Document


Title

Elevated CO2 and conifer roots: effects on growth, life span and turnover
Document Type: Journal
Author(s): David T. Tingey ; Donald L. Phillips ; Mark G. Johnson
Publication Year: 2000

Cataloging Information

Keyword(s):
  • CO2 - carbon dioxide
  • conifer
  • coniferous forests
  • fire dependent species
  • forest management
  • life span
  • loblolly pine
  • minirhizotron
  • Monterey pine
  • pine forests
  • Pinus ponderosa
  • Pinus radiata
  • Pinus sylvestris
  • Pinus taeda
  • plant growth
  • ponderosa pine
  • root growth
  • root turnover
  • roots
  • roots
  • Scots pine
Topic(s):
Record Maintained By:
Record Last Modified: May 15, 2019
FRAMES Record Number: 51307
Tall Timbers Record Number: 28145
TTRS Location Status: Not in file
TTRS Call Number: Available
TTRS Abstract Status: Fair use, Okay, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.

Description

Elevated CO2 increases root growth and fine (diam. £2 mm) root growth across a range of species and experimental conditions. However, there is no clear evidence that elevated CO2 changes the proportion of C allocated to root biomass, measured as either the root : shoot ratio or the fine root : needle ratio. Elevated CO2 tends to increase mycorrhizal infection, colonization and the amount of extramatrical hyphae, supporting their key role in aiding the plant to more intensively exploit soil resources, providing a route for increased C sequestration. Only two studies have determined the effects of elevated CO2 on conifer fine-root life span, and there is no clear trend. Elevated CO2 increases the absolute fine-root turnover rates; however, the standing crop root biomass is also greater, and the effect of elevated CO2 on relative turnover rates (turnover : biomass) ranges from an increase to a decrease. At the ecosystem level these changes could lead to increased C storage in roots. Increased fine-root production coupled with increased absolute turnover rates could also lead to increases in soil organic C as greater amounts of fine roots die and decompose. Although CO2 can stimulate fine-root growth, it is not known if this stimulation persists over time. Modeling studies suggest that a doubling of the atmospheric CO2 concentration initially increases biomass, but this stimulation declines with the response to elevated CO2 because increases in assimilation are not matched by increases in nutrient supply.© New Phytologist (2000).

Citation:
Tingey, D. T., D. L. Phillips, and M. G. Johnson. 2000. Elevated CO2 and conifer roots: effects on growth, life span and turnover. New Phytologist, v. 147, no. 1, p. 87-103.