Dynamics of fungi colonization on the surface of Scots pine wood during natural weathering in different European climate zones
F Poohphajai, O Myronycheva, O Karlsson, L Rautkari, J Sandak, A Sandak
Wood The presence of fungi leads to biomaterial decay and/or changes in aesthetical appeal. The start of fungi colonization as well as the following growth on wood are primarily influenced by four factors: ambient temperature, moisture history of the object, access to oxygen, and intrinsic properties of the exposed wood, considered here as a source of nutrients for microorganisms. A prevalence of fungal spores in a close vicinity, combined with favourable environmental conditions are indispensable for the initiation of the growth of microorganisms. All the above factors are highly dependent on the local circumstances and especially climate conditions. It is important to understand the effect of weather on the diversity and distribution of endemic fungal communities in advance, to identify plausible remedies as related to the present global climatic changes. It is foreseen that the composition of fungal cultures as well as their growth kinetics on various wood substrates may evolve in the near future. The goal of this study was to investigate the relationship between specific weather conditions, representing diverse climate zones, on the occupancies and colonization dynamics of fungi/mould species.
The test was performed on untreated Scots pine (Pinus sylvestris L.) wood samples exposed to natural weathering for 12 weeks from July to September 2021, in two locations: 1) Izola (Slovenia, 45°32'12.98"N, 13°39'42.98"E), representing the mild Mediterranean climate of southern Europe, and 2) Skellefteå (Sweden, 64°45'2.41"N, 20°57'10.04"E) representing Scandinavian or northern Europe climate zone. The local weather conditions recorded during the exposure period were used for modelling the growth kinetics. Fungi colonizing wood surfaces were manually collected from twin samples at each location, every second week, by swabs and cultured on nutrient media. The identification of fungi was performed visually according to the mycological keys of the detected genus. The presence of fungi was first noticed after 2 weeks of exposure. The majority of species detected were Ascomycetes from the genus Cladosporium, Aureobasidium, and Aspergillus. The combination of climatic parameters influences the compositions and colonisation of microorganisms on Scots pine wood. However, the obtained results showed fluctuations in the colonisation of the spores of culturable fungi. This might be the influence of other factors including geographic location, sensitivity of each fungal species to environmental factors, animals, plants, human activities, and pollutants that need to be taken in account.