Abstract:The relationship between vine diameter at breast height (DBH) and its host tree DBH in the natural forests in Hunan Province, China, has been studied using field surveys of sample trees and statistical analysis tools including the SPSS13.0 computer software and 11 mathematical equations. The results demonstrate: (1) The ratio of the DBH of all vines to the DBH of their host trees is 1:6.36; the ratio of DBH of each climbing type: twining, curling, hooking and adhering, to the DBH of their host trees is 1:5.61, 1:4.92, 1:5.89 and 1:15.46, respectively, among which the average DBH of the host trees for adhering vines is the largest. (2) The relationship of the DBH of the vines (y) to the DBH of the host trees (x) is y=-4.75×10-1+3.44×10-1x-1.13×10-2x2+1.61×10-4x3 for all vines combined; y=2.68×10-1x0.829 for the twining vines; y1=1.88×10-1x0.9811 or y2=e(1.93-12.222/x2) for the curling vines; y=6.92-8.74×10-1x+4.95×10-2x2-7.45×10-4x3 for the hooking vines; and y=-1.16+3.64×10-1x-1.72×10-2x2+2.56×10-4x3 for the adhering vines.
