Bryophyte species density and composition in young forests regenerating after clear-cut logging, wildfire and spruce budworm outbreak
(English)Manuscript (preprint) (Other academic)
The disturbance regime in the interface of the boreal forests and the north-temperate deciduous forests in eastern Canada is characterized by both natural disturbances such as wildfires and insect outbreaks as well as anthropogenic disturbances such as production forestry. The current understanding of how understorey plant assemblages respond to different disturbances is mostly based on short-term wildfire-logging comparisons and has traditionally emphasized vascular plants. In this study we explore patterns of species density and composition of four bryophyte guilds in young forests (approximately 40 years old) regenerating after clear-cut logging, wildfire, and spruce budworm outbreak in the Acadian forest region of New Brunswick, eastern Canada. Although being similar in overall species density at the scale of 1000 m2 all three young forest types had fewer species than mature reference forests. All groups were found to be compositionally distinct. Stands developed after spruce budworm outbreaks had the highest canopy closure and the highest amount of coarse woody debris. These stands had similar number of woody debris species as mature forests and an overall species composition that was most similar to mature forests among the three groups. Wildfire-disturbed sites were characterized by a high litter cover, perhaps due to the larger deciduous component of the canopy. A high number of treebase species was typical of these sites. Finally, young managed forest had the highest number of forest floor bryophytes at the scale of 100 m2 among the three young forest types, but was compositionally very far from mature forests in their woody debris flora. In conclusion, young seral stages of forest succession following different disturbances seem to have complementary roles in maintaining landscape level diversity, but if natural disturbances are eliminated certain species (e.g., among the epixylics and treebase species) might become more restricted to older stands in the landscape.
boreal forest, bryophyte, Canada, clear-cut logging, disturbance, environmental constraint, recolonization, spruce budworm, succession, wildfire
Research subject Plant Ecology
IdentifiersURN: urn:nbn:se:su:diva-38899OAI: oai:DiVA.org:su-38899DiVA: diva2:317328