兴城油松种子园无性系生长比较研究

在兴城油松种子园,经过两年对具有代表性的12个无性系各3个植株的生长状况做了定期观测。按主梢年生长量判断,该种子园无性系之间的生长差异是显著的。生长周期呈典型S曲线。顶梢长度生长与气温关系最密切,当日平均气温稳定在12℃时开始速生期(>0.4厘米/天),持续30—48天。各无性系顶梢年生长量与速生期天数,最高日生长速率以及顶梢上针叶束数呈极显著正相关。侧枝萌动时间与顶梢一致,但结束较早,第二轮枝生长速度最快,向下各轮有减慢趋势。直径生长较顶梢长度生长约晚10—15天,且在6月底—7月初有停滞现象。直径和长度生长顶峰值出现时间相互错开。

A COMPARATIVE STUDY ON GROWTH PATTERNS OF PINUS TABULAEFORMIS CLONES IN XINGCHENG SEED ORCHARD, LIAONING PROVINCE.

The growth patterns of 12 Pinus tabulaeformis clones in Xingcheng Seed Orchard were observed periodically for two years. Difference in leading shoot increment among the clones were evident. Typical pattern of annual growth is a sigmoid curve. The growth in length of leading shoots was closely related to air temperature. If the daily air temperature was in an average of 15℃ steadily, the leading shoots would be in the fast-growing phase (more than 0.4 cm/day) which lasted for 30-48 days, The annual height increment of all clones observed showed significant positive correlation with the duration of fast-growing phase, the highest rate of daily growth and the number of needle fascicles on leading shoot. In the spring, growth of the lateral shoots started simultaneously with the leading shoot,but stopped a little earlier in summer. The most rapid growth was found in 2nd whorl of the tree, while lower whorls showed much slower growth. Diameter growth of the bole started about 10-15 days later than the height growth, with an apparent pause at about the end of June. There was some overlapping in the 1st stage of diameter and height growth, but they reached their maxima at different periods.