Study On The Provenance Selection And The Growth Process Of Liriodendron Pulp Forest

This paper are based on the investigation of forest growth,stem analysis and wood chemical analysis of 20 trail forest provenances of 13 years old Liriodendron., and the growth attribute,shape attribute and the chemical component of wood which effect the productivity and quality of pulp forest are studied, the result are as follows:1. The analysis of variance of 20 provences of Liriodendron indicates that The investigation and statistical analysis shows that:there were significant differences in main criterions of pulp forest such as tree height, diameter at breast height and stem volume among provenances. The analysis of variance indicates that the 64.21 percent of high variance was contributed by provenance,25.48 percent of diameter at breast variance was contributed by provenance, and 48.53 percent of volume variance was contributed by provenance.2. The ratios of high to diameter and breast-height form factor are used as the indicator of shape attribute. The investigation on forest planted on hilly land showed that most of the provenances of the Liriodendron are:strong adaptability, straight and well-developed stem, low differentiation, tidy forest form high productivity. Only small parts of the provenances of the Liriodendron are not.3. The analysis of wood chemical component showed that the content of fiber in Liriodendron wood is high, the average content of fiber is 50.91 percent. The content of lignin is low, which means the Liriodendron is very suit to be pulp forest. The variance of fiber content is helpful for provenance selection.4. Three principal content were extract from tree height,diameter at breast height,volume,breast-height form factor,ratio of height to diameter,fiber content and wood denisty by factor analysis. And the three principal content were used in cluster analysis. Cluster analysis showed that 20 provenance of Liriodendron can divided into 3 cluster. The first cluster is the best choice to develop pulp forest, they are Liping, Songtao Guizhou,Xuyong Youyan Sichuan,Fuyan ZheJiang,Hefeng Hubei,HeFong HuBei,Missouri and Georgia USA. The second cluster is the second choice to develop pulp forest. The third cluster is not suit for pulp afforestation.5. The process of height,diameter at breast height and volume growth was studied by stem analysis. The Logistic equation of tree height,diameter at breast height and volume were found out by non-liner regression. The study of Logistic cure showed that:the high growth and diameter growth was synchronous, the velocity of high growth and diameter growth entered the fast-growing phase in 3 years old, both of the velocitys get the peak in 6 years, at 8 years old, the velocity of diameter slacken up and the velocity of high growth slacken up at 9 years old. So the whole process of Liriodendron growth was revealed, and the whole process was divided into 4 phases reasonably, that is young stand stage, half-mature stage, mature-approximating stage and mature stand stage.