Population Dynamic and Driving Factors of Tetraena mongolica Maxim.

Using technology of remote sensing and geographical information system, the paper analyzed four remote sensing images of Tetraena mongolica distribution area in different periods (1977, 1990, 2000, 2005) to study the dynamic changes and influence factors of T.mongolica population quantity. On this basis, Principal component analysis method was applied to quantitative analyze the impact strength and the contribution rate of different driving factors on population dynamics of T.mongolica. The results showed that T.mongolica population decrease rapidly in quantity in recent years. It had been reduced 19.36% and 13.40 km²/a during 28 years. The dynamic changes of T.mongolica population was closely associated with drought trend aggravating and human disturbance enhancement in the T.mongolica distribution area. Human activities such as the development of industry and agriculture and urbanization were the main reasons for the decrease of T.mongolica population area.