Palynological evidence for palaeoenviromental change and human activity in Ningde of Fujian Province during Holocene

Analyzed by this paper are 42 pollen samples from the core of NDQK2, a 17.3 m long drilling core on the eastern coast of Ningde city, Fujian Province. Three optical stimulated luminescence (OSL) and nine AMS¹⁴C samples are dated. It is revealed that the core is made of with the deposits from Late Last Deglaciation and Holocene. Pollen are used as a major mean to reconstruct the Holocene palaeo-environment and to explore the possible impact of human activities on vegetation succession. Together with the published pollen data from adjacent cores of NDGK2 and NDQK5, it is found that subtropical evergreen broad-leaved forest and pine forest prevailed since marine isotope stage (MIS) 5a (～85 kaBP). However, Poaceae-dominated non-arboreal pollen component and Dicranopteris-dominated spores component increased sharply since 0.777～0.497 kaBP. The pollen assemblages are significantly different from other intervals of MIS5a, but similar to those in modern soils and marine sediments. If the expansion of Dicranopteris dichotoma and Poaceae plants is due to the destruction of subtropical broad-leaved forests by human activities, it suggests that human being had colonized in this region around 0.777～0.497 kaBP. The deforest by human being changed the natural forest composition, and resulted in the expansion of secondary plants such as Dicranopteris dichotoma and Poaceae distributed along the boarder of forest. The spatial and temporal distribution of archaeological evidence along southeast China indicates a possible link of human activities between the the study area and the migration of ancient culture from the lower Yangtze River during Mid-Late Holocene.