Global evidence on nitrogen saturation of terrestrial ecosystem net primary productivity
- DOI
- Language of the publication
- English
- Date
- 2016-02-19
- Type
- Article
- Author(s)
- Tian, Dashuan
- Wang, Hong
- Sun, Jian
- Niu, Shuli
- Publisher
- IOP Publishing
Abstract
The continually increasing nitrogen (N) deposition is expected to increase ecosystem aboveground net primary production (ANPP) until it exceeds plant N demand, causing a nonlinear response and N saturation for ANPP. However, the nonlinear response of ANPP to N addition gradient and the N saturation threshold have not been comprehensively quantified yet for terrestrial ecosystems. In this study, we compiled a global dataset of 44 experimental studies with at least three levels of N treatment. Nitrogen response efficiency (NRE, ANPP response per unit N addition) and the difference in NRE between N levels (ΔNRE) were quantified to test the nonlinearity in ANPP response. We found a universal response pattern of N saturation for ANPP with N addition gradient across all the studies and in different ecosystems. An averaged N saturation threshold for ANPP nonlinearity was found at the N addition rates of 5–6 g m−2 yr−1. The extent to which ANPP approaches N saturation varied with ecosystem type, N addition rate and environmental factors. ANPP in grasslands had lower NRE than those in forests and wetlands. Plant NRE decreased with reduced soil C:N ratio, and was the highest at intermediate levels of rainfall and temperature. These findings suggest that ANPP in grassland or the ecosystems with low soil C:N ratio (or low and high rainfall or temperature) is easier to be saturated with N enrichment. Overall, these results indicate that the beneficial effect of N deposition on plant productivity likely diminishes with continuous N enrichment when N loading surpasses the N saturation threshold for ANPP nonlinearity.
Subject
- Nature and environment
Keywords
- nitrogen deposition
Pagination
1-9
Peer review
Yes
Open access level
Gold
Identifiers
- ISSN
- 1748-9326
Article
- Journal title
- Environmental Research Letters
- Journal volume
- 11
- Journal issue
- 2
- Article number
- 024012
- Accepted date
- 2016-02-04
- Submitted date
- 2015-10-08
Citation(s)
Tian, D., Wang, H., Sun, J., & Niu, S. (2016). Global evidence on nitrogen saturation of terrestrial ecosystem net primary productivity. Environmental Research Letters, 11(2), Article 24012. https://doi.org/10.1088/1748-9326/11/2/024012