Skip to page content
USDA Forest Service
  
Treesearch

Research & Development Treesearch

 
Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Northern
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help
 

Science.gov - We Participate


USA.gov  Government Made Easy


Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.
20090-6090

(202) 205-8333

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

Publication Information

View PDF (1.2 MB)

Title: Resource-dependent growth models for Sierran mixed-conifer saplings

Author: Bigelow, S.W.; North, M.P.; Horwath, W.R.;

Date: 2009

Source: The Open Forest Science Journal 2: 31-40

Publication Series: Scientific Journal (JRNL)

Description:

Thinning to reduce wildfire hazard is a common management practice in frequent-fire forests of the American west, but it is uncertain whether projects will help regenerate fire-resistant, shade-intolerant pines. We studied naturally established saplings of six conifer species in mixed-conifer forest in northern California, USA to determine how three environmental resources - light, soil moisture, and soil mineralizable nitrogen - affect stem radial growth. Likelihood principles were used to select among models of growth as a function of resources, age and size. There was support for models of growth as an exponential function of light for three species. Pinus jeffreyi growth was slow even at 40% full sun but increased sharply at higher light. Light-dependent growth of Pinus ponderosa and Calocedrus decurrens was contingent upon age: some young (<20 y) saplings grew rapidly at 16% full sun, but older saplings required higher light for rapid growth. No relationship of light or other resources to growth was detected for three other species; instead, null models of size-dependent (Abies concolor, Pseudotsuga menziesii) or age-dependent (Pinus lambertiana) growth provided the most parsimonious explanations of growth patterns. These results suggest the latter species will not grow rapidly under more open canopies, but the scope of this inference is limited because few individuals of these more tolerantspecies were found in high-light environments. In contrast, large openings or patchy canopy are required for rapid growth of P. jeffreyi; smaller openings will increase growth of P. ponderosa, but increases may be modest unless saplings are young.

Keywords: Irradiance, hemispherical image analysis, light-dependent growth, carbon isotope, mixed-conifer, sapling, Michaelis-Menten, Sierra Nevada USA, soil moisture

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.

XML: View XML

Citation:


Bigelow, S.W., M.P. North, and W.R. Horwath. 2009. Resource-dependent growth models for Sierran mixed-conifer saplings. The Open Forest Science Journal 2: 31–40.

 


 [ 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.