Grzyby saproksyliczne w resztkach pozrębowych sosny zwyczajnej

Awareness of the importance of the presence of deadwood in forest ecosystems has increased in recent decades. Today, deadwood is not only recognized as a key element in carbon sequestration, nutrient supply and water retention, but is also known to be a reservoir of saproxylic species (species associated with the decay of wood on living and dead trees). The amount of deadwood in clear−cut forest is currently higher than 100 years ago. The issue of how much deadwood and of what quality (including size) there should be in order to promote the conservation of saproxylic biodiversity and sustainable forest management is still vivid. Mycological analyses to determine (i) structure of fungal communities in Scots pine wood debris, (ii) sources and reservoirs of fungi, (iii) nutritional preferences of fungi, and (iv) potential rate and dynamics of wood decomposition were carried out on an ‘old' and ‘fresh' wood (stumps, branches and boughs) from Jedwabno Forest District (north−eastern Poland). Fungi from 62 wood samples were isolated on two artificial media (PDA and SNA) and identified according to their morphology. Eleven species of Zygomycota, 79 of Ascomycota and 15 of Basidiomycota were detected. The majority of species (91%) colonized many samples. Only 9% of species colonized single samples only. The most common species, with high rates of colonization, included Acremonium spp., Alternaria sp., Aspergillus spp., Aureobasidium pullulans, Cladosporium spp., Epicoccum nigrum, Lecythophora spp., Mariannaea elegans, Ophiostoma + Sporothrix spp., Penicillium spp., Phialocephala spp., Phialophora spp., Phlebiopsis gigantea, Phoma spp., Sarocladium strictum, Scytalidium lignicola, Sydowia polyspora, Trichoderma spp. (mainly T. harzianum and T. viride) and Umbelopsis spp. A few species occurred only on stumps or only on branches. More species occurred on 'old' wood than on 'fresh' wood. The average level of sample colonization by a single fungal species was higher (non−significantly) on 'old' than on 'fresh' wood, and on branches than on stumps. The results show that deadwood is a habitat for many fungal species that occur in succession. The presence of deadwood in clear−cut forest and in its neighborhood is necessary for the conservation of saproxylic fungal diversity and ecological sustainability of forests.