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Increasing levels of atmospheric CO2 may change C and N dynamics in pasture ecosystems. The present study was conducted to examine the impact of four years of CO2 enrichment on soil and root composition and soil N transformation in natural pastureland. Plots of open-top growth chambers were continuously injected with ambient CO2 (350 µL L–1) and elevated CO2 (625 µL L–1). Soil cores exposed to ambient and elevated CO2 treatment were incubated and collected each year. Net N-mineralization rates in soil (NH4+-N plus NO3ˉ–-N), in addition to total C and N content (%) of soil and root tissues were measured. Results revealed that elevated CO2 caused a significant reduction in soil NO3 (P &lt; 0.05), however, no significant CO2 effect was found on total soil C and N content (%). Roots of plants grown under elevated CO2 treatment had higher C/N ratios. Changes in root C/N ratios were driven by changes in root N concentrations as total root N content (%) was significantly reduced by 30% (P &lt; 0.05). Overall, findings suggest that the effects of CO2 enrichment was more noticeable on N content (%) than C content (%) of soil and roots; elevated CO2 significantly affected soil N-mineralization and total N content (%) in roots, however, no substantial change was found in C inputs in CO2-enriched soil.
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Increasing levels of atmospheric CO2 may change C and N dynamics in pasture ecosystems. The present study was conducted to examine the impact of four years of CO2 enrichment on soil and root composition and soil N transformation in natural pastureland. Plots of open-top growth chambers were continuously injected with ambient CO2 (350 µL L–1) and elevated CO2 (625 µL L–1). Soil cores exposed to ambient and elevated CO2 treatment were incubated and collected each year. Net N-mineralization rates in soil (NH4+-N plus NO3ˉ–-N), in addition to total C and N content (%) of soil and root tissues were measured. Results revealed that elevated CO2 caused a significant reduction in soil NO3 (P < 0.05), however, no significant CO2 effect was found on total soil C and N content (%). Roots of plants grown under elevated CO2 treatment had higher C/N ratios. Changes in root C/N ratios were driven by changes in root N concentrations as total root N content (%) was significantly reduced by 30% (P < 0.05). Overall, findings suggest that the effects of CO2 enrichment was more noticeable on N content (%) than C content (%) of soil and roots; elevated CO2 significantly affected soil N-mineralization and total N content (%) in roots, however, no substantial change was found in C inputs in CO2-enriched soil.

The effect of long-term CO2 enrichment on carbon and nitrogen content of roots and soil of natural pastureland

Department of Plant Sciences, Faculty of Sciences

Department of Ecology, Evolution and Organismal Biology

McGill University, 1205 Docteur Penfield Avenue, Montréal

Folia Oecologica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

The effect of long-term CO enrichment on carbon and nitrogen content of roots and soil of natural pastureland

Increasing levels of atmospheric CO2 may change C and N dynamics in pasture ecosystems. The present study was conducted to examine the impact of four years of...

The effect of long-term CO₂ enrichment on carbon and nitrogen content of roots and soil of natural pastureland

Published Online: Jul 31, 2021

Page range: 180 - 190

Received: Dec 22, 2020

Accepted: Jun 10, 2021

DOI: https://doi.org/10.2478/foecol-2021-0018

Keywords
CO enrichment, C sequestration, pastureland, root C/N, soil C, soil N

© 2021 Manal Al-Traboulsi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

The effect of long-term CO2 enrichment on carbon and nitrogen content of roots and soil of natural pastureland

Published Online: Jul 31, 2021

Page range: 180 - 190

Received: Dec 22, 2020

Accepted: Jun 10, 2021

DOI: https://doi.org/10.2478/foecol-2021-0018

KeywordsCO enrichment, C sequestration, pastureland, root C/N, soil C, soil N

© 2021 Manal Al-Traboulsi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

The effect of long-term CO₂ enrichment on carbon and nitrogen content of roots and soil of natural pastureland

Keywords
CO enrichment, C sequestration, pastureland, root C/N, soil C, soil N