Biodiversity of the alpine vascular flora of the NW North American Cordillera: The evidence from phyto-geography
Biodiversity of the alpine vascular flora of the NW North American Cordillera: The evidence from phyto-geography
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DOI：
10.3112/erdkunde.2007.04.05
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发表时间：
2007-10-01
期刊：
影响因子：
1.4
通讯作者：
Harris, Stuart A.
中科院分区：
文献类型：
--
作者：
Harris, Stuart A.
在威斯康星州冰川末期，高山维管植物只有大约3.5ka，一旦冰融化，高山维管植物就可以在加拿大西部1600公里的以前冰川地带的南北方向上定居，然后温度导致它们在个别山脉上变得孤立。本文描述了源区/避难所，并评估了从每个源地迁徙的效果。基本数据由阿拉斯加北海岸和科罗拉多州之间29个高山地区的现代植被细节组成。加拿大科迪勒拉山脉70%以上的高山物种只在这块大陆上发现。个别物种的分布是零星的，可能是因为可用于殖民的时间很短。在冰川作用期间，每个避难所都发生了相当大的物种形成，这可能是因为突变的成功程度更高，这些突变在新的条件下比它们的双亲生存得更好。这些新种可以确定每个避难所的植物区系。现有的大约629种根据现有的分布被分成9个组。每一类别物种百分比的图表显示，高原山附近的科迪勒兰中部避难所和夏洛特皇后群岛的物种主要沿邻近山脉向北和向南迁徙。由于以前的冰川地形更潮湿和更冷，从南部科迪勒拉物种的招募有限。新的柏林纪物种表现出喜忧参半的成功，而北科迪勒人、北美和科迪勒人物种在可用时间内殖民了整个科迪勒拉。来自邻近草原的少数物种仅有少量入侵。
At the end of the Late Wisconsin glaciation, the alpine vascular flora had only about 3.5 ka in which to colonize the 1,600 kin north-south extent of the formerly glaciated terrain in western Canada as soon as the ice melted, before the temperatures caused them to become isolated on individual mountains. This paper describes the source areas/refugia, and estimates the efficacy of the migration from each source.Basic data consists of details of the present-day vegetation from 29 alpine sites between the north coast of Alaska and Colorado. Over 70% of the alpine species in the Canadian Cordillera are only found on this continent. Distribution of individual species is sporadic, probably due to the short time available for colonization. Considerable speciation had occurred in each refugium during the glaciation, probably due to the greater success of mutations that could survive better than their parents in the new conditions. These new species allow the flora of each refugium to be identified.The ca. 629 species present were categorized into nine groups based on existing distributions. Plots of the percentages of species in each category produced maps showing that the species present in the Middle Cordilleran refugium in the vicinity of Plateau Mountain and on the Queen Charlotte Islands mainly migrated north and south along the adjacent mountain ranges. There was limited recruitment from the Southern Cordilleran species due to the wetter and colder conditions in the formerly glaciated terrain. New Beringian species showed mixed success, whereas the North Cordilleran, North American and Cordilleran species colonized the whole Cordillera in the available time. There was limited invasion of a few species from the adjacent Prairies.