Elevated CO2 and O3 alter soil nitrogen transformations beneath trembling aspen, paper birch, and sugar maple
Authors: | William E. Holmes, Donald R. Zak, Kurt S. Pregitzer, John S. King |
Year: | 2006 |
Type: | Scientific Journal |
Station: | Northern Research Station |
Source: | Ecosystems. 9: 1354-1363. |
Abstract
Nitrogen cycling in northern temperate forest ecosystems could change under increasing atmospheric CO2 and tropospheric O3 as a result of quantitative and qualitative changes in plant litter production. At the Aspen Free Air CO2-O3 Enrichment (FACE) experiment, we previously found that greater substrate inputs to soil under elevated CO2 did not alter gross N transformation rates in the first 3 years of the experiment. We hypothesized that greater litter production under elevated CO2 would eventually cause greater gross N transformation rates and that CO2 effects would be {}ified by elevated O3. Following our original study, we continued measurement of gross N transformation rates for an additional four years.