Abstract: The objective of this study is to elucidate the ecologic function of AM fungi and the interaction between sandfixation plants and AM fungi so as to provide more information for utilizing AM fungi and regenerating environment in desert regions. The study was carried out in the rhizosphere of Artemisia ordosica and A. sphaerocephala in north sandy land of Yulin city. The soil samples in profile of 50 cm in the rhizosphere of two host plants were collected at depths of 0-10, 10-20, 20-30, 30-40 and 40-50 cm in April, July and October 2007. The results show that both the host plants could form well symbionts with AM fungi in desert. The hyphal colonization of AM fungi of A. ordosica was 90.72%, that of A. sphaerocephala was 89.63%, and both of them formed the intermediate type mycorrhizas. The highest value of spore density occurred in soil layer of 0-10 cm, and the spore density was decreased with the increase of soil depth from 0 to 50 cm. The highest value of spore density occurred in July and was much higher than that in April and October, but the arbuscular colonization was reverse. Spore density of A. ordosica was significantly and positively correlated with available P, organic matter content, temperature and alkaline phosphatase. Arbuscular colonization was negatively correlated with available P, organic matter content and alkaline phosphatase. Spore density of A. scoparia was much higher than that of other two plants, but hyphal, vesiclar and arbuscular colonizations of AM fungi were much lower.

Key words: AM fungi, spatiotemporal distribution, Artemisia ordosica, Artemisia sphaerocephala, Yulin city, Shaanxi Province