Abstract: Based on the investigation on gaps and non-gap stands of the Karst forest in Maolan National Nature Reserve , Guizhou Province, the quantitative characteristics and dynamic changes of seed rain and seed bank in gaps were analyzed . The results showed that the total seed rain number was reached 117 .4±32 .6 seeds􊄯m2 during the period of observing , among them, the number of immature seed , damaged mature seed and germinable mature seed was 56. 3±10. 3 seeds/m2 , 15 .7±4 .7 seeds/m2 and 45 .4±8. 2 seeds/m2 , respectively . It suggested that it was rich in seed for gap regeneration . Seed rain in gaps had space-time heterogeneity characteristics and it would affect regeneration pattern of gap plant deeply. From the gradient of gap center to non-gap stand , the density of seed , number of species and Shannon-wiener richness index of coarse debris layer was reduced gradually , but it was increased in soil . The density of seed in gap center , near gap center and gap border area were 2415±639 seeds/m2 , 2218±421 seeds/m2 and 1815±311 seeds/m2 , respectively. It showed that gap plant had good regeneration latent. In gaps and non-gap stands, Jaccard similarity index of seed between coarse debris layers was the greatest, 5 - 10 cm was second and 0 - 5 cm was small. Jaccard index between soil seed bank and present community was great in coarse debris layer , but decrease with the soil depth both in gaps and non-gap stands . The results showed that soil seed bank was the main resource of gap regeneration in karst forest of Maolan , it contributed to gap regeneration greatly .

Key words: Karst forest

摘要： 以贵州茂兰国家级自然保护区喀斯特森林为研究对象, 研究了林隙植被的种子雨、种子库的数量特征及动态变化规律。结果表明: 观察期林隙种子雨量达117 .4±32 . 6 粒􊄯m2 , 其中未成熟种子56 . 3±10 . 3 粒/m2 , 成熟被害种子15. 7±4 . 7 粒/m2 , 成熟有效种子45 . 4±8 . 2 粒/m2 , 林隙更新的种子来源比较丰富。林隙中种子雨的丰富度具有时空异质性特征, 将对林隙植物的更新格局产生深刻影响。枯落物层中的种子密度、物种数及Shannon-wiener 多样性指数从林隙中心至非林隙林地递减, 而土层中的种子变化则相反。林隙中心、近中心、林隙边缘的种子密度分别为2415±639 粒/m2 、2218±421 粒/m2 和1815±311 粒/m2 , 林隙植物有很好的更新潜力。林隙与非林隙中枯落物层种子的相似性系数最大, 5～10 cm 土层的次之, 0～5cm 土层的相似性系数最小。林隙与非林隙中均表现为枯落物层的种子库与现存植被的相似性较大, 并随土层的加深而减小。研究结果表明茂兰喀斯特森林林隙植被的更新主要来源于土壤种子库, 土壤种子库对林隙填充与发育的贡献较大。

关键词: 喀斯特森林, 林隙, 种子雨, 种子库, 茂兰FONT