Vegetation changes and human influences on Qian''an Basin since the middle holocene

Authors Xu, QH; Kong, ZC; Yang, XL; Liang, WD; Sun, LM

Journal ACTA BOTANICA SINICA , MAY 2002,5:44

Abstract Vegetation changes and human influences on natural environments since 5 000 a BP were discussed based on the pollen data supported by radiocarbon dating from Cangumiao and Yujiawa profiles in Qian''an Basin, the southern area of Yanshan Mountain. The research indicates that (1) from 4 600 to 3 100 a BP, deciduous broad-leaved forests dominated by Quercus grew in the Basin, (2) after 3 100 a BP, broad-leaved species reduced and Pinus increased, in response to the cooling climate, (3) since 1 600 a BP, forests had been destroyed seriously due to the increase of agricultural activities, and (4) pollen analysis showed that Castanea trees had been cultivated for 1 600 years, and Oryza had been planted for 700 years in Qian'' an Basin.

Species covered 栎属 Quercus