Epsilon Archive for Student Projects

Abstract

Lichens are sensitive indicators of changes in environmental factors such as moisture, light intensity and air pollution. They are easily affected by forest fragmentation and by recent increases in forest edges as a result of intensive use of forest resources. The aim of this study was to describe previously unknown ecological characteristics of the Micarea globulosella lichen by (1) comparing the occupancy and cover of M. globulosella in old and young forest production stands, (2) investigating whether M. globulosella is affected by stand edges and (3) exploring the effect of high M. globulosella occupancy in old stands on lichen regeneration in young stands. The impacts of other landscape factors on M. globulosella, including altitude and latitude, were also tested. Most profoundly, M. globulosella was found in young forest stands. This contradicts current information which states that the lichen predominantly grows in old-growth forests with long tree continuity. Lichen occupancy and cover increased with stand age. M. globulosella responded to forest edges. In old South facing stands, there was a significant increase in occupancy with increasing distance from the stand edge towards the forest interior. In young North facing stands, lichen occupancy decreased significantly with increasing distance from the stand edge towards the forest interior of the young stand. In young South facing stands, contrary to expectations, there was a significant decrease in lichen occupancy with an increasing distance from the stand edge towards the forest interior of the young stand. A positive correlation between high lichen occupancy in old stands and increased lichen occupancy in the directly adjacent young stands was found. This study’s findings suggest that M. globulosella regeneration and occupancy is affected by both microclimate and dispersal interactions.