CAS Workshop on Ecosystem Succession Theory and Practice of Ecological Restoration

贡嘎山东坡林线附近峨眉冷杉种群研究：II. 多尺度时空格局[1] 

沈泽昊¹  方精云¹  刘增力¹   伍杰²

（¹北京大学城市与环境学系，北京 100871；²四川省甘孜州林科所，姑咱 626001） 

摘要：通过对贡嘎山东坡林线附近1.0hm²样地冷杉种群的定位调查，探讨极端环境中冷杉种群在种子萌发、竞争自疏和受扰死亡3 方面的特征、相互作用及环境因子的影响。结果表明：1）冷杉的更新苗木、死株和各级同生群分别在不同尺度上显示聚集格局。>250龄级的个体在各尺度上呈均匀分布。2）多尺度分析显示了100～150年一代的冷杉同生群斑块，表明干扰周期为100～150年，其结果导致各龄级斑块构成冷杉林景观的流动镶嵌结构。3）种群时空格局反映了对分析尺度的依赖。在空间上分析尺度越大，小尺度的格局和机制就被忽略得越多，具有小尺度格局的对象聚集强度随尺度增大而降低；在时间尺度上，小尺度的相关格局只发生于低龄级群体之间，因为它们之间存在较直接的因果联系；随着个体年龄增长和自疏作用的累积影响，聚集性格局将会逐渐演变成随机性格局。随着种群密度减小，小尺度因子作用消失，大尺度因子的作用开始显示出来。

关键词：冷杉；种群结构；更新；自疏；干扰；格局 

Studies on Abies fabri population near the alpine timberline

on the east slope of Gongga Mountain:

II. Multiscale spatial and temporal patterns

 Shen Zehao¹  Fang Jingyun¹  Liu Zengli¹Wu Jie² 

(¹Department of urban and environmental sciences, Peking University Beijing, Beijing 100871, China; ²Institute of forestry science of Ganzi State in Sichuan Province, Guzan 626001, China) 

Abstract: Through an investigation of a 1.0 hm² plot near the alpine treeline on the east slope of Gongga Mountain, this paper aims to study population dynamics of Abies fabri near the alpine timberline, focusing on the characteristics in regeneration, competition self-thinning and death, their interaction and the influences of environmental factors. The results suggested that:

The regeneration stems have an agglomerate pattern on all scales of analysis. The Smaller the scale, the higher the degree of agglomeration. Gap makers and the consortive group of 50~100yr also have similar patterns. From the scale of 5×5m² on, the consortive group of 150-200yr shows an agglomerate pattern; It is also the case for that of 150-200yr at the scale of 20×20m². It seems that the spatial and temporal pattern of population depends on the scale of study. On the dimension of spatial, the larger the scale of analysis depends, the more the microscale patterns and mechanisms are neglected.  So the agglomerate degree of object with microscale pattern tends to decrease as the study scale is enlarged. On the temporal dimension, the microscale correlative pattern only occurs in the young groups, because of more direct relation between them. As the influences of individual growth and self-thinning cumulate, the population density decrease, and the spatial pattern will shift from agglomerate to random type. The effects of the microscale factors eliminate gradually, and those of the macroscale factors become prominent..

The relativity between the consortive groups and environmental factors were analyzed on 6 sampling scales, and the patches of 100~150 years old consortive groups were shown to exist in Abies fabri population, spatially separated with each other. This means that the gap disturbance have a rotation period of 100~150 yr in this area. As Abies fabri population has a life estimate of 400yr. As a result, the forest landscape will be structured as a shifting mosaic of Abies fabri consortive groups of different age class.

Key words: timberline; pattern; disturbance; self-thinning; recruitment; Abies fabric 

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