been established in the Korqin Sandy Lands, a cross-breeding program with P. simonii initiated and afforestation trials started, and significant results have been achieved. The project has played an important role in enhancing sustainable development of forestry sector of China, and in reserving and conserving forest genetic resources. It is also of strategic importance for the conservation of bio-diversity and for increasing the tolerance of protection forests to

2 the harsh environmental conditions of the Region. To summarize the work, the Project has compiled this booklet, a first step towards a comprehensive monograph of the species, to demonstrate the achievement of the Three-North Program in the field of international cooperation. Included in the booklet are in-depth descriptions on historical distribution, increase and decrease, research results, evolution of the genetic resources of P. simonii, making clear the historic significance of further conserving, developing as well as researching the genetic resources of the species. I hope that the booklet will contribute to increase the importance and use of the species and provide a foundation for research in the future. Pan Yingzhen Deputy Director General Bureau of the Three-North Shelterbelt Programme, the State ........