Mitigating the effects of climate change, emerging disease and invasive species on native amphibian populations in the UK

两栖动物是最受威胁的脊椎动物群体，全球数量下降是由新出现的传染病、入侵物种和气候变化驱动的，并与之相关（North et al. 2015； O'Hanlon et al. 2018; Pounds et al. 2006）。严重影响两栖动物种群的两种新出现的传染病是壶菌病（chytridiomycosis），由一种新型真菌Batrachochytrium dendroatidis引起（Bd； O'Hanlon et al. 2018），以及由一组Iridoviridae家族病毒引起的ranavirosis （Price et al. 2014）。为了减轻新出现的疾病驱动的两栖动物数量下降，我们需要了解宿主-病原体的相互作用。病原体成功的关键是水库宿主，它们作为病原体来源，但不会出现任何疾病迹象（Garner 2018）。当易感两栖动物宿主种群数量下降并走向灭绝时，这些宿主是病原体感染阶段的一致来源；在许多情况下，这些水库宿主是入侵的两栖动物物种。英国威尔士有一个理想的两栖动物系统来研究这些宿主-病原体的相互作用，既有本地的，数量下降的两栖动物，也有新发现的光滑和高山蝾螈，它们是该地区的入侵物种。气候变化已经影响了野生青蛙的ranavirus疾病动态，但目前尚不清楚未来的变化将如何影响其他宿主的疾病动态，或者两栖动物群落组成将如何影响结果（Price et al. 2018）。

Amphibians are the most threatened group of vertebrates, with global declines driven by and associated with emerging infectious disease, invasive species and climate change (North et al. 2015; O'Hanlon et al. 2018; Pounds et al. 2006). Two emerging infectious diseases severely impacting amphibian populations are chytridiomycosis, caused by a novel lineage of the fungus Batrachochytrium dendrobatidis (Bd; O'Hanlon et al. 2018), and ranavirosis, caused by a group of viruses from the Iridoviridae family (Price et al. 2014). To mitigate emerging disease-driven amphibian declines, we need to understand host-pathogen interactions. Key to pathogen success are reservoir hosts which serve as a pathogen source, but do not develop any signs of the diseases (Garner 2018). These reservoir host are a consistent source of the infective stage of pathogens when the susceptible amphibian host populations decline and are pushed towards extinction; in many cases these reservoir hosts are invasive amphibian species. Wales, UK, has an ideal amphibian system to study these host-pathogen interactions, with both native, declining populations of amphibians as well as newly discovered smooth and alpine newts, which are an invasive species to the area. Climate change has already affected ranavirus disease dynamics in wild frogs, but it is currently unknown how future changes will affect disease dynamics in other hosts, or how amphibian community composition will impact outcomes (Price et al. 2018).