Mycobiota of English Oak: Retrospective, Current State of Knowledge, Promising Problems

This review aims to evaluate the current state of knowledge regarding the mycobiota of English oak, focusing on biodiversity conservation, ecological and trophic aspects of fungi–plant interactions, forest phytopathology, and biotechnology. It also seeks to identify potential research opportunities for studying this vital tree species in European Russia. A retrospective examination of the fungal and oomycete biodiversity associated with English oak has been conducted, addressing the trophic classification challenges of these organisms. A comprehensive framework for assessing the trophic status of fungi is proposed, incorporating multiple criteria: (1) nutritional type (e.g., biotrophs, necrotrophs, saprotrophs, and hybrid categories such as “necrotrophs with residual saprotrophic activity” and “saprotrophs with necrotrophic activity”); (2) tissue specificity (including bark, cambium, sapwood with functional xylem, heartwood with nonfunctional xylem, wood detritus, and sclerenchyma in fruits and leaves); and (3) impact on living plants or mortality dynamics (e.g., pathogens or detrital saprobes). The review offers detailed data on the distribution of fungi and oomycetes across different ecological macroniches. These include the phyllosphere (30 species), terminal shoots (26 species), trunks and skeletal branches undergoing senescence (475 species), wounds on living trees (230 species), litter (62 species), rhizosphere and mycorrhizosphere (47 + 137 species), and oak seedlings (83 species). Additionally, key diseases affecting English oak and corresponding pathogen management strategies are discussed. The article examines studies focused on assessing oak stand conditions and developing forest scaling systems. It also highlights biotechnological and pharmacological research dedicated to specific fungal species associated with English oak. Finally, promising avenues for further investigation into the mycobiota of English oak are outlined.