定苗密度对峦大杉1年生苗木生长的影响

以当年生峦大杉幼苗为试验对象，开展了不同定苗密度试验。采用定株观测，并应用Logistic方程拟合生长动态的方法，分析其对苗木生长动态、苗木综合表现和生长节律的影响效应。结果表明：定苗密度影响苗高、地径生长效应随处理时间推移呈动态变化过程。定苗密度对峦大杉苗高、地径生长效应不同，高密度对苗高有着促进效应，但对地径有抑制效应。定苗密度显著影响峦大杉苗高、地径以及1级苗、合格苗产量和苗木综合表现，综合表现随定苗密度增加呈现先升后降的变化。用Logistic方程能够很好的拟合峦大杉苗高、地径生长。定苗密度显著影响苗高和地径的线性生长始期、线性生长终期、线性生长期、线性生长速率、最大线性生长速率和线性生长量等生长节律。高定苗密度减小苗高、地径线性生长终期，缩短了线性生长期；低定苗密度显著降低苗高线性生长量、线性生长速率和最大线性生长速率，但显著提高地径线性生长量；CK显著降低了地径线性生长量、线性生长速率和最大线性生长速率。依据定苗密度的不同，调整速生期的养分供给十分重要。

Effects of Seedling Density on Seedling Growth of One-year-old Cunninghamia konishii

The experiment of seedling density of Cunninghamia konishii was carried out with annual seedlings. The effects of seedling density on seedling growth dynamics, comprehensive performance and growth rhythm were analyzed by using the method of fixed plant observation and fitting seedling growth dynamics with Logistic equation. The results showed that the effects of seedling density on seedlings height, ground diameter growth appeared with the time after treatment, and it is a dynamic process. The effect of seedling density on seedling height and ground diameter of C. konishii is different. High seedling density had promoting effect on seedling height, but restraining effect on ground diameter. Seedling density significantly affected the seedlings height and ground diameter, the yield of first grade seedlings, qualified seedlings, and seedling comprehensive performance, the comprehensive performance appeared first increased and then decreased with the increase of seedling density. Logistic equation fitted well the growth of height and ground diameter of C. konishii seedling. Seedling density significantly affected the height and ground diameter growth rhythms of C. konishii seedlings, such as the linear beginning days, linear final days, linear growth duration, linear growth rate, maximum linear growth rate and total linear growth. High seedling density reduced seedling height and ground diameter linear growth final days, and shortened linear growth duration. Low seedling density significantly reduced total linear growth, linear growth rate and the maximum linear growth rate of seedling height, but significantly increased total linear growth of ground diameter. The CK significantly reduced total linear growth, linear growth rate and the maximum linear growth rate of ground diameter. It is important to adjust the nutrient supply of fast-growing stage according to the different seedling densities.