Abstract: With pot experiment, this paper studied the degradation effect of Fraxinus sogdiana inoculated with ectomycorrhizal fungi E1-Hebeloma mesophaeusm, E2-Lactarius insulsns, E3-Strobilomyces floccopus, and E4-Cortinarius russus on the petroleum hydrocarbon in soil of Shenfu sewage irrigation area. The results showed that the degradation rate of soil petroleum hydrocarbon was enhanced by 23.6% when the F. sogdiana was inoculated with the 4 species of ectomycorrhizal fungi together, and by 21.0% and 12.7% when inoculated with E1E3, and E2E4, respectively, compared with the control. Inoculation with ectomycorrhizal fungi could improve the growth of F. sogdiana, and especially, increase its root biomass and the number of side-roots. When inoculated with E1E3, E2E4, and four associated ectomycorrhizal fungi, the number of side-roots increased by 100%, 67%, and 81%, respectively, and a significant positive correlation was observed between the degradation rate of soil petroleum hydrocarbon and the number of side-roots, suggesting that the increase of side-root number was the main reason for the increasing degradation rate of petroleum hydrocarbon in soil.

Key words: Ecological services, Sand-fixed poplar forest, Wind-declining index, Soil surface wind erosion, Dust retention