Selection thinning

n. A thinning that removes trees in the dominant and emergent crown classes in order to favor the lower crown classes (Helms 1998).


  • Discussion


A selection thinning is rarely an appropriate thinning method for mitigating crown fire potential because it is unlikely to affect canopy base height, and usually has little effect on canopy bulk density.




The hypothesis behind selection thinning is that the dominant and emergent trees have nearly all the growing space needed for maximum growth and vigor, so thinning to retain them cannot significantly improve their status; in contrast, the growth and vigor of the lower crown classes (codominant, intermediate and suppressed) could be increased by removal of the dominant trees.