论滇南西双版纳的森林植被分类

本文基于多年研究成果的总结,对西双版纳森林植被的分类、主要植被类型及其特征进行了系统归纳,并讨论了它们与世界类似热带森林植被的关系。以群落的生态外貌与结构、种类组成和生境特征相结合作为植被分类的原则和依据,可以将西双版纳的热带森林植被分类为热带雨林、热带季节性湿润林、热带季雨林和热带山地常绿阔叶林四个主要的植被型,包括有至少二十个群系。热带雨林包括热带季节雨林和热带山地(低山)雨林二个植被亚型。热带季节雨林具有与赤道低地热带雨林几乎一样的群落结构和生态外貌特征,是亚洲热带雨林的一个类型,但由于发生在季风热带北缘纬度和海拔的极限条件下,受到季节性干旱和热量不足的影响,在其林冠层中有一定比例的落叶树种存在,大高位芽植物和附生植物较逊色而藤本植物和在叶级谱上的小叶型植物更丰富,这些特征又有别于赤道低地的热带雨林。热带山地雨林是热带雨林的山地亚型,是该地区热带山地较湿润生境的一种森林类型,它在植物区系组成和生态外貌特征上类似于热带亚洲的低山雨林,隶属于广义热带雨林植被型下的低山雨林亚型。热带季节性湿润林分布在石灰岩山坡中、上部,在群落外貌上类似热带山地常绿阔叶林但在植物区系组成上与后者不同,它是石灰岩山地垂直带上的一种植被类型。热带季雨林是分布在该地区开阔河谷盆地及河岸受季风影响强烈的生境的一种热带落叶森林,是介于热带雨林与萨王纳之间的植被类型。热带山地常绿阔叶林(季风常绿阔叶林)是西双版纳的主要山地植被类型,它分布在热带季节雨林带之上偏干的山地生境。它在植物区系组成上不同于该地区的热带季节雨林,在生态外貌特征上亦不同于热带山地雨林,是发育在受地区性季风气候强烈影响的热带山地的一种森林植被类型。     

On the Classification of Forest Vegetation in Xishuangbanna,Southern Yunnnan

Xishuangbanna of southern Yunnan is a region of extremely interest to biologists and also a hotspot for biodiversity conservation . It is located in a transitional zone from tropical Southeast Asia to temperate East Asia biogeographically. The present paper reviewed vegetation types of Xishuangbanna and suggested a revised classification system based on theupdated study results over the last two decades . By combining physiognomic and floristic characteristics with ecological performances and habitats , the primary forest vegetation in Xishuangbanna can be organized into four main vegetation types: tropical rain forest, tropical seasonal moist forest, tropical montane evergreen broad-leaved forest and tropical monsoon forest. The tropical rain forest can be classified into two subtypes , i. e. tropical seasonal rain forest in the lowlands and tropical montane rain forest on higher elevations. The tropical seasonal rain forest in this region shows similar forest profile and physiognomic characteristics to those of equatorial lowland rain forests and is a type of world tropical rain forest. Because of conspicuous similarity on floristic composition , the tropical seasonal rain forest in Xishuangbanna is a type of tropical Asian rain forest . However , since the tropical seasonal rain forest occurs at the northern edge of tropical SE Asia, it differs from typical lowland rain forests in equatorial areas in maintaining some deciduous trees in the canopy layer , fewer megaphanerophytes and epiphytes but more abundant lianas and more plants with microphyll . It is a type of semi-evergreen rain forest at the northern edge of the tropical zone . The tropical montane rain forest occurs in wet montane habitats and is similar to the lower montane rain forests in equatorial Asia in floristic composition and physiognomy . It is a variety of lower montane rain forests at the northern tropical edges of tropical rain forests . The tropical seasonal moist forest occurs on middle and upper limestone mountains and is similar to the tropical montane evergreen broad-leaved forest of the region in physiognomy, but it differs from the latter in floristic composition. The monsoon forest in Xishuangbanna is a tropical deciduous forest under the influence of a strong monsoon climate and is considered to be a transitional vegetation type between tropical rain forest and savanna in physiognomy and distribution. The tropical montane evergreen broad- leaved forest is the main vegetation type in mountain areas . It is dominated by the tree species of Fagaceae , Euphorbiaceae , Theaceae and Lauraceae in majority. It differs from the tropical montane rain forests in lack of epiphytes and having more abundant lianas and plants with compound leaves . It is considered to be a distinct vegetation type in the northern margin of mainland southeastern Asia controlling by a strong monsoon climate, based on its floristic and physiognomic characteristics.     

滇南勐宋热带山地雨林的物种多样性与生态学特征

 研究了鲜为人知的滇南勐宋地区的原始山地雨林植被, 根据分布生境、群落结构和种类组成特征,可将该山地雨林区分为沟谷和山坡两个类型, 分别定义为八蕊单室茱萸(Mastixia euonymoides)-大萼楠(Phoebe megacalyx)林和云南拟单性木兰(Parachmeria yunnanensis)-云南裸花(Gymnanthes remota)林。该山地雨林的外貌仍以单叶、革质、全缘、中叶为主的常绿中、小高位芽植物组成为特征,层间木质藤本植物仍较丰富,草本高位芽植物和附生植物丰富,但板根和茎花现象少见,属于热带山地垂直带上低山雨林或山地雨林植被类型。与该地区的典型热带季节雨林和赤道热带雨林相比, 勐宋的山地雨林群落中的大、中高位芽植物和藤本高位芽植物比例相对减少, 小、矮高位芽植物和草本高位芽植物比例相对增加,单叶、革质、非全缘叶和小叶比例相对增加,板根现象少见。与中国热带北缘-南亚热带地区（季风）常绿阔叶林比较, 勐宋的山地雨林有较多的附生植物和草本高位芽植物,相对较少的小高位芽植物和矮高位芽植物,小叶比例亦较少,非全缘叶和革质叶比例相对较低。故勐宋山地雨林是滇南热带北缘山地的一种较湿润生境的植被类型, 与所谓的季风常绿阔叶林不同。在物种多样性上,勐宋热带山地雨林在单位面积植物种数上并不比该地区的热带季节雨林低, 物种多样性指数与低丘季节雨林相当,比沟谷季节雨林低, 明显高于季风常绿阔叶林。     

滇东南马关古林箐热带雨林望天树群落的研究

云南东南部马关县古林箐的望天树群落以龙脑香科植物望天树为乔木层优势种,无患子科植物番龙眼为亚优势种,外貌以常绿大、中高位芽植物组成为特征,林内板根和茎花现象普遍,层间木质藤本和维管附生植物丰富,属于一种热带季节性雨林群落类型。在植物区系组成上,该群落以樟科、番荔枝科、楝科、大戟科、桑科、无患子科、橄榄科、柿树科等为主要组成科,在重要值统计上,以大戟科、无患子科、柿树科、龙脑香科、番荔枝科、樟科、楝科、橄榄科、桑科等为较优势的科,与东南亚热带雨林很接近,故为东南亚热带雨林的北缘类型。     

Geological History,Flora, and Vegetation of Xishuangbanna,Southern Yunnan,China1

Xishuangbanna of southern Yunnan is biogeographically located at a transitional zone from tropical Southeast (SE) Asia to subtropical East Asia, and is at the junction of the Indian and Burmese plates of Gondwana and the Eurasian plate of Laurasia. The flora of the region consists of a recorded 3336 native seed plant species, belonging to 1140 genera in 197 families, among which 83.5 percent are tropical genera and 32.8 percent are endemic to tropical Asia, suggesting a strong affinity to tropical Asian flora. The vegetation of Xishuangbanna is organized into four forest types: tropical rain forest, tropical seasonal moist forest, tropical montane evergreen broad‐leaved forest, and tropical monsoon forest. The tropical rain forest in Xishuangbanna has the same floristic composition of families and genera as some lowland equatorial rain forests in SE Asia, and is dominated (with a few exceptions) by the same families both in species richness and stem dominance. The exceptions include some deciduous trees in the canopy layer, fewer megaphanerophytes and epiphytes, and a higher abundance of lianas and microphyllic plants. We consider the tropical rain forest of Xishuangbanna as a type of tropical Asian rain forest, based on their conspicuous similarities in ecological and floristic characteristics.     

Ecological and biogeographical studies on the tropical rain forest of south Yunnan,SW China with a special reference to its relation with rain forests of tropical Asia

Abstract. Ecological and biogeographic analyses of the tropical rain forest in south Yunnan were made using data from seventeen sample plots and floristic inventories of about 1000 species of seed plants. The rain forest is shown to be a type of true tropical rain forest because it has almost the same profile, physiognomic characteristics, species richness per unit area, numbers of individuals in each tree species and diameter classes of trees as classic lowland tropical rain forests. As the area is at the northern margin of monsoonal tropics, the rain forest differs from equatorial lowland rain forests in having some deciduous trees in the canopy layer, fewer megaphanaerophytes and epiphytes but more species of lianas as well as more species of microphylls. In its floristic composition, about 80% of total families. 94% of total genera and more than 90% of total species are tropical, of which about 38% of genera and 74% of species are tropical Asian. Furthermore, the rain forest has not only almost the same families and genera, but also the same families rank in the top ten both in species richness and in dominance of stems, as lowland forests in southeast Asia. It is indisputable that the flora of the rain forest is part of the tropical Asian flora. However, most of the tropical families and genera have their northern limits in south Yunnan and most have their centre of species diversity in Malesia. More strictly tropical families and genera have relatively lower species richness and importance compared with lowland rain forests in tropical southeast Asia. Thus, the flora also shows characteristics of being at the margin of the tropics. Based mainly on physiognomy and floristic composition the tropical rain forest of Yunnan is classified into two types, i.e. seasonal rain forest and wet seasonal rain forest, the latter is further divided into two subtypes, i.e. mixed rain forest and dipterocarp rain forest. From analysis of geographic elements it is also shown that the tropical rain forest of Yunnan occurs at a geographical nexus with its flora coming mainly from four sources, i.e. Malesia, south Himalayas, Indochina and China.     

Forest Structure and Biomass of a Tropical Seasonal Rain Forest in Xishuangbanna,Southwest China1

Xishuangbanna is a region located at the northern edge of tropical Asia. Biomass estimates of its tropical rain forest have not been published in English literature. We estimated forest biomass and its allocation patterns in five 0.185–1.0 ha plots in tropical seasonal rain forests of Xishuangbanna. Forest biomass ranged from 362.1 to 692.6 Mg/ha. Biomass of trees with diameter at 1.3 m breast height (DBH) ≥ 5 cm accounted for 98.2 percent of the rain forest biomass, followed by shrubs (0.9%), woody lianas (0.8%), and herbs (0.2%). Biomass allocation to different tree components was 68.4–70.0 percent to stems, 19.8–21.8 percent to roots, 7.4–10.6 percent to branches, and 0.7–1.3 percent to leaves. Biomass allocation to the tree sublayers was 55.3–62.2 percent to the A layer (upper layer), 30.6–37.1 percent to the B layer (middle), and 2.7–7.6 percent to the C layer (lower). Biomass of Pometia tomentosa, a dominant species, accounted for 19.7–21.1 percent of the total tree biomass. The average density of large trees (DBH ≥100 cm) was 9.4 stems/ha on two small plots and 3.5 stems/ha on two large plots, illustrating the potential to overestimate biomass on a landscape scale if only small plots are sampled. Biomass estimations are similar to typical tropical rain forests in Southeast Asia and the Neotropics.     

Species Composition,Physiognomy and Plant Diversity of the Tropical Montane Evergreen Broad-leaved Forest in Southern Yunnan

Species composition, physiognomy and plant diversity of the less known tropical montane forests in southern Yunnan were studied based on the data from 15 sampling plots in three sites. These forests are mainly dominated by the families Theaceae, Fagaceae, Lauraceae and Euphorbiaceae in floristic composition, and dominated by evergreen phanerophytes with mesophyllous leaves. These forests are similar to lower montane rain forests in equatorial southeastern Asia in floristic composition and altitudinal distributions, but differ in physiognomy by having few epiphytes, but more lianas and more plants with compound leaves. These differences could be due to strongly seasonal climate and so-called mass elevation effect in southern Yunnan. They also differ from the tropical seasonal rain forests at lower altitudes in southern Yunnan by having conspicuously lower species richness, few epiphytes, fewer mega-mesophanerophytes, more abundant micro-nanophanerophytes and hemicryptophytes and more plants with microphyllous leaves. It is suggested that these forests could be termed tropical montane evergreen broad-leaved forests, and be a vegetation type from the northern margin of mainland southeastern Asia controlled by a strongly seasonal climate.     

西双版纳青梅林的群落学研究

本文对分布在西双版纳勐腊县南部以龙脑香科植物版纳青梅为标志树种的热带森林作了群落学分析,认为它具有热带雨林的结构和基本特征,在性质上属于热带季节雨林。由于分布海拔偏高和生境特殊,它的上层乔木几乎常绿,在外貌上与望天树林和本地区典型的季节雨林有一定差异,在区系组成上向山地雨林过渡,它表现为一种季节雨林向山地雨林过渡的类型,同时也是一种热带北缘地区季节雨林的海拔极限类型。