豆科黄华族植物地理学的初步研究

A Preliminary Study on Phytogeography of the Tribe Thermopsideae (Papilionaceae)

在系统演化和地理分布及古植物学资料的基础上,利用形态-地理学的原理和方法,对豆科Papilionaceae黄华族Tribe Thermopsideae 进行了植物地理学的初步研究。结果表明,(1)黄华族可能是古地中海起源的,它的起源地在古北大陆的南岸,大约相当于现在的中纬度地区;(2)起源时间可能早于早第三纪,大约处在白垩纪末和始新世之间。当时有一个所谓的“北热带植物群”Boreotropical Flora发生;(3)本族6个属基本上构成一个比较自然的单元。它们是由原始槐族类祖先演化而来的;(4)木本类是本族原始的、早出的类群,它们基本上处于孑遗状态;草本类是本族进化的、晚出的类群,它们种类多,分布区有扩大的趋势;(5)Thermopsis间断分布于亚洲(包括中亚和东亚)、北美(包括北美东部和北美西部)。东亚太平洋沿岸和北美大西洋沿岸最有可能是它的原始保存地,而不是起源地。它们主要是通过古地中海海道而发生联系的。造成原始类群星散分布的格局不是由一次,而是多次地史和气候变化的结果;(6)晚第三纪亚洲腹地造山运动引起的喜马拉雅的隆起和青藏高原的抬升,以及北美落基山山体抬升引起的水温条件的急剧变化是某些类群(包括Piptanthus和Thermopsis)物种局部分化的主要动力。

Based on the phylogeny and modern distribution of T hermopsideae (Papilionaceae) , and available fossil records of the tribe,a preli minary phytogeographic study has bean carried out through the theory and method of morphology-geography. The study shows that (1) The tribe very probably had a Tertiary Tethyan origin, its birthplace was near the southern Laurasia and had a mid-latitude source;(2)It probably rised before the Paleogene but after the lat e Cretaceous when there was a so-called boreotropical flora occuring in the N. H emisphere; (3)The tribe is basically a natural one; (4)Its woody taxa were primi tive groups which probably originated from woody Sophora-like ancestors whil e the herbaceous were the advanced derived from it later; (5)Both Asia and N. Am erica are probably the modern refugia rather than the original regions of Ther mopsis which has an Asia-N. America disjunction pattern. The interchange betwe en N. America and Asia in the genus probably occurred along the ancestral path o f the Tethys. This disjunction pattern may not be simple, it may involv multiple historical events in different geographical times; (6)With the uplift of Himala yas and Qinghai-Xizang plateau caused by the late Tertiary orogeny in Asia and t he uplift of Rocky Mts. in western N. America, the humidity and temperature cond itions among these regions changed profoundly, and they became the principal imp etus of specialization process,especially. in Piptanthus and Thermopsis.