Zhu Hua, Chai Yong, Zhou Shisun, Yan Lichun, Shi Jipu, Yang Guoping
Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Xue-Fu Road 88, Kunming, Yunnan 650223, PR China.
Plant Divers. 2016 Nov 10;38(6):295-302. doi: 10.1016/j.pld.2016.11.001. eCollection 2016 Dec.
The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous, island-like, distribution. It is diverse, rich in endemic species, and likely to be sensitive to climate change. Six 1-ha sampling plots were established across the main distribution area of the upper montane evergreen broad-leaved forest in Yunnan. All trees with d.b.h. > 1 cm in each plot were identified. Patterns of seed plant distributions were quantified at the specific, generic and family levels. The forests are dominated by the families Fagaceae, Lauraceae, Theaceae and Magnoliaceae, but are very diverse with only a few species shared between sites. Floristic similarities at the family and generic level were high, but they were low at the specific level, with species complementarity between plots. Diversity varied greatly among sites, with greater species richness and more rare species in western Yunnan than central Yunnan. The flora is dominated by tropical biogeographical elements, mainly the pantropic and the tropical Asian distributions at the family and genus levels. In contrast, at the species level, the flora is dominated by the southwest or the southeast China distributions, including Yunnan endemics. This suggests that the flora of the upper montane forest in Yunnan could have a tropical floristic origin, and has adapted to cooler temperatures with the uplift of the Himalayas. Due to great sensitivity to climate, high endemism and species complementarity, as well as the discontinuous, island-like, distribution patterns of the upper montane forest in Yunnan, the regional conservation of the forest is especially needed.
云南山地常绿阔叶林主要分布于常年云雾缭绕的区域，呈间断性的岛状分布。该森林类型多样，特有物种丰富，且可能对气候变化较为敏感。在云南山地常绿阔叶林的主要分布区域内设立了6个1公顷的采样区。对每个采样区内胸径大于1厘米的所有树木进行了鉴定。在科、属、种水平上对种子植物的分布格局进行了量化。这些森林以壳斗科、樟科、山茶科和木兰科为主，但种类非常多样，不同地点之间仅有少数物种相同。科和属水平上的区系相似性较高，但种水平上的相似性较低，不同样地间存在物种互补性。不同地点的多样性差异很大，云南西部的物种丰富度更高，珍稀物种也比云南中部更多。该植物区系以热带生物地理成分占主导，在科和属水平上主要为泛热带分布和热带亚洲分布。相比之下，在种水平上，该植物区系以中国西南或东南分布为主，包括云南特有种。这表明云南山地森林的植物区系可能起源于热带植物区系，并随着喜马拉雅山脉的隆升适应了较低的温度。由于对气候高度敏感、特有性高、物种互补性强，以及云南山地森林呈间断性的岛状分布格局，该森林的区域保护尤为必要。
