太白红杉径向生长的预测模型

The DBH increment model of individual trees growing for Larix chinensis

关键词:  太白红杉  径向生长  生长模型

Key words:  Larix chinensis  diameter increment  growth model

摘要:

采用多元回归的方法构建了太白红杉的生长模型,模型中主要考虑了植株自身大小(胸径和冠幅比)、竞争状况和立地因子(海拔、坡度和坡向)三类因子的作用。结果发现,太白红杉近2年生长量与植株自身大小、竞争状况和海拔因子有较高的相关性; 坡度、坡向与生长量的相关性较小,但其综合作用在一定程度上影响着太白红杉的生长。所构建的生长模型充分考虑了太白红杉自身的生物学特性,具有较高的回归优度(r=0.938,P<0.001),能很好地预测其生长动态。

Abstract:

A model for predicting DBH growth of L.chinensis in different environments was developed by using multiple regression method. Data for this study were collected in Taibai Mountain Natural Reserve of Shaanxi Province of China. Ten plots of 40 m×40 m were investigated,and every plot was stem-mapped,and species,DBH,total height,and crown length were recorded for each tree that had reached a diameter of 5 cm at breast height. Plant size variables(breast height diameter,the crown ratio),competition,environmental factors(elevation,slope angle,slope aspect)were used in the model. The results showed that the function of plant size,competition and elevation were significant. Even though site factors(slope and aspect)accounted for a small percentage of the variation and the function of most factors were not significant,but they were very important,because these factors were often interaction,and the total function to the growth of L.chinensis was significant. The variables in the model correspond quite well with ecological expectations and forestry understanding. Because the sample base was so strong,and the r-value was 0.938 and the p value was less than 0.001,the resulting growth models can be recommended for many regions with similar growth conditions of L.chinensis community in Taibai Mountain.