Abstract
Background and aims: The feather moss Pleurozium schreberi (Brid.) Mitt. is colonized by cyanobacteria, which fix substantial amounts of atmospheric nitrogen (N) in pristine and N-poor ecosystems. Cyanobacterial N2 fixation is inhibited by N deposition. However, the threshold of N input that leads to the inhibition of N2 fixation has not been adequately investigated. Further, the ability of N2 fixation to recover in mosses from high N deposition areas has not been studied to date. Methods: We conducted two laboratory studies in which we (1) applied a range of concentrations of N as NH4NO3 to mosses from low N-deposition areas, and (2) we deprived mosses from a high N-deposition area of N to test their ability to recover N2 fixation. Results: Higher addition rates (up to 10 kg N ha-1) did not systematically inhibit N2 fixation in P. schreberi. Conversely, upon weeks of N deprivation of mosses from a high N environment, N2 fixation rates increased. Conclusions: The threshold of total N deposition above which N2 fixation in P. schreberi is inhibited is likely to be > 10 kg N ha-1. Further, cyanobacteria are able to recover from high N inputs and are able to fix atmospheric N2 after a period of N deprivation.
| Original language | English |
|---|---|
| Journal | Plant and Soil |
| Volume | 374 |
| Issue number | 1-2 |
| Pages (from-to) | 513-521 |
| Number of pages | 9 |
| ISSN | 0032-079X |
| DOIs | |
| Publication status | Published - Jan 2014 |
| Externally published | Yes |