Contrasting the abundance, nitrogen, and carbon of epiphytic macrolichen species between host trees and soil types in a sub-boreal forest

Abstract

Differences in lichen diversity and abundance and lichen N and C pools were examined across the two dominant host tree species ( Picea engelmannii Parry ex Engelm. × Picea glauca (Moench) Voss) and Abies lasiocarpa (Hook.) Nutt.)) and two soil types (fine- and coarse-textured soils) in an old-growth sub-boreal forest in central British Columbia, Canada. Forty-four epiphytic macrolichen species were identified across the study area. Hair lichen species, particularly nonsorediate Bryoria species, were more abundant in spruce on coarse-textured soils, while cyanolichens were most commonly observed in subalpine fir on fine-textured soils. Overall macrolichen biomass and C pools were greatest in subalpine fir trees on coarse-textured soils. The tripartite species Lobaria pulmonaria (L.) Hoffm. was the dominant macrolichen, particularly over fine-textured soils where its stand level biomass was greater than that of all other species combined. The N pools of L. pulmonaria in combination with the less abundant N-rich bipartite cyanolichens amounted to 7.5 ± 1.9 kg N·ha–1on fine-textured soils. These results indicate that epiphytic cyanolichens may make substantial contributions to ecosystem N despite their relatively insignificant contributions to overall forest biomass and C stocks.