Stand development following precommercial thinning and fertilization treatments in a western redcedar (Thuja plicata) dominated forest

摘要: Western redcedar (Thuja plicata Donn ex D. Don.) is an important North American tree species, but little infor- mation available on its long-term responses to silvicultural treatments. Stand (mortality, ingrowth, basal area and volume growth, distributions of trees by diameter height classes) were followed for 25 years after thinning fertilization treatments (alone in combination) applied a naturally regenerated, low site quality western stand the Olympic Peninsula Washington, USA. Mortality was overall, densest stands experienced competition-related mortality. Thinning resulted additional stem recruitment; years, number ingrowth exceeded cohort left thinning. Fertilization (with nitrogen phosphorus) flattened size skewed them larger classes. plus largest indi- vidual most large trees, also many wide range The recruitment second did not result two-storied stand. without greatest vol- ume, as well with fewer live lower branches. Resume´ : Le thuya geant est une espece d'arbre importante en Amerique du Nord, mais peu d'informations sont disponibles concernant sa reaction long terme aux traitements sylvicoles. Les reactions ` l'echelle peuplement (la mortalite ´, le recrutement, la croissance surface terriere et volume, ainsi que distribu- tion des arbres par classes de diametre hauteur) ont etemesurees pendant periode ans qui suivi l'appli- cation d'eclaircie fertilisation (seuls ou combines) dans un naturellement regeneresur station faible qualitede presqu'oˆle Olympique l'ouest l'Etat Etats-Unis.