Iron mining is an important economic activity in the North American Canadian Shield but has caused large-scale disturbance and physical upheaval of boreal ecosystems. Lichens grow abundantly on abandoned iron ore mine tailings as early successional taxa, yet their role in the successional processes of these post-industrial landscapes is not fully understood. Accounting for the impacts of nonvascular vegetation such as lichens is a key but often overlooked area for improving restoration outcomes. We investigated how lichens could facilitate natural revegetation on mine tailings through three potential mechanisms: amelioration of soil temperature, soil moisture, and nutrient availability. Through experiments in the field and in the greenhouse, we studied how lichens modify the microenvironment for saplings of Pinus banksiana Lamb. (jack pine) and Populus balsamifera L. (balsam poplar) on mine tailings. Lichens significantly increased the water content of the mine tailings and kept soil temperature cooler than exposed tailings. They were also found to intercept nitrogen deposition, specifically of nitrate. Lichens play a critical role as microclimate engineers in this ecosystem and its succession after intensive mining. Key words: lichens, microclimate amelioration, mine restoration, primary succession, revegetation.