【摘要】 对西双版纳勐腊县麻木树地区的热带雨林刀耕火种撂荒后形成的不同演替阶段的野芭蕉先锋植物群落进行了植物种类组成、区系成分、结构特征及种群数量与年龄结构的动态变化分析。结果表明 :在 10 0 0m2 的样地上 ,随着群落的发展和演替的进行 ,群落的科、属、种组成日趋复杂 ,从侵入阶段的 17科 2 7属 30种 ,上升到定居阶段的5 0科 74属 98种 ,至扩散阶段已达 5 5科 87属 113种。 3个不同林龄阶段的群落区系组成可分为 9种类型 ,均以热带区系成分为主 ,占 90 %左右。随着群落的发展 ,泛热带分布、热带亚洲 (印度—马来西亚 )分布所占的比例随林龄逐渐增大 ,而旧世界热带分布及东亚至北美洲间断分布所占的比例在逐渐减少。群落的层次结构由简单趋于复杂 ,野芭蕉的种群数量急剧增长 ,各龄级的个体分布逐渐增多 ,群落正向着湿润性的热带森林方向发展。更多还原

【Abstract】 Musa acuminata , a huge herbaceous plant, usually develops a mono dominant plant community in tropical regions. In order to understand the successional dynamics and structure characteristics of this community, three pioneer Musa acuminata communities of different ages on the same slope, each of which regenerated from tropical rain forest after slash and burn cultivation in Mamushu, Mengla County, Xishuangbanna, were chosen for establishment of three 1000 m 2 permanent plots. A grid (5 m×5 m) was used to record all individuals over 2.0 cm DBH in each plot. Shrub and herb species were investigated in 2 m×2 m sub quadrats. Plant species composition, floral distribution types, structural characteristics, and the age structure and number of the Musa acuminata populations in each community were analyzed. The results showed that, in each 1000 m 2 plot, plant species richness increased with community development from 30 species, 27 genera and 17 families at the invasion stage to 98 species, 74 genera and 50 families in the habitation stage, and further to 113 species, 87 genera and 55 families in the expansion stage. The floral composition in each plot can be divided into nine distributional types, of which the tropical distribution comprised 90%. The ratio of Pan tropic and Asian tropic (Indo-Malesia) increased, while the ratio of Old World tropics and East Asia to North American disjunction decreased with forest age. The tree species diversity index (Shannon Wiener index) in the arboreal layer increased from 1.79 in invasion stage to 2.83 in habitation stage, and then decreased to 1.87 in the expansion stage. Diversity in the understory also increased from 2.78 in habitation stage to 3.56 in expansion stage. The structure of communities became more and more complex, and the number of individual stems in each plot and the individual frequency in each age class of the Musa acuminata population sharply increased with development. The development of the Musa acuminata community has no effect on the directionality of community succession, which is proceeding towards a humid tropical rain forest community.更多还原