峨眉山冷杉种群研究

依据 5 1个 2 0 m× 2 0 m冷杉乔木层样方和 1 0 2个 4 m× 4 m灌木层样方有关冷杉种群的调查资料和典型区域内冷杉种群的年龄和生长指标的测定 ,对峨眉山冷杉种群配置、重要参数、更新与生长状况进行了研究 ,揭示了当地冷杉种群及其所组成的森林的现状与演替趋势。指出 ,峨眉山冷杉种群的径级配置与海拔高度为主导的环境要素变化相关 ,2 80 0 m以下的冷杉种群缺乏胸径 5～ 2 0 cm的小径个体 ;尤其是在“混交”状的冷杉林下株高小于 5 m的幼龄个体稀少且其年龄与应有的生长量相差甚远 ,由此作者认为该海拔段以下的冷杉种群正面临衰退 ,其构成的冷杉森林正处于退化演替的过程之中 ,并有可能在今后 5 0 a或许更短的时间内显现严重后果。同时 ,本研究表明冷杉主要通过林窗和林缘更新。通过对冷杉 -箭竹 -泥炭藓森林群落中冷杉种群状况的研究 ,阐述了冷杉种群在特定的逆境条件下生殖策略由 K选择向 r选择方向的转化趋势 ,讨论了冷杉种群在泥炭藓发育的局部沼泽化的环境中得以生存的机制 ;本文还就冷杉种群在林内自然更新和迹地更新条件下的胸径生长规律作了比较研究 ,说明密度制约机制对冷杉种群更新具有重要作用 ;并就更新情况相对较好的冷杉 -箭竹 +金顶杜鹃 -草类林、冷杉 -箭竹 -藓类林和冷杉 -峨眉玉山

Study on the population of Abies fabri in Mt. Emei

Based on study of the pattern,important parameters, regeneration and growth of the Abies fabri population, this paper deals with the population status and its forest succession tendency according to the data of 51 quadrants (each 20 m×20 m) of the tree layer and 102 quadrants (each 4 m×4 m) of the shrub layer and the index of the population age and growth at the representative areas in Mt. Emei. It is found that the HDB pattern of the population is relation to the elevation. There are few little individuals (HDB 5 ～20 cm) below 2 800 al. and especially in the "mixed" forests, the young individuals (height<5 m) is seldom seen and the relationship of their age and development is maladjustment. Based on these above, we consider that the population are facing to decline below the elevation and the forest is in deterioration succession. The serious consequence could happen within 50 years or even shorter. In the same time, the reseach shows the regeneration of the population is major through the windows and edge of forest and it is expatiated that the reproduction strategy of the population changes from choose "k" to choose "r" in the special adversity habitant and the existent mechenism of the population is discussed in the site with some coverage of sphagnum and swamp by studing the population status in the forest types of Abies fabri -Bashania fangiana -peat moss. We believe that the mechanism of density restriction is very important in the regeneration of the population through constractive reseach on grouth rule of DBH on conditions of natural regeneration and slash regeneration. We also study the relations between age and height of young individuals and their growth status in three forest types, Abies fabri -Bashania fangiana+Rhododendron faberi - grass, Abies fabri-Bashania fangiana-grass, Abies fabri-Yushania brevipaniculata-moss, that have regenerated relatively better, but the status of the individual height growth and quality is not ideality.