Disease-causing plant pathogens are an emerging global threat to forests, compromising carbon sequestration and shifting forests from carbon sinks to sources. Phytophthora agathidicida , the causal agent of a host-specific lethal root rot disease, kauri dieback, infects Agathis australis (New Zealand kauri). The disease causes progressive canopy decline and mortality of kauri, threatening forests where kauri dominate. We hypot...