A validation of TWIGS for Illinois forests

D. G. Kowalski, G. Z. Gertner

Research output: Contribution to journalArticlepeer-review


The Central States growth and yield system TWIGS 3.0, evaluated for Illinois consistently overpredicted mean stand diameter and underpredicted tree survival over a 30-yr growth projection. The combined result of prediction errors in diameter growth and tree survival was a consistent underprediction of basal area per acre. Percent error at the 20th year of projection was - 6% for mean stand diameter, 18% for tree survival, and 6% for basal area. TWIGS, with its simulation features and small relative prediction errors for some major timber species, is an adequate growth and yield system for Illinois' mixed hardwood forests. -from Authors

Original languageEnglish (US)
Pages (from-to)154-156
Number of pages3
JournalNorthern Journal of Applied Forestry
Issue number4
StatePublished - 1989
Externally publishedYes

ASJC Scopus subject areas

  • Forestry
  • Materials Science(all)
  • Plant Science


Dive into the research topics of 'A validation of TWIGS for Illinois forests'. Together they form a unique fingerprint.

Cite this