微生物群落对土壤微生物呼吸速率及其温度敏感性的影响

通过灭菌和重新接种不同土壤微生物群落的方法,探索了改变土壤微生物群落对土壤微生物呼吸速率及其温度敏感性的影响.结果表明,灭菌海伦黑土接种未灭菌的哈尔滨黑土、封丘潮土和祁阳红壤后,15℃时土壤CO2的累积释放量分别为684.25、753.97和644.91μg,25℃时土壤CO2的累积释放量分别为963.06、1 015.44和852.31μg,35℃时土壤CO2的累积释放量分别为1 252.55、380.36和1 177.88μg;土壤CO2的累积释放量随接种剂土壤pH增加而增加,而与接种剂土壤有机质含量高低、接种剂土壤与被接种土壤的地理距离无关.15、25和35℃时,接种不同微生物群落的土壤呼吸速率表现差异的持续时间分别为104、277和1 177 h,差异持续时间随培养温度增高而延长.接种未灭菌的哈尔滨黑土、封丘潮土和祁阳红壤后,土壤呼吸温度敏感性指数Q10在0～104 h分别为1.63、1.49和1.80,在0～277 h分别为1.43、1.39和1.46,在0～1 609 h分别为1.35、1.35和1.35;呼吸温度敏感性随接种剂土壤pH降低而增加,随培养时间延长而减小.本研究表明改变土壤微生物群落将影响土壤微生物呼吸速率及其温度敏感性.

Altered Microbial Communities Change Soil Respiration Rates and Their Temperature Sensitivity

Inoculating common sterilized soil with different non-sterilized soils was used to investigate the potentials of altered microbial communities to change rate and temperature sensitivity of soil microbial respiration. Results showed that accumulative CO2 emission of sterilized Hailun black soils inoculated with non-sterilized Harbin black soil, Fengqiu fluvo-aquic soil and Qiyang red soil were 684.25, 753.97 and 644.91 microg, respectively, at 15 degrees C; were 963.06, 1 015.44 and 852.31 microg, respectively, at 25 degrees C; and were 1 252.55, 380.36 and 1 177.88 microg, respectively, at 35 degrees C. The soil accumulative CO2 emissions increased with pH of inoculant soils, but did not relate to organic content of and geographical distance from inoculant soils. Difference of microbial respiration rates among the three inoculant soils kept for 104, 277 and 1 177 h at 15 degrees C, 25 degrees C and 35 degrees C, respectively. Temperature sensitivity quotients (Q10) of microbial respiration of sterilized Hailun black soils inoculated with non-sterilized Harbin black soil, Fengqiu fluvo-aquic soil and Qiyang red soil were 1.63, 1.49 and 1.80, respectively, during 0-104 h; were 1.43, 1.39 and 1.46, respectively, during 0-277 h and were 1.35, 1.35 and 1.35, respectively, during 0-1 609 h. The Q10 decreased with pH of inoculant soils and incubation time. The results suggest that altered microbial community would change rate and temperature sensitivity of soil microbial respiration.