• Norris, Logan
  Oregon State University
  
• Radosevich, Steven
  
• Newton, Michael
  
• Walstad, John
  
• Brodie, Douglas
  
• Dost, Frank
  
• Mater, Jean
  

In forest regeneration, small conifers must exist with the components of early plant succession for a prolonged period of time. In most situations the association of the tree with its neighbors is considered to be detrimental. Many studies have been conducted which explore the relative aggressiveness of brush or herbaceous plants to conifer seedlings (Stewart 1984). These studies are useful since they assess the biological or economical costs of mixed plant association on tree yield and demonstrate the value of site preparation and competition release. In general, a negative hyperbolic relationship exists between tree yield and brush or herb abundance.