Abstract: The suggestions on returning farmland to forests and grassland are listed here.1.The natural forests have seldom existed in the steppe,desert and frigid alpine regions due to the natural conditions of the bio-climatic zone.However in some non-climatic zone areas,Northward mountain slopes,valleys of some mountains,river shores and lakesides and the sandlands with more moisture,the forests do exist and trees could be planted.Such dialectical relationship between tree planting and bio-climatic zone is worth consideration.Moreover,the purpose of afforestation in the region,the conception of forestry,the structure of the forests and the tree species to be chosen must adjust to the arid or semiarid and the non-forest climat.The forestry andministration the scrubs and shrubbery groves with trees and forests.It could bring confusions to the conception of biology,ecology,forestry geography.2.Returning of farmland to grassland must be recognized as a brilliant start of our forage inducstry,which with grasses and animal husbandry,as its core combining feed production,eco-protective forestry,and intensive culture of useful endemic species of the steppe desert and alpine regions,form a holistic ecological and systematic project.Included in the forage industry systematic project are the vast natural grassland and the fenced and rotative grazing pastures,Grazing them is not an out dated pattern of grassland utilization,but a advanced accelerated biological nutrient cycling system,perticularly significant to China.

Key words: Development of the western regions, Farmlands returning to forests and grassland, Forage industry ecosystem project

摘要： 关于退耕还林还草,提出了两个方面的建议:1.在草原、荒漠和高寒高原地区,由于生物气候带规律性的制约,天然林基本上是不存在的,但在非林地带的局部地段,如:山地阴坡、沟谷底部、河岸湖滨低地和含水较多的沙地,则有森林存在,而且宜于造林。种树与生物气候带之间的这种辩证关系应予以更多的考虑。不仅如此,在营林目的、林业的概念、森林结构以及树种等方面都要求作相应的修改,以适应干旱-半干旱的非森林气候。目前在林业经营管理上存在着把灌木和灌丛等同于林木和森林的荒诞问题。它可能给生态学、生物学、林学甚至自然地理学带来概念上的混乱。2.还草,应看作“草业”的光辉起点。草业,以草和畜为核心,同农业饲料生产、生态保护性的林业、草原荒漠和高原特殊有用植物的集约栽培相结合,为一个整体的生态系统工程。围绕着这样的草业系统工程还包括广大天然草原围栏轮牧系统。在这里,放牧并非古老落后的草场利用方式,而是一种有先进科学含义的生物学营养循环的系统,对中国尤其具有主要意义。

关键词: 西部地区开发, 退耕还林还草, 草业生态系统工程