Study On Growth Regulartity And Distribution Of Manchurian Catalpa In Yuntai Mountainous Areas Of JiangSu Province

Manchurian Catalpa tree is the rare and valuable tree species for the garden view, which traditionally be cultivated in China. Many scholars are carrying out more systematic study on its main biological characteristics, the status of germplasm resources, classification, breeding, seedling breeding, afforestation technology. This paper is to research on the growth regularity and stand structure of Manchurian Catalpa tree in Yuntai mountainous area.By the way of the stem analysis, the regularity of the Catalpa tree on the diameter at breast height, tree height, growth factors such as volume, which changes with age, are studied. The results shows that the growth speed of the Manchurian Catalpa tree is slow in Yuntai mountainregion, which is inconsistent with the general slow growth of trees slow——fast——slow"S"-shaped curve. The result of analysing the diameter at breast height of the three Manchurian Catalpa trees, which be selected, shows that the growth of wood forms a straight line. The tree grows faster in early than later in height, and the growth of the volum also presents inverted "J" shape. These three trees still have not reached a mature age in number in 70 years. The mathematical models be selected, such as Richards, Korf, Gompertz model get great fitting results on diameter at breast height, tree height, volume growth, but the fitting result of the Logistic equation is relatively not well.By the method of analysing the relative diameter and the probability distribution function, the distribution rythem of Manchurian Catalpa tree in Yuntai mounatiness area is studied. Regardless of the distribution of the diameter or the distribution of tree height, the results show that, the location of the average stand diameter (D_g) and the average stand tree height (D_h) in the cumulative distribution curve of number of trees are betwen55% to 65%. In the distribution simulation test of the 10 standard block,βblock gets the best fitting distribution, reaching 100%, followed by a normal distribution and Weibull distribution , more than 60%, and the Logistic distribution is the lowest, the acceptance rate of fitting plot is less than 1/2.