[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.