Lakeside riparian forests support diversity of wood fungi in managed boreal forests

Abstract

Riparian forests often have a more diverse tree species composition and more woody debris than neighboring upland forests, but little is known about their importance for the conservation of deadwood-dependent species. We studied the forest characteristics and the diversity of wood fungi (poroid Aphyllophorales) in lakeside riparian (flat and sloping topography) and upland boreal forests in eastern Finland. Riparian forests had a higher density of broadleaved trees and broadleaved debris than did upland forests. A total of 48 species of wood fungi were recorded, including eight red-listed or old-growth forest indicator species. Overall, more species and records and greater diversity were observed in the flat riparian sites than in the sloped riparian and upland sites. The mean species richness did not differ significantly among site categories, indicating greater β diversity among the flat riparian sites. Species composition was more similar between the two riparian categories than between the riparian and upland sites. Riparian sites also hosted more fungal species associated with broadleaved trees. The results show that riparian forests support the diversity of wood fungi in managed boreal forests. Diversity of deadwood-dependent organisms can be promoted by leaving wider and completely unharvested riparian buffer zones.