Abstract
Carbon (C) and nitrogen (N) coupling processes in terrestrial ecosystems have the potential to modify the sensitivity of the global C cycle to climate change. But the degree to which C-N interactions contribute to the sequestration of terrestrial ecosystem C (Cseq), both now and in the future, remains uncertain. In this study, we used a meta-analysis to quantitatively synthesize C and N responses from field experiments on grasslands subjected to simulated warming and assessed the relative importance of three properties (changes in ecosystem N amount, redistribution of N among soil, litter and vegetation, and modifications in the C:N ratio) associated with grassland Cseq in response to warming. Warming increased soil, litter and vegetation C:N ratios and approximately 2% of N shifted from the soil to vegetation and litter. Warming-induced grassland Cseq was the result of the net balance between increases in vegetation and litter C (111.2 g m-2) and decreases in soil C (30.0 g m-2). Warming-induced accumulation of C stocks in grassland ecosystems indicated that the three processes examined were the main contributors to Cseq, with the changes in C:N ratios in soil, litter and vegetation as the major contributors, followed by N redistribution, whilst a decrease in total N had a negative effect on Cseq. These results indicate that elevated temperatures have a significant influence on grassland C and N stocks and their coupling processes, suggesting that ecological models need to include C-N interactions for more accurate predictions of future terrestrial C storage.
Original language | English (US) |
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Pages (from-to) | 733-742 |
Number of pages | 10 |
Journal | Journal of Plant Ecology |
Volume | 15 |
Issue number | 4 |
DOIs | |
State | Published - Aug 1 2022 |
Keywords
- carbon sequestration
- carbon-nitrogen interactions
- climate change
- grasslands
- nitrogen limitation
- stoichiometry
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Ecology
- Plant Science