Research on the Growth Law of Larix chinensis in the Qinling Mountains on the Basis of the Tree-ring Width

Studies were made of the relationship between BAI (Basal Areas Increment) and topographical factors (elevation, gradient and exposure), and discussion was made on the growth law of Larix chinensis by using correlation analysis method, time sequence ARIMA model and inspection. There was negative correlation between BAI and elevation or gradient. The larger the elevation or gradient were, the slower BAI would be. BAI growth tendency in the South Slope had the larger amplitude than that in the North Slope. The 1st growth peak of BAI appeared at the age of 20 a. The big peak and small peak occurred in 16 a~20 a and in 4 a~6 a, respectively. The historical minimum and maximum appeared in 1840 and 1997. BAI had the negative correlation with elevation and gradient. The suitable elevation and gradient were 3 050 m~3 150 m and 10°~20°, respectively. The growth law showed that BAI of young-aged L. Chinensis was in the stage of rapid growth, BAI of middle and later age had slower growth, but the general growth exhibited in the stably rising tendency.