Analysis of the Influence Factors of Pinus yunnanensis Forest Volume

Based on the data of 7^th national forest resources inventory of Pinus yunnanensis in 2007, 503 natural pure forest sample plots of P. yunnanensis were selected, 13 influencing factors were combined by factor analysis method, and the regression model of P. yunnanensis stand based on common factors was fitted to analyze the influence of common factors on the stand of P. yunnanensis. Factor analysis and multiple linear regression results showed that the 5 common factors extracted were temperature factor, stand factor, water factor, density factor and light factor, and the cumulative variance contribution rate was 83.6%. The absolute value of the stock of P. yunnanensis varying with common factor was in the order of stand factor > density factor > water factor > temperature factor > light factor. The stand volume of P. yunnanensis varying with stand factors was the most significant, it was insensitive to temperature factors and light factors, the areas with good water conditions were not suitable for the growth of P. yunnanensis.