关键词: 土壤生物多样性, CO2, CH4, N2O, 土壤微生物, 土壤动物

AbstractWinter burning and cutting facilitate growth and reproduction of certain plant species. These two human dis-turbances occurred in winter as a result of economic activities at Chongming Dongtan, where saltmarsh cordgrass (Spartina alterniflora), an American native, has been naturalized. To test the hypothesis that these two disturbances can also facilitate the growth and reproduction of S. alterniflora, a simulated field experiment was carried out at Dongtan. At the same time, the effect of elevation was also considered in the experiment. We found that both winter burning and cutting, to a certain extent, promoted regeneration of S. alterniflora, as they significantly increased ramet density and heading ratio, and reduced culm diameter. This effect was probably caused by the changes of habitat and the improvement of light conditions due to the dis-turbances. The effects of the two disturbances on S. alterniflora were unexpectedly weaker than those of ele-vational variation based on Wilks’ λ from multivariate ANOVA. Little difference occurred in the effects be-tween the two disturbances. We can conclude that disturbances should be managed appropriately because they might facilitate invasion of S. alterniflora.

Key words: soil biodiversity, carbon dioxide, methane, nitrous oxide, soil microorganism, soil fauna