Macrofungi on Three Nonnative Coniferous Species Introduced 130 Years Ago, Into Warmia, Poland

In fall 2018 and 2019, we assessed colonization by fungi on Douglas fir trees [ Pseudotsuga menziesii (Mirb.) Franco], white pine ( Pinus strobus L.), and red cedar ( Thuja plicata D. Don.) on selected experimental plots of the former Prussian Experimental Station, where nonnative tree species were introduced from North America over a century ago. The presence of sporocarps on trunks, root collars, and stumps as well as the litter layer in the soil within a radius of 0.5 m around the trunk of the tree was determined. Additionally, the volume of dead wood on the forest floor of the entire plot was assessed. We recorded numerous fungi on trees and stumps as well as in the litter and soil. For the 31 plots in 12 forest districts, we determined 745 sporocarps of 48 taxa, with 335/19 on the wood of P. menziesii trees and stumps, 377/15 on P. strobus , and 33/6 on T. plicata trees. The highest share of trees with various trunk damage levels was found for T. plicata (70.3%) and the lowest for P. menziesii (6.2%). Among the root parasitic fungi, Heterobasidion sp. and Armillaria sp. were found, especially on the collars and stumps of T. plicata and P. strobus ; we did not find basidiomata of both pathogens on P. menziesii . The volume of dead wood within the P. menziesii plots averaged 7.1 m3/ha, whereas in T. plicata plots, it was 56.3 m3/ha. We identified 10 taxa that have not been reported in association with P. strobus for Poland ( Cylindrobasidium laeve , Dacrymyces sp., Exidia pithya , E. saccharina , Gymnopilus pnetrans , Leptoporus mollis , Mycena sanguinolenta , Tapinella panuoides , Trametes versicolor , and Xylaria hypoxylon ) and three taxa ( Exidia pithya , Leptoporus mollis , Serpula himantioides ) associated with T. plicata .