Study On The Latewood Percentage Variation Of Inner Mongolia Larix Gmelinii And Its Responses To Climate Factors

This thesis takes four natural Larix gmelinii from Genhe of Great Khingan Mountains as the samples of the study. Using correlation analysis method, it aims to analyze the relation between the latewood percentage of Larix gmelinii and climatic factors, in which way to reveal the reaction of Larix gmelinii’s radial growth latewood percentage to the changes of main climatic factors. According to the changing condition of the different height of the Larix gmelinii latewood percentage,adopts recurrence analysis curve method to imitate the equation model that suit the changing regulation of the latewood precentage the most. The statistics show:1.Larix gmelinii’s latewood percentage shows obvious relation to the changes of temperature in both the early and growing stages, especially relates to the average temperature of the year. The relations of the 4 samples are:0.594,0.655,0.695,0.665, showing positive correlation on level 0.01; Besides, the relation to the temperature of the months Performance obvious, and are significantly positive correlation.2.during the analysis of the relationship between tree ring width and climate factor of 4 samples, only Sample 2 and Sample 3 are closely linked to the climatic factors. Among them, the relation between Sample 2 and the temperature in summer, autumn, winter in last year, and spring temperature, temperature of summer in this year shows correlation at 0.01 level was negatively correlated. with the temperature in the fall of that year showed a significant negative correlation at 0.05 level. the relation between Sample 3 and the temperature of last summer and winter, and this summer and fall,mean annual temperature correlation at 0.01 level was significantly negatively correlated; the relation between it and the temperature of last autumn and spring of significant negative correlation at 0.05 level.3.The precipitation of Larix gmelinii exist "lag effect". Whether in Larix gmelinii ring width and precipitation were analyzed by correlation analysis or precipitation of latewood percentage, both of which just related to the winter precipitation, and the correlation of latewood percentage is more obvious. The correlation analysis of precipitation in each month further verified this effect, significant correlation in four samples of ring width and latewood percentage only related to early growth season in the winter months precipitation.4.in the study of the regulation of Larix gmelinii change with the height of Larix gmelinii latewood percentage,6 different linear equation models are used to intimidated, including quadratic curve, cubic curve, growth curve, exponential curve and Logistic curve. using coefficient of determination as the main basis for the selection of the optimal model, the results show that:quadratic curve fitting is the best, the number of R2 which is more than 0.8 is 34, reaching 70.4% of the total.