Effect of Site Conditions on the Growth of Cotinus coggygria in Yiling District of Yichang Municipality

With stands of Cotinus coggygria located at the Yiling District of Yichang Municipality, a research on the influence of five site conditions i.e., the slope aspect, slope gradient, slope position, canopy density and the thickness of humus layer on the growth of C. coggygria trees was conducted. The results showed that although C. coggygria could invade, ecesize, grow, regenerate and form its community, its growth was significant affected by site conditions. There were positive correlations between the DBH and the height of C. coggygria trees, and between the DBH value and the crown diameter. There were negative correlations between the slope gradient and canopy density, and between slope gradient and the thickness of humus layer. The major components were selected from five site factors by means of applying Principal Component Analysis and they were respectively named as the stand factors and the topographic factors.