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Phytophthora cinnamomi is an oomycete found in the soil and capable of invading the roots of a wide range of host plants globally, potentially killing them and affecting the ecosystems they inhabit. This pathogen is often inadvertently dispersed in natural vegetation on the footwear of humans. A range of equipment is often provided or recommended to be carried for cleaning footwear in places where P. cinnamomi poses a threat to biodiversity. These are typically a brush for mechanically removing soil and/or a disinfectant for killing the pathogen. Despite their widespread use, to our knowledge, the majority of hygiene measures have not been experimentally tested for their efficacy. In the current study, we tested whether two types of brush and the two most widely used disinfectants (70% methylated spirits and benzalkonium chloride) were effective in removing the pathogen from boots. We tested the brushes and disinfectants in two soil types and two moisture levels. All hygiene measures were found to be better than doing nothing, although some were only effective with sandy or dry soils. Benzalkonium chloride was largely ineffective as a spray but highly effective when used in a footbath. Brushing did not improve cleaning when used with 70% methylated spirits. None of the hygiene measures was completely effective for cleaning boots that had been in wet loamy soil. Our findings have important implications for management of this threat because some recommended hygiene practices are not doing what they claim.

Prevention is regarded as a cost-effective management action to avoid unwanted impacts of non-native species. However, targeted prevention can be difficult if little is known about the traits of successfully invading non-native species or habitat characteristics that make native vegetation more resistant to invasion. Here, we surveyed mountain roads in seven regions worldwide, to investigate whether different species traits are beneficial during primary invasion (i.e. spread of non-native species along roadside dispersal corridors) and secondary invasion (i.e. percolation from roadsides into natural adjacent vegetation), and to determine if particular habitat characteristics increase biotic resistance to invasion. We found primary invasion up mountain roads tends to be by longer lived, non-ruderal species without seed dispersal traits. For secondary invasion, we demonstrate that both traits of the non-native species and attributes of the receiving natural vegetation contribute to the extent of invasion. Non-native species that invade natural adjacent vegetation tend to be shade and moisture tolerant. Furthermore, non-native species invasion was greater when the receiving vegetation was similarly rich in native species. Our results show how mountain roads define which non-native species are successful; first by favouring certain traits in mountain roadsides (the key dispersal pathway to the top), and secondly by requiring a different set of traits when species invade the natural adjacent vegetation. While patterns in species traits were observed at a global level, regional abiotic and biotic variables largely generated region-specific levels of response, suggesting that management should be regionally driven. Fil: McDougall, Keith. La Trobe University; Australia. Office of Environment and Heritage; Australia Fil: Lembrechts, Jonas. Universiteit Antwerp; Bélgica Fil: Rew, Lisa J.. State University of Montana; Estados Unidos Fil: Haider, Sylvia. Martin Luther University Halle-Wittenberg; Alemania. German Centre for Integrative Biodiversity Research; Alemania Fil: Cavieres, Lohengrin A.. Universidad de Concepción; Chile Fil: Kueffer, Christoph. Instituto de Ecología y Biodiversidad; Chile. Institute of Integrative Biology; Suiza Fil: Milbau, Ann. Research Institute for Nature and Forest; Bélgica Fil: Naylor, Bridgett J.. United States Department of Agriculture; Estados Unidos Fil: Nuñez, Martin Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Pauchard, Anibal. Universidad de Concepción; Chile. Instituto de Ecología y Biodiversidad; Chile Fil: Seipel, Tim. State University of Montana; Estados Unidos Fil: Speziale, Karina Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Wright, Genevieve T.. Office of Environment and Heritage; Australia Fil: Alexander, Jake M.. Universite de Lausanne; Suiza

Phytophthora species are associated with disease in horticulture, agriculture and natural vegetation worldwide but are not well known in cold areas. In Australia, alpine regions have been regarded as unsuitable for the survival and disease expression of Phytophthora cinnamomi, which has caused catastrophic damage to vegetation in other parts of the country. Phytophthora cambivora, on the other hand, has been detected recently in the roots of an endemic alpine shrub (Nematolepis ovatifolia) and may already be exerting pressure on alpine vegetation. We conducted glasshouse susceptibility trials on nine Australian alpine and subalpine shrub species to P. cambivora and P. cinnamomi. The pathogens were re-isolated from the roots of most test species but for some species, few replicates were infected and few died. One species (Phebalium squamulosum) was regarded as highly susceptible with most plants in inoculated pots dying and both pathogens being commonly isolated from roots. The climatic conditions of most populations of the test species are currently unsuitable for disease expression from P. cinnamomi. However, the projected change in temperature in the Australian Alps with climate change will expose most populations of eight of the species to P. cinnamomi activity by 2070. Pathogens are likely to be important drivers of future vegetation in many mountainous areas which are currently not within their range of survival and pathogenesis. Management of these areas should include hygiene and pathogen monitoring, and minimise disturbances that heighten stress for susceptible species.

Eucalyptus marginata is the dominant tree of a forest community in south-western Australia. It is susceptible to infection by Phytophthora cinnamomi and is usually rare on long-infested sites. Ex situ stem inoculation was used to compare the susceptibility of E. marginata plants in long-infested sites and adjoining uninfested sites. Plants were found to be less susceptible on some long-infested sites but other factors may also be important in regulating regeneration and survival of E. marginata.

Phytophthora cinnamomi is causing the death of a dominant understorey shrub (Oxylobium arborescens) in subalpine woodland at Barrington Tops National Park, northern New South Wales. A threatened species, Tasmannia purpurascens, is also affected. The diseased area is about 5 ha, which is large in New South Wales where P. cinnamomi has not been regarded as a serious pathogen. The infestation is unusual in such high altitude vegetation.