本文采用种子雨收集器、土壤种子库筛选、室内萌发实验及野外实地调查等手段,研究了贡嘎山海螺沟内不同林龄和海拔分布上下界限的6 个峨眉冷杉(Abies fabri) 林的土壤种子库、种子雨的组成和时空分布特征。结果表明:土壤种子库分布随土壤深度增加而减少,主要集中在凋落物层;在同一海拔,随着林龄增加,土壤种子库和种子雨大小先增加再降低,成熟林达到最大值,且其完整种子比例最高,整体质量最好;不同海拔,林龄相近的成熟林调查结果显示,海拔分布上下界限的峨眉冷杉林土壤种子库和种子雨显著小于海拔分布中段的成熟林,这可能与海拔引起的水热条件差异有关;峨眉冷杉林的最佳结实阶段在成熟林,其种子质量好,且散布后在林下保存得最好;树种生物学特性和林下微生境可能是主要原因。

By the methods of collecting seed rain with traps, sieving soil seed bank, laboratory seed germination experiment, and field investigation, this paper studied the compositions and spatiotemporal distribution features of soil seed bank and seed rain in six Abies fabri forests with different ages and at different altitudes in Gongga Mountain of Southwest China. The size of soil seed bank decreased with increasing soil depth, and the seeds mainly concentrated in litter layer. At the same altitudes, the sizes of soil seed bank and seed rain decreased after an initial increase with increasing forest age, and the biggest values were found in mature forests. Moreover, the percentage and the overall quality of intact seeds were the highest in mature forests. At different altitudes, the seed density of soil seed bank and seed rain in the mature forests with similar ages were apparently lower at higher and lower altitudes than at intermediate altitudes, which could be related to the differences of water and heat conditions. It was suggested that mature A. fabri forests had the best productive phase, their seed quality was good, and their micro-habitat condition was most suitable for the seed conversation after dispersal, possibly because of the unique biological features of A. fabri and its micro-habitat condition.