Impacts of fine root turnover on forest NPP and soil C sequestration potential.
Estimates of forest net primary production (NPP) demand accurate estimates of root production and turnover. We assessed root turnover with the use of an isotope tracer in two forest free-air carbon dioxide enrichment experiments. Growth at elevated carbon dioxide did not accelerate root turnover in either the pine or the hardwood forest. Turnover of fine root carbon varied from 1.2 to 9 years, depending on root diameter and dominant tree species. These long turnover times suggest that root production and turnover in forests have been overestimated and that sequestration of anthropogenic atmospheric carbon in forest soils may be lower than currently estimated.
Matamala
Roser
R
Environmental Research Division, Argonne National Laboratory, Argonne, IL 60439, USA. matamala@anl.gov
Gonzàlez-Meler
Miquel A
MA
Jastrow
Julie D
JD
Norby
Richard J
RJ
Schlesinger
William H
WH
D001272:Atmosphere; D018533:Biomass; D002244:Carbon / Q000032:analysis* / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D002247:Carbon Isotopes / Q000032:analysis; D017753:Ecosystem; D031317:Liquidambar / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D009657:North Carolina; D041603:Pinus taeda / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D018517:Plant Roots / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D012621:Seasons; D012987:Soil / Q000032:analysis*; D013714:Tennessee; D013997:Time Factors; D014197:Trees
D002247:Carbon Isotopes; D012987:Soil; D002245:Carbon Dioxide; D002244:Carbon