Articles | Volume 14, issue 4
Peer-reviewed comment
17 Feb 2017
Peer-reviewed comment |  | 17 Feb 2017

Nitrogen mineralization, not N2 fixation, alleviates progressive nitrogen limitation – Comment on “Processes regulating progressive nitrogen limitation under elevated carbon dioxide: a meta-analysis” by Liang et al. (2016)

Tobias Rütting
Short summary
The response of ecosystems to elevated atmospheric CO2 is affected by nitrogen (N) availability. It has been hypothesized that N limitation becomes progressively stronger (progressive N limitation, PNL). Most long-term free air CO2 enrichment studies did not see a PNL. This paper shows that enhanced biological N2 fixation only prevents PNL in plant communities with symbiotic N2 fixation. In most ecosystems a stimulation of gross N mineralization prevents the development of a PNL.
Final-revised paper