Abstract: Two temporal satellite images were used for vegetation mapping of Wolong nature reserve.Through overlay analysis of the vegetation maps and DEM data, the authors studied the distribution pattern variation of different vegetation types along the topographic gradients. The Study resulted that: (1) The extensive deforestation activity beginning at medium 1960's made intensively impact on the vegetation distribution pattern, and the aftereffect can be distinguished clearly even in medium 1980's. (2) The productive afforestation during timber production period from medium 1960's to 1970's and the continually protective afforestation after the setting up of the nature reserve were the primary causes of the significant variation for vegetation distribution pattern along topographic gradients during the study period. Furthermore, natural recovery process also gave an impulse to the pattern changing. (3) Some obvious phenomena of human impact on natural vegetation can also be watched in our working area. Decreasing of coniferous forest and broad-leaved forest with the simultaneous increasing of shrub reflected the type and spatial characteristics of human disturbance activities in working area. The related management department should consider the above problems more seriously.

Key words: Wolong nature reserve, vegetation pattern, topographic impact, human impact

摘要： 利用卧龙自然保护区1987年和1997年两个时段的卫星遥感影像进行植被制图，并与DEM模型数据进行叠图分析，研究不同植被类型在各种地形梯度上的分布格局及变化特点。结果表明：(1)20世纪60年代中期大规模森林砍伐活动使林地的分布格局受到强烈干扰，这种影响一直延续到80年代中期；(2) 研究时段内的生产性育林活动、保护性育林活动和自然植被恢复过程，对森林植被类型的地形分布格局产生了显著的影响；(3)保护区目前仍存在着一些显著的人为干扰现象，针叶林及阔叶林比重的减少和灌丛数量的相应增加，反映出保护区目前人为干扰活动的主要类型和空间分布特征，应当引起管理部门的足够重视。

关键词: 卧龙自然保护区, 植被格局, 地形影响, 人为影响