Traits of natural regeneration seedlings of natural forest of Pinus sylvestris var. mongolica on Hulunbuir sandyland were studied. Result shows that：number and age structure of natural regeneration seedlings significantly different with different densities of seed trees ; age structure of natural regeneration seedlings for Pinus sylvestris var. mongolica has obvious discontinuity in time ; densities of natural regeneration seedlings are obviously different due to differences in forest types. Open woodland （30-year-old tree） , the density of average regeneration seedlings are 13 trees per 2 500 mE ;density of the average regeneration seedlings in the burned area are 28.5 trees per 600 mE ; average density of regeneration seedlings for individual Pinu~ sylvestris var. mongolica in the sample plots are 118.8 trees per 600 m2. Reserved density ＆ mean annual precipitation of natural regeneration seedlings with different ages have significant or very significant relationship; density of natural regeneration seedlings in the study area decrease with the increase of canopy density.%通过对呼伦贝尔沙地樟子松天然林天然更新苗特征及其影响因素的研究，结果表明：母树密度不同．天然更新苗数量和年龄结构存在明显差异；樟子松天然更新苗年龄结构在时间上具有明显的不连续性，樟子松天然更新苗密度因林分类型的差异明显不同。在疏林地（树龄30a），平均更新苗密度每2500m2为13株，在火烧迹地平均更新苗密度每600m2为28．5株，樟子松单株样地平均更新苗密度每600m2为118．8株。不同年龄的天然更新苗保存密度和年平均降水量有显著或极显著关系，且随着林分郁闭度的增加，研究区天然更新苗密度呈现降低的趋势。
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