A STUDY ON THE TREND OF GEOGRAPHIC EPIDEMIC OF CHINESE FIR STERILE SEED
杉木种子涩籽地理流行趋势的研究

The paper, applying trend-surface analysis (TSA) to the geographic epidemic of Chinese fir seeds in Fujian Province by giving the quadratic polynomial model, interpreting the Chinese fir sterile seed epidemic pattern, drawing the sterile seed epidemic figure and dividing it into four areas: 1. The progressively decreasing region for the sterile seed epidemic in the southwest of Fujian; 2. The progressively increasing region for the sterile seed epidemic in the southeast of Fujian; 3. The progressively decreasing region for the sterile seed epidemic in the north of Fujian; and 4. the progressively steady region for the sterile seed epidemic in the centre and the northwest of Fujian. It is suggested that the habitat of China-fir seed orchard should be selected in Jianou in the progressively steady region.