【摘要】 本文根据对杉科的系统发育、现代分布和化石分布的研究,结合古地理和古气候资料,讨论了杉科的起源、演化和现代分布格局的成因。杉科基本上是一个亚热带科,我国长江、秦岭以南至华南一带是其现代分布中心。东亚中高纬度的东北地区可能是其起源中心和早期分化中心。起源时间为早侏罗纪或晚三叠纪。杉科植物的各种类型很可能在早白垩纪甚至晚侏罗纪就已分化出来。杉科植物于东亚起源后,在当时劳亚古陆尚未完全解体、气候分带现象尚不甚明显的情况下跨越欧亚大陆散布到北美,并扩散到南半球。自晚白垩纪,白令陆桥和北大西洋陆桥对其在北半球的散布发挥了重要作用。杉科植物目前虽处于衰退状态,但在地质史上却曾经经历过极其繁盛的时代。在中生代中晚期和早第三纪,杉科植物种类繁多,广布于北半球,向北扩散到北极圈内的高纬度地区,是当时的大科。大多数现存属曾分别有过3个或2个分布中心:水松属、落羽杉属和北美红杉属在东亚、北美西部和欧洲;水杉属在东亚和北美西部;柳杉属、杉木属,很可能也包括台湾杉属在东亚和欧洲;巨杉属在欧洲、北美和东亚。在晚白垩纪和第三纪,现存属特别是水松属、落羽杉属、水杉属、北美红杉属和巨杉属,曾是北半球森林植被的重要组成成分。南半球也曾有少量种类,分布亦远较现代普遍。更多还原

【Abstract】 In the present paper, the distribution center,the place and time of origin, the way of dispersal and the formation of modern distribution patterns of the Taxodiaceae were discussed based upon studies of phylogeny, fossil history and modern distribution, with reference to the paleogeography and paleoclimatology.The Taxodiaceae, containing 9 genera, 12 species and 3 varieties, is a small family of subtropical to warm temperate trees with highly disjunct and restricted distribution, occur-ing in East Asia, North America and Australia. Of these nine genera, seven are monotypic, i. e. , Cryptomeria, Glyptostrobus, Sequoiadendron, Sequoia, Metasequoia, Cunninghamia and Taiwania, while the other two are oligotypic, i. e. , Taxodium consisting of 2 species and Athrotaxis containing 3 species. Moreover, none of the genera is distributed on more than one continent. Athrotaxis, endemic to Tasmania, is the only genus that is found in the Southern Hemisphere. Metasequoia and Glyptostrobus are endemic to China. Cryptomeria is found in China and Japan. Cunninghamia is widely distributed in China and northern Viet Nam. Taiwania is native in the Chinese mainland, Taiwan and northern Myanmar. Sequoiadendron and Sequoia are endemic to western America. Taxodium is distributed in southeastern North America, Mexico and Guatemala.According to Takhtajan’s (1986) regionalization of the world flora, the number of species in every region of the world was statistically surveyed. East Asia Region, with 5 genera and 5 species, is most aboundant in number of genera and species. In China, according to Wu’s (1979) regionalization of Chinese flora, Sino-Japanese forest subkingdom, with 5 genera and 5 species, is richest in genera and species,Sino-Himalayan forest subkingdom, with 3 genera and 3 species, ranks second. The region ranging from the Yangtze river, Qinling Mts. to South China (the southern part of East Asia Region) is the modern distribution center of the Taxodiaceae, where the genera are found to reflect basically main phylo-genetic stages of the family, including the most primitive genus Cryptameria, more primitive genus Glyptostrobus, relatively advanced genus Metasequoia, the more advanced genus Cun-ninghamia and the most specialized genus Ta.iwa.nia.Despite the limited numbers of extant genera and species,and their restricted geographical distribution, the Taxodiaceae, with a great number of fossil remains, was a very large group of plants in geological times and once played an important role in the forest vegetation of the Northern Hemisphere. The fossil distribution maps of all the living genera and several important extinct genera were drawn. The developments of these genera and the family were discussed. The earliest appearance of the Taxodiaceae was in the deposits of the Middle Jurassic in Eurasia, and it began to occur in North America during the Early Cretaceous. In the Cretaceous times, the Taxodiaceae, containing all the modern genera and a large number of fossil genera with most of them extinct after the Mesozoic, attained its greatest diversity. During the Middle-Late Mesozoic and the Early Tertiary, the Taxodiaceae was highly diverse and widely distributed throughout the Northern Hemisphere , reaching the higher latitude region of the Arctic Circle, such as New Siberian Islands, Greenland,Spitzbergen , Franz Josef Land and Ellesmere Islands at about 82癗. Most of the extant genera once had three or two distribution centers: Glyptostrobus, Taxodium and Sequoia in East Asia, western North America and Europe; Metasequoia in East Asia and western North America; Cryptomeria, Cunninghamia and probably Taiwania in East Asia and Europe; and Se-quoiadendron in Europe, North America and East Asia. The extant genera, especially Glyptostrobus, Taxodium, Sequoiadendron, Sequoia and Metasequoia, were very important elements of the temperate flora in the Northern Hemisphere during the Late Cretaceous and Tertiary.Later than in East Asia and North America, most of the living genera began to appear in Europe during the Early Terti更多还原