章古台沙地赤松人工林土壤种子库及天然更新特征

研究了章古台沙地赤松人工林土壤种子库及天然更新特征。结果表明：在赤松人工林土壤种子库中，47．47％的种子分布在枯枝落叶层中，种子平均密度可达253粒？m^-2；52．53％的种子分布在0～5 cm 深的土层中，种子平均密度为280粒？m^-2。从种子品质来看，空粒种子占种子总数的40．90％，腐烂种子占39．96％，完整种子占19．14％。赤松天然更新主要为林下更新，更新幼树呈不规则分布，密度为20348～71798株？hm^-2；其次为林隙更新，更新幼树以群团状分布为主，带状分布为辅，密度为7659～14836株？hm^-2；赤松林缘更新的主要条件是有林缘扩展带，林缘更新密度为856～10810株？hm^-2。

The Characteristics of Soil Seed Bank and Natural Regeneration of Pinus densiflora Plantation in Zhanggutai Sandyland

This paper studied the characteristics of soil seed bank and natural regeneration of Pinus densiflora planta-tion in Zhanggutai .The result showed that in the seed bank of Pinus densiflora plantation ,47 .47% of the seeds was distributed in the litter layer ,with the average density up to 253 grain ？m^- 2 ;52 .53% of the seeds was distributed in soil layer of 0 to 5cm depth ,with average density 280 grain ？m^- 2 .From the point of seed quality ,empty seeds ,rot-ten seeds and complete seeds accounted for 40 .90% ,39 .96% and 19 .14% of the total number of seeds separately . The leading natural regeneration of Pinus densiflora was under forest canopy that regenerated saplings were distrib-uted irregularly with the density from 20 348 to 71 798 plant ？hm^- 2 .The secondly natural regeneration was in the gap which the distribution of the regenerate saplings was principal in shape of cluster and supplementary in shape of zone ,with the density from 7 659 to 14 836 plant ？hm^- 2 .The main condition of natural regeneration in plantation edge was with forest edge extension zone ,with the density from 856 to 10 810 plant ？hm^- 2 .