沙地樟子松天然林自然落种和土壤种子库的特征

Characteristics of Natural Seed Dispersal and Soil Seed Bank for Natural Pinus sylvestris var.mongolica Forests in Sandy Land

研究了呼伦贝尔沙地3种类型的樟子松天然林内天然母树的自然落种和土壤种子库特征。结果表明:土壤种子库中种子数量的空间分布特征和母树自然落种数量的空间分布规律相同。从树干或林缘向外,随着传播距离的增加,土壤种子库的种子数量和母树自然落种的种子数量均有降低的趋势。从树干或林缘向外4～5 m范围内樟子松母树自然落种数量最多,而后随着距离的增加,自然落种数量明显减少。樟子松天然林母树自然落种的传播距离范围可以达到25 m,表明在适宜条件下,沙地樟子松天然林通过自然更新,能够迅速扩展林缘,扩大种群。

A survey was conducted to study the characteristics of natural seed dispersal and soil seed bank in three types of natural Pinus sylvestris var. mongolica forests in Hulunbeier sandy land. Results show that the spatial distribution characteristics of seed quantity in soil seed bank are similar to the spatial distribution pattern of amount of natural dispersal of seeds. With the increase of distance, both the seed quantity in soil seed bank and the amount of natural dispersal of seeds at outside trunk or forest edge tend to decrease. Within the range of 4 - 5 m outside the trunks or forest edge, there is the highest amount of natural dispersal of seeds for seed trees in natural P. sylvestris var. mongolica forests, and the amount of natural dispersal of seeds obviously decreases along with the increase of distance. The propagation distance of natural seed dispersal for seed trees reached 25 meters, which shows that under the suitable conditions, P, sylvestris var. mongolica forests in sandy land can rapidly extend its forest edge and enlarge the population through natural regeneration.