title: Stimulation of grassland nitrogen cycling under carbon dioxide enrichment.
abstract: Nitrogen (N) limits plant growth in many terrestrial ecosystems, potentially constraining terrestrial ecosystem response to elevated CO2. In this study, elevated CO2stimulated gross N mineralization and plant N uptake in two annual grasslands. In contrast to other studies that have invoked increased C input to soil as the mechanism altering soil N cycling in response to elevated CO2, increased soil moisture, due to decreased plant transpiration in elevated CO2, best explains the changes we observed. This study suggests that atmospheric CO2concentration may influence ecosystem biogeochemistry through plant control of soil moisture.
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, CA 94720, USA, , , , , , US.
authors.forename: B A
authors.initials: BA
authors.lastname: Hungate
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, CA 94720, USA, , , , , , US.
authors.forename: F S
authors.initials: FS
authors.lastname: Chapin Iii
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, CA 94720, USA, , , , , , US.
authors.forename: H
authors.initials: H
authors.lastname: Zhong
authors.affiliation: National Center for Atmospheric Research, Boulder, CO 80307, USA, , , , , , US.
authors.forename: E A
authors.initials: EA
authors.lastname: Holland
authors.affiliation: Department of Plant Biology, Carnegie Institution of Washington, Stanford, CA 94305, USA, , , , , , US.
authors.forename: C B
authors.initials: CB
authors.lastname: Field
keywords: Annual grasslands; Elevated CO2; Key words N mineralization; Soil moisture