[Causes for change in producing areas of geo-authentic herbs].

Geo-authentic herbs lay stress on their producing areas. The producing areas of most geo-authentic herbs have never changed since the ancient times. However, many other geo-authentic herbs have experienced significant changes in the long history. There are two main causes for the change in producing areas of herbs-change of natural environment and development of human society, which are restricted by each other and play a great role throughout the development process of geo-authentic herbs.