What can possibly go wrong?: The risks of introducing soil microorganisms from Antarctica into South America

Abstract

SUMMARYEndophytic fungi form mutualistic associations with plant roots which can increase plant survival and resistance to stress. Recently, it has been proposed that endophytic fungi from Antarctica should be used to facilitate reintroduction and establishment of native plants in xeric environments of northern Chile. In this note, we suggest this is a risky proposition and may lead to biological invasions. It is difficult to predict which endophytic fungi will become invasive, where they will invade, or what their impacts will be. Organisms that move across continents may or may not become invasive depending on the interaction between the species and the invaded community; unexpected outcomes may occur due to adaptation and novel interactions of the introduced species in the new environment. The fact that these endophytes are mutualistic does not imply that they will not have negative effects on the recipient community, since they might promote invasion of other non-native species or may change the competitive relationships among native species. Further, taxonomically uncharacterized fungal isolates from plant roots are likely to contain non-beneficial species. The fact that these endophytic fungi species are from Antarctica does not ensure that they cannot invade elsewhere. It should be recognized that invasive microorganisms are extremely difficult to control. We strongly suggest that the further translocation, use and spread of endophytes from Antarctica should be halted until a risk assessment is undertaken. Biosecurity measures must be taken when considering transcontinental experiments. Based on previous experiences, it is likely that the risk and potential costs of introducing these new species significantly exceed any potential benefits of their introductions.Key words: biological invasions, endophytes, fungi, pathogens, soil biota. RESUMENLos hongos endófitos forman asociaciones mutualísticas con raíces de plantas y pueden mejorar la sobrevivencia y resistencia al estrés. Recientemente se ha propuesto usar hongos endófitos de la Antártida para facilitar la reintroducción y establecimiento de plantas nativas en formaciones xerofíticas del norte de Chile. En esta nota se sugiere que aquello es una propuesta riesgosa y puede conducir a invasiones biológicas. Es difícil predecir qué especies se convertirán en invasoras, dónde lo harán o cuáles serán sus efectos. Los organismos transportados entre continentes pueden o no convertirse en invasores, según las interacciones entre especies y con la comunidad invadida, y pueden ocurrir resultados inesperados debido a adaptaciones de especies invasoras al nuevo ambiente y a novedosas interacciones con especies introducidas en el nuevo ambiente. Estos endófitos mutualistas pueden tener efectos negativos en la comunidad receptora, como promover invasiones de otras especies exóticas o cambiar relaciones de competencia entre especies nativas. Los hongos endófitos de la Antártida no garantizan que no puedan invadir otros lugares. La falta de identificación taxonómica d...

The emerging science of linked plant–fungal invasions

“…Global movement of plants and fungal pathogens has increased the probability that plants and fungi native to different regions of the world will encounter each other in a common introduced range, potentially establishing co‐xenic (‘with foreigner’) novel associations (Nuñez & Dickie, ). This term was coined to describe the observed association of Eucalyptus from Australia with ectomycorrhizal Amanita muscaria from Europe in New Zealand (Nuñez & Dickie, ), but is common in pathogens. For example, the oomycete Phytophthora cinnamomi , presumed native to southern Asia and noted as a pathogen on >3000 host species world‐wide, has been introduced into many temperate and subtropical regions, where it has established novel associations with many plant species, both native and alien, in primary production, ornamental plantings and natural ecosystems, for example with Q. rubra in France (Delatour, ).…”

“…Defining interaction motifs hinges on understanding species concepts and whether those species are native or alien to a given region. This can be difficult to determine for fungi (Box 1), especially for epiphytic and endophytic fungi (Shipunov et al, 2008), hence investigation into the potential role of these fungal communities in invasion has just begun (Aschehoug et al, 2012;Nuñez et al, 2015;Cleary et al, 2016). Nonetheless, there are sufficient cases where fungal species can be defined and identified as alien to allow meaningful discussion and progress.…”

“…Humans also clearly facilitate invasions by dispersing fungi to new regions and spreading fungi within regions after introductions (Dickie et al, 2016). In many cases, human-mediated dispersal is unintentional, for example when live plants are moved with soil and associated biota (Jules et al, 2002;Liebhold et al, 2012), but fungi are also intentionally introduced and spread for biocontrol (Ellison et al, 2008;Winston et al, 2014) and to promote the growth of plants (Schwartz et al, 2006;Vellinga et al, 2009;Nuñez et al, 2015).…”

“…Some fungi are deliberately introduced for biological control or to promote plant growth. A better understanding of spillover and spillback processes, particularly in the context of changing environmental conditions, will help improve assessments of the potential beneficial and detrimental effects of these translocations (Schwartz et al, 2006;Nuñez et al, 2015;Blackburn & Ewen, 2016).…”

Symbiotic Interaction Enhances the Recovery of Endangered Tree Species in the Fragmented Maulino Forest

“…Nonetheless, our findings should be viewed with caution. Nuñez et al (2015) argued that unexpected outcomes such as promoting invasion of non-native plants or changing competitive relationships among native species could result from inoculation with non-native microorganisms. Nevertheless, in this study the manipulative inoculation did not affect bacteria and fungi soil microorganisms, indicating that the use of Antarctic fungal endophytes has not negative indirect effects microorganism inhabiting the rhizozpheric soil of the ruil individuals.…”