Skip to page content
USDA Forest Service

Research & Development Treesearch

Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help - We Participate  Government Made Easy

Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (223 KB)

Title: Age-dependent radial increases in wood specific gravity of tropical pioneers in Costa Rica

Author: Williamson, Bruce G.; Wiemann, Michael C.;

Date: 2010

Source: Biotropica. Vol. 42, no. 5 (2010): p. 590-597.

Publication Series: Miscellaneous Publication

Description: Wood specific gravity is the single best descriptor of wood functional properties and tree life-history traits, and it is the most important variable in estimating carbon stocks in forests. Tropical pioneer trees produce wood of increasing specific gravity across the trunk radius as they grow in stature. Here, we tested whether radial increases in wood specific gravity were dependent on a tree’s diameter or its age by comparing trees of different diameters within cohorts. We cored trunks of four pioneer species in naturally regenerating, even-aged stands in the lowland, wet forests of Costa Rica. For each core, specific gravity was determined for 1-cm radial wood segments, pith to bark. Increases across the radius were evident in all four species studied, and in four different stands for one species. For any given species in a given stand, the rate of radial increase in specific gravity as a function of radial distance from the pith was greater in smaller diameter trees. As the trees in a stand represent a colonizing cohort, these results strongly suggest that the radial increases in specific gravity in lowland pioneers are associated with tree age, not with tree diameter. Furthermore, the specific gravity of the outermost wood was not associated with tree radius, further negating size dependence. One consequence of these results is that species-specific biomass estimates for trees in secondary forests are likely to be confounded by age, as diameter alone may be a poor indicator of specific gravity in individual trees for pioneers of tropical wet forests.

Keywords: Wood density, specific gravity, Bursera simaruba, Ochroma pyramidale, tropical trees, tree anatomy, tree age, Costa Rica, Heliocarpus appendiculatus, Trema micrantha, tropical woods, wood anatomy, pioneer species, diameter, Gumbo-limbo, Busera simaruba, Heliocarpus appendiculatus, Ochroma pyramidale, Trema micrantha

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.



Williamson, Bruce G.; Wiemann, Michael C. 2010. Age-dependent radial increases in wood specific gravity of tropical pioneers in Costa Rica. Biotropica. Vol. 42, no. 5 (2010): p. 590-597.


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.