The Seed Yield Calculation Pattern for Qingyuan Chinese Fir Seed Orchard in Zhejiang Province

Based on the data of seed yield of Chinese Fir Seed Orchard in Qingyuan Forest Farmfrom1981～1993 and the biological factors(X1～X3),meteorological factors(X6～X14) and site factors (X4～X5) affecting the seed yield of Chinese fir seed orchard,themulti unit linear patterns were established by using linear regression to determine the key factors affecting seed yield:the annualmean yield per unit area Y1=60.04746+0.00167X7 (annual precipitation)-0.11695 X8,9 (low temperature index in flowering period)-0.01579 X10 (precipitation in flowering period)+0.00816 X12 (sunshine time in flowering period)+0.00444 X13 (precipitation in high temperature and drought period)-2.26872 X14 (mean temperature in July and August);the annual seed yield in seed orchard plot Y2=-603.42710+34.14267X4 (slope orientation)+0.07220 X6 (≥10 ℃ annual accumulated temperature)+0.04210 X7-18.89739X8,9-0.34941X11 (rainy days in flowering period)+6.86478 X12 +0.935 31X13 ;the annualmean seed yield in the plot of seed orchard Y5=1.95776+2.43938X31 (C.lanceloata clones in general production area)+2.45786 X41 (sunny slope)+1.30000 X51 (good soil fertility)-0.07488 X52 (middle soil fertility).The rate of calculation accuracy of themodels above was 81.04%～95.40%.