The suppression of growth rings in jack pine in relation to defoliation by the Swaine jack-pine sawfly
Document Type: Journal Article
Author(s): L. C. O'Neil
Publication Year: 1963

Cataloging Information

  • arthropods
  • Canada
  • competition
  • dendrochronology
  • foliage
  • forest management
  • insects
  • mortality
  • Neodiprion
  • pine forests
  • Pinus banksiana
  • plant growth
  • Quebec
  • trees
Record Maintained By:
Record Last Modified: June 1, 2018
FRAMES Record Number: 36011
Tall Timbers Record Number: 10348
TTRS Location Status: In-file
TTRS Call Number: Abstract only. Abstract reproduced by permission of The Canadian Journal of Botany.
TTRS Abstract Status: Okay, Fair use, 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.


An investigation of the radial growth of jack pine (Pinus banksiana Lamb.) defoliated by the Swaine jack-pine sawfly (Neodiprion swainei Midd.) disclosed that growth rings were discontinuous and missing in cross-sectional disks from severly damaged trees. In young and open-grown trees with dead tops, the incidence of such deficiencies in radial growth was especially high in disks from upper regions of the stems, in the vicinity of the dead tops; radial growth was suspended for one year and subsequently resumed in disks from the lower regions of some stems. Cambial inactivity was more generalized in trees from an old and dense stand and it was detected in disks representing major portions of some of the stems sampled; the death of some trees followed 2 to 6 years of camdial inactivity in disks cut at various heights along their entire stems. Growth deficiencies in the young stand were clearly effects of severe sawfly defoliation. Data from the old, dense stand indicated that sawfly defoliation had perhaps merely hastened the gradual deterioration of the stand in which intertree competition was intense.©NRC Canada

Online Link(s):
O'Neil, L. C. 1963. The suppression of growth rings in jack pine in relation to defoliation by the Swaine jack-pine sawfly. Canadian Journal of Botany, v. 41, no. 2, p. 227. 0008-4026.