西南山区亚高山暗针叶林是四川森林的主体，是长江上游重要的生态屏障。峨眉冷杉（Afies fabiri (Mast.) Craib）是亚高山暗针叶林的主要树种，在贡嘎山地区海拔3000～3650 m范围内有大面积分布。探讨峨眉冷杉林种子雨、土壤种子库的时空分布特点以及早期幼苗的更新潜力，可为贡嘎山地区亚高山针叶林生态系统生物多样性保护、森林保育以及资源的可持续利用提供科学依据。本文采用种子收集器、土壤种子库筛选、室内萌发实验及野外样地实地调查等方法，研究了贡嘎山海螺沟内峨眉冷杉林（中龄林、近熟林、成熟林、过熟林以及分布于海拔上、下限的成熟林）的种子雨、土壤种子库和累计幼苗库的时空格局特征，结果表明：

1. 不同林龄峨眉冷杉林种子雨总量大小顺序为过熟林<中龄林<近熟林<成熟林，分别为（124±31.13）粒/m2、（132±36.99）粒/m2、（272±50.46）粒/m2和（348±66.15）粒/m2，其中成熟林种子雨中完整种子数最多，所占比例最高，整体质量最好，对群落的更新的贡献潜力也最大；成熟林（下限）<成熟林（上限），分别为（20±4.63）粒/m2和（104±18.44）粒/m2，后者约为前者的5倍，虽然成熟林（下限）种子雨总量小于成熟林（上限），但其完整种子数比例高，腐烂种子和发育不完全种子比例较低，因此其种子质量要好于成熟林（上限）。

2.土壤种子库大小依次是：中龄林<过熟林<近熟林<成熟林，分别为：（94.09±94.28）粒/m2<（117.6±110.41）粒/m2<（171.78±135.41）粒/m2<（180.98±106.45）粒/m2；成熟林（下限）<成熟林（上限），大小为（10.67±18.16）粒/m2<（86.86±97.27）粒/m2。其中，中龄林、近熟林、成熟林和过熟林的种子库中腐烂种子所占比例均高于55%，加之干瘪和空粒种子，三种种子总和超过了种子库的90%；而在成熟林（上限）和成熟林（下限）种子库中腐烂、干瘪和空粒种子所占比例分别达到了80%和50%。

3. 土壤种子库中峨眉冷杉种子主要都集中在枯枝落叶层（大约在73%左右），其次为0~2 cm层（约17%左右），2~5 cm层占7.5%左右，5~10 cm所占比例最小，大约在2.5%左右。但分布于上、下限的峨眉冷杉种子主要集中在0~2 cm层中，约占60%，凋落物层占约40%。

4. 中龄林、近熟林、成熟林、过熟林、成熟林（上限）以及成熟林（下限）累计幼苗数分别为0.433株/m2、0.723株/m2、1.420株/m2、0.398株/m2、0.130株/m2和0.050株/m2，其种子转化为幼苗的比率分别为2.11%、2.13%、2.47%、1.78%、0.96%和0.94%。

5. 峨眉冷杉种子的发芽率、发芽势和发芽指数在20 ℃恒温培养下均明显高于5 ℃、10 ℃、15 ℃、25 ℃以及30 ℃，分别为（78.67±3.40）%、（56.00±5.89）%和（9.92±0.68）%。

6.根据本研究在野外开展的调查工作，提出了峨眉冷杉林更新潜力的计算公式——更新潜力指数（IRP），指数越大则更新潜力越大。据此，4种不同龄林和分布于上、下限的峨眉冷杉林的更新潜力大小顺序为（括号内为更新潜力指数）：成熟林（1.42）>近熟林（0.72）>中龄林（0.42）>过熟林（0.40）；成熟林（上限）（0.13）>成熟林（下限）（0.05）。

本研究还对影响峨眉冷杉林更新潜力的内在因素和外在因素进行了分析。主要的内在影响因素为种子雨大小和幼苗的转化率。外在影响因素包括：1）种子霉烂和动物取食造成大量种子被损耗。2）低温影响。3）凋落物通过机械阻碍作用、分解过程中产生化感作用、改变土壤理化性质间接对其产生影响等途径影响峨眉冷杉种子萌发与幼苗生长，从而影响峨眉冷杉林潜在更新。

Subalpine dark coniferous forests dominate most parts of the forested areas in western Sichuan, and they are important ecological barriers in the upper reaches of the Yangtze River. Afies fabiri (Mast.) Craib is the main species in dark coniferous forests, and it mostly distribute during the elevation from 3000 to 3650 meters. Understanding their self-regeneration potential can have some insights on the management of these natural forests and the establishment of following forest resources. In this study we used seed collecting traps, sieving method for soil seed bank, seed germination experiments and seedling investigations in the field to comparatively study the seed rain, soil seed bank and seedlings bank in Afies fabiri of different ages and distribution forest in Gongga mountain Sichuan province, southwestern China. The main results are as follows. 1. The seed rain intensities of different ages following the increasing order were over-mature forest (124±31.13) grain·m­­­­­­­­­­­­­­­­­­­­­­­-2, half-mature forest (132±36.99) grain·m­­­­­­­­­­­­­­­­­­­­­­­-2, near-mature forest (272±50.46) grain·m­­­­­­­­­­­­­­­­­­­­­­­-2 ­­­and mature forest (348±66.15) grain·m­­­­­­­­­­­­­­­­­­­­­­­-2; the mature forest (distribution cap)(104±18.44) grain. m­­­­­­­­­­­­­­­­­­­­­­­-2 and the mature forest floor(20±4.63) grain·m­­­­­­­­­­­­­­­­­­­­­­­-2. In comparison to all stands, intact seeds produced in mature forest were the most in number and the best in quality, and the mature forest (distribution cap) is better than the mature forest (distribution floor). 2. The soil seed bank density in different ages and distribution forest showed significant difference, the order for the size of soil seed bank in different age of Afies fabiri is: mature forest (180.98±106.45) grain·m­­­­­­­­­­­­­­­­­­­­­­­-2, near-mature forest(171.78±134.41) grain·m­­­­­­­­­­­­­­­­­­­­­­­-2, half-mature forest (117.6±110.41) grain·m­­­­­­­­­­­­­­­­­­­­­­­-2and over-mature forest (94.09±94.28) grain·m­­­­­­­­­­­­­­­­­­­­­­­-2. The order for the size in different distribution limits is: mature forest ( distribution cap) (86.86±97.27) grain·m­­­­­­­­­­­­­­­­­­­­­­­-2 , and the mature forest (distribution floor) (10±18.16) grain·m­­­­­­­­­­­­­­­­­­­­­­­-2. The quality of former is better than latter. The invalid seeds up to 90 percent of all soil seed bank in different ages, and this proportion of mature forest (distribution cap) and mature forest (distribution floor) up to 80 % and 50 % respectively. Loss of the soil seed bank was mainly resulted from decay after death or being attacked by soil pathogens, followed by animal predations. While the proportion of seeds output from soil seed bank through germination was quite low. 3. Considering the vertical distribution in soil, nearly 73% of the total seeds in the soil bank of different ages age mainly distributed on the litter layer, about 17% in the layer of 0~2cm, around 7.5% in the layer of 2~5cm, and only about 2.5% in the layer 5~10cm. Nearly 60% of the total seeds in soil bank distribute in 2~2 cm of mature forest in distribution cap and floor, nearly 40% in the litter layer. 4. The accumulative seedling densities in half-mature forest, near-mature forest, mature forest ,over-mature forest, mature forest (distribution cap) and mature forest (distribution floor) were 0.433 seedling·m-2, 0.723 seedling·m-2, 1.420 seedling·m-2, 0.398 seedling·m-2, 0.130 seedling·m-2 and 0.050 seedling·m-2 respectively, and the rates from viable seeds to seedling of the tree stands following the same order were 2.11%, 2.13%, 2.47%, 1.78%, 0.96% and 0.94%. 5. The germination temperature ranges for seed of Afies fabiri was between 5 ℃ and 30℃, and the optimal temperature was 20 ℃. The germination percentage, germinative energy and germination index of seed in 20 ℃ were (78.67±3.40)%, (56.00±5.89)% and (9.92±0.68)% respectively. The seed germination was restrained below 5 ℃ and above 30 ℃. 6. On the basis of the field work of this study, we proposed a formula for evaluating the regeneration potential of Abies fabric - regeneration potential index of Abies fabric. And we proposed that the larger the index, the larger the regeneration potential. In terms of the index, the regeneration potentials of the four different aged forests and the forests that grow at the upper and lower bounds of the Abies fabri distribution range are ranked as follows (in the parenthesis is the corresponding regeneration potential index): mature forest（1.42）> near-mature forest（0.72）> middle-aged forest（0.42）> over-mature forest（0.40）; upper bound mature forest（0.13）> lower bound mature forest（0.05）. This study also analysed the internal and external factors which affect the regeneration potential of Abies fabric. The major internal factors were seed rain intensity and seedling transformation rate. While the major external factors included: 1）large quantities of seed being spoiled by rotting and animal feeding. 2）Low temperatures. 3）litter indirectly affecting seed germination and seedling growth of Abies fabric through such means as mechanical hindering, litter-decomposion-caused allelopathy which changes the physicochemical properties of soil, thereby affecting the regeneration potential of Abies fabric.