Response of the post-fire bryophyte community to salvage logging in boreal mixedwood forests of northeastern Alberta, Canada

Salvage logging is common practice in the boreal forest of northeastern Alberta, Canada. Fire-killed aspen snags are harvested as soon as is feasible after fire, and in the case of the House River fire (which burned over 250,000 ha in May and June 2002), planning and harvesting began before the fire was extinguished and continued until summer 2003. The ecological consequences of salvage logging are poorly understood, and unknown for bryophytes. Frequency of bryophyte occurrence was sampled during the first (2003) and second (2004) growing seasons after fire, in both burned and salvage logged stands. Because many bryophytes are substrate-specific, and because burned wood and scorched soil are important post-fire substrates, bryophytes in these microhabitats were targeted. Post-fire specialists and ubiquitous species dominated the communities on both substrates in burned stands and included Aulacomnium palustre, Ceratodon purpureus, Funaria hygrometrica, Leptobryum pyriforme, Marchantia polymorpha, Pohlia nutans, and Polytrichum juniperinum. Salvage logging had a greater negative affect on bryophytes on burned wood than those observed on scorched soil. On burned wood, species richness was lower and the community differed in salvage logged stands compared to burned stands; these observations were consistent over both years of study. On scorched soil, species richness was lower and community composition differed in salvage logged stands compared to burned stands in the first year after salvage logging, but these differences were overcome by the second year after salvage logging. To preserve bryophytes on a managed landbase, particularly those found on wood, management objectives should include provisions to protect bryophyte substrate.