Abstract: Five sites along the precipitation gradient (336〖KG-*2〗-〖KG-*7〗24
9 mm·a-1) from east to west in Ordos Plateau were selected to study the spat
ial distribution pattern of Artemisia ordosica population and its responses
to the precipitation gradient by the methods of variance mean ratio, aggregative
 index, and point pattern analysis. The reduction of precipitation affected the
spatial distribution pattern of A. ordosica population significantly. With d
ecreasing precipitation gradient, the spatial pattern of A. ordosica populat
ion changed from uniform to random in small scale, and from random to clumpy in
large scale, suggesting that in the ecological restoration of Ordos Plateau, a r
ational arrangement of A. ordosica should be made.

Key words: Ordos Plateau, Artemisia ordosica, distribution pattern, precipitation gradient, point pattern, variance mean ratio method, nano-selenium, fluoride, carp, liver, antioxidant capacity, histopathology.