Enhanced human activity altered the late Holocene vegetation composition in subtropical East Asia.

Understanding past climate and vegetation changes is essential to assessing the role of climate and human activity in dominating regional vegetation compositions. Here we show a wetting trend from mid- to late-Holocene over subtropical East Asia based on peat cellulose δ18O and a compilation of other robust hydroclimatic records. Under such a wetter condition, subtropical East Asia is expected to be covered by denser forests. However, our peat pollen records, together with those of other studies, show that the vegetation composition did not follow as envisaged but changed from evergreen broad-leaved forests to more open landscapes since the late Holocene over the extended subtropical East Asia. We ascribe this dramatic vegetation shift to the contemporaneous enhanced human activities, which is further confirmed by the sharp increases in peat charcoal concentrations and the number of regional archaeological sites. Proper policies are therefore necessary to protect the regional ecology and sustainability. • Changes in peat cellulose δ18O are ascribed to precipitations. • A late Holocene wetting trend was observed over subtropical East Asia. • Late Holocene vegetation composition changed from evergreen broad-leaved forests to more open landscapes. [ABSTRACT FROM AUTHOR]