Effects of reactive nitrogen deposition on terrestrial and aquatic ecosystems

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. (C) 2014 Elsevier B.V. All rights reserved.