14个香椿种源生长节律的观测与分析

    Observation and analysis on growth rhythms of Toona sinensis of 14 provenances

    • 摘要:
      目的 掌握我国特有珍贵速生用材树种香椿Toona sinensis的苗期生长节律,提高苗木培育质量和幼林抚育效果。
      方法 从香椿分布区选择有代表性的14个地点采种,对苗木生长进行为期1年的连续观测,并利用Logistic方程拟合其苗高和地径生长过程,划分苗木生长阶段。
      结果 香椿各种源苗高生长在1—4月为缓慢生长期,5月中旬—9月末为快速生长期,之后生长趋于缓慢,呈“S”型,即表现为“慢-快-慢”的生长过程。地径的生长节律也呈“S”型,但地径速生期起始时间普遍早于苗高,持续时间也普遍比苗高长,可持续至10月中、下旬。不同种源间苗木生长节律差异明显。南方种源苗高快速生长期为4—9月,持续时间长,而北方种源苗高快速生长期集中在6—7月,持续时间短。南方种源地径在8、9月还能快速生长,而北方种源在7月或8月进入缓慢生长期,9月中旬后基本停止生长。各种源苗高、地径Logistic方程拟合精度高。
      结论 北方种源不适合广东栽培。根据生长曲线,将香椿各种源划分为3个生长阶段;速生期是关键,应抓住速生期加强水肥管理,促进香椿的快速生长。

       

      Abstract:
      Objective To find out the growth rhythms of the seedlings of Chinese unique precious fast-growing timber species Toona sinensis, for raising seedling quality and tending effect of young stand.
      Method The seeds were collected from 14 representative locations of T. sinensis distribution area. Seedling growth was observed continuously for one year. Logistic equations were used to fit the growth in seedling height and ground diameter, and seedling growth stages were divided.
      Result The growth in seedling height of different provenances had three stages. Slow growth period was from January to April. Rapid growth period was from mid-May to the end of September, followed with another slow growth period. The "Slow-Fast-Slow" growth process showed "S" type rhythm. The growth rhythm of the ground diameter also showed as "S" type, whereas the beginning time of rapid growth period was generally earlier than that of height growth, and the duration of rapid growth was generally longer by continuing until mid- or late October. There were significant differences in growth rhythms among seedlings of different provenances. The rapid growth period of southern provenances was from April to September, lasting for a long time. The rapid growth period of northern provenances was relatively short and was mainly in June and July. The ground diameters of southern provenances continued to grow fast in August and September. However, the northern provenances step into a slow growth period in July or August, and in general stopped growing after mid-September.
      Conclusion Northern provenances are not suitable for cultivation in Guangdong. There are high precisions in the logistic equations used to fit growth in height and ground diameter for seedlings of different provenance. According to the seedling growth curves, the growth process of T. sinensis provenances can be divided into three stages. Rapid growth stage is the key time for seedling growth. During this stage the management of water and fertilizer should be reinforced to promote T. sinensis growth.

       

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