Communities of fungi in decomposed wood of oak and pine

Abstract

The abundance and diversity of wood decomposing fungi were investigated by isolating and cultivating filamentous fungi from wood and by detection of fruit bodies of ascomycetous and basidiomycetous fungi. The objective was to study the impact of forest management on fungi in 100-year-old oak and 87-year-old Scots pine forests in Northern Poland. Fungi were found on coarse woody debris of decayed stumps and fallen logs, boughs and branches in each of the three (managed and unmanaged) examined stands. In total, 226 species of Oomycota and fungi were recorded. Oak wood was colonized by one species of Oomycota and 141 species of fungi including Zygomycota (19 species), Ascomycota (103 species) and Basidiomycota (19 species). Scots pine wood was also colonized by one species of Oomycota and 138 species of fungi including Zygomycota (19 species), Ascomycota (90 species) and Basidiomycota (29 species). In the first, second and third stages of decomposition, the oak wood was colonized by 101, 89 and 56 species of fungi respectively and pine wood was colonized by 82, 103 and 47 species respectively. Eighty three of the observed species (37%) occurred on both types of wood, while the other species displayed nutritional preferences. A decrease in the number of species with advancing decay indicates the necessity for a continuous supply of dead wood to the forest ecosystem. This supply would secure the continuity of fauna and flora and guarantee a stable forest development. The nutritional and ecological preferences of many fungal species furthermore indicate the necessity of supplying the forests with wood of different species. In commercially managed forests the results obtained here will aid in: (i) the development of strategies for effective dead wood management in the context of forest productivity and future wood stock growth, as well as (ii) finding a compromise between forest management requirements and environmental protection.

Abundance and diversity of fungi in oak wood

“…Armillaria gallica and A. cepistipes were most abundant in wood in the 2 nd decay class, consistent with earlier findings (Kwaśna et al, 2016b). Both species are known as opportunistic parasites in weakened or stressed trees (particularly A. gallica in oak).…”

“…In the six 3-30-year-old Q. petraea logs there were 264 307 different OTUs, which is 127-fold more than the 2 080 OTUs found in nine samples of 3-year-old Q. rubra logs using high-throughput sequencing (by van der Wal et al, 2017), but less than the 687 662 and 1 861 279 OTUs found in 20 samples of broadleaved trees from two locations in neotropical Atlantic forests using massively parallel sequencing (Vaz et al, 2017). There were also 277 fungal taxa, which is more than the 141 taxa detected in deadwood of Quercus robur L. using the classical method based on isolation and microscopic analysis (Kwaśna et al, 2016b), the 100 taxa detected in neotropical Atlantic forests (Vaz et al, 2017), and the 15 species detected in Q. rubra logs (by van der Wal et al, 2017). In two other tree species, beech and Scots pine, respectively 96 and 138 fungal taxa were detected by isolation and microscopic analysis (Fukasawa et al, 2009;Kwaśna et al, 2016b).…”

“…There were also 277 fungal taxa, which is more than the 141 taxa detected in deadwood of Quercus robur L. using the classical method based on isolation and microscopic analysis (Kwaśna et al, 2016b), the 100 taxa detected in neotropical Atlantic forests (Vaz et al, 2017), and the 15 species detected in Q. rubra logs (by van der Wal et al, 2017). In two other tree species, beech and Scots pine, respectively 96 and 138 fungal taxa were detected by isolation and microscopic analysis (Fukasawa et al, 2009;Kwaśna et al, 2016b). The impressive total of 277 taxa was recorded despite the presence of a microbial barrier and selection for specialized rotting fungi, which can decompose the highly resistant oak wood containing such organic compounds as tannins and suberin (Vane et al, 2006;van der Wal et al, 2017).…”

“…Many Ascomycota taxa detected were soft rot fungi, meaning that they can break down cellulose and hemi-cellulose, but not harder structural substances such as lignin (Mäkelä et al, 2015). The high abundance of Ascomycota in oak wood was expected since they are more frequent in wood of deciduous than coniferous trees (Gutowski et al, 2004;Kwaśna et al, 2016b). Deciduous trees are more susceptible than coniferous trees to colonization by Ascomycota because of their higher content of cellulose and hemicellulose, but not of lignin, which is in greater amounts in conifers.…”

Coarse woody debris and wood-colonizing fungi differences between a reserve stand and a managed forest in the Taborz region of Poland

“…In our research, the amount of woody debris and the fungal richness (12 species) were lower in the managed stand than in the reserve (28 species), but higher than in other managed state forests. Kwaśna et al (2016) described 21 Basidiomycota species colonizing 100-year-old Scots pine CWD in the Torzym Forest District.…”