Year: 2018, Issue: LXVI, Pages: 125 - 146
The present-day distribution of Ambrosia artemisiifolia L. is discussed, together with data on the subrecent pollen assemblages and on those recovered from the Holocene deposits in the Primorski Krai (Maritime Province) area. Since the end of the early Holocene the Ambrosia, known also as common ragweed, low ragweed, or annual ragweed, occurred in the plant communities in the east of the Asian continent. In the south of the Far East of Russia it appeared in the middle Holocene at the latest. Its pollen presence in the sediments in the west of the lacustrine Khanka Plain is correlatable with the early man appearance. The maximum proportion of its pollen has been recorded in the deposits dated to the Little Ice Age. The interval since the 19th century to the mid-60s of the 20th century is marked by its complete absence from the territory. The isolated center of the plant spreading in the southern Far East of Russia came into being at the 2nd half of the 20th century. The data at hand strongly suggest the process of the species secondary range development to be still running in the southern Far East. The secondary centers of the Ambrosia artemisiifolia distribution developed in the east and west of Eurasian continent independently. It should be stressed that equally independent was the formation of the ragweed secondary ranges in Southeastern China and the Russian Far East.