Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): S.W. BigelowM.P. North; W.R. Horwath
    Date: 2009
    Source: The Open Forest Science Journal 2: 31-40
    Publication Series: Scientific Journal (JRNL)
    Station: Pacific Southwest Research Station
    PDF: View PDF  (1.16 MB)

    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.

    Publication Notes

    • You may send email to psw_communications@fs.fed.us to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • 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.

    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.

    Keywords

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

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/34063