Distribution Law of Tree Height-to-Diameter Ratio in Each Stratum of Typical Natural Broad-Leaved Forest in Mid-Subtropical Zone

【Objective】To reveal the distribution law of tree height-to-diameter ratio in each stratum of typical natural broadleaved forest in mid-subtropical zone, to provide a typical reference in the aspect of height-to-diameter ratio of broad-leaved trees for the sustainable management of artificial broad-leaved forest, semi-natural broad-leaved forest and natural broad-leaved forest in mid-subtropical zone.【Method】In Jian'ou Wanmulin provincial nature reserve, 50 m×50 m plots were set up in 5 typical natural broad-leaved forest in mid-subtropical zonerespectively. Themean tree height-to-diameter ratio and standard deviation of each stratum in the typical stand was calculated to analyze its changes with the stratum, and the Mann-Whitney U test was used to analyze the significance test of the difference between the average height-to-diameter ratio in each stratum. Skewness and kurtosis are used to describe the degree of deviation and dispersion of the height-to-diameter ratio distribution. The normal distribution and