Studies On The Stand Structure And Growing Roles Of Pinus Sylvestris L. Var. Mongolica Litv.'s Forest In Inner Mongolia

The diameter distribution of Pinus sylvestris L. var. mongolica Litv.'s forest is near to normal distribution and following the decrease of stand density the curve moved rightward in Narisitai Forest Farm, Wulanchbu, Inner Mongolia. Using normal distribution function can precisely imitate the diameter distribution. the law of Stand height structure indicate that the tree's height increased with the accretion of tree's diameter, then decreased dissymmetrical to the two poles; the most wood is near to the average diameter and the average height; the tree's number of small diameter class is more than big one's and the similar regulation is displayed roughly in the same tree's diameter class. Using three parameter Weibull function can precisely imitate the height distribution.From the growing status of Pinus sylvestris L. var. mongolica Litv.'s forest on different site condition, the growth increment of Pinus sylvestris L. var. mongolica Litv.'s at lower part of the half-sunny slope is bigger than at upper part of the sunny slope, and the upper part of sunny slope's growth increment is bigger than the upper part of shade slope. The cone distribution of Pinus sylvestris L. var. mongolica Litv.'s forest indicate that the cone number of each hectare increased with accretion of crown density and reach the maximum when crown density at 0.75, then it decreased with accretion of crown density. The stand density has a slight influence to the height growth process of Pinus sylvestris L. var. mongolica Litv.'s forest. And its influence is significant at the growth of the DBH and the growth of the volume. Except from stand density, the temperature is a main weather factors influencing the growth of Pinus sylvestris L. var. mongolica Litv. .