Polypore communities in broadleaved boreal forests

Abstract

The cover and extent of boreal broadleaved forests have been decreasing due to modern forest management practices and fire suppression. As decomposers of woody material, polypores are ecologically important ecosystem engineers. The ecology and conservation biology of polypores have been studied intensively in boreal coniferous forests. However, only a few studies have focused on the species living on broadleaved trees. To increase knowledge on this species group we conducted polypore surveys in 27 broadleaved forests and 303 forest compartments (539 ha) on the southern boreal zone in Finland and measured dead wood and forest characteristics. We detected altogether 98 polypore species, of which 13 are red-listed in Finland. 60% of the recorded species are primarily associated with broadleaved trees. The number of species in a local community present in a broadleaved forest covered approximately 50 species, of which 30-40 were primarily associated with broadleaved trees. The size of the inventoried area explained 67% of the variation in the species richness, but unlike in previous studies conducted in coniferous forests, dead wood variables as well as forest structure had very limited power in explaining polypore species richness on forest stand level. The compartments occupied by red listed Protomerulius caryae had an especially high volume of living birch, but otherwise the occurrences of red-listed species could not be predicted based on the forest structure.

Characteristics of boreal and hemiboreal herb-rich forests as habitats for polypore fungi

“…In comparison to old-growth forests, relatively few red-listed species were found from our data set of herb-rich forests, as only 30 occurrences of 12 red-listed species were recorded on the total area of 63 hectares. This supports the earlier studies, in which it has been suggested that deciduous forests (Markkanen and Halme 2012) and woodland key-habitats, including herb-rich forests , do not support as high densities of red-listed species as oldgrowth spruce forests. One possible factor to explain the scarcity of red-listed species may be that, at present, herb-rich forests mainly exist as small-sized, fragmented patches (Raunio et al 2008).…”

“…Comparison with species counts in earlier findings in other boreal forest types is problematic, as sampling methods and sample sizes are inconsistent. Nevertheless, our results indicate that the herb-rich forests may on the average host a higher number of species than broadleaved boreal forests (Markkanen and Halme 2012) or managed boreal forests (Ylisirniö et al 2012), but a considerably lower number than old-growth spruce forests (Penttilä et al 2004). In the few studies, which have compared polypore assemblages between habitat types, the highest number of polypore species were found in herb-rich forests (Sippola et al 2004;Juutilainen et al 2016).…”

The role of novel forest ecosystems in the conservation of wood‐inhabiting fungi in boreal broadleaved forests

“…According to our results, deadwood-associated fungal species richness was highest in natural herb-rich forests, especially in medium-and large-diameter deadwood fractions. This is not surprising as the high overall biodiversity of natural herb-rich forests (Tonteri et al 2008) and deciduous CWD (Heilmann-Clausen and Christensen 2004; Norden et al 2004;Markkanen and Halme 2012;Abrego and Salcedo 2013) is well established. However, we found that fungal species richness in small-diameter deadwood was highest in afforested fields.…”

“…) and deciduous CWD (Heilmann‐Clausen and Christensen ; Norden et al. ; Markkanen and Halme ; Abrego and Salcedo ) is well established. However, we found that fungal species richness in small‐diameter deadwood was highest in afforested fields.…”

Contributions to the Finnish aphyllophoroid funga (Basidiomycota): new and rare species.

“…Normally, aphyllophoroid species are divided into morphological groups, like polypores, corticioids and tremelloids, and the studies usually focused on just one or two of these (e.g. Pippola & Kotiranta 2008, Juutilainen et al 2011, Markkanen & Halme 2012. Especially the collection of non-poroid aphyllophoroid fungi is time-consuming: for example the basidiocarps of corticioids are small in size and mostly grow underneath the substrate.…”