秃杉引种幼龄生长规律初步研究

 引种研究表明,秃杉幼苗生长缓慢,苗期生长为双峰倒“W”形,春秋两季速生,盛夏趋于停滞。幼树造林初期生长缓慢,3年后加快;5—10年速生,生长量已接近或超过原产地。季节生长：春末夏初(5—6月)速生,6月出现峰值,盛夏遇高温减缓,生长呈单峰倒“V”形。树高昼夜生长：夜间>白天;阴雨天>阴天>晴天。引种地气温,相对湿度,净日照时数是影响幼龄秃杉生长的重要气象因子。秃杉幼树年生长与观察年树龄的关系可用数学模型y= a+bt表示;季节生长与观察月份的关系可用数学模型y=a+blnt表示。

A PRILIMINARY STUDY ON GROWTH REGULARITY OF INTRODUCTED TAIWANIA FLOUSIANA YOUNG SEEDLING

The tree introduction test results show that Taiwania flousiana seedlinggrows slowly and seedling growth curve appears to be "M" shape with double growth peaks, owing to the fact that it grows fast in spring and autum, but tends to stop in hot summer. During the initial stage of planttation, the young tree seedling grows slowly, but after 3 years it grows faster and faster and from the 5th to 10th year, it grows very fast. Annual growth of seedling is near or above its prdvenance growth. Seasonal growth reqularity of T. flousiana seedling is that it grows fast during the late spring and early summer (May and June), its growth peak appears in June, and then,the growth speed slows down in hot summer because of the high temperature, therefore the growth curve shows only one peak as a reversal "V" shape.Day -night. growth of young T. flousiana seedling shows night>day;the daily growth appears in that order:rainy day>cloudy day>shiny day. The following factors are the important ones which influence the young tree growth:air temperature, relative humidity and shining hours on the introduction locality.The relationship between young tree growth and seedling, age could be expressed by the model of y=a+bt; the model y=a+blnt can be used to express the relationship between seedling growth and the observation month, and the average annual growth, annual increment and monthly net increment could be described by the model y=a+bt ct~2.