【目的】研究青钱柳(Cyclocarya paliurus)种子雨的季节动态及土壤种子库特征,以阐明其种群更新和演替规律。【方法】以江苏溧阳大石山3种林分密度(1 050、720和525株/hm²,代号依次为C1、C2、C3)青钱柳人工林为对象,对其种子雨季节动态及种子性状进行观测和分析;在江西九岭山5个青钱柳天然群落设样方调查,并对样方内的土壤种子库分枯枝落叶层(Ⅰ层)和土壤层(Ⅱ层)进行种子筛选和分析。【结果】根据青钱柳种子雨密度,将落种时期分为3个阶段:落种前期(8月20日—9月20日)、落种中期(9月21日—12月10日)和落种后期(12月11日—12月30日);种子雨出现2个高峰(9月10日和12月20日),落种前期和落种后期其单位面积落种量分别占全年的42.4%和43.5%;不同落种阶段的种子雨密度和具生活力的种子数差异显著,但其他种子性状差异不显著。林分密度显著影响青钱柳饱满种子数和种子千粒质量,但未影响其他种子性状。青钱柳天然群落的土壤种子库密度均呈现为Ⅰ层(37.4 粒/m²)>Ⅱ层(17.9粒/m²),群落间的种子库密度差异达显著水平;Ⅱ层种子直径、厚度及体积均小于Ⅰ层种子。青钱柳群落土壤种子库的种子饱满度和生活力均较低,分别为13.0%~27.1%和0~10.4%;相比较而言,Ⅰ层种子生活力和饱满度总体上大于Ⅱ层,说明种子库中的种子寿命随着时间的延长呈下降趋势。【结论】青钱柳林分种子雨呈双峰特征,林分密度显著影响了种子雨密度和千粒质量,但对种子饱满度和生活力的影响不大;土壤种子库枯枝落叶层(Ⅰ层)种子数量和质量均优于土壤层(Ⅱ层)种子,贮存在土壤种子库的种子休眠被解除,有利于青钱柳群落的更新和演替。

【Objective】 This study investigated the role of succession and regeneration for populations of Cyclocarya paliurus; in particular, seasonal dynamics of seed rain and soil seed bank characteristics were investigated.【Method】 Investigation of seasonal dynamics of seed rain was performed in plantations of C. paliurus with three densities (C1: 1 050 plant/hm², C2: 720 plant/hm², and C3: 525 plant/hm²), which were planted in Dashishan, Liyang, Jiangsu Province; the traits of seeds were also analyzed. In addition, we surveyed and dissected the soil seed banks dispersed in five natural populations located in Jiuling Mountain, Jiangxi Province. The soil seed banks in two layers, named as litter layer (Ⅰ) and soil layer (Ⅱ), were separately analyzed.【Result】 According to the density of seed rain, the duration of seed falling was divided into three stages: early stage (8.20-9.20), medium stage (9.20-12.10), and late stage (12.10-12.30); two peaks of seed rain were recorded at 9.10 and 12.20, respectively; the amount of seed rain during these two peaks in the early and late stage accounted for 42.4% and 43.5% of the whole annual production, respectively. The differences of seed rain and number of viable seeds at various stages were significant, but the other seed traits were insignificant. Moreover, the effects of plantation density on the number of full seeds and 1 000-seed weigh were significant, but no effect on the other seed traits was detected. In five natural populations of C. paliurus, the density of soil seed bank in the Ⅰ layer (37.4 grain/m²) was higher than that in the Ⅱ layer (17.9 grain/m²), and this parameter presented an obvious divergence among populations. Moreover, the seed diameter, thickness and volume from the Ⅱ layer were all smaller than those from the Ⅰ layer. More importantly, seed fullness and viability from the soil seed banks were lower by 13.0%-27.1% and 0%-10.4%, respectively. However, these indicators of seeds from the Ⅰ layer were generally higher those from the Ⅱ layer, indicating a descending tendency in seed quality as duration increases. 【Conclusion】 There were two peaks of seed rain in plantations of C. paliurus, and stand density affected the density of seed rain and 1 000-seed weigh more than seed fullness or viability. Both the quantity and quality of seeds in the soil banks from the Ⅰ layer were superior to those from the Ⅱ layer. The dormancy of seeds stored in soil is relieved in favor of regeneration and succession of C. paliurus populations.