Lichens from the area drained by the Peel and Mackenzie rivers, Yukon and Northwest Territories, Canada. I. Macrolichens

Abstract

The distribution and general ecology of 249 macrolichen taxa is described for 230 000 km2 of coniferous forest, open fens, and alpine terrain along the Mackenzie River in the District of Mackenzie, Northwest Territories, and the Peel River, a major tributary which rises in the Yukon Territory. Permafrost plays a major role in determining the plant communities that are present. Fire and man-made disturbances initiate succession. There are 45 new reports for the District of Mackenzie and 30 for the Yukon. Of the taxa, 86% are found in Europe, Asia, and North America, 9% are known from Asia and North America, whereas only 4% are restricted to North America. Pilophorus robustus is new to Canada. High mountains in the western part of the area, generally nonglaciated during the Wisconsinian, support a flora that contains many Arctic and Arctic–Alpine taxa. Amphi-Beringian species occur primarily in the north.