Justify the relationship between climate and natural vegetation in reference to the monsoon climate. Though Nepal lies in tropical monsoon region, there is a vast difference between the natural vegetation of mountain and terai region, why ?

Relationship between climate and vegetation in tropical monsoon region. 

Due to high temperature an plenty of rainfall, the vegetation in tropical monsoon region is green everywhere in summer because of the new leaves in trees but they look leafless and desert like because of cold and dryness in winter. 

Nepal is a country with tropical monsoon climate but there is vast difference between the vegetation of the mountain and the terai. The main reason of this is the difference in altitude. 

In the Terai region : 

Since the terai region lies at low plain land, tropical climate is found there and plenty of rainfall occurs during summer. Therefore, tropical evergreen forest with hard wooded trees like sal, teek, sisau, etc is found in Terai region.

In the Mountain region: 

Since cold climate is found with frequent snowfall, coniferous vegetation with soft wood, needle like leaves, and cone shaped trees like pine, fir, spruce etc is found in the mountain region.