On the Holocene history of sweet chestnut forests in Belasitsa mountain, Southwestern Bulgaria

The Holocene history of sweet chestnut (Castanea sativa Mill.) on the northern slopes of Belasitsa Mountain was studied by pollen analysis and radiocarbon dating of a core collected from a small mire. The results showed that more than 8000 years ago this tree was spontaneously growing in the mountain before the first Neolithic inhabitants settled in the Struma River Valley and its tributaries. The enlargement of the areas occupied by sweet chestnut started with its wide cultivation since the time of the Roman colonization. The new palynological information supports the hypothesis for possible existence of refugia for Castanea sativa in Southwestern Bulgaria.