Abstract: By the methods of soil coring and trenching, this paper studied the spatiotemporal variation of soil moisture around the roots of Artemisia halodendron, a native shrub mainly growing on the semifixed sand dunes in Horqin sandy land, before and after rainfall during the growth season of 2006, as well as the relationships between the soil moisture content and the water content of A. halodendron roots. The water balance was also calculated. The results showed that A. halodendron played a temporary storage role after rainfall. Under the action of main stem flow, the soil moisture content at the center of the shrub cluster was much higher than that at the places out of the center. 6 hours after rainfall, the correlation coefficient between the soil moisture content at the center of the shrub cluster and the water content of A. halodendron roots was -0.89 (P<0.01); and 126 hours after rainfall, the water content of A. halodendron roots showed a stresspulse batch reaction. The soil evapotranspiration rate under the shrub cluster was lower than that at the place 1 m away from the edge of the shrub cluster, suggesting that A. halodendron cover decreased soil evapotranspiration rate.

Key words: Winter host mosses of gall aphids, Plagiomnium, Photosynthesis, Light response curve, Temperature response curve