A continuous record of vegetation and climate change over the past 50,000 years in the Fujian Province of eastern subtropical China

A 425 cm core has been collected from the Gantang subalpine peat bog, in Pingnan County, Fujian Province of Southern China. High-resolution pollen analysis of the core has allowed for the reconstruction of past vegetation and climate changes over the last 50,000 years. Today, Fujian province is located in the eastern part of middle subtropical zone where the dominant vegetation is evergreen broadleaved forest that receives its precipitation from the East Asian Monsoon. The pollen record testifies that the vegetation in Fujian varied between subtropical evergreen and warm temperate deciduous forests during the last glacial-interglacial cycle. It appears that during Marine Oxygen Isotope Stage 3, this area was covered with broadleaved forest suggesting warm and wet subtropical condition, whereas the flora was quite different with many ancient elements. The Last Glacial Maximum is distinguished by an increase in warm temperate deciduous taxa, particularly Fagus and Alnus accompanied by abundant Ericaceae, implying a spatial shift of zonal vegetation during this coldest episode in the world. Local swamp developed soon after the Younger Dryas event coinciding with the formation of peatlands in the Northern Hemisphere possibly linked with atmospheric carbon accumulation. A rapid increase in evergreen broadleaved taxa that dominated the local forest occurred at ~ ca. 8.2 cal ka BP, indicating the inception of the regional thermal maximum during the Holocene, which was generally characterised by more humid conditions. The middle to late Holocene sees a progressive decline in arboreal elements, and an increase in grasses and Ericaceae. These changes beginning from around 4 ka cal BP were concordant with the general weakening of the East Asian Monsoon during the Holocene, corresponding with an orbitally induced reduction of boreal summer insolation. This is the first terrestrial high-resolution record from eastern part of middle subtropical areas that evaluates the forest changes through the last glacial-interglacial cycle.

► We observe some substantial changes of vegetation within the last 50 ka.
► Temperate deciduous forest replaced subtropical evergreen forest at the LGM.
► A post-Younger Dryas development of local swamp began at ~ 11.5 cal ka BP.
► Evergreen broadleaf forest expended since deglaciation related to the Summer Monsoon.
► High evergreen percentages at 8.2–4 ka BP indicate the Holocene Thermal Maximum.