Globally, acute increases in anthropogenic emissions of reactive nitrogen (Nr) have led to change of N
process in terrestrial and aquatic ecosystem. Although excessive Nr deposition is known to drastically
alter global N cycling, the consequences of excessive Nr deposition on N processes occurring in terrestrial
and aquatic ecosystems have not been well depicted. Owing to the unique influencing effects Nr
deposition have on different ecosystems, different N demands will result in different N critical loads and
dynamic equilibration point. Sharp increases in anthropogenic Nr emissions lead to the direct toxicity
to plant growth, long-term negative effects on increased NH3 and NH4
+ availability, and soil and water
acidification, so the study proposes the critical value of Nr deposition health threshold for terrestrial and
aquatic ecosystems. In present study, we summarize the health effect thresholds to different ecosystem
type under threat of progressively increasing Nr deposition, while effective emission-control strategies
can be developed for Nr deposition detrimental effects control in the near future.