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 (285 KB bytes)

Title: The statistical reason why some researchers say some silvicultural treatments "wash-out" over time

Author: South, David B.; VanderSchaaf, Curtis L.;

Date: 2006

Source: Gen. Tech. Rep. SRS-92. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. pp. 333-337

Publication Series: Miscellaneous Publication

   Note: This article is part of a larger document. View the larger document

Description: The initial effects of a silvicultural treatment on height or volume growth sometimes decline over time, and the early gains eventually disappear with very long rotations. However, in some reports initial gains are maintained until harvest but due to statistical analyses, a researcher might conclude the treatment effect has "washed-out" by ages 10 to 18 years (even when the gain is 6 green tons per acre or more). This claim is sometimes made even when the volume gains have increased over time. Researchers who end up making Type II statistical errors do so because of the inherent variability which increases with stand age (i.e., statistical power declines over time). To avoid making Type II errors, some researchers have decided to model their data instead of applying statistics to a data set that has low power.

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

XML: View XML

Citation:


South, David B.; VanderSchaaf, Curtis L. 2006. The statistical reason why some researchers say some silvicultural treatments "wash-out" over time. Gen. Tech. Rep. SRS-92. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. pp. 333-337

 


 [ 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.