Between 10,000 and 8,000 cal. yr BP, proglacial lake Ojibway covered the Abitibi-Timiskaming and the north of Ontario. At this time, islands were present and became hills after lake Ojibway withdrawal into James Bay (for example the Abijévis Hills). Then boreal forest came and grew. Paleo-island role in forest development in Abitibi-Timiskaming is questioned. Small headwater lakes sediments will help us to understand paleo-island history and to reconstruct vegetation evolution (pollen and plants macro rests), fire evolution (charcoals) and initial biodiversity (metabarcoding). The acquired knowledge of factors controlling the boreal forests evolution will allow to adjust present speed and models of vegetation colonization and succession.