Climate remained a major driving factor of vegetation dynamics over the past 600 years in Huangshan Mountain, Southeast China

Abstract

Holocene vegetation change is a complex process driven by climate and human activity, distinguishing their relative contributions is important to understand and adapt to the changing planet. Southeast China has a long history of human occupation and the evergreen broadleaved forests of the region have been strongly affected by human activity and replaced widely by anthropogenic vegetation in the last millennium. Pines exist both in natural and anthropogenic vegetation, therefore the interrelationship between pine and other species offers a means of differentiating natural from anthropogenic vegetation changes. Both climate and population in southeast China have undergone substantial change during the late Holocene, but the response of vegetation at centennial scale has not been fully resolved. In this study, we present a palynological analysis of a sediment core obtained from a high-elevation wetland on the Huangshan Mountain, which is known for its remarkably steep topography. The core provides evidence of vegetation history since the onset of the Little Ice Age. Results show that Huangshan vegetation shifted from montane mixed forest to upper montane grassland at the beginning of the Little Ice Age and that, although forest recovery thereafter was gradual, the coexistence of forest and grassland has been maintained since 1800 CE. Climate is shown to be the main driver of Huangshan vegetation change over the last six centuries as a whole, although the expansion of pines into broadleaved forests under the pressure of population growth, commonly reported at other sites in southeast China, is also observed in the Huangshan record from 1800 CE onward. Nevertheless, vegetation on the mountain appears to have been less impacted by human activity than in other parts of the region, possibly as result of the unique topography of Huangshan that restricts its accessibility. In conclusion, the study reveals climate still played an important role in driving last-millennium vegetation change.