Natural environment's restriction on ethnic Miao's economic development in the Ming and Qing dynasties

The ethnic Miao people originally lived in the Central Plains,but later they were forced to move to the southwestern mountainous areas,where they became a part of the local inhabitants in the Ming and Qing dynasties.The natural environments of the mountainous areas exerted much influence on the Miao's econovic develpment.Their life\|style and production have not undergone many changes.This makes us to think a problem:what relation should be established between ethnic economic development and natural conditions.