【摘要】 目前世界上已耕作的土地，只占地球全部土地的9％，大多在南北纬30～60度范围内。虽然从土地利用上看还远远没有达到极限，但实际上差不多最适宜耕作的土地已经被利用。改造那些对栽培作物来说条件恶劣的自然环境，这一课题显得尤为重要。本文探讨了植物在改造环境中的部分作用。更多还原

【Abstract】 The cultivated land in the world is only 9% of the land on the earth at present,which islocated mostly in the scope of 30°~60° north and south latitude. Though in the view of land usage thenumber is far from the limit,in fact, the 1and most suitable to cultivate has nearly been used up. So thissubject— to remake the adverse circumstances for cultivating——is much more important. This paperprobes into the partial function of plants’ remaking the evironment.更多还原