CO2 enrichment increases carbon and nitrogen input from fine roots in a deciduous forest
Article first published online: 5 JUN 2008
No claim to original US government works. Journal compilation © New Phytologist (2008)
Volume 179, Issue 3, pages 837–847, August 2008
How to Cite
Iversen, C. M., Ledford, J. and Norby, R. J. (2008), CO2 enrichment increases carbon and nitrogen input from fine roots in a deciduous forest. New Phytologist, 179: 837–847. doi: 10.1111/j.1469-8137.2008.02516.x
- Issue published online: 15 JUL 2008
- Article first published online: 5 JUN 2008
- Received: 3 March 2008 Accepted: 20 April 2008
- fine roots;
- root biomass;
- root diameter;
- root mortality;
- root N content;
- root turnover;
- soil C storage
- • Greater fine-root production under elevated [CO2] may increase the input of carbon (C) and nitrogen (N) to the soil profile because fine root populations turn over quickly in forested ecosystems.
- • Here, the effect of elevated [CO2] was assessed on root biomass and N inputs at several soil depths by combining a long-term minirhizotron dataset with continuous, root-specific measurements of root mass and [N]. The experiment was conducted in a CO2-enriched sweetgum (Liquidambar styraciflua) plantation.
- • CO2 enrichment had no effect on root tissue density or [N] within a given diameter class. Root biomass production and standing crop were doubled under elevated [CO2]. Though fine-root turnover declined under elevated [CO2], fine-root mortality was also nearly doubled under CO2 enrichment. Over 9 yr, root mortality resulted in 681 g m−2 of extra C and 9 g m−2 of extra N input to the soil system under elevated [CO2]. At least half of these inputs were below 30 cm soil depth.
- • Increased C and N input to the soil under CO2 enrichment, especially below 30 cm depth, might alter soil C storage and N mineralization. Future research should focus on quantifying root decomposition dynamics and C and N mineralization deeper in the soil.