Aspen-inhabiting Aphyllophoroid fungi in a managed forest landscape in Estonia

Abstract

In northern Europe, the biologically rich European aspen (Populus tremula) tends to disappear both from intensively managed and strictly protected forests, thus representing a biodiversity conservation challenge. This study describes the distribution of Aphyllophoroid fungi inhabiting aspen in a hemiboreal mixed-forest landscape where clear-cutting was usually followed by natural regeneration. In a 4-km² area in Estonia, 181 individual forest stands and cut areas were surveyed. Sixty-one percent of the 2831 live aspen trees found were concentrated in 11% of the area. Thirty-six polypore species were recorded on aspen, with old stands and naturally created deadwood hosting most species. Among the records of 14 pre-defined aspen-specific basidiomycetes, Phellinus tremulae comprised about 95%. Six species (Ceriporiopsis aneirina, Clavicorona pyxidata, Funalia trogii, Phellinus populicola, Rigidoporus corticola, Steccherinum pseudozilingianum) were infrequent to rare, but widely distributed, inhabiting various stand-age classes, and mostly occurring outside “key habitats”. All the seven species absent are of conservation concern and frequent in Estonian old-growth forests. Thus, rotational management with natural aspen regeneration only provided habitat for some aspen-specific species. For sustaining all species, such landscapes should probably be complemented with stands managed using modified thinning and partial harvesting techniques in aspen-containing mixed stands.

Keywords:

• Deadwood
• even-aged management
• hemiboreal
• natural regeneration
• polypore
• Populus tremula
• threatened species

Acknowledgements

I thank Renno Nellis (the State Forest Management Centre) for providing data on stand age and harvesting history, and Kaupo Kohv and Raul Rosenvald for discussing the silvicultural issues. Three anonymous reviewers and the Editor constructively commented on the manuscript. The research was supported by the Estonian Science Foundation (grant 7402), the State Forest Management Centre, the Estonian Ministry of Education and Science (project SF0180012s09) and the European Union through the European Regional Development Fund (Centre of Excellence FIBIR).