Nitrification is the primary source for NO in N-saturated subtropical forest soils: Results from in situ 15 N
Ronghua Kang1,2, Longfei Yu2,3, Peter Dörsch2
1CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.
Rationale:
Acidic subtropical forest soils that receive high atmospheric nitrogen (N) deposition have been identified as important sources of nitric oxide (NO). The relative importance of major processes producing NO is unclear.
Methods:
To partition NO sources, we conducted an in situ tracing experiment with 15 NH4 NO3 and NH4 15 NO3 in well-drained acid soils of an N-saturated subtropical forest in Chongqing, southwest China.
Results:
In the 15 NH4 NO3 treatment, the 15 N signature of NO emitted from the foot of the hillslope (Lower site) was similar to that of the NH4 + pool, indicating predominant autotrophic nitrification for NO formation. In the NH4 15 NO3 treatment, the 15 N enrichment of NO was smaller than that of the NO3 - pool, suggesting minor contribution of denitrification to NO production (~15%).
Conclusions:
Nitrification is the main process responsible for NO emissions, even in monsoonal summers when soil water-filled pore space values are relatively high.
Related Concept Videos
Overview of Nitrogen Metabolism
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...
Inorganic Nitrogen Assimilation
The Nitrogen Cycle
The Roles of Bacteria and Fungi in Plant Nutrition
2° Amines to N-Nitrosamines: Reaction with NaNO2
Key Elements for Plant Nutrition


