Tiwari Achyut, Uprety Yadav, Rana Santosh Kumar
Department of Botany, Tri-Chandra Campus, Tribhuvan University, Kathmandu, Nepal.
Central Department of Botany, Tribhuvan University, Kirtipur, Kathmandu, Nepal.
Plant Divers. 2019 Apr 20;41(3):174-182. doi: 10.1016/j.pld.2019.04.004. eCollection 2019 Jun.
Nepal is located in the central part of the greater Himalayan range with a unique series of mountain chains formed by recent mountain building geological events. As one of the youngest mountains in the world it contributes to diversity of plants and also provided barriers to and corridors through which plants migrated during the ice ages. The higher altitudinal variation with the high mountains, deep river valleys and lowland plains combine with the effects of the summer monsoon and dry winter result with an extraordinary diversity of ecosystems including flora and fauna in a relatively small land area. The existing checklists for Nepal record some 6000 species of flowering plants and about 530 ferns. However, the botanical experts estimate that numbers may go up to 7000 when the poorly known remote regions are fully explored. The information on plant endemism in Nepal Himalaya is not adequately known as Nepal is still struggling to complete long awaited Flora of Nepal project. Endemic species are confined to specific areas and are the first to be affected by land use and other global changes. We sought to explore the spatial distribution of endemic plant species in Nepal in relation to the consequences associated with climatic and geologic changes over time in the region with the help of published literature. It was found that the endemism showed marked spatial variation between open moist habitat and dry inner valleys, the former with higher endemism. The updated records showed 312 flowering plant species to be endemic to Nepal with higher endemism around the elevation of 3800-4200 m at sea level. The recent human population explosion, intensified deforestation, habitat fragmentation and modern day environmental changes are posing greater threats to endemic plant in Nepal. The conservation status and threats to these peculiar species are unknown. Nevertheless, environmental degradation and high poverty rates create a potent mix of threats to biodiversity in this landscape.
尼泊尔位于大喜马拉雅山脉中部，近期的造山地质事件形成了一系列独特的山脉。作为世界上最年轻的山脉之一，它促进了植物多样性，同时也在冰河时代为植物迁移提供了屏障和通道。高山、深邃河谷和低地平原的高度海拔变化，加上夏季季风和干燥冬季的影响，导致在相对较小的陆地区域内拥有包括动植物在内的极其多样的生态系统。尼泊尔现有的植物名录记录了约6000种开花植物和约530种蕨类植物。然而，植物专家估计，当鲜为人知的偏远地区得到充分探索时，这个数字可能会上升到7000种。由于尼泊尔仍在努力完成期待已久的《尼泊尔植物志》项目，关于尼泊尔喜马拉雅地区植物特有性的信息尚未得到充分了解。特有物种局限于特定区域，并且是最先受到土地利用和其他全球变化影响的物种。我们试图借助已发表的文献，探索尼泊尔特有植物物种的空间分布，以及该地区随时间推移与气候和地质变化相关联的后果。研究发现，特有性在开阔湿润栖息地和干燥内陆山谷之间表现出明显的空间差异，前者具有更高的特有性。更新后的记录显示，有312种开花植物为尼泊尔特有物种，在海拔3800 - 4200米左右（海平面）特有性较高。近期人口爆炸、森林砍伐加剧、栖息地破碎化和现代环境变化，对尼泊尔的特有植物构成了更大威胁。这些独特物种面临的保护现状和威胁尚不清楚。尽管如此，环境退化和高贫困率对这一地区的生物多样性构成了强大的威胁组合。
