PARENT SESSION
Poster Session 19: Biodiversity
Wednesday, August 10, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Terrestrial bryophyte and lichen diversity and abundance in old-growth and young second-growth sub-boreal spruce forest.

Botting, Rachel^*,1, Fredeen, Arthur^{1, 2}, ¹ Ecosystem Science and Managment, Prince George, BC, Canada² Faculty of Natural Resources and Environmental Studies, Prince George, BC, Canada

ABSTRACT- The diversity and distribution of terrestrial moss, liverwort and lichen species and the impacts of anthropogenic disturbance on these species have not been extensively studied in the Sub-Boreal Spruce biogeoclimatic zone of British Columbia. Forest harvesting is a major landscape altering process in central BC. Forest management in the form of clearcut logging can affect terrestrial bryophyte and lichen communities through changes to substrate and microclimate and through habitat fragmentation. The effects that extensive forest management is having on bryophytes and lichens in the Sub-Boreal Spruce zone and whether these effects are uniform across different types of forest stand is not well documented. This study surveyed and compared the diversity and biomass of terrestrial bryophyte and lichen species in the Aleza Lake Research Forest in central BC. This study aimed to examine the effect of both forest age and soil texture type on the diversity, relative abundance and biomass of these species. Stands studied included young, second-growth and old-growth sub-boreal spruce forests on fine and coarse textured soil types. In total, 116 terrestrial species of bryophyte and lichen were identified in all stands. Diversity and biomass patterns were different for moss, lichen and liverwort species respectively. As well, diversity patterns varied depending upon the scale at which they were examined. Liverwort species were more diverse and 25-fold more abundant in old-growth forests. Lichen cover was twice as great in second-growth stands and different assemblages of lichen species occurred in second-growth versus old-growth stands. Moss abundance and diversity was similar between forest ages, however, second-growth stands were dominated by a single moss species. There was increased bryophyte and lichen biomass in second-growth stands compared with old-growth and on fine textured soils compared with coarse textured soils. This research suggests the importance of considering temporal and spatial scales in forest management. The time required for a cleared forest area to return to the species dynamics of the old-growth stand is not well understood. It is not known if current rotation times will be adequate to maintain diversity and if sufficient habitat patches of old-growth are being maintained on the landscape.

Key words: bryophyte, lichen, diversity, forest managment