Abstract:

This paper studied the growth variability of Pinus densiflora plantations with different densities in Laoshan Forest Farm, as well as the correlation between DBH and crown width. The results showed that under different densities, the diameter distribution of P. densiflora plantations increased first and then decreased. With the increase of stand density, DBH growth decreased significantly and the diameter class ratio decreased. The average tree height, clear length, and crown diameter of P. densiflora plantation were all on the rise. There was no significant difference in tree height growth between P. densiflora with different densities, and the clear length was significantly different, and the difference in DBH was very significant. The crown diameter of P. densiflora plantation was decreased with the increasing of stand density, but the crown ellipsoid volume was the opposite. Through analysis, the quadratic polynomial equation was obtained as the optimal model between DBH and crown width of P. densiflora plantation, and the relationship equation was obtained, which provided the basis for forestry production.

Key words: density, Pinus densiflora plantation, Laoshan Forest Farm, growth difference