Macrolichens of the Coppermine, Hood, and Thomsen Rivers, Northwest Territories, Canada

Abstract

One hundred and sixty-three taxa of foliose and fruticose lichens are reported from three regions of the Canadian Arctic. The northernmost collecting region, and that with the most severe climate, is the Thomsen River valley on Banks Island. Also included are the Hood River valley, entirely north of the arctic treeline, and the Coppermine River valley, which flows northward through the forest-tundra border. Newly reported for Banks Island are Cladonia alaskana, Peltigera rufescens, Solorina bispora, S. saccata, and Vulpicida pinastri. Of these Jive, C. alaskana and V. pinastri have not previously been reported on any of the arctic islands. The macrolichen flora of these areas consists primarily of wide-ranging arctic-alpine and arctic-boreal species. This study was undertaken in order to increase the understanding of the distributions of the foliose and fruticose lichens in the areas surrounding the Coppermine, Hood, and Thomsen Rivers in the Northwest Territories of Canada. No complete col- lections have been made along the lengths of these rivers although some have been done at the mouth of the Coppermine (Thomson 1970), in the Bathurst Inlet area (Thomson & Scotter 1983), and along the upper Coppermine to the Kendall River junction (Robinson et al. 1989). The study area is located in the central Canadian arctic (Fig. 1) and includes areas from the northern edge of the boreal forest to the southern edge of the high arctic. METHODS Field work was done during the summers of 1990 and 1991, with collections being made at 25 localities. Eight localities were along the Coppermine River, three along the Thomsen River, and 14 along the Hood River (Fig. 1). Collecting was done concurrently with teaching a field course for the University of Colorado. Travel was down- stream by inflatable kayak. Collections from each river were loosely stored in waterproof packs and carried for the duration of each month-long trip. A total of 2,147 specimens were collected. Localities were chosen to in- clude areas with internal homogeneity of vegetation type, with an attempt to collect in as many habitats as were encountered.