Subscribe Now Subscribe Today
Science Alert
 
Blue
   
Curve Top
Journal of Applied Sciences
  Year: 2008 | Volume: 8 | Issue: 5 | Page No.: 866-870
DOI: 10.3923/jas.2008.866.870
 
Facebook Twitter Digg Reddit Linkedin StumbleUpon E-mail

Improving the Precision of Forestry Experimentation with Covariance Analysis

I.C. Zobi, J.P. Pascal, P. Couteron and K.B. Kouadio

Abstract:
This study aims to provide a tool of study to forester and forest survey researchers. It deals with the effect of a method of thinning on tropical forest dynamic. In this method, elimination of trees species of no commercial value was done in order to increase the growth rate of the whole group of commercial ones. Specifically, this study shows how a statistical method which is covariance analysis can be used to solve an inadequacy of experimental design. This inadequacy results from a difference between the initial total basal area of the treated quadrants and that of the untreated (standard) quadrants. The gain of precision is 1.054. It provided the following estimates of the increase rate in basal area of the commercial species: 0.73 m2 ha-1 year-1 for the treated quadrants and 0.92 m2 ha-1 year-1 for the untreated ones. When the initial total basal area of the quadrants is not considered like an auxiliary variable, the values of the basal area of the commercial species are: 0.53 m2 ha-1 year-1 for the treated quadrants and 1.05 m2 ha-1 year-1 for the untreated ones.
PDF Fulltext XML References Citation Report Citation
How to cite this article:

I.C. Zobi, J.P. Pascal, P. Couteron and K.B. Kouadio, 2008. Improving the Precision of Forestry Experimentation with Covariance Analysis. Journal of Applied Sciences, 8: 866-870.

DOI: 10.3923/jas.2008.866.870

URL: https://scialert.net/abstract/?doi=jas.2008.866.870

COMMENT ON THIS PAPER
 
 
 

 

 
 
 
 
 
 
 
 
 

 
 
 
 
 
 
 

Curve Bottom