• Zaerr, Joe B.
  Oregon State University
  

A 5-year field study was conducted to determine the effect of three methods of site preparation in combination with three levels of shrub suppression on subsequent microenvironmental, shrub and tree responses. Shrub canopy volume and survival, growth, and water potential of planted ponderosa pine, sure pine, and white fur were measured. Ponderosa pine survived better than sugar pine or white fir regardless of shrub presence or absence. Shrub canopy volume did not influence tree survival; however, the presence of shrub debris form some treatments increased planting difficulty and resulted in increased tree morality. Predawn and midday water potential, height, stem diameter, and canopy volume of conifers were highest when shrub canopy volumes were low.