【摘要】 本文研究了攀枝花山地两个高山栲低密度种群的种子雨模式和种子雨动态,并讨论了种子产量、种子存留和种子对幼苗建成的贡献。研究结果表明:(1)种子雨持续时间超过两个月,但种子下落的高峰期存在样地间差异;(2)该地区高山栲的种子产量很低,种子雨散落的密度不大(样地1和样地2的密度为2.3个.m-2和2.8个.m-2)。(3)在种子雨过程中,地表种子库各组成的动态不同,霉烂种子和萌发种子为零,完好种子和虫蛀种子有轻微的波动,完好种子的存留密度为0.13个.m-2;和它们相反,地表的壳斗和败育种子存在积累效应。(4)动物捕食是地表种子损失的主要原因,样地1和样地2分别占91.3%和97.83%,地表种子的存留率仅为8.7%和2.17%。(5)研究样地的高山栲种群低的种子生产量、地表种子存留率和幼苗建成困难等三个环节都限制了高山栲种子途径的种群更新。更多还原

【Abstract】 The arid evergreen hardwood forests in mountainous regions are distributed in the upper edge of dry-hot valleys of the Jinsha River in Panzihua City,Castanopsis delavayi being one of the main constructive species.Castanopsis delavayi forest is a typical arid evergreen hardwood forest.By the inventory of seed rain pattern and dynamics during seed rain in two low density populations of Castanopsis delavayi in the mountainous area in Southwest Sichuan,the discussion was made on seed productions,seed retentions and their contributions to seedling establishments.The conclusions were made as follow:（1） The duration of seed rain was above 2 months,but there was a different top time between the studied sites;（2） The seed production of Castanopsis delavayi was low in the studied population,showing a low dispersing density (2.3 grains·m^-2 in sampling site 1 and 2.8 grains·m^-2 in site 2);（3） During the whole seed raining process,decayed and germinating seeds in the soil seed bank were never found.The sound seeds and the damaged seeds by insects slightly undulated.The retaining density of sound seeds was 0.13 grain·m^-2.In contrast with them,there were accumulative effects of cups and aborted seeds in the soil seed bank.Therefore,various constituents of soil seed bank had different dynamics;（4） Animal predation was the main cause of soil seed bank losing,with a 91.3% lost in site l and 97.83% lost in site 2.Only 8.7% and 2.17% of dispersing seeds were retained until the seed rain termination;（5） Three key stages,that is,the low seed production,the low seed retaining in soil seed bank and difficult seedling establishments were found to limit the population regeneration of Castanopsis delavayi.更多还原