速生杨引种苗期对比试验及生长模型的建立

Using four poplar breeds as experimental material, different densities of 2a root with 1a 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 obviously diverse in the three experimental areas. The Logistic equation was 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. We have drawn a conclusion: the best poplar breed is Populus sua veolens Fisch in the Chao’Er experimental area; the best poplar breed is Populus psedosimonii×nigra CV‘Baicheng’in A’Lihe and Da’Yangshu experimental areas.