Comparison of methods to prioritise plant diseases and their hosts for surveillance

Abstract

Abstract Non-native plant pests/pathogens are a mostly overlooked threat to biodiversity. Surveillance for plant diseases is key to early detection yet is rarely undertaken in semi-natural habitats. Currently there is no standard methodology available to help managers prioritise where surveillance should occur. This study compared five potential methods (M). Prioritisation of: pests/pathogens most likely to establish (M1); plant genera known to host the pests/pathogens most likely to establish (M2); habitats known to host the greatest number of pests/pathogens most likely to establish (M3); plants classed as foundation species (those that drive ecosystem functioning and support populations of dependent biodiversity) (M4); habitats with low plant species diversity and hence low resilience (M5). Twelve habitats and 22 heathland vegetation communities in the UK were used as a case-study. M1 gave 91 pests/pathogens to monitor and relied on having up-to-date lists of pests/pathogens relevant to plant species in semi-natural habitats. M2 gave 121 plant genera to monitor across all habitats and 14 within heathlands. M3 and M5 prioritised different habitats because M3 is based on existing lists of pests which are biased towards those of commercial importance. M4 gave 272 foundation species for surveillance across all habitats and 14 within heathlands. Surveillance of habitats and plants prioritised on potential ecological impact (M4-5) is recommended rather than known pests/pathogens (M2-3) as this avoids biases within existing lists of pests/pathogens, removes the need for the prioritisation to be regularly updated as new pests/pathogens are identified and takes account of impacts on associated biodiversity and ecosystem functions.