西藏天然云杉林兼容性材积生长率模型系统研究

Compatible model system of volume growth rates of natural spruce forest in Tibet

实施限额采伐是我国森林资源管理的一项基本制度,而准确的森林生长量估测值,是确定森林采伐限额的重要依据。利用西藏自治区2006年森林资源连续清查的127个天然云杉林实测样地资料,通过代数和控制与比例控制方法,构建了两套非线性联合估计模型系统,建立了天然云杉林材积总生长率、进界生长率、保留生长率三者一致兼容的以林分龄组A和平均胸径D为解释变量的估测模型。对比分析表明,比例控制模型系统效果较好,其结果为:总生长率P0=32.780A-0.92772D-0.60180,保留生长率P1=1/(1+517.27A-0.69639D-3.6004)×32.780A-0.92772×D-0.60180,进界生长率P2=1/(1+1/517.27A0.69639D3.600 4)×32.780A-0.92772D-0.60180。研究结果为西藏天然云杉林的生长量估测提供了参考依据,研究方法为林分材积生长率模型及类似模型的研建提供了经验和借鉴。

Cutting quota system is a basic system for forest resource management in China and the accurate estimation of forest growth is used as important reference to determine the cutting quota. Using the data of 127 sample plots of natural spruce （ Picea asperata ） forest in continuous forest inventory of Tibet in 2006, two non- linear dependently estimated model systems were established by algebra control and proportional control. Compatible models of total growth rate, ingrowth rate and surviror growth rate were constructed and stand age class A and mean diameter D were chosen as explanation variables. The results show that the model system by proportional control is better than the other one. Total growth rate P0 was 32.780A^-0.92772D^-0.60180, surviror growth rate P1 was 1 / （ 1 ＋ 5 17.27 A^- 0.696 39 D^- 3 600 4 ） ×32.780A^-0.92772×D^-0.60180 and ingrowth rate P2 was 1/（1＋1/517.27A^0.69639D^3.600 4）×32.780A^-0.92772D^-0.60180. The model system can be used for prediction of stand volume growth of natural spruce forest in Tibet and the method of building compatible model system can be referenced to establishing volume growth rate model and other similar models.