1. Effects of Litter Inputs on N2O Emissions from a Tropical Rainforest in Southwest China.
- Author
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Gao, Jinbo, Zhou, Wenjun, Liu, Yuntong, Zhu, Jing, Sha, Liqing, Song, Qinhai, Ji, Hongli, Lin, Youxing, Fei, Xuehai, Bai, Xiaolong, Zhang, Xiang, Deng, Yun, Deng, Xiaobao, Yu, Guirui, Zhang, Junhui, Zheng, Xunhua, Grace, John, and Zhang, Yiping
- Subjects
RAIN forests ,NITROUS oxide ,SOIL temperature ,HUMUS - Abstract
Litter inputs are expected to have a strong impact on soil N
2 O efflux. This study aimed to assess the effects of the litter decomposition process and nutrient efflux from litter to soil on soil N2 O efflux in a tropical rainforest. A paired study with a control (L) treatment and a litter-removed (NL) treatment was followed for 2 years, continuously monitoring the effects of these treatments on soil N2 O efflux, fresh litter input, decomposed litter carbon (LCI) and nitrogen (LNI), soil nitrate (NO3 − -N), ammonium (NH4 + -N), dissolved organic carbon (DOC), and dissolved nitrogen (DN). Soil N2 O flux was 0.48 and 0.32 kg N2 O-N ha−1 year−1 for the L and NL treatments, respectively. Removing the litter caused a decrease in the annual soil N2 O emission by 33%. The flux values from the litter layer were higher in the rainy season as compared to the dry season (2.10 ± 0.28 vs. 1.44 ± 0.35 μg N m−2 h−1 ). The N2 O fluxes were significantly correlated with the soil NO3 − -N contents (P < 0.05), indicating that the N2 O emission was derived mainly from denitrification as well as other NO3 − reduction processes. Suitable soil temperature and moisture sustained by rainfall were jointly attributed to the higher soil N2 O fluxes of both treatments in the rainy season. The N2 O fluxes from the L were mainly regulated by LCI, whereas those from the NL were dominated jointly by soil NO3 − content and temperature. The effects of LCI and LNI on the soil N2 O fluxes were the greatest in the 2 months after litter decomposition. Our results show that litter may affect not only the variability in the quantity of N2 O emitted, but also the mechanisms that govern N2 O production. However, further studies are still required to elucidate the impacting mechanisms of litter decomposition on N2 O emission from tropical forests. [ABSTRACT FROM AUTHOR]- Published
- 2018
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