长白山北坡云冷杉林和落叶松林物种组成与群落结构

Species composition and community structure of a spruce-fir forest and a larch forest on the northern slope of Changbai Mountains,Northeast China

云冷杉林是长白山北坡保存最完整的森林植被,而落叶松林是长白山的隐域性森林植被.为了更好地了解其物种组成和群落结构等基本特征,于2010年在长白山北坡自然保护区内分别建立了4 hm2的云冷杉林和落叶松林长期监测样地,对样地内所有胸径≥1 cm的木本植物进行了定位、调查和挂牌.结果表明:云冷杉林样地木本植物有22种,隶属于6科12属;落叶松林样地木本植物有22种,隶属于8科16属.两样地物种组成差异不大,区系组成基本上都属于北温带成分.云冷杉林样地木本植物独立个体数为8640株,包括分支数为9257株;落叶松林样地木本植物独立个体数为3696株,包括分支数为4060株.两样地优势种明显,云冷杉林样地,臭冷杉和长白落叶松处于优势地位,其重要值分别占所有物种的38.7%和23.9%;落叶松林样地,长白落叶松占绝对优势,其重要值占所有物种的61.9%.两样地群落更新良好,径级结构均呈倒"J"型.云冷杉林样地,臭冷杉径级结构呈倒"J"型,长白落叶松径级结构呈正态分布;落叶松林样地,长白落叶松胸径≥10 cm个体的径级结构呈正态分布.主要物种空间分布在两个样地中随径级和空间尺度的变化表现出不同的格局,共有种在不同样地间表现出不同的格局.

Spruce-fir forest is the best protected forest vegetation on the northern slope of Changbai Mountains. sition and community structure, we established a 4 hm2 vegetation, while larch forest is intrazonal To further understand their species compo- forest permanent plot in each of these two forests in 2010. All free-standing plant species with DBH （diameter at breast height） ≥ 1 cm were mapped, tagged, and identified to species. The results showed that there were 9257 stems belong- ing to 8640 genotype individuals, 22 species, 6 genera and 12 families in the spruce-fir forest plot, while 4060 stems belonging to 3696 genotype individuals, 22 species, 8 genera and 16 families in the larch forest plot. Species composition in the two plots was very similar. Most of the species be- longed to the Changbai Mountains plant flora. The analysis of species＇ importance values showed that there were dominant species in both communities. The spruce-fir forest was dominated by Abies nephrolepis and Larix olgensis, whose importance values accounted for 38.7% and 23.9% of the sum of importance values over all species in the plot, respectively. The larch forest was dominatedsolely by L. olgensis, whose importance value accounted for 61.9% of the sum of importance values over all species in the plot. Both forests were in good condition of regeneration and showed a reversed ＇J＇ type in tree size distributions at community level. However, different species showed different shapes in size distribution in the two forests. A. nephrolepis showed a reversed ＇J＇ type size distribu- tion in the spruce-fir forest, while L. olgensis with DBH≥ 10 cm showed a hump-shaped distribution in the larch forest. Spatial distribution patterns of the main species changed differently with size class and spatial scales. Common species had different spatial distribution patterns in the two plots.