Abstract: Aimed to approach the effects of alien plant invasion on soil ecosystem, this paper studied the change patterns of soil nutrient contents and enzyme activities under different levels of Flaveria bidentis invasion. Comparing with non-vegetated and native plant soils, the F. bidentis invaded soil had higher contents of soil organic carbon, total nitrogen, NO₃^--N, and NH⁺₄-N but lower contents of soil total and available phosphorus, and the change trends of these parameters became more obvious with increasing invasion level. Comparing with those in native plant soil, the organic carbon and total nitrogen contents in F. bidentis heavily invaded soil increased by 5.7% and 23.4%, while the total and available phosphorus contents decreased by 85% and 50%, respectively. The urease activity in F. bidentis heavily and lightly invaded soils was 0.04 and 0.03 mg·g^-1·24 h^-1, respectively, being higher than that in non-vegetated and native plant soils, the phosphatase activity changed with same manner, while the polyphenol oxidase activity had less change. It was suggested that F. bidentis invasion induced the changes of soil nutrient contents and enzyme activities, and in return, endowed the superiority of  F. bidentis in its inter-specific competition.

Key words: Dust absorption effect, Amount of dust absorption, Dust pollution, Evergreen conifer