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Topography-driven soil properties modulate effects of nitrogen deposition on soil nitrous oxide sources in a subtropical forest.
- Source :
- Biology & Fertility of Soils; Aug2022, Vol. 58 Issue 6, p707-720, 14p
- Publication Year :
- 2022
-
Abstract
- An ex-situ <superscript>15</superscript> N–<superscript>18</superscript>O tracing experiment with soils collected from the valley and slope, respectively, of a subtropical secondary karst forest with three N addition levels, i.e., 0, 50, and 100 kg N ha<superscript>−1</superscript> year<superscript>−1</superscript> for each topographic position to investigate N<subscript>2</subscript>O production pathways. Autotrophic nitrification pathways (ammonia oxidation, nitrifier denitrification, and nitrification-coupled denitrification) accounted for > 70% of total N<subscript>2</subscript>O production, but denitrification pathways (heterotrophic denitrification and co-denitrification) were the minor source of N<subscript>2</subscript>O at both topographic positions. In the valley, chronic N addition stimulated ammonia oxidation-derived N<subscript>2</subscript>O, which was paralleled by increased ammonia-oxidizing archaea (AOA) amoA gene transcript abundance, but inhibited nitrifier denitrification- and nitrification-coupled denitrification–derived N<subscript>2</subscript>O along with suppressed ammonia-oxidizing bacteria (AOB) amoA gene transcript abundance and stimulated nosZII gene transcript abundance, respectively. On the slope, chronic N addition stimulated ammonia oxidation-derived N<subscript>2</subscript>O along with increased AOB amoA gene transcript abundance, and enhanced nitrifier denitrification-derived N<subscript>2</subscript>O congruent with increased AOB amoA and decreased nirK gene transcript abundances. In addition, chronic N addition reduced the relative contribution of heterotrophic denitrification to N<subscript>2</subscript>O production but had no significant influence on heterotrophic denitrification-derived N<subscript>2</subscript>O on the slope. Overall, our results provide a comprehensive view in terms of how topography-driven soil properties regulate N<subscript>2</subscript>O production and its pathways in a subtropical forest. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 01782762
- Volume :
- 58
- Issue :
- 6
- Database :
- Complementary Index
- Journal :
- Biology & Fertility of Soils
- Publication Type :
- Academic Journal
- Accession number :
- 158563972
- Full Text :
- https://doi.org/10.1007/s00374-022-01653-w