欧美杨新无性系苗期年生长规律的研究

Annual Growth Rules of Populus Aigeiros at Nursery Stage

以3个欧美杨(P.×euramericana)无性系为材料,利用Logistic方程对各个无性系的一年生扦插苗木的苗高、地径的年生长节律进行拟合。根据因素列的几何形状发展态势的接近程度,将苗木的生长量与影响苗木生长的气象因子空气温度、空气相对湿度、降水量和日照时数组成一个灰色系统,进行面积关联度分析。结果表明:利用Logistic方程拟合效果显著,相关系数皆在0.94以上。并以此将无性系扦插苗的生长过程分为成活期、生长前期、速生期和生长后期四个时期,年生长量表现出明显的“慢—快—慢—快—慢”的节律,其中速生期内的苗高生长量占总生长量的比率平均为58.2％,地径生长量占总生长量的比率平均为70.1％。并对各个生长时期的生长特点进行了分析,探讨了苗木的年生长规律。关联度分析表明空气温度对苗木的高生长影响最大,日照时数影响最小;而日照时数对苗木的粗生长影响最大,降水量影响最小。通过对苗木年生长节律和影响苗木生长主要环境因子进行分析,为加强苗木生产管理,提高苗木的质量和土地的生产力,提供了理论依据。

Logistic equation was used to model growth increment of Populus Aigeiros at nursery stage. Influence of climatic factors such as air temperature, relative humidity, precipitation and illuminating hours on the seedling growth were analyzed. The results showed that correlation of the modeling was significant and the correlation coefficients were higher than 0. 94. Based on the equation,annual growth of the seedlings could be divided into four periods, namely survival period, pre-growth period , fast-growth period and post-growth period. Average height and ground diameter in fast-growth period were 58. 2% and 70.1% of the total annual growth respec- tively. Growth performance of each period was also described and discussed. Air temperature was believed to have the most significant influence on the height growth and illuminating hours the least whilst illuminating hours had the most significant influence on the ground diameter growth and precipitation the least.