Forest structure and site conditions of boreal felt lichen (Erioderma pedicellatum) habitat in Cape Breton, Nova Scotia, Canada

Abstract

Boreal felt lichen [Erioderma pedicellatum (Hue) P.M. Jorg. (1972)] occurs on mainland Nova Scotia as well as Cape Breton, growing almost entirely on balsam fir [Abies balsamea (L.) Mill.] in wet coastal forests. A Geographical Information System (GIS) based predictive model for E. pedicellatum habitat in Nova Scotia has facilitated surveys and guided conservation. We used this model to examine the relationship between presence of E. pedicellatum and forest structure (tree DBH, height, age, and crown closure, inter-tree distance, basal area of live and dead trees, and percent cover of shrubs, herbs, Sphagnum spp., and other mosses), and site conditions (topographic position, slope, aspect, and drainage) as well as the presence of lichen indicator species. Erioderma pedicellatum sites had significantly older trees, higher density of live trees, lower crown closure, lower basal area of live Picea mariana (Mill.) Britton, Sterns & Poggenb., lower basal area of live trees, higher basal area of dead trees, higher Sphagnum spp. cover, and lower shrub cover than unoccupied habitat. Erioderma pedicellatum sites were significantly less well drained and occurred on steeper slopes with a north or east aspect. Four macrolichens (Coccocarpia palmicola, Platismatia norvegica, Lobaria scrobiculata, and Sphaerophorus globosus) occurred at a significantly higher frequency at E. pedicellatum sites.