滇南热带季雨林的一些问题讨论

 通过分析云南南部的水、热条件及植被分布，讨论了季雨林植被类型及其特征，认为云南南部的季雨林是介于热带雨林与萨王纳之间的，在干季基本上是落叶的一种森林植被类型，符合Schimper (1903)定义的热带季雨林植被，并考虑它是一种生态学意义上的经向地带性植被，与该地区的纬向地带性植被热带季节雨林一起共同构成云南南部的水平地带性植被。在云南南部的石灰岩山坡分布的过去被认为是季雨林的森林植被，尽管也受到季节性干旱的影响而不同程度地具有落叶成分，但它在群落外貌上与典型的季雨林不相同，在植物区系组成上也明显不同于该地区非石灰岩山地的季风常绿阔叶林，在分布上亦是在石灰岩低山沟谷的热带季节性雨林水平地带性植被带之上，根据其生态外貌、植物区系组成和生境特点，我们建议用“热带季节性湿润林”来称呼这类石灰岩山地森林类型，在性质上属东南亚热带北缘石灰岩山地垂直带上的一种植被类型。

RECLASSIFICTION OF MONSOON TROPICAL FORESTS IN SOUTHERN YUNNAN,SW CHINA

Southern Yunnan is located biogeographically at a transitional zone between tropical Southeast (SE) Asia and subtropical East Asia, and though far north of the Equator and at a relatively high altitude, has a rich and diverse tropical flora. The terminology used to describe the different tropical forest types in the region are confusing because the classification schemes used come from different disciplines. Using the classification scheme of tropical plant formations by Schimper (1903) and Richards (1996) , which is based primarily on climatic factors, we discuss a new classification scheme of the tropical forests in southern Yunnan. Horizontal vegetation types in southern Yunnan are represented by tropical seasonal rain forests and monsoon forests. The tropical seasonal rain forest is a tropical Asian rain forest at altitudinal and latitudinal limits, while the monsoon forest is considered to be a transitional vegetation type between tropical rain forests and savannas based on their physiognomy and distribution. The monsoon forest is largely leafless during the dry season. The forests that occur on the middle and upper limestone slopes in southern Yunnan, which was called a monsoon forest in some Chinese botanical references, is reclassified as a seasonal moist forest. These forests are not equivalent to classical monsoon forests in their physiognomy, despite of the fact that it is affected by seasonal dryness and contains a high percentage of deciduous trees. The floristic composition also is different from monsoon evergreen broad-leaved forests in the region. This limestone forest, which abuts the seasonal rain forest on lower slopes and in the limestone valleys, is an altitudinal vegetation type on limestone bedrock in southern Yunnan.