Towards management of invasive ectomycorrhizal fungi

Abstract

Ectomycorrhizal fungi are increasingly recognized as invasive species. Invasive ectomycorrhizal fungi can be toxic to humans, may compete with native, edible or otherwise valuable fungi, facilitate the co-invasion of trees, and cause major changes in soil ecosystems, but also have positive effects, enabling plantation forestry and, in some cases, becoming a valuable food source. Land-managers are interested in controlling and removing invasive fungi, but there are few available strategies for management and none are based on robust scientific evidence. Nonetheless, despite the absence of relevant experiments, we suggest that knowledge of the fundamental ecology of fungi can help guide strategies. We review the literature and suggest potential strategies for prevention, for slowing the spread of invasive fungi, for eradication, and for long-term management. In many cases the most appropriate strategy will be species and context (including country) specific. In order to effectively address the problems posed by invasive ectomycorrhizal fungi, land managers and scientists need to work together to develop and robustly test control and management strategies.

The emerging science of linked plant–fungal invasions

“…Here, we have attempted to: (1) highlight the diversity, ecological importance and potential complexity of plant–fungal invasions; (2) categorize this diversity into broadly applicable, simplified motifs that apply to both mutualistic and pathogenic interactions; (3) apply these motifs to the invasion process and demonstrate the potential effect of these interactions on the outcomes of plant invasions; (4) consider the effects of symbiont specificity, dependence, effect size, and the abiotic environment on the type or strength of interactions; and (5) consider mechanisms by which linked plant–fungal invasions influence ecosystem‐level impacts and management outcomes. Linked plant–fungal processes can be critical to determining the outcomes and impacts of both plant and fungal invasions, yet research in these areas remains limited (Dickie et al ., ; Preston et al ., ).…”

“…These have been described for European ectomycorrhizal fungi (Amanita spp.) in North America, New Zealand and Argentina, Australian ectomycorrhizal fungi (Laccaria) in Spain, and a few other species (Diez, 2005;Wolfe & Pringle, 2012;Dickie et al, 2016;Berch et al, 2017). Novel associations of alien pathogens with native plants are a main cause of emerging plant diseases (Anderson et al, 2004;Parker & Gilbert, 2004;Desprez-Loustau et al, 2007), especially in forests (Santini et al, 2013).…”

“…Further investigation of linked plant-fungal invasions may improve management of new invasions, allow us to mitigate the impacts of invasive plants and fungi, and improve evaluation of both positive and negative effects of invasions (e.g. provision of ecosystem services; Dickie et al, 2016). At present, most plant risk assessment is based on the assumption that plant and fungal traits are static.…”

Native and invasive populations of the ectomycorrhizal death capAmanita phalloidesare highly sexual but dispersal limited

“…The potentially ruderal niche of the death cap also suggests an effective management strategy (Dickie et al ., 2016). The mushrooms of the death cap are deadly, and each year in California there are poisonings (Zevin et al ., 1997; Bonacini et al ., 2017; Vo et al ., 2017).…”

“…The mushrooms of the death cap are deadly, and each year in California there are poisonings (Zevin et al ., 1997; Bonacini et al ., 2017; Vo et al ., 2017). An increasingly public discussion has focused attention on whether the fungus can be eradicated from local landscapes (Dickie et al ., 2016; Quirós 2016; Childs 2019). In fact, our data suggest a control strategy: as a sporocarp of the death cap develops, its spore-bearing surface is covered by a partial veil.…”