INTERACTING DRIVERS OF HOLOCENE VEGETATION CHANGE IN THE LOWER YANGTZE RIVER, CHINA

Abstract:

Variations in summer monsoon intensity linked to insolation have been a major component of Holocene climatic variability in East Asia and have been cited as a direct driver of vegeation change in the lower Yangtze River. Sediment evidence from the Yantgtze Delta and adjoining low-lying areas indicates a more complex relationship, however, and that monsoonal effects on vegetation were mediated through anthropogenic and other environmental processes, resulting in considerable local variation in outcomes. Thus increased activity of the summer monsoon in the early Holocene may have been an important factor influencing the development of agriculture and technological innovation, particularly on the southern plain of the Yangtze Delta, and therefore vegetation indirectly. Likely environmental processes mediating the direct effects of climate change on vegetation included marine transgression and geomorphological changes as the delta accreted. This paper summarises the available evidence, much of it new, of the nuanced climatic effects on vegetation in the lower Yangtze River during the Holocene, and provides a reminder of the need to adopt a holistic view when inferring the drivers of change from palaeoenvironmental evidence, and when considering the possible impacts of projected future climate changes.