Different impacts of external ammonium and nitrate addition on plant growth in terrestrial ecosystems: A meta-analysis

Terrestrial plant growth is strongly limited by the availability of nitrogen (N). Atmospheric deposition of N has been rapidly increasing since the industrial revolution, associated with fast compositional shifts between ammonium- (NH4+) and nitrate-N (NO3−) globally. However, whether and how such composition changes of deposition will affect the response of terrestrial plant growth to N deposition remains unclear. To fill the gaps, this study...