Study on the Yield Modelling System of Chinese Fir Plantation

By using the biological law that height growth of dominant tree is inde-pendent of its plantation density and it's a function of the site an stand age and that diametergrowth can indicate a multifactor effect,and by the use of taking the dominant height as anindependent variant and introducing it into other related models,a yield modelling system forChinese fir plantation has been constructed.It helps to provide a growth modelling fornatural growth and post-thinning growth of Chinese fir plantation.It can help to build astandard tree height curve,a compatible predicting model for diameter and cross-sectionalarea and a thinning modelling system.In addition,a mathematical equation on the nongrowthincrease caused by thinning can be deduced.