1. N fertilization affects on soil respiration, microbial biomass and root respiration in Larix gmelinii and Fraxinus mandshurica plantations in China.
- Author
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Shuxia Jia, Zhengquan Wang, Xingpeng Li, Yue Sun, Xiaoping Zhang, and Aizhen Liang
- Subjects
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BACTERIA , *LARCHES , *ASH (Tree) , *NITROGEN , *SOIL respiration , *SOIL temperature , *BIOMASS , *PLANT cells & tissues , *PLANT roots - Abstract
The response of belowground biological processes to soil N availability in Larix gmelinii (larch) and Fraxinus mandshurica (ash) plantations was studied. Soil and root respiration were measured with Li-Cor 6400 and gas-phase O2 electrodes, respectively. Compared with the control, N fertilization induced the decreases of fine root biomass by 52% and 25%, and soil respiration by 30% and 24% in larch and ash plantations, respectively. The average soil microbial biomass C and N were decreased by 29% and 42% under larch stand and 39% and 47% under ash stand, respectively. While the fine root tissue N concentration under fertilized plots was higher 26% and 12% than that under control plots, respectively, the average fine root respiration rates were increased by 10% and 13% in larch and ash stands under fertilized plot, respectively. Soil respiration rates showed significantly positive exponential relationships with soil temperature, and a seasonal dynamic. These findings suggest that N fertilization can suppress fine root biomass at five branch orders (<2 mm in diameter), soil respiration, and soil microbial biomass C and N, and alter soil microbial communities in L. gmelinii and F. mandshurica plantations. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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