Concentric rings formed in wood that record a history of the periodic growing seasons for the plant. In temperate climates, growth rings are sometimes called annual rings because the two growing cycles each year are distinctly visible (springwood and summerwood). The springwood portion contains large cells due to the rapid rate of stem growth during this period. The summerwood region has smaller, denser cells due to the slower growth rate at the end of the growing season. Counting the annual rings from its bark to the center of the trunk can give an accurate tree age. The sequential combination of ring width and density produces patterns related to a trees environmental growing conditions. Wet growing seasons produce wider growth rings than dry growing seasons. In some tropical areas, tree growth continues with little interruption resulting in indistinct growth rings. The overall pattern of annual rings on trees have been used for dendrochronological dating.
See also dendrochronology.
Synonyms and Related Terms
annual ring; cerne (Fr.); anillo de crecimiento (Esp.); camada de crescimento anual (Port.); anello annuale (It.); growth increment; growth layer
Sources Checked for Data in Record
- R. Bruce Hoadley, Identifying Wood, The Taunton Press, Newton, CT, 1990
- Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
- Mary-Lou Florian, Dale Paul Kronkright, Ruth E. Norton, The Conservation of Artifacts Made from Plant Materials, The Getty Conservation Institute, Los Angeles, 1990
- Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
- Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
- The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998