“Forgotten” terrestrial sources of N-gases

Numerous studies have been conducted on N2O emissions from agricultural (fertilized) fields. Emission data on NO from agricultural soils are far less abundant. Flux data from natural vegetation (e.g. forests, riparian buffers) are even more limited. In this paper, special attention goes to a few ecosystems of lower interest with regard to emission of N2O and NO: forests with elevated N deposition and riparian zones with high nitrate loads via groundwater. With regard to NO also emission data are presented from arable land. The NO emissions from the N polluted forest ranged between 17 and 94 ng N m− 2 s− 1 while from a sandy arable soil it ranged between 19 and 237 ng N m− 2 s− 1, indicating that NO emissions from N polluted forests could be of the same order of magnitude as those from arable land. These data are also of comparable order of N2O emissions (− 0.3–84.2 ng N2O–N m− 2 s− 1) from arable land. The N2O emissions from natural vegetation (forest and riparian zones) ranged between − 0.6 to 1.5 and 6.9 to 28.9 ng N2O–N m− 2 s− 1, respectively. This is in the lower range as compared to emissions from agricultural fields.