Abstract<? Pub Inc> Under the current rapid climate change, trees are of critical interest because of diverse ecosystem services that they provide. Although increasing landscape connectivity is though to be crucial in order to maximize their migration capabilities, there are few studies indicating where exactly such increases might best take place. To understand the impact of fragmentation on species climate-change induced migrations and source populations, I calculated migration pathways and source populations under six climate change scenarios in southern Ontario where> 70% of forest has been lost through human-use. The results showed that although forest fragmentation increased species required migration rates, the most important migration corridors and source populations were quite similar across all migration models and were concentrated in exiting forest corridors and extensively forested areas, including northeast of Lake Ontario, the Niagara Escarpment, and the Oak Ridges Moraine.