Increases in nitrogen uptake rather than nitrogen-use efficiency support higher rates of temperate forest productivity under elevated CO2.

ABSTRACT: Forest ecosystems are important sinks for rising concentrations of atmospheric CO(2). In previous research, we showed that net primary production (NPP) increased by 23 +/- 2% when four experimental forests were grown under atmospheric concentrations of CO(2) predicted for the latter half of this century. Because nitrogen (N) availability commonly limits forest productivity, some combination of increased N uptake from the soil and more efficient use of the N already assimilated by trees is necessary to sustain the high rates of forest NPP under free-air CO(2) enrichment (FACE). In this study, experimental evidence demonstrates that the uptake of N increased under elevated CO(2) at the Rhinelander, Duke, and Oak Ridge National Laboratory FACE sites, yet fertilization studies at the Duke and

SUBMITTER: Finzi AC 

PROVIDER: S-EPMC1955801 | biostudies-literature | 2007 Aug

REPOSITORIES: biostudies-literature