印楝实生苗年生长规律研究

Study on Annual Growth Dynamics of Azadirachta indica Seedling

研究了1年生印楝实生苗生长动态、苗木生物量积累与分配模式以及苗木生长与气象因子的关系,结果表明:印楝苗的年生长规律符合Logistic曲线特征,据此方程可以建立苗高、地径与生长时间的拟合模型,结合二次多项式对苗木连日生长量的动态模拟,可将苗木生长划分为4个阶段:出苗期、生长初期、速生期和生长后期,其中处于速生阶段苗木的高和地径生长量均超过全年总量的70%,地径处于生长初期阶段的时间短于苗高,但生长量占全年总量之比是苗高的2倍;苗木生物量积累与苗高和地径的相关性极为密切,其中地上部分生物量占全株的69.1%,全株含水量是干质量的1.58倍;在制约苗木生长节律的气象因子中,偏相关分析表明:温度是苗木生长的主导因子。

Annual growth dynamics of one-year seedling, the accumulation and distribution of biomass and relation between growth of Azadirachta indica seedling and the meteorologic factors were studied. The result showed that annual growth dynamics of seedling agreed Logistic＇ s curve feature. According to this equation, fitting model about height and caliper of seeding with meteorologic factors could be created. According to Logistic＇ s model and continuous growth model of quadratic polynomial, the growing period of seedling could be divided into 4 stages , i. e. emergence phase, initiation phase, prosporous phase ,and later phase. The growth of prosperous phase was over 70% of total increment. Period of caliper＇ s initiation phase was shorter than that of the height increment, but the percentage of caliper＇ s initiation period increment vs total was 2 times of height increment. The biomass＇ accumulation of seedling was closely related to height and caliper of seedling. The aboveground biomass was 69.1% of all biomass. The moisture content of whole tree was 1.58 times of total dry biomass. According to partial correlation analysis ,the air temperature is the key factor affecting the growth of seedling among all meteorologic factors which restrict the growth of seedling.