Phenolic compounds in Scots pine heartwood: are kelo trees a unique woody substrate?

Abstract

Deadwood quality can be a highly significant factor in determining the occurrence of deadwood-dependent organisms such as saproxylic fungi. Rare deadwood substrates that are produced only after a lengthy senescence such as kelo trees may have unique deadwood qualities. Using high-performance liquid chromatography, we compared the phenolic composition of six types of Scots pine (Pinus sylvestris L.) substrates: living mature trees with no fungal sporocarps, living mature trees with Phellinus pini sporocarps, fallen non-kelo trees, soon-to-be kelo (standing), standing kelo, and fallen kelo. The fungal-infected living trees and fallen kelos were found to have more similarities in their phenolic composition when compared with the living and fallen trees and the standing kelos, which gets further pronounced with increasing decay. The results also highlight the uniqueness of the fungal-infected living trees and the fallen kelos and illustrate a possible correlation between fungal infection and the heartwood phenolic composition of Scots pine. However, it remains unclear to what extent the differences in phenolic compositions are caused by fungal infection and fungal decomposition. We also observed a previously undocumented correlation between the phenolic groups and fire scars on the trunks of the trees. The variation in substrate quality warrants further consideration when deadwood restoration activities are planned, as the quality of the deadwood could be as equally important as the quantity.

Green and Sustainable Valorization of Bioactive Phenolic Compounds from Pinus By-Products

“…The chemical composition of the extracts depends on the type of pine used (species, location), on the part of the plant, on the method of extraction, and on the solvent. For example, the main group of polyphenols compounds found in the P. sylvestris is the group of stilbenes [151], while in P. pinaster, the main group of compounds are the flavonoids [59]. As one can see from Table 3, the main polyphenol compounds found in extracts from pine needles are p-coumaric acid and epicatechin, in pine seeds eriodictyol and taxifolin, and in pine bark catechin, gallic acid, and taxifolin.…”

“…The chemical composition of the extracts depends on the type of pine used (species, location), on the part of the plant, on the method of extraction, and on the solvent. For example, the main group of polyphenols compounds found in the P. sylvestris is the group of stilbenes [ 151 ], while in P. pinaster , the main group of compounds are the flavonoids [ 59 ].…”

Wood-inhabiting fungal responses to forest naturalness vary among morpho-groups

“…Furthermore, pine trees also gain special qualities and fungal communities when aging, especially when a pine grows and dies slowly and becomes a kelo tree, i.e. a dried barkless snag that remains standing for decades or centuries before falling to the ground 58 , 59 . Thus, the wood quality of a pine trees died young vs. old can be more different than that of birch, spruce and aspen, leading to a higher stand level diversity with increasing level of forest naturalness.…”

Diversity and distribution of Finnish aphyllophoroid and heterobasidioid fungi (Basidiomycota): An update

“…Here, we use the Finnish term 'kelo' to refer to dead and old-growth trunks of Scots pine (Pinus sylvestris) with a silvery-grey, decorticated appearance. Kelo trees are special substrata for fungi due to their extremely slow decay rate (even hundreds of years), long-lasting hard surface and chemical compounds (Leikola 1969;Niemelä et al 2002;Venugopal et al 2016). Classification of habitat types follows, to a large extent, the Red List assessment of habitat types in Finland (Kontula & Raunio 2018).…”