title: Alteration of forest succession and carbon cycling under elevated CO2.
abstract: Regenerating forests influence the global carbon (C) cycle, and understanding how climate change will affect patterns of regeneration and C storage is necessary to predict the rate of atmospheric carbon dioxide (CO2 ) increase in future decades. While experimental elevation of CO2 has revealed that young forests respond with increased productivity, there remains considerable uncertainty as to how the long-term dynamics of forest regrowth are shaped by elevated CO2 (eCO2 ). Here, we use the mechanistic size- and age- structured Ecosystem Demography model to investigate the effects of CO2 enrichment on forest regeneration, using data from the Duke Forest Free-Air Carbon dioxide Enrichment (FACE) experiment, a forest chronosequence, and an eddy-covariance tower for model parameterization and evaluation. We find that the dynamics of forest regeneration are accelerated, and stands consistently hit a variety of developmental benchmarks earlier under eCO2 . Because responses to eCO2 varied by plant functional type, successional pathways, and mature forest composition differed under eCO2 , with mid- and late-successional hardwood functional types experiencing greater increases in biomass compared to early-successional functional types and the pine canopy. Over the simulation period, eCO2 led to an increase in total ecosystem C storage of 9.7 Mg C ha(-1) . Model predictions of mature forest biomass and ecosystem-atmosphere exchange of CO2 and H2 O were sensitive to assumptions about nitrogen limitation; both the magnitude and persistence of the ecosystem response to eCO2 were reduced under N limitation. In summary, our simulations demonstrate that eCO2 can result in a general acceleration of forest regeneration while altering the course of successional change and having a lasting impact on forest ecosystems.
authors: Conservation Ecology Center, Smithsonian Conservation Biology Institute, National Zoological Park, 1500 Remount Rd., Front Royal, VA, 22630, USA.|Institute for Sustainability, Energy, and Environment, University of Illinois at Urbana-Champaign, 1101 W. Peabody, Suite 350 (NSRC), MC-635, Urbana, IL, 61801, USA.
authors: Adam D
authors: AD
authors: Miller
authors: Department of Earth and Environment, Boston University, 685 Commonwealth Avenue, Boston, MA, 02215, USA.
authors: Michael C
authors: MC
authors: Dietze
authors: Institute for Sustainability, Energy, and Environment, University of Illinois at Urbana-Champaign, 1101 W. Peabody, Suite 350 (NSRC), MC-635, Urbana, IL, 61801, USA.|Department of Plant Biology, University of Illinois at Urbana-Champaign, 265 Morrill Hall, MC-116, 505 South Goodwin Avenue, Urbana, IL, 61801, USA.
authors: Evan H
authors: EH
authors: DeLucia
authors: Conservation Ecology Center, Smithsonian Conservation Biology Institute, National Zoological Park, 1500 Remount Rd., Front Royal, VA, 22630, USA.|Center for Tropical Forest Science-Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Panamá, Repúblic of Panamá
authors: Kristina J
authors: KJ
authors: Anderson-Teixeira
mesh_terms: D001272:Atmosphere / Q000737:chemistry; D018533:Biomass; D057486:Carbon Cycle; D002245:Carbon Dioxide / Q000378:metabolism*; D057231:Climate Change; D065928:Forests; D008962:Models, Theoretical; D009584:Nitrogen / Q000378:metabolism; D014197:Trees / Q000254:growth & development* / Q000378:metabolism
chemical_list: D002245:Carbon Dioxide; D009584:Nitrogen
keywords: climate change; duke FACE; ecosystem demography model; forest regeneration; simulation; succession