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Agroforestry Systems

, Volume 16, Issue 1, pp 41–54 | Cite as

Modelling cork oak production in Portugal

  • M. C. Ferreira
  • A. M. Carvalho Oliveira
Article

Abstract

The layout of 32 permanent plots in the most important cork production regions of Portugal and the measurement of the most representative tree parameters were performed for statistically sound cork weight modelling. The establishment of cork weight equations is presented for the different cork oak study areas considered alone or grouped according to the most representative tree parameters. For the presented cork weight models was chosen independent variable the total stripping surface (artmax). For the selection criteria five statistic were used, including PRESS, APRESS and Mallows's statistic. The crossvalidation of the best classified models was performed and to discuss the importance of the “study area” factor, a regression analysis with “dummy” variables was performed.

Key words

Quercus suber cork weight models validation 

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Copyright information

© Kluwer Academic Publishers 1991

Authors and Affiliations

  • M. C. Ferreira
    • 1
  • A. M. Carvalho Oliveira
    • 2
  1. 1.Direcção Geral das FlorestasLisboaPortugal
  2. 2.Departamento de Engenharia FlorestalTapada da AjudaLisboa codexPortugal

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