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Nitrogen-induced new net primary production and carbon sequestration in global forests.
- Source :
- Environmental Pollution; Nov2018:Part B, Vol. 242, p1476-1487, 12p
- Publication Year :
- 2018
-
Abstract
- Abstract Nitrogen (N) deposition and biological N fixation (BNF) are main external N inputs into terrestrial ecosystems. However, few studies have simultaneously quantified the contribution of these two external N inputs to global NPP and consequent C sequestration. Based on literature analysis, we estimated new net primary production (NPP) due to external N inputs from BNF and N deposition and the consequent C sinks in global boreal, temperate and tropical forest biomes via a stoichiometric scaling approach. Nitrogen-induced new NPP is estimated to be 3.48 Pg C yr<superscript>−1</superscript> in global established forests and contributes to a C sink of 1.83 Pg C yr<superscript>−1</superscript>. More specifically, the aboveground and belowground new NPP are estimated to be 2.36 and 1.12 Pg C yr<superscript>−1</superscript>, while the external N-induced C sinks in wood and soil are estimated to be 1.51 and 0.32 Pg C yr<superscript>−1</superscript>, respectively. BNF contributes to a major proportion of N-induced new NPP (3.07 Pg C yr<superscript>−1</superscript>) in global forest, and accounts for a C sink of 1.58 Pg C yr<superscript>−1</superscript>. Compared with BNF, N deposition only makes a minor contribution to new NPP (0.41 Pg C yr<superscript>−1</superscript>) and C sinks (0.25 Pg C yr<superscript>−1</superscript>) in global forests. At the biome scale, rates of N-induced new NPP and C sink show an increase from boreal forest towards tropical forest, as mainly driven by an increase of BNF. In contrast, N deposition leads to a larger C sink in temperate forest (0.11 Pg C yr<superscript>−1</superscript>) than boreal (0.06 Pg C yr<superscript>−1</superscript>) and tropical forest (0.08 Pg C yr<superscript>−1</superscript>). Our estimate of total C sink due to N-induced new NPP approximately matches an independent assessment of total C sink in global established forests, suggesting that external N inputs by BNF and atmospheric deposition are key drivers of C sinks in global forests. Graphical abstract Image 1 Highlights • Nitrogen-induced new NPP and C sequestration is estimated in global forests. • N deposition and BNF contributed 3.48 Pg C yr<superscript>−1</superscript> to NPP of global forests. • N deposition and BNF contributed 1.83 Pg C yr<superscript>−1</superscript> to the C sink of global forests. • BNF dominates nitrogen-induced new NPP and C sinks in global forests. • New N inputs are key drivers of C sinks in global forests. Based on a stoichiometric scaling approach, we estimated that nitrogen-induced new net primary production is a key driver of C sinks in global forests. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 02697491
- Volume :
- 242
- Database :
- Supplemental Index
- Journal :
- Environmental Pollution
- Publication Type :
- Academic Journal
- Accession number :
- 131900086
- Full Text :
- https://doi.org/10.1016/j.envpol.2018.08.041