Solar energy then becomes more important inside the crown. The improved photosynthetic efficiency of this energy influences the retention time of needles, especially in the lower part of the crown. Furthermore, the length, diameter, and area, of the crown, and the size of the root system all increase after thinning.
As solar energy becomes more prominent within the crown, it enhances the photosynthetic efficiency, leading to longer needle retention, particularly in the lower part of the crown.  Furthermore, the crown's length, diameter, and area, along with the size of its root system, increase after thinning.