The potential effect of megafaunal extinctions on modern conservation of horse chestnut <scp> <i>Aesculus hippocastanum</i> </scp>

Societal Impact Statement Many plant species worldwide are struggling to regenerate due to the ongoing effects of climate change. These effects appear to be further exacerbated by the loss of keystone megafauna, which were important seed dispersers. By identifying the traits commonly seen in seeds spread by modern elephants, it is possible to predict which species likely depended on megafaunal distribution in the past. One such species is the European horse chestnut tree, which is failing to regenerate in its native range in the Balkans, likely due to an inability to spread north after the ice age as Europe's elephants were hunted to extinction. Assisted migration north to start genetically diverse founder populations is urgently needed to protect this species against the effects of climate change and disease.