Ophiostomatoid and basidiomycetous fungi associated with green, red, and grey lodgepole pines after mountain pine beetle (Dendroctonus ponderosae) infestation

Abstract

The mountain pine beetle (MPB) is a major concern for lodgepole pine (Pinus contorta var. latifolia Engelm.) forests in British Columbia, Canada. MPB and the ophiostomatoid staining fungi for which they serve as vector have a close, mutualistic relationship. In this work, we determined which fungi colonized MPB-killed standing trees with green, red, and grey crowns and quantified how rapidly the fungi stained and reduced the moisture content of sapwood. Green trees were mainly colonized by Ophiostoma clavigerum (Robinson-Jeffrey & Davidson) Harrington, Ophiostoma montium (Rumbold) von Arx, Ophiostoma nigrocarpum (Davidson) De Hoog, Ophiostoma minutum (Olchow. & Reid) Hausner, and unknown Leptographium species. In red and grey pines (2 and 3 years after the original MPB attack, respectively), the frequency of the original fungal colonizers decreased, and other sapstaining fungal species were encountered. Among basidiomycetous fungi, decay fungi were rarely present in green trees but were isolated more frequently in red and grey trees. The frequency and the type of decay fungi isolated varied between harvesting sites.