关键词: 木质藤本, 草质藤本, 攀援方式, 喜马拉雅地区, 印度河-恒河平原

Abstract

The Himalayas are a biodiversity hotspot. In this study, the taxonomic diversity of climbing plants in the Himalayan region and its connection with neighbouring regions were analyzed, the distribution patterns of climbers in the Himalayas and the Indo-Gangetic Plain were compared, and mechanisms were discussed. Results showed that: (1) The Himalayan region harbored a total of 1,083 climbing species in 309 genera and 72 families. Approximately 66.9% (725 species) of these species were woody or semi-woody climbers (lianas) and the remaining 33.1% (358 species) were herbaceous (vines). Twining climbers accounted for 51.3% of the climbing plants in this region. (2) The climbing plant flora in the Himalayas was significantly affected by neighboring floras. About 74.1% (802 species) of the climbers in the Himalayas were also found in Southeast Asia, 548 species (50.6%) were found in South Asia, and 530 species (48.9%) were found in Southwest China. Only 125 climbers (11.5%) were endemic to this region and no endemic genus was recorded. (3) Species diversity of climbing plants and their proportion in the flora gradually decreased from east to west in the Himalayas. Twining climbers and lianas became more dominant in the western regions. At the genus level, species diversity of most climber-rich genera decreased westward across the Himalayas and species diversity of only a few genera (e.g. Vicia and Cuscuta) showed an increase from east to west. (4) The distribution patterns of climbing plants in the Himalayas and the Indo-Gangetic Plain were consistent. However, species diversity was higher in the Himalayas and its decreasing trend westward was more significant. At the genus level, the average decreasing rate of climber-containing genera from east to west is 8.4 genera per 100 km in the Himalayas and 6.3 genera per 100 km in the Indo-Gangetic Plain. A total of 272 climber-containing genera in the Himalayas were shared with the Indo-Gangetic Plain, and 196 genera were not found in the west regions (Central Asia and Iranian plateau). In the 196 genera, 61 genera (31.1%) were distributed more to the west in the Himalayas than in the Indo-Gangetic Plain, while only 8 genera (4.1%) were distributed more to the west in the Indo-Gangetic Plain than in the Himalayas. In conclusion, species diversity and distributional characteristics of climbers in the Himalayas were attributed in part to the geographical location of this region, the altitudinal and longitudinal gradients of climate and habitats, and the diversification of adjacent floras. The similarities of the distribution patterns of climbing plants in the Himalayas and the Indo-Gangetic Plain may be primarily due to similar east-west water gradients.

Key words: liana, vine, climbing method, Himalayan region, Indo-Gangetic Plain