Preliminary assessment of the ectomycorrhizal fungi ofQuercus garryanaon Vancouver Island, British Columbia, Canada

Abstract

Garry oak ( Quercus garryana Douglas ex Hook.) is the only oak native to British Columbia (BC), where it occupies the northernmost extent of its range. The ecosystem it occupies in BC has been greatly reduced in size and fragmented by European settlement. Garry oak forms ectomycorrhizas that are essential to its existence and will likely play an important role in the response of this tree to climate change. Yet, relatively little is known about the ectomycorrhizal fungi associated with Garry oak in BC. In this study, we have documented the occurrence of fungi forming ectomycorrhizas with Garry oak at six locations on Vancouver Island by sequencing the internal transcribed spacer region of ectomycorrhizal root tips collected from Garry oak stands. Of the 47 species we detected, only about 20% can be confidently assigned to known species because not all species have been sequenced and many sequences in public databases are incorrectly or incompletely identified, but the majority of them belong to a community of fungi associated primarily with oaks or other members of Fagaceae. The uniqueness of this community of ectomycorrhizal fungi indicates that the possible expansion of the range of Garry oak in BC in response to climate change may be limited by the co-migration of its ectomycorrhizal fungi.