依据Altingiaceae和Juglandaceae孢粉化石探讨我国第三纪植物群及气候特征

TERTIARY FLORA AND CLIMATE IN CHINA INFERRED FROM FOSSIL RECORDS OF ALTINGIACEAE AND JUGLANDACEAE

依据化石花粉Caryapollenites和Liquidambarpollenites的现存对应植物的生态特征 ,探讨我国第三纪一些孢粉组合的植物群及其所反映的古气候特征。得出 :1)我国第三纪植被 ,从第三纪初至末 ,东西部就有明显区别 ;2 )我国第三纪的孢粉组合所反映的古植被可以和我国现存的植被进行比较 ,从而获得气候特征 ;3)从孢粉资料判断 ,Carya属和Altingiaceae科植物从第三纪初至今 ,生长地带纬向南移了 10°多。

The fossil pollen of Altingiaceae and Carya (Juglandaceae) in Tertiary are called respectively Liquidambarpollenites Raatz, 1938 ex Potonie, 1960 and Caryapollenites Raatz, 1937 ex Potonie, 1960. About 8 species of the former genus have been discovered in Chinese Tertiary, such as L. major, L. mangelsdorfianus, L. minutus, L. orientaliformis, L. pachydermus, L. pauciporus, L. stigmosus and L. styracifluaeformis. The species of L. major and L. orientaliformis might be associated with extant plants of Liquidambar orientalis , while L. stigmosus, L. styracifluaeformis to extant plants of L. formosus and L. styracifluae respectively; the other 4 species to extant plants of Altingia , especially Liquidambarpollenites pachydermus . About 6 species have been found in the latter genus and they are called Caryapollenites granulatus, C. juxtaporites, C. minor, C. polarannulus, C. simplex and C. triangulus. Among the species, Caryapollenites granulatus and C. simplex are related to extant plants Carya tonkinensis and C. cathayensis respectively, the others are perhaps connected with Annamocarya sinensis which mainly distribute in the southwest China and Vietnam. The pollen of Annamocarya sinensis is similar to that of Carya. Based on Tertiary palynological assemblages in China, the following aspects are recognized: 1) Since the earliest Tertiary, the difference between east China flora and west China flora had existed. Caryapollenites and Liquidambarpollenites were often present in the former, but few Caryapollenites and Liquidambarpollenites pollen occurred in the latter. 2) Based on the relationship between the fossil pollen of Caryapollenites and Liquidambarpollenites and their extant plants. The features of early Tertiary floras (mainly Late Paleocene to Eocene) in China can be briefly described as follows: a. The flora in northeast China was characterized with Cyclobalanopsis glauca, Castanopsis sclerophylla forest in the Zhe Wan montane area; of northern middle subtropical evergreen broadleaved forest in the Zhe Wan montane area; b. The floras in Bohai area and northern China were represented by the mixed characters of the Castanopsis eyrei Schima superba forest and Cyclobalanopsis Castanopsis forest of northern middle subtropical evergreen broadleaved forest in the Zhe Min montane and Xian Gang hill areas; c. The floras in southeast China and its coastal regions were characterized by southern middle subtropical evergreen broadleaved forest; d. The flora in southern part of Nanling Mountains was marked with northern tropical semi evergreen monson, wet rain forest. While late Tertiary (chiefly Miocene) floras in the above stated areas were northern subtropical evergreen deciduous broadleaved mixed forest; northern middle subtropical evergreen broadleaved forest; southern middle subtropical evergreen broadleaved forest; and monsoon, rain forest (including the northern continental shelf of South China Sea) respectively. 3) According to the palynological data, Caryapollenites and Liquidambarpollenites often distributed in southeastern China, southeastern coastal regions and nearby Bohai in early Tertiary; while in Late Tertiary, they stretched to southern area of Nanling Mountains. Based on their modern distribution, it can be deduced that Carya and Altingiaceae might migrate southwards about 10°N (probably more than 10°N )(from 42°N—Bohai area to 32°N—the mouth of Yangtze River) from Early Tertiary to Late Tertiary even to present day.