关键词: 毛竹凋落物, 土壤, 微生物群落, 碳源利用

Abstract: To investigate the effect of bamboo leaves on soil microorganism a microcosm experiment of soil mixture with different percentage of bamboo leaf powder was conducted.The biolog GN2 microtial plate was used to determine diversity indices of microorganism with the incubation time. The results showed that significant differences in microbial activities measured by average well color density(AWCD) were found among treatments,and treatments 2(with 2% of leaf powder) was lower AWCD than(P<0.05) the other treatments in the 10^th) week.Control(with 0% of leaf powder) was higher AWCD than(P<0.05) the treatments with bamboo leaf powder in the 20^th and the 30^th week.It was found that in short-term bamboo leaf had improved the soil microbial activity,and AWCD values of treatments 1(with 1% of leaf powder),2 and 3(with 4% of leaf powder) respectively reached the maximum during 2 and 10 weeks,2 and 5 weeks,5 and 10 weeks,which ware all bigger(P<0.05) than that of non-cultured soil.However,a sharp decline was observed from the time of week 20 to week 30 at which the AWCD values of treatments 1,2 and 3 with 192(hour's) incubation after microbes being inoculated were decreased by 64.8%,55.7% and 60.4% respectively compared with non-cultured soil.The control was found no remarkable changes before the 20^th week,and then a sharp decline(by 40.4% compared to non-cultured soil) was measured from the 20^th to the 30^th week.No significant changes in Shannon index(H) and Evenes index(J) in the control were found,whereas a sharp decline(P<0.05) was observed for treatments with bamboo leaf from the 20^th to the 30^th week.McIntosh index(U) sharply decline(P<0.05) for leaf treatments from the 10^th to the 20^th week and till the end of this experiment(week 30),while a significant decline in McIntosh index of the control was found from the 20^th to the 30^th week.In summary the added amount of leaves did not led significant difference in soil microbial diversity indices analyzed.The diversity indices of control are significantly greater(P<0.05) than the leaf treatments at the 30^th week,which indicated that single litter input of bamboo leaf for long-term caused a reduction of microbial functional diversity.

Key words: phyllostachy pubescens litter, soil, microbial community, carbon sources utilization