退化 become vestigial; degenerate; deteriorate; retrograde; devolution; retrogradation; retrogression; retroversion; regression; involution; degeneration; degenerescence; degeneracy; cataplasia; catagenesis; atresia 鸡的翅膀逐渐退化, 不会在空中飞行了。 the wings of the chicken have become vestigial; it can no longer fly. 土豆种了几年之后就会退化。 after a few years' planting, the quality of the potato crop deteriorates
毁林和森林退化的根本原因会议 meeting on the underlying causes of deforestation and forest degradation
森林砍伐和退化的根本原因全球讲习班 global workshoon addressing the underlying causes of deforestation and forest degradation