江西井冈山地区沟谷季雨林及其超地带性特征

江西井冈山地区位于中国东部中亚热带地区南缘,属北半球湿润区。该地区地处罗霄山脉中段,地势高耸,沟谷深切,生境极富多样化,在其沟谷地区保存有典型亚热带季风常绿阔叶,常称季雨林。选择6个典型沟谷季雨林群落,开展群落生态学和生物地理学的研究,结果表明:(1)群落组成以典型的热带性科属为特征,如樟科Lauraceae、壳斗科Fagaceae、山茶科Theaceae、茜草科Rubiaceae、金缕梅科Hamamelidaceae等;种子植物属的地理成分以热带-亚热带成分占优势,占总属数的64.71%—77.94%,高于同纬度地区其他山体,接近甚至高于南亚热带季风常绿阔叶林中的热带性成分。(2)群落结构具有多优势种及明显的特征性标志种,与具单优势种或少数优势种的亚热带常绿阔叶林有明显差异。(3)Shannon-Wiener指数为4.44—5.46之间,物种多样性较丰富,表现出明显的南亚热带植被特征。(4)其它热带雨林性质的特征还包括:大型木质藤本,板根现象,绞杀现象,滴水叶尖,丰富的寄生、附生植物、兰科植物、树蕨等。整体上,井冈山地区亚热带沟谷季雨林群落具有热带雨林向亚热带常绿阔叶林过渡的明显特征,与南亚热带季雨林性质相似,在演替上常被称为侵入群落,或为历史时期长期演化形成的超地带性植物群落。

The ravine monsoon rain forest in Jinggangshan of Jiangxi Province and its super zonal characteristics

Located in the south rim of the mid-subtropical area in East China, Mount Jinggangshan region in Jiangxi Province is a humid area of the northern hemisphere. With its location in the middle of Luoxiao Mountains, it has towering topography, deep valleys, extremely diverse habitats, and conserves typical monsoon forests in its valleys. We selected six typical ravine monsoon forest communities, aiming to investigate the characteristics of the communities'' synecology and biogeography. The results show that: (1) The community composition is characterized by rich and typical tropical family, such as the Lauraceae, Fagceae, Theaceae, Rubiaceae, Hamamelidaceae, etc.; tropical-subtropical element is dominant in the geographic component of seed plants, accounting for 64.71%-77.94% of the total genera, which is higher than in other mountains of the same latitude, close to or even higher than the monsoon broad-leaved evergreen forests in south sub-tropical zone. (2) The community structure has poly-dominant species and typical key-stone species, and is much different from the subtropical evergreen broad-leaved forests which is often mono-dominant or few species dominant in structure. (3) Shannon-Wiener index for the species diversity is 4.44-5.46, the species are quite rich, showing obvious tropical vegetation features in south subtropical zone. (4) The ravine monsoon forests in Mount Jinggangshan region are indicative of obvious characteristics of tropical rain forests in ecological habit, such as typical large woody climber, buttress root, garroting phenomenon, draining point, rich parasitic plants and epiphytes, orchids and tree ferns. There is no doubt that monsoon forest communities in subtropical valleys of Mount Jinggangshan region has distinguishing characteristics of transition from tropical rain forests to the subtropical evergreen broad-leaved forests, which is often known as intrusion communities in terms of succession, or super zonal plant communities formed through long-term evolution.