植物生态学报 ›› 2003, Vol. 27 ›› Issue (5): 603-609.doi: 10.17521/cjpe.2003.0087

• 论文 • 上一篇    下一篇

神农架地区米心水青冈-曼青冈群落的结构与格局研究

张谧, 熊高明, 赵常明, 陈志刚, 谢宗强   

  • 出版日期:2003-05-10 发布日期:2003-05-10
  • 通讯作者: 张 谧

he Structures and Patterns of A Fagus engleriana-Cyclobalanopsis oxyodon Community in Shennongjia Area, Hubei Province

ZHANG Mi, XIONG Gao-Ming, ZHAO Chang-Ming, CHEN Zhi-Gang, XIE Zong-Qiang   

  • Online:2003-05-10 Published:2003-05-10
  • Contact: BAI Li-Xin

摘要:

米心水青冈(Fagus engleriana)-曼青冈(Cyclobalanopsis oxyodon)常绿落叶阔叶混交群落是神农架山地植被垂直带谱的重要类型。通过分析乔木层结构及优势种的分布格局,探讨群落的特点及动态。结果表明,群落乔木层可分为3个亚层:第一亚层落叶阔叶树种占优势,势树种为米心水青冈;第二及第三亚层以常绿树种为主,优势种为曼青冈。应用偏离指数、Lloyd的平均拥挤度和聚块性指数及Morisita指数,在8个尺度下对米心水青冈及曼青冈两种优势树种进行格局分析,发现两者总体上均为聚集分布,米心水青冈的聚集强度高于曼青冈。按1~4cm, 4~8cm及8cm以上3个径级对曼青冈分布格局进行比较,各径级间聚集强度相似,没有自疏现象。由于米心水青冈及曼青冈占据乔木层不同的高度,且均不缺乏更新贮备,因此形成稳定共存的群落。

Abstract:
Beeches are important constructive species in humid temperate forests in the Northern Hemisphere. China contains rich species of genus Fagus, 5 out of the 11 distributed in the country. Although there were many reports about Fagus in China, most of them referred to the south of the Fagus distribution region, and specifically to F. lucida. In this paper, we examined the size class structure and distribution pattern of a deciduous and evergreen mixed beech forest dominated by F. engleriana and Cyclobalanopsis oxyodon to discuss the relationship of the two species, and the community dynamic. The research plot was located in Shennongjia area of Hubei province (31°19′04″ N, 110°29′44″ E), which was in the northern part of the Fagus distribution region. This area crosses the mid-subtropical and north-subtropical zones of China, and is also a transition area of landform. The unique geographic position causes its particular plant species diversity and antiquity. Beech community is an important type of mountain forest in the local vegetation. F. engleriana, F. long ipetiolata and F. lucida are all distributed there, and F. engleriana is the most common species. The 0.96 hm2 permanence plot was established in 2001, and was divided into 384 subplots. All the stems over 1 cm in DBH were identified, measured, tagged, and mapped.The community consisted of 46 woody plant species, belonging to 22 families and 27 genera. The dominant families were Fagaceae, Aceraceae, Ericaceae, Cornaceae and Rosaceae. The tree layer could be divided into three sub-layers. In the first layer, deciduous trees made up 80.7% of the layer, and evergreen species were 19.3%; dominant species were Fagus engleriana and Cyclobalanopsis oxyodon. In the second and third layers, evergreen species increased from 55.9% to 80.5%.C.oxyodon and Rhododendron hypoglaucum were dominant species. The size-class distribution of Fagus engleriana and Cyclobalanopsis oxyodon showed positive pyramidal type, which indicated that both species had rich sapling banks and regenerated well. Three hundred and fourteen stems including 289 sprouting ones were counted for Fagus engleriana in the 0.96 hm2 plot. The sprouting stems were 90.8% of the total stems, and some researches showed sprouting could be the major method of recruitment of the population. C.oxyodon had 1 576 stems, 74.6% sprouting. Although sprouting was a large part of the stems, C.oxyodon was mainly regenerated by seed. Distribution patterns were analyzed using David and Moore’s index, Lloyd’s index and Mosisita index in plot sizes of 1 m × 1 m, 3 m × 3 m, 5 m × 5 m, 7 m × 7 m, 9 m × 9 m, 11 m × 11 m, 13 m ×13 m, and 15 m × 15 m. The Cyclobalanopsis oxyodon population was divided into three size classes as DBH 1-4 cm, DBH 4-8 cm and DBH > 8 cm. The distributions of all of these classes were clumped. This may be because the life span of C.oxyodon was so short that no self-thinning happened during this period. The distribution pattern of F.engleriana was also clumped. The possible reasons were: 1) the recruitment of F. engleriana needed open canopies. The pattern in fact showed the disturbance history. 2) compared with other beech forests, this community had not reached maturity. In this stage of succession the distribution pattern was clumped. 3) the distribution could be influenced by topography. The slope of the plot is 49.5 degree on average. This could highly affect seed distribution, and so also affect the pattern of the population. The studied Fagus engleriana-Cyclobalanopsis oxyodon community had rich species diversity and clear structure. AlthoughC.oxyodon was the most important species in the community, it was not a canopy tree at this elevation. So F.engleriana was the constructive species and C.oxyodon was a co-dominator. The two species both had sufficient regeneration storage that the community could exist stably.