关键词: 速生杨, 引种, 扦插密度, 苗期, Logistic方程, 生长模型

Abstract: By using four poplar breeds as experimental material, different densities of 2 a root with 1 a stock seedlings were carried out in three experimental areas, which situated on the Daxing' Anling woodlands of Inner Mongolia. The results show that the differences between the survival ratios and growth increments are obvious in the three experimental areas. The Logistic equation is applied to model growth increments of four poplar breeds' nursery stage. The results show that the correlations of modeling are significant and all the correlation coefficients are higher than 0.988. Based on the equation, annual growth of the seedlings can be divided into four periods, namely survival period, pre-growth period, fast-growth period and post-growth period. In the three experimental areas, average height and ground diameter in fast-growth period are 64.2%, 68.7%, 67.6% and 59.0%, 62.2%, 58.9% of the total annual growth respectively. Growth performance of each period is also described and discussed. This paper has provided theoretical basis for the production of high quality poplar seedlings and enhancement of land productivity. The conclusion is drawn as the following:the most suitable breed for Chao'Er experimental area is Populus sua veolens Fisch, for A'Lihe area and Da'Yangshu area is Populus psedosimonii×nigra CV‘Baicheng’.

Key words: fast-growing poplar, introduction, planting density, seedling, Logistic equation, growth model