Abstract
In many spruce stands, trees are frequently attacked by the pathogen Heterobasidion parviporum, albeit without visible symptoms in the crown. In the present work, the results of the presence of stem rot, assessed by PICUS Sonic Tomography, and the fungal biota on trees and stumps in eight plots in the Puszcza Borecka Forest are described. The plots were located in stands on original forest soil (4) and on post-agricultural soil (4), where around a stump with H. parviporum symptoms (signs of internal rot and basidiocarps), 30 trees were selected and examined for internal rot. Wood samples were collected from two selected trees for fungal molecular analysis. A total of 79 fungal taxa were found, including 57 taxa in plots on post-agricultural soil and 45 on forest soil. There were 395 fungal records on stumps and 22 records on trees, therein, from the inner parts of felled trunks. Significant differences in the Chao-1 diversity index indicate that the origin of the soil—post-agricultural or forest soil—influenced the alpha diversity of the fungal communities in the forests studied. The values of the Shannon and Simpson indices show that the two communities were similar in terms of species numbers. The presence of basidiomata of H. parviporum and two species of Armillaria (mainly A. cepistipes) in samples on all plots is striking, although Armillaria spp. was detected more frequently. Most of the species identified were typical saprotrophs, although rare species were also found, such as Entoloma byssisedum, Onnia tomentosa, Physisporinus vitreus, Postia ptychogaster, and Ramaria apiculata. The presence of H. parviporum in the inner woody parts was confirmed by PCR analysis, and decay was detected even up to a stem height of 6 m. Armillaria was the dominant genus in the studied stands and plays a significant and underestimated role in heartwood decay of old spruce trees in Puszcza Borecka Forest.
Highlights
Since H. parviporum is a major cause of infection and death of mature trees in spruce stands in many countries [36,37,38], the aim of the present study was to determine the proportion of this pathogen in commercial spruce stands over 50 years old in the Borecka Forest, northeastern
Our results show that trees older than 50 years, regardless of the type of soil on which the spruce stands grow, are subjected to advanced internal wood rot
This means that the infection of the roots took place many years earlier and that the development of the pathogen, detected by tomography inside the trunk, takes at least a dozen years
Summary
The decomposition of wood leads to the release of D-glucose and its oxygenation, binding water and carbon dioxide [9,10,11,12]. These processes produce large amounts of energy and various metabolites, including nitrogen compounds, that can be used by other organisms [13,14,15,16,17,18]. As a result of the infection of live spruce trees by H
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
